shithub: jbig2

Download patch

ref: 334291542ffca67df67ca59b71d21c96bba0f893
parent: b22b368ffdf92ff126754152e73bab723537a0f9
author: Robin Watts <[email protected]>
date: Fri Nov 16 12:56:46 EST 2018

Bug 700205: Bring jbig2dec's copy of memento up to date.

--- a/memento.c
+++ b/memento.c
@@ -1,16 +1,14 @@
-/* Copyright (C) 2001-2018 Artifex Software, Inc.
+/* Copyright (C) 2009-2018 Artifex Software, Inc.
    All Rights Reserved.
 
    This software is provided AS-IS with no warranty, either express or
    implied.
 
-   This software is distributed under license and may not be copied,
-   modified or distributed except as expressly authorized under the terms
-   of the license contained in the file LICENSE in this distribution.
-
-   Refer to licensing information at http://www.artifex.com or contact
-   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
-   CA 94945, U.S.A., +1(415)492-9861, for further information.
+   This software is distributed under license and may not be copied, modified
+   or distributed except as expressly authorized under the terms of that
+   license. Refer to licensing information at http://www.artifex.com
+   or contact Artifex Software, Inc.,  1305 Grant Avenue - Suite 200,
+   Novato, CA 94945, U.S.A., +1(415)492-9861, for further information.
 */
 
 /* Inspired by Fortify by Simon P Bullen. */
@@ -19,11 +17,8 @@
  * to speed the operation */
 /* #define MEMENTO_LEAKONLY */
 
-#ifndef MEMENTO_STACKTRACE_METHOD
-#ifdef __GNUC__
-#define MEMENTO_STACKTRACE_METHOD 1
-#endif
-#endif
+/* Set the following to keep extra details about the history of blocks */
+#define MEMENTO_DETAILS
 
 /* Don't keep blocks around if they'd mean losing more than a quarter of
  * the freelist. */
@@ -31,23 +26,165 @@
 
 #define COMPILING_MEMENTO_C
 
+/* SHUT UP, MSVC. I KNOW WHAT I AM DOING. */
+#define _CRT_SECURE_NO_WARNINGS
+
+/* We have some GS specific tweaks; more for the GS build environment than
+ * anything else. */
+/* #define MEMENTO_GS_HACKS */
+
 #ifdef MEMENTO_GS_HACKS
 /* For GS we include malloc_.h. Anyone else would just include memento.h */
 #include "malloc_.h"
-#ifdef __MACH__
-#include <string.h>
-#else
-#ifndef memset
-void *memset(void *, int, size_t);
-#endif
-#endif
+#include "memory_.h"
 int atexit(void (*)(void));
 #else
 #include "memento.h"
 #include <stdio.h>
+#endif
+#ifndef _MSC_VER
+#include <stdint.h>
+#include <limits.h>
+#endif
+
 #include <stdlib.h>
+#include <stdarg.h>
+
+#ifdef __ANDROID__
+#define MEMENTO_ANDROID
+#include <stdio.h>
 #endif
 
+/* Hacks to portably print large sizes */
+#ifdef _MSC_VER
+#define FMTZ "%llu"
+#define FMTZ_CAST _int64
+#else
+#define FMTZ "%zu"
+#define FMTZ_CAST size_t
+#endif
+
+#define UB(x) ((intptr_t)((x) & 0xFF))
+#define B2I(x) (UB(x) | (UB(x)<<8) | (UB(x)<<16) | (UB(x)<<24))
+#define B2P(x) ((void *)(B2I(x) | ((B2I(x)<<16)<<16)))
+#define MEMENTO_PREFILL_UBYTE ((unsigned char)(MEMENTO_PREFILL))
+#define MEMENTO_PREFILL_USHORT (((unsigned short)MEMENTO_PREFILL_UBYTE) | (((unsigned short)MEMENTO_PREFILL_UBYTE)<<8))
+#define MEMENTO_PREFILL_UINT (((unsigned int)MEMENTO_PREFILL_USHORT) | (((unsigned int)MEMENTO_PREFILL_USHORT)<<16))
+#define MEMENTO_PREFILL_PTR (void *)(((uintptr_t)MEMENTO_PREFILL_UINT) | ((((uintptr_t)MEMENTO_PREFILL_UINT)<<16)<<16))
+#define MEMENTO_POSTFILL_UBYTE ((unsigned char)(MEMENTO_POSTFILL))
+#define MEMENTO_POSTFILL_USHORT (((unsigned short)MEMENTO_POSTFILL_UBYTE) | (((unsigned short)MEMENTO_POSTFILL_UBYTE)<<8))
+#define MEMENTO_POSTFILL_UINT (((unsigned int)MEMENTO_POSTFILL_USHORT) | (((unsigned int)MEMENTO_POSTFILL_USHORT)<<16))
+#define MEMENTO_POSTFILL_PTR (void *)(((uintptr_t)MEMENTO_POSTFILL_UINT) | ((((uintptr_t)MEMENTO_POSTFILL_UINT)<<16)<<16))
+#define MEMENTO_ALLOCFILL_UBYTE ((unsigned char)(MEMENTO_ALLOCFILL))
+#define MEMENTO_ALLOCFILL_USHORT (((unsigned short)MEMENTO_ALLOCFILL_UBYTE) | (((unsigned short)MEMENTO_ALLOCFILL_UBYTE)<<8))
+#define MEMENTO_ALLOCFILL_UINT (((unsigned int)MEMENTO_ALLOCFILL_USHORT) | (((unsigned int)MEMENTO_ALLOCFILL_USHORT)<<16))
+#define MEMENTO_ALLOCFILL_PTR (void *)(((uintptr_t)MEMENTO_ALLOCFILL_UINT) | ((((uintptr_t)MEMENTO_ALLOCFILL_UINT)<<16)<<16))
+#define MEMENTO_FREEFILL_UBYTE ((unsigned char)(MEMENTO_FREEFILL))
+#define MEMENTO_FREEFILL_USHORT (((unsigned short)MEMENTO_FREEFILL_UBYTE) | (((unsigned short)MEMENTO_FREEFILL_UBYTE)<<8))
+#define MEMENTO_FREEFILL_UINT (((unsigned int)MEMENTO_FREEFILL_USHORT) | (((unsigned int)MEMENTO_FREEFILL_USHORT)<<16))
+#define MEMENTO_FREEFILL_PTR (void *)(((uintptr_t)MEMENTO_FREEFILL_UINT) | ((((uintptr_t)MEMENTO_FREEFILL_UINT)<<16)<<16))
+
+#ifdef MEMENTO
+
+#ifndef MEMENTO_CPP_EXTRAS_ONLY
+
+#ifdef MEMENTO_ANDROID
+#include <android/log.h>
+
+static char log_buffer[4096];
+static int log_fill = 0;
+
+static char log_buffer2[4096];
+
+static int
+android_fprintf(FILE *file, const char *fmt, ...)
+{
+    va_list args;
+    char *p, *q;
+
+    va_start(args, fmt);
+    vsnprintf(log_buffer2, sizeof(log_buffer2)-1, fmt, args);
+    va_end(args);
+
+    /* Ensure we are always null terminated */
+    log_buffer2[sizeof(log_buffer2)-1] = 0;
+
+    p = log_buffer2;
+    q = p;
+    do
+    {
+        /* Find the end of the string, or the next \n */
+        while (*p && *p != '\n')
+            p++;
+
+        /* We need to output from q to p. Limit ourselves to what
+         * will fit in the existing */
+        if (p - q >= sizeof(log_buffer)-1 - log_fill)
+                p = q + sizeof(log_buffer)-1 - log_fill;
+
+        memcpy(&log_buffer[log_fill], q, p-q);
+        log_fill += p-q;
+        if (*p == '\n')
+        {
+            log_buffer[log_fill] = 0;
+            __android_log_print(ANDROID_LOG_ERROR, "memento", "%s", log_buffer);
+            usleep(1);
+            log_fill = 0;
+            p++; /* Skip over the \n */
+        }
+        else if (log_fill >= sizeof(log_buffer)-1)
+        {
+            log_buffer[sizeof(log_buffer2)-1] = 0;
+            __android_log_print(ANDROID_LOG_ERROR, "memento", "%s", log_buffer);
+            usleep(1);
+            log_fill = 0;
+        }
+        q = p;
+    }
+    while (*p);
+
+    return 0;
+}
+
+#define fprintf android_fprintf
+#define MEMENTO_STACKTRACE_METHOD 3
+#endif
+
+/* _WIN64 defined implies _WIN32 will be */
+#ifdef _WIN32
+#include <windows.h>
+
+static int
+windows_fprintf(FILE *file, const char *fmt, ...)
+{
+    va_list args;
+    char text[4096];
+    int ret;
+
+    va_start(args, fmt);
+    ret = vfprintf(file, fmt, args);
+    va_end(args);
+
+    va_start(args, fmt);
+    vsnprintf(text, 4096, fmt, args);
+    OutputDebugStringA(text);
+    va_end(args);
+
+    return ret;
+}
+
+#define fprintf windows_fprintf
+#endif
+
+#ifndef MEMENTO_STACKTRACE_METHOD
+#ifdef __GNUC__
+#define MEMENTO_STACKTRACE_METHOD 1
+#endif
+#ifdef _WIN32
+#define MEMENTO_STACKTRACE_METHOD 2
+#endif
+#endif
+
 #if defined(__linux__)
 #define MEMENTO_HAS_FORK
 #elif defined(__APPLE__) && defined(__MACH__)
@@ -57,8 +194,8 @@
 /* Define the underlying allocators, just in case */
 void *MEMENTO_UNDERLYING_MALLOC(size_t);
 void MEMENTO_UNDERLYING_FREE(void *);
-void *MEMENTO_UNDERLYING_REALLOC(void *, size_t);
-void *MEMENTO_UNDERLYING_CALLOC(size_t, size_t);
+void *MEMENTO_UNDERLYING_REALLOC(void *,size_t);
+void *MEMENTO_UNDERLYING_CALLOC(size_t,size_t);
 
 /* And some other standard functions we use. We don't include the header
  * files, just in case they pull in unexpected others. */
@@ -73,8 +210,6 @@
 #define MEMENTO_MAXPATTERN 0
 #endif
 
-#ifdef MEMENTO
-
 #ifdef MEMENTO_GS_HACKS
 #include "valgrind.h"
 #else
@@ -88,21 +223,70 @@
 #endif
 
 enum {
-    Memento_PreSize = 16,
+    Memento_PreSize  = 16,
     Memento_PostSize = 16
 };
 
+/* Some compile time checks */
+typedef struct
+{
+    char MEMENTO_PRESIZE_MUST_BE_A_MULTIPLE_OF_4[Memento_PreSize & 3 ? -1 : 1];
+    char MEMENTO_POSTSIZE_MUST_BE_A_MULTIPLE_OF_4[Memento_PostSize & 3 ? -1 : 1];
+    char MEMENTO_POSTSIZE_MUST_BE_AT_LEAST_4[Memento_PostSize >= 4 ? 1 : -1];
+    char MEMENTO_PRESIZE_MUST_BE_AT_LEAST_4[Memento_PreSize >= 4 ? 1 : -1];
+} MEMENTO_SANITY_CHECK_STRUCT;
+
+#define MEMENTO_UINT32 unsigned int
+#define MEMENTO_UINT16 unsigned short
+
+#define MEMENTO_PREFILL_UINT32  ((MEMENTO_UINT32)(MEMENTO_PREFILL  | (MEMENTO_PREFILL <<8) | (MEMENTO_PREFILL <<16) |(MEMENTO_PREFILL <<24)))
+#define MEMENTO_POSTFILL_UINT16 ((MEMENTO_UINT16)(MEMENTO_POSTFILL | (MEMENTO_POSTFILL<<8)))
+#define MEMENTO_POSTFILL_UINT32 ((MEMENTO_UINT32)(MEMENTO_POSTFILL | (MEMENTO_POSTFILL<<8) | (MEMENTO_POSTFILL<<16) |(MEMENTO_POSTFILL<<24)))
+#define MEMENTO_FREEFILL_UINT16 ((MEMENTO_UINT16)(MEMENTO_FREEFILL | (MEMENTO_FREEFILL<<8)))
+#define MEMENTO_FREEFILL_UINT32 ((MEMENTO_UINT32)(MEMENTO_FREEFILL | (MEMENTO_FREEFILL<<8) | (MEMENTO_FREEFILL<<16) |(MEMENTO_FREEFILL<<24)))
+
 enum {
     Memento_Flag_OldBlock = 1,
     Memento_Flag_HasParent = 2,
     Memento_Flag_BreakOnFree = 4,
-    Memento_Flag_BreakOnRealloc = 8
+    Memento_Flag_BreakOnRealloc = 8,
+    Memento_Flag_Freed = 16,
+    Memento_Flag_KnownLeak = 32
 };
 
+enum {
+    Memento_EventType_malloc = 0,
+    Memento_EventType_calloc = 1,
+    Memento_EventType_realloc = 2,
+    Memento_EventType_free = 3,
+    Memento_EventType_new = 4,
+    Memento_EventType_delete = 5,
+    Memento_EventType_newArray = 6,
+    Memento_EventType_deleteArray = 7,
+    Memento_EventType_takeRef = 8,
+    Memento_EventType_dropRef = 9,
+    Memento_EventType_reference = 10
+};
+
+static const char *eventType[] =
+{
+    "malloc",
+    "calloc",
+    "realloc",
+    "free",
+    "new",
+    "delete",
+    "new[]",
+    "delete[]",
+    "takeRef",
+    "dropRef",
+    "reference"
+};
+
 /* When we list leaked blocks at the end of execution, we search for pointers
  * between blocks in order to be able to give a nice nested view.
  * Unfortunately, if you have are running your own allocator (such as
- * Ghostscript's chunk allocator) you can often find that the header of the
+ * postscript's chunk allocator) you can often find that the header of the
  * block always contains pointers to next or previous blocks. This tends to
  * mean the nesting displayed is "uninteresting" at best :)
  *
@@ -118,62 +302,132 @@
 #endif
 #endif
 
-typedef struct Memento_BlkHeader Memento_BlkHeader;
+#define MEMENTO_CHILD_MAGIC   ((Memento_BlkHeader *)('M' | ('3' << 8) | ('m' << 16) | ('3' << 24)))
+#define MEMENTO_SIBLING_MAGIC ((Memento_BlkHeader *)('n' | ('t' << 8) | ('0' << 16) | ('!' << 24)))
 
-struct Memento_BlkHeader {
-    size_t rawsize;
-    int sequence;
-    int lastCheckedOK;
-    int flags;
-    Memento_BlkHeader *next;
-    Memento_BlkHeader *parent;  /* Only used while printing out nested list */
+#ifdef MEMENTO_DETAILS
+typedef struct Memento_BlkDetails Memento_BlkDetails;
+
+struct Memento_BlkDetails
+{
+    Memento_BlkDetails *next;
+    char                type;
+    char                count;
+    int                 sequence;
+    void               *stack[1];
+};
+#endif /* MEMENTO_DETAILS */
 
-    const char *label;
+typedef struct Memento_BlkHeader Memento_BlkHeader;
 
-    /* Entries for nesting display calculations */
-    Memento_BlkHeader *child;
-    Memento_BlkHeader *sibling;
+struct Memento_BlkHeader
+{
+    size_t               rawsize;
+    int                  sequence;
+    int                  lastCheckedOK;
+    int                  flags;
+    Memento_BlkHeader   *next;
+    Memento_BlkHeader   *prev; /* Reused as 'parent' when printing nested list */
 
-    char preblk[Memento_PreSize];
+    const char          *label;
+
+    /* Entries for nesting display calculations. Set to magic
+     * values at all other time.  */
+    Memento_BlkHeader   *child;
+    Memento_BlkHeader   *sibling;
+
+#ifdef MEMENTO_DETAILS
+    Memento_BlkDetails  *details;
+    Memento_BlkDetails **details_tail;
+#endif
+
+    char                 preblk[Memento_PreSize];
 };
 
 /* In future this could (should) be a smarter data structure, like, say,
  * splay trees. For now, we use a list.
  */
-typedef struct Memento_Blocks {
+typedef struct Memento_Blocks
+{
     Memento_BlkHeader *head;
-    Memento_BlkHeader **tail;
+    Memento_BlkHeader *tail;
 } Memento_Blocks;
 
+/* What sort of Mutex should we use? */
+#ifdef MEMENTO_LOCKLESS
+typedef int Memento_mutex;
+
+static void Memento_initMutex(Memento_mutex *m)
+{
+    (void)m;
+}
+
+#define MEMENTO_DO_LOCK() do { } while (0)
+#define MEMENTO_DO_UNLOCK() do { } while (0)
+
+#else
+#if defined(_WIN32) || defined(_WIN64)
+/* Windows */
+typedef CRITICAL_SECTION Memento_mutex;
+
+static void Memento_initMutex(Memento_mutex *m)
+{
+    InitializeCriticalSection(m);
+}
+
+#define MEMENTO_DO_LOCK() \
+    EnterCriticalSection(&memento.mutex)
+#define MEMENTO_DO_UNLOCK() \
+    LeaveCriticalSection(&memento.mutex)
+
+#else
+#include <pthread.h>
+typedef pthread_mutex_t Memento_mutex;
+
+static void Memento_initMutex(Memento_mutex *m)
+{
+    pthread_mutex_init(m, NULL);
+}
+
+#define MEMENTO_DO_LOCK() \
+    pthread_mutex_lock(&memento.mutex)
+#define MEMENTO_DO_UNLOCK() \
+    pthread_mutex_unlock(&memento.mutex)
+
+#endif
+#endif
+
 /* And our global structure */
 static struct {
-    int inited;
+    int            inited;
     Memento_Blocks used;
     Memento_Blocks free;
-    size_t freeListSize;
-    int sequence;
-    int paranoia;
-    int paranoidAt;
-    int countdown;
-    int lastChecked;
-    int breakAt;
-    int failAt;
-    int failing;
-    int nextFailAt;
-    int squeezeAt;
-    int squeezing;
-    int segv;
-    int pattern;
-    int nextPattern;
-    int patternBit;
-    size_t maxMemory;
-    size_t alloc;
-    size_t peakAlloc;
-    size_t totalAlloc;
-    size_t numMallocs;
-    size_t numFrees;
-    size_t numReallocs;
-} globals;
+    size_t         freeListSize;
+    int            sequence;
+    int            paranoia;
+    int            paranoidAt;
+    int            countdown;
+    int            lastChecked;
+    int            breakAt;
+    int            failAt;
+    int            failing;
+    int            nextFailAt;
+    int            squeezeAt;
+    int            squeezing;
+    int            segv;
+    int            pattern;
+    int            nextPattern;
+    int            patternBit;
+    int            leaking;
+    size_t         maxMemory;
+    size_t         alloc;
+    size_t         peakAlloc;
+    size_t         totalAlloc;
+    size_t         numMallocs;
+    size_t         numFrees;
+    size_t         numReallocs;
+    Memento_mutex  mutex;
+} memento;
 
 #define MEMENTO_EXTRASIZE (sizeof(Memento_BlkHeader) + Memento_PostSize)
 
@@ -185,14 +439,506 @@
 #define MEMBLK_FROMBLK(B)   (&((Memento_BlkHeader*)(void *)(B))[-1])
 #define MEMBLK_TOBLK(B)     ((void*)(&((Memento_BlkHeader*)(void*)(B))[1]))
 #define MEMBLK_POSTPTR(B) \
-          (&((char *)(void *)(B))[(B)->rawsize + sizeof(Memento_BlkHeader)])
+          (&((unsigned char *)(void *)(B))[(B)->rawsize + sizeof(Memento_BlkHeader)])
 
-void
-Memento_breakpoint(void)
+enum
 {
+    SkipStackBackTraceLevels = 4
+};
+
+#if defined(MEMENTO_STACKTRACE_METHOD) && MEMENTO_STACKTRACE_METHOD == 1
+extern size_t backtrace(void **, int);
+extern void backtrace_symbols_fd(void **, size_t, int);
+extern char **backtrace_symbols(void **, size_t);
+
+#define MEMENTO_BACKTRACE_MAX 256
+
+/* Libbacktrace gubbins - relies on us having libdl to load the .so */
+#ifdef HAVE_LIBDL
+#include <dlfcn.h>
+
+typedef void (*backtrace_error_callback) (void *data, const char *msg, int errnum);
+
+typedef struct backtrace_state *(*backtrace_create_state_type)(
+    const char *filename, int threaded,
+    backtrace_error_callback error_callback, void *data);
+
+typedef int (*backtrace_full_callback) (void *data, uintptr_t pc,
+                                        const char *filename, int lineno,
+                                        const char *function);
+
+typedef int (*backtrace_pcinfo_type)(struct backtrace_state *state,
+                                     uintptr_t pc,
+                                     backtrace_full_callback callback,
+                                     backtrace_error_callback error_callback,
+                                     void *data);
+
+typedef void (*backtrace_syminfo_callback) (void *data, uintptr_t pc,
+                                            const char *symname,
+                                            uintptr_t symval,
+                                            uintptr_t symsize);
+
+typedef int (*backtrace_syminfo_type)(struct backtrace_state *state,
+                                      uintptr_t addr,
+                                      backtrace_syminfo_callback callback,
+                                      backtrace_error_callback error_callback,
+                                      void *data);
+
+static backtrace_syminfo_type backtrace_syminfo;
+static backtrace_create_state_type backtrace_create_state;
+static backtrace_pcinfo_type backtrace_pcinfo;
+static struct backtrace_state *my_backtrace_state;
+static void *libbt;
+static void (*print_stack_value)(void *address);
+static char backtrace_exe[4096];
+static void *current_addr;
+
+static void error2_cb(void *data, const char *msg, int errnum)
+{
+}
+
+static void syminfo_cb(void *data, uintptr_t pc, const char *symname, uintptr_t symval, uintptr_t symsize)
+{
+    if (sizeof(void *) == 4)
+        fprintf(stderr, "    0x%08lx %s\n", pc, symname?symname:"?");
+    else
+        fprintf(stderr, "    0x%016lx %s\n", pc, symname?symname:"?");
+}
+
+static void error_cb(void *data, const char *msg, int errnum)
+{
+    backtrace_syminfo(my_backtrace_state,
+                     (uintptr_t)current_addr,
+                     syminfo_cb,
+                     error2_cb,
+                     NULL);
+}
+
+static int full_cb(void *data, uintptr_t pc, const char *fname, int line, const char *fn)
+{
+    if (sizeof(void *) == 4)
+        fprintf(stderr, "    0x%08lx %s(%s:%d)\n", pc, fn?fn:"?", fname?fname:"?", line);
+    else
+        fprintf(stderr, "    0x%016lx %s(%s:%d)\n", pc, fn?fn:"?", fname?fname:"?", line);
+    return 0;
+}
+
+static void print_stack_libbt(void *addr)
+{
+    current_addr = addr;
+    backtrace_pcinfo(my_backtrace_state,
+                     (uintptr_t)addr,
+                     full_cb,
+                     error_cb,
+                     NULL);
+}
+
+static void print_stack_libbt_failed(void *addr)
+{
+    char **strings = backtrace_symbols(&addr, 1);
+
+    if (strings == NULL || strings[0] == NULL)
+    {
+        if (sizeof(void *) == 4)
+            fprintf(stderr, "    [0x%08lx]\n", (uintptr_t)addr);
+        else
+            fprintf(stderr, "    [0x%016lx]\n", (uintptr_t)addr);
+    }
+    else
+    {
+        fprintf(stderr, "    %s\n", strings[0]);
+    }
+    (free)(strings);
+}
+
+static int init_libbt(void)
+{
+    libbt = dlopen("libbacktrace.so", RTLD_LAZY);
+    if (libbt == NULL)
+        libbt = dlopen("/opt/lib/libbacktrace.so", RTLD_LAZY);
+    if (libbt == NULL)
+        libbt = dlopen("/lib/libbacktrace.so", RTLD_LAZY);
+    if (libbt == NULL)
+        libbt = dlopen("/usr/lib/libbacktrace.so", RTLD_LAZY);
+    if (libbt == NULL)
+        libbt = dlopen("/usr/local/lib/libbacktrace.so", RTLD_LAZY);
+    if (libbt == NULL)
+        goto fail;
+
+    backtrace_create_state = dlsym(libbt, "backtrace_create_state");
+    backtrace_syminfo      = dlsym(libbt, "backtrace_syminfo");
+    backtrace_pcinfo       = dlsym(libbt, "backtrace_pcinfo");
+
+    if (backtrace_create_state == NULL ||
+        backtrace_syminfo == NULL ||
+        backtrace_pcinfo == NULL)
+    {
+        goto fail;
+    }
+
+    my_backtrace_state = backtrace_create_state(backtrace_exe,
+                                                1 /*BACKTRACE_SUPPORTS_THREADS*/,
+                                                error_cb,
+                                                NULL);
+    if (my_backtrace_state == NULL)
+        goto fail;
+
+    print_stack_value = print_stack_libbt;
+
+    return 1;
+
+ fail:
+    libbt = NULL;
+    backtrace_create_state = NULL;
+    backtrace_syminfo = NULL;
+    print_stack_value = print_stack_libbt_failed;
+    return 0;
+}
+#endif
+
+static void print_stack_default(void *addr)
+{
+    char **strings = backtrace_symbols(&addr, 1);
+
+    if (strings == NULL || strings[0] == NULL)
+    {
+        fprintf(stderr, "    [0x%p]\n", addr);
+    }
+#ifdef HAVE_LIBDL
+    else if (strchr(strings[0], ':') == NULL)
+    {
+        /* Probably a "path [address]" format string */
+        char *s = strchr(strings[0], ' ');
+
+        if (s != strings[0])
+        {
+            memcpy(backtrace_exe, strings[0], s - strings[0]);
+            backtrace_exe[s-strings[0]] = 0;
+            if (init_libbt())
+                print_stack_value(addr);
+        }
+    }
+#endif
+    else
+    {
+        fprintf(stderr, "    %s\n", strings[0]);
+    }
+    free(strings);
+}
+
+static void Memento_initStacktracer(void)
+{
+    print_stack_value = print_stack_default;
+}
+
+static int Memento_getStacktrace(void **stack, int *skip)
+{
+    size_t num;
+
+    num = backtrace(&stack[0], MEMENTO_BACKTRACE_MAX);
+
+    *skip = SkipStackBackTraceLevels;
+    if (num <= SkipStackBackTraceLevels)
+        return 0;
+    return (int)(num-SkipStackBackTraceLevels);
+}
+
+static void Memento_showStacktrace(void **stack, int numberOfFrames)
+{
+    int i;
+
+    for (i = 0; i < numberOfFrames; i++)
+    {
+        print_stack_value(stack[i]);
+    }
+}
+#elif defined(MEMENTO_STACKTRACE_METHOD) && MEMENTO_STACKTRACE_METHOD == 2
+#include <Windows.h>
+
+/* We use DbgHelp.dll rather than DbgHelp.lib. This avoids us needing
+ * extra link time complications, and enables us to fall back gracefully
+ * if the DLL cannot be found.
+ *
+ * To achieve this we have our own potted versions of the required types
+ * inline here.
+ */
+#ifdef _WIN64
+typedef DWORD64 DWORD_NATIVESIZED;
+#else
+typedef DWORD DWORD_NATIVESIZED;
+#endif
+
+#define MEMENTO_BACKTRACE_MAX 64
+
+typedef USHORT (__stdcall *My_CaptureStackBackTraceType)(__in ULONG, __in ULONG, __out PVOID*, __out_opt PULONG);
+
+typedef struct MY_IMAGEHLP_LINE {
+    DWORD    SizeOfStruct;
+    PVOID    Key;
+    DWORD    LineNumber;
+    PCHAR    FileName;
+    DWORD_NATIVESIZED    Address;
+} MY_IMAGEHLP_LINE, *MY_PIMAGEHLP_LINE;
+
+typedef BOOL (__stdcall *My_SymGetLineFromAddrType)(HANDLE hProcess, DWORD_NATIVESIZED dwAddr, PDWORD pdwDisplacement, MY_PIMAGEHLP_LINE Line);
+
+typedef struct MY_SYMBOL_INFO {
+    ULONG       SizeOfStruct;
+    ULONG       TypeIndex;        // Type Index of symbol
+    ULONG64     Reserved[2];
+    ULONG       info;
+    ULONG       Size;
+    ULONG64     ModBase;          // Base Address of module containing this symbol
+    ULONG       Flags;
+    ULONG64     Value;            // Value of symbol, ValuePresent should be 1
+    ULONG64     Address;          // Address of symbol including base address of module
+    ULONG       Register;         // register holding value or pointer to value
+    ULONG       Scope;            // scope of the symbol
+    ULONG       Tag;              // pdb classification
+    ULONG       NameLen;          // Actual length of name
+    ULONG       MaxNameLen;
+    CHAR        Name[1];          // Name of symbol
+} MY_SYMBOL_INFO, *MY_PSYMBOL_INFO;
+
+typedef BOOL (__stdcall *My_SymFromAddrType)(HANDLE hProcess, DWORD64 Address, PDWORD64 Displacement, MY_PSYMBOL_INFO Symbol);
+typedef BOOL (__stdcall *My_SymInitializeType)(HANDLE hProcess, PSTR UserSearchPath, BOOL fInvadeProcess);
+
+static My_CaptureStackBackTraceType Memento_CaptureStackBackTrace;
+static My_SymGetLineFromAddrType Memento_SymGetLineFromAddr;
+static My_SymFromAddrType Memento_SymFromAddr;
+static My_SymInitializeType Memento_SymInitialize;
+static HANDLE Memento_process;
+
+static void Memento_initStacktracer(void)
+{
+    HMODULE mod = LoadLibrary("kernel32.dll");
+
+    if (mod == NULL)
+        return;
+    Memento_CaptureStackBackTrace = (My_CaptureStackBackTraceType)(GetProcAddress(mod, "RtlCaptureStackBackTrace"));
+    if (Memento_CaptureStackBackTrace == NULL)
+        return;
+    mod = LoadLibrary("Dbghelp.dll");
+    if (mod == NULL) {
+        Memento_CaptureStackBackTrace = NULL;
+        return;
+    }
+    Memento_SymGetLineFromAddr =
+            (My_SymGetLineFromAddrType)(GetProcAddress(mod,
+#ifdef _WIN64
+                                                       "SymGetLineFromAddr64"
+#else
+                                                       "SymGetLineFromAddr"
+#endif
+                                        ));
+    if (Memento_SymGetLineFromAddr == NULL) {
+        Memento_CaptureStackBackTrace = NULL;
+        return;
+    }
+    Memento_SymFromAddr = (My_SymFromAddrType)(GetProcAddress(mod, "SymFromAddr"));
+    if (Memento_SymFromAddr == NULL) {
+        Memento_CaptureStackBackTrace = NULL;
+        return;
+    }
+    Memento_SymInitialize = (My_SymInitializeType)(GetProcAddress(mod, "SymInitialize"));
+    if (Memento_SymInitialize == NULL) {
+        Memento_CaptureStackBackTrace = NULL;
+        return;
+    }
+    Memento_process = GetCurrentProcess();
+    Memento_SymInitialize(Memento_process, NULL, TRUE);
+}
+
+static int Memento_getStacktrace(void **stack, int *skip)
+{
+    if (Memento_CaptureStackBackTrace == NULL)
+        return 0;
+
+    *skip = 0;
+    /* Limit us to 63 levels due to windows bug */
+    return Memento_CaptureStackBackTrace(SkipStackBackTraceLevels, 63-SkipStackBackTraceLevels, stack, NULL);
+}
+
+static void Memento_showStacktrace(void **stack, int numberOfFrames)
+{
+    MY_IMAGEHLP_LINE line;
+    int i;
+    char symbol_buffer[sizeof(MY_SYMBOL_INFO) + 1024 + 1];
+    MY_SYMBOL_INFO *symbol = (MY_SYMBOL_INFO *)symbol_buffer;
+
+    symbol->MaxNameLen = 1024;
+    symbol->SizeOfStruct = sizeof(MY_SYMBOL_INFO);
+    line.SizeOfStruct = sizeof(MY_IMAGEHLP_LINE);
+    for (i = 0; i < numberOfFrames; i++)
+    {
+        DWORD64 dwDisplacement64;
+        DWORD dwDisplacement;
+        Memento_SymFromAddr(Memento_process, (DWORD64)(stack[i]), &dwDisplacement64, symbol);
+        Memento_SymGetLineFromAddr(Memento_process, (DWORD_NATIVESIZED)(stack[i]), &dwDisplacement, &line);
+        fprintf(stderr, "    %s in %s:%d\n", symbol->Name, line.FileName, line.LineNumber);
+    }
+}
+#elif defined(MEMENTO_STACKTRACE_METHOD) && MEMENTO_STACKTRACE_METHOD == 3
+
+#include <unwind.h>
+#include <dlfcn.h>
+
+/* From cxxabi.h */
+extern char* __cxa_demangle(const char* mangled_name,
+                            char*       output_buffer,
+                            size_t*     length,
+                            int*        status);
+
+static void Memento_initStacktracer(void)
+{
+}
+
+#define MEMENTO_BACKTRACE_MAX 256
+
+typedef struct
+{
+    int count;
+    void **addr;
+} my_unwind_details;
+
+static _Unwind_Reason_Code unwind_populate_callback(struct _Unwind_Context *context,
+                                                    void *arg)
+{
+    my_unwind_details *uw = (my_unwind_details *)arg;
+    int count = uw->count;
+
+    if (count >= MEMENTO_BACKTRACE_MAX)
+        return _URC_END_OF_STACK;
+
+    uw->addr[count] = (void *)_Unwind_GetIP(context);
+    uw->count++;
+
+    return _URC_NO_REASON;
+}
+
+static int Memento_getStacktrace(void **stack, int *skip)
+{
+    my_unwind_details uw = { 0, stack };
+
+    *skip = 0;
+
+    /* Collect the backtrace. Deliberately only unwind once,
+     * and avoid using malloc etc until this completes just
+     * in case. */
+    _Unwind_Backtrace(unwind_populate_callback, &uw);
+    if (uw.count <= SkipStackBackTraceLevels)
+        return 0;
+
+    *skip = SkipStackBackTraceLevels;
+    return uw.count-SkipStackBackTraceLevels;
+}
+
+static void Memento_showStacktrace(void **stack, int numberOfFrames)
+{
+    int i;
+
+    for (i = 0; i < numberOfFrames; i++)
+    {
+        Dl_info info;
+        if (dladdr(stack[i], &info))
+        {
+            int status = 0;
+            const char *sym = info.dli_sname ? info.dli_sname : "<unknown>";
+            char *demangled = __cxa_demangle(sym, NULL, 0, &status);
+            int offset = stack[i] - info.dli_saddr;
+            fprintf(stderr, "    [%p]%s(+0x%x)\n", stack[i], demangled && status == 0 ? demangled : sym, offset);
+            free(demangled);
+        }
+        else
+        {
+            fprintf(stderr, "    [%p]\n", stack[i]);
+        }
+    }
+}
+
+#else
+static void Memento_initStacktracer(void)
+{
+}
+
+static int Memento_getStacktrace(void **stack, int *skip)
+{
+    *skip = 0;
+    return 0;
+}
+
+static void Memento_showStacktrace(void **stack, int numberOfFrames)
+{
+}
+#endif /* MEMENTO_STACKTRACE_METHOD */
+
+#ifdef MEMENTO_DETAILS
+static void Memento_storeDetails(Memento_BlkHeader *head, int type)
+{
+    void *stack[MEMENTO_BACKTRACE_MAX];
+    Memento_BlkDetails *details;
+    int count;
+    int skip;
+
+    if (head == NULL)
+        return;
+
+#ifdef MEMENTO_STACKTRACE_METHOD
+    count = Memento_getStacktrace(stack, &skip);
+#else
+    skip = 0;
+    count = 0;
+#endif
+
+    details = MEMENTO_UNDERLYING_MALLOC(sizeof(*details) + (count-1) * sizeof(void *));
+    if (details == NULL)
+        return;
+
+    if (count)
+        memcpy(&details->stack, &stack[skip], count * sizeof(void *));
+
+    details->type = type;
+    details->count = count;
+    details->sequence = memento.sequence;
+    details->next = NULL;
+    VALGRIND_MAKE_MEM_DEFINED(&head->details_tail, sizeof(head->details_tail));
+    *head->details_tail = details;
+    head->details_tail = &details->next;
+    VALGRIND_MAKE_MEM_NOACCESS(&head->details_tail, sizeof(head->details_tail));
+}
+#endif
+
+void (Memento_bt)(void)
+{
+#ifdef MEMENTO_STACKTRACE_METHOD
+    void *stack[MEMENTO_BACKTRACE_MAX];
+    int count;
+    int skip;
+
+    count = Memento_getStacktrace(stack, &skip);
+    Memento_showStacktrace(&stack[skip-2], count-skip+2);
+#endif
+}
+
+static void Memento_bt_internal(int skip2)
+{
+#ifdef MEMENTO_STACKTRACE_METHOD
+    void *stack[MEMENTO_BACKTRACE_MAX];
+    int count;
+    int skip;
+
+    count = Memento_getStacktrace(stack, &skip);
+    Memento_showStacktrace(&stack[skip+skip2], count-skip-skip2);
+#endif
+}
+
+static int Memento_checkAllMemoryLocked(void);
+
+void Memento_breakpoint(void)
+{
     /* A handy externally visible function for breakpointing */
-#if 0                           /* Enable this to force automatic breakpointing */
-#ifdef DEBUG
+#if 0 /* Enable this to force automatic breakpointing */
+#ifndef NDEBUG
 #ifdef _MSC_VER
     __asm int 3;
 #endif
@@ -200,14 +946,33 @@
 #endif
 }
 
-static void
-Memento_addBlockHead(Memento_Blocks *blks, Memento_BlkHeader *b, int type)
+static void Memento_init(void);
+
+#define MEMENTO_LOCK() \
+do { if (!memento.inited) Memento_init(); MEMENTO_DO_LOCK(); } while (0)
+
+#define MEMENTO_UNLOCK() \
+do { MEMENTO_DO_UNLOCK(); } while (0)
+
+/* Do this as a macro to prevent another level in the callstack,
+ * which is annoying while stepping. */
+#define Memento_breakpointLocked() \
+do { MEMENTO_UNLOCK(); Memento_breakpoint(); MEMENTO_LOCK(); } while (0)
+
+static void Memento_addBlockHead(Memento_Blocks    *blks,
+                                 Memento_BlkHeader *b,
+                                 int                type)
 {
-    if (blks->tail == &blks->head) {
-        /* Adding into an empty list, means the tail changes too */
-        blks->tail = &b->next;
+    if (blks->tail == NULL)
+        blks->tail = b;
+    b->next    = blks->head;
+    b->prev    = NULL;
+    if (blks->head)
+    {
+        VALGRIND_MAKE_MEM_DEFINED(&blks->head->prev, sizeof(blks->head->prev));
+        blks->head->prev = b;
+        VALGRIND_MAKE_MEM_NOACCESS(&blks->head->prev, sizeof(blks->head->prev));
     }
-    b->next = blks->head;
     blks->head = b;
 #ifndef MEMENTO_LEAKONLY
     memset(b->preblk, MEMENTO_PREFILL, Memento_PreSize);
@@ -214,33 +979,41 @@
     memset(MEMBLK_POSTPTR(b), MEMENTO_POSTFILL, Memento_PostSize);
 #endif
     VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_POSTPTR(b), Memento_PostSize);
-    if (type == 0) {            /* malloc */
+    if (type == 0) { /* malloc */
         VALGRIND_MAKE_MEM_UNDEFINED(MEMBLK_TOBLK(b), b->rawsize);
-    } else if (type == 1) {     /* free */
+    } else if (type == 1) { /* free */
         VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_TOBLK(b), b->rawsize);
     }
     VALGRIND_MAKE_MEM_NOACCESS(b, sizeof(Memento_BlkHeader));
 }
 
-static void
-Memento_addBlockTail(Memento_Blocks *blks, Memento_BlkHeader *b, int type)
+static void Memento_addBlockTail(Memento_Blocks    *blks,
+                                 Memento_BlkHeader *b,
+                                 int                type)
 {
-    VALGRIND_MAKE_MEM_DEFINED(blks->tail, sizeof(Memento_BlkHeader *));
-    *blks->tail = b;
-    blks->tail = &b->next;
+    VALGRIND_MAKE_MEM_DEFINED(&blks->tail, sizeof(Memento_BlkHeader *));
+    if (blks->head == NULL)
+        blks->head = b;
+    b->prev = blks->tail;
     b->next = NULL;
-    VALGRIND_MAKE_MEM_NOACCESS(blks->tail, sizeof(Memento_BlkHeader *));
+    if (blks->tail) {
+        VALGRIND_MAKE_MEM_DEFINED(&blks->tail->next, sizeof(blks->tail->next));
+        blks->tail->next = b;
+        VALGRIND_MAKE_MEM_NOACCESS(&blks->tail->next, sizeof(blks->tail->next));
+    }
+    blks->tail = b;
 #ifndef MEMENTO_LEAKONLY
     memset(b->preblk, MEMENTO_PREFILL, Memento_PreSize);
     memset(MEMBLK_POSTPTR(b), MEMENTO_POSTFILL, Memento_PostSize);
 #endif
     VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_POSTPTR(b), Memento_PostSize);
-    if (type == 0) {            /* malloc */
+    if (type == 0) { /* malloc */
         VALGRIND_MAKE_MEM_UNDEFINED(MEMBLK_TOBLK(b), b->rawsize);
-    } else if (type == 1) {     /* free */
+    } else if (type == 1) { /* free */
         VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_TOBLK(b), b->rawsize);
     }
     VALGRIND_MAKE_MEM_NOACCESS(b, sizeof(Memento_BlkHeader));
+    VALGRIND_MAKE_MEM_NOACCESS(&blks->tail, sizeof(Memento_BlkHeader *));
 }
 
 typedef struct BlkCheckData {
@@ -248,176 +1021,183 @@
     int preCorrupt;
     int postCorrupt;
     int freeCorrupt;
-    int index;
+    size_t index;
 } BlkCheckData;
 
-static int
-Memento_Internal_checkAllocedBlock(Memento_BlkHeader *b, void *arg)
-{
 #ifndef MEMENTO_LEAKONLY
-    int i;
-    char *p;
-    int corrupt = 0;
-    BlkCheckData *data = (BlkCheckData *) arg;
+static int Memento_Internal_checkAllocedBlock(Memento_BlkHeader *b, void *arg)
+{
+    int             i;
+    MEMENTO_UINT32 *ip;
+    unsigned char  *p;
+    BlkCheckData   *data = (BlkCheckData *)arg;
 
-    p = b->preblk;
-    i = Memento_PreSize;
+    ip = (MEMENTO_UINT32 *)(void *)(b->preblk);
+    i = Memento_PreSize>>2;
     do {
-        corrupt |= (*p++ ^ (char)MEMENTO_PREFILL);
+        if (*ip++ != MEMENTO_PREFILL_UINT32)
+            goto pre_corrupt;
     } while (--i);
-    if (corrupt) {
+    if (0) {
+pre_corrupt:
         data->preCorrupt = 1;
     }
+    /* Postfill may not be aligned, so have to be slower */
     p = MEMBLK_POSTPTR(b);
-    i = Memento_PreSize;
+    i = Memento_PostSize-4;
+    if ((intptr_t)p & 1)
+    {
+        if (*p++ != MEMENTO_POSTFILL)
+            goto post_corrupt;
+        i--;
+    }
+    if ((intptr_t)p & 2)
+    {
+        if (*(MEMENTO_UINT16 *)p != MEMENTO_POSTFILL_UINT16)
+            goto post_corrupt;
+        p += 2;
+        i -= 2;
+    }
     do {
-        corrupt |= (*p++ ^ (char)MEMENTO_POSTFILL);
-    } while (--i);
-    if (corrupt) {
+        if (*(MEMENTO_UINT32 *)p != MEMENTO_POSTFILL_UINT32)
+            goto post_corrupt;
+        p += 4;
+        i -= 4;
+    } while (i >= 0);
+    if (i & 2)
+    {
+        if (*(MEMENTO_UINT16 *)p != MEMENTO_POSTFILL_UINT16)
+            goto post_corrupt;
+        p += 2;
+    }
+    if (i & 1)
+    {
+        if (*p != MEMENTO_POSTFILL)
+            goto post_corrupt;
+    }
+    if (0) {
+post_corrupt:
         data->postCorrupt = 1;
     }
     if ((data->freeCorrupt | data->preCorrupt | data->postCorrupt) == 0) {
-        b->lastCheckedOK = globals.sequence;
+        b->lastCheckedOK = memento.sequence;
     }
     data->found |= 1;
-#endif
     return 0;
 }
 
-static int
-Memento_Internal_checkFreedBlock(Memento_BlkHeader *b, void *arg)
+static int Memento_Internal_checkFreedBlock(Memento_BlkHeader *b, void *arg)
 {
-#ifndef MEMENTO_LEAKONLY
-    int i;
-    char *p;
-    BlkCheckData *data = (BlkCheckData *) arg;
+    size_t         i;
+    unsigned char *p;
+    BlkCheckData  *data = (BlkCheckData *)arg;
 
-    p = MEMBLK_TOBLK(b);
+    p = MEMBLK_TOBLK(b); /* p will always be aligned */
     i = b->rawsize;
     /* Attempt to speed this up by checking an (aligned) int at a time */
-    do {
-        if (((size_t) p) & 1) {
-            if (*p++ != (char)MEMENTO_FREEFILL)
-                break;
-            i--;
-            if (i == 0)
-                break;
-        }
-        if ((i >= 2) && (((size_t) p) & 2)) {
-            if (*(short *)p != (short)(MEMENTO_FREEFILL | (MEMENTO_FREEFILL << 8)))
-                goto mismatch;
-            p += 2;
-            i -= 2;
-            if (i == 0)
-                break;
-        }
+    if (i >= 4) {
         i -= 4;
-        while (i >= 0) {
-            if (*(int *)p != (MEMENTO_FREEFILL | (MEMENTO_FREEFILL << 8) | (MEMENTO_FREEFILL << 16) | (MEMENTO_FREEFILL << 24)))
-                goto mismatch;
+        do {
+            if (*(MEMENTO_UINT32 *)p != MEMENTO_FREEFILL_UINT32)
+                goto mismatch4;
             p += 4;
             i -= 4;
-        }
+	} while (i > 0);
         i += 4;
-        if ((i >= 2) && (((size_t) p) & 2)) {
-            if (*(short *)p != (short)(MEMENTO_FREEFILL | (MEMENTO_FREEFILL << 8)))
-                goto mismatch;
-            p += 2;
-            i -= 2;
-        }
+    }
+    if (i & 2) {
+        if (*(MEMENTO_UINT16 *)p != MEMENTO_FREEFILL_UINT16)
+            goto mismatch;
+        p += 2;
+        i -= 2;
+    }
+    if (0) {
+mismatch4:
+        i += 4;
+    }
 mismatch:
-        while (i) {
-            if (*p++ != (char)MEMENTO_FREEFILL)
-                break;
-            i--;
-        }
-    } while (0);
+    while (i) {
+        if (*p++ != (unsigned char)MEMENTO_FREEFILL)
+            break;
+        i--;
+    }
     if (i) {
         data->freeCorrupt = 1;
-        data->index = b->rawsize - i;
+        data->index       = b->rawsize-i;
     }
     return Memento_Internal_checkAllocedBlock(b, arg);
-#else
-    return 0;
-#endif
 }
+#endif /* MEMENTO_LEAKONLY */
 
-static void
-Memento_removeBlock(Memento_Blocks *blks, Memento_BlkHeader *b)
+static void Memento_removeBlock(Memento_Blocks    *blks,
+                                Memento_BlkHeader *b)
 {
-    Memento_BlkHeader *head = blks->head;
-    Memento_BlkHeader *prev = NULL;
-
-    while ((head) && (head != b)) {
-        VALGRIND_MAKE_MEM_DEFINED(head, sizeof(*head));
-        prev = head;
-        head = head->next;
-        VALGRIND_MAKE_MEM_NOACCESS(prev, sizeof(*prev));
+    VALGRIND_MAKE_MEM_DEFINED(b, sizeof(*b));
+    if (b->next) {
+        VALGRIND_MAKE_MEM_DEFINED(&b->next->prev, sizeof(b->next->prev));
+        b->next->prev = b->prev;
+        VALGRIND_MAKE_MEM_NOACCESS(&b->next->prev, sizeof(b->next->prev));
     }
-    if (head == NULL) {
-        /* FAIL! Will have been reported to user earlier, so just exit. */
-        return;
+    if (b->prev) {
+        VALGRIND_MAKE_MEM_DEFINED(&b->prev->next, sizeof(b->prev->next));
+        b->prev->next = b->next;
+        VALGRIND_MAKE_MEM_NOACCESS(&b->prev->next, sizeof(b->prev->next));
     }
-    VALGRIND_MAKE_MEM_DEFINED(blks->tail, sizeof(*blks->tail));
-    if (*blks->tail == head) {
-        /* Removing the tail of the list */
-        if (prev == NULL) {
-            /* Which is also the head */
-            blks->tail = &blks->head;
-        } else {
-            /* Which isn't the head */
-            blks->tail = &prev->next;
-        }
+    if (blks->tail == b)
+        blks->tail = b->prev;
+    if (blks->head == b)
+        blks->head = b->next;
+}
+
+static void free_block(Memento_BlkHeader *head)
+{
+#ifdef MEMENTO_DETAILS
+    Memento_BlkDetails *details = head->details;
+
+    while (details)
+    {
+        Memento_BlkDetails *next = details->next;
+        MEMENTO_UNDERLYING_FREE(details);
+        details = next;
     }
-    if (prev == NULL) {
-        /* Removing from the head of the list */
-        VALGRIND_MAKE_MEM_DEFINED(head, sizeof(*head));
-        blks->head = head->next;
-        VALGRIND_MAKE_MEM_NOACCESS(head, sizeof(*head));
-    } else {
-        /* Removing from not-the-head */
-        VALGRIND_MAKE_MEM_DEFINED(head, sizeof(*head));
-        VALGRIND_MAKE_MEM_DEFINED(prev, sizeof(*prev));
-        prev->next = head->next;
-        VALGRIND_MAKE_MEM_NOACCESS(head, sizeof(*head));
-        VALGRIND_MAKE_MEM_NOACCESS(prev, sizeof(*prev));
-    }
+#endif
+    MEMENTO_UNDERLYING_FREE(head);
 }
 
-static int
-Memento_Internal_makeSpace(size_t space)
+static int Memento_Internal_makeSpace(size_t space)
 {
     /* If too big, it can never go on the freelist */
     if (space > MEMENTO_FREELIST_MAX_SINGLE_BLOCK)
         return 0;
     /* Pretend we added it on. */
-    globals.freeListSize += space;
+    memento.freeListSize += space;
     /* Ditch blocks until it fits within our limit */
-    while (globals.freeListSize > MEMENTO_FREELIST_MAX) {
-        Memento_BlkHeader *head = globals.free.head;
-
+    while (memento.freeListSize > MEMENTO_FREELIST_MAX) {
+        Memento_BlkHeader *head = memento.free.head;
         VALGRIND_MAKE_MEM_DEFINED(head, sizeof(*head));
-        globals.free.head = head->next;
-        globals.freeListSize -= MEMBLK_SIZE(head->rawsize);
-        MEMENTO_UNDERLYING_FREE(head);
+        memento.free.head = head->next;
+        memento.freeListSize -= MEMBLK_SIZE(head->rawsize);
+        free_block(head);
     }
     /* Make sure we haven't just completely emptied the free list */
     /* (This should never happen, but belt and braces... */
-    if (globals.free.head == NULL)
-        globals.free.tail = &globals.free.head;
+    if (memento.free.head == NULL)
+        memento.free.tail = NULL;
     return 1;
 }
 
-static int
-Memento_appBlocks(Memento_Blocks *blks, int (*app)(Memento_BlkHeader *, void *), void *arg)
+static int Memento_appBlocks(Memento_Blocks *blks,
+                             int             (*app)(Memento_BlkHeader *,
+                                                    void *),
+                             void           *arg)
 {
     Memento_BlkHeader *head = blks->head;
     Memento_BlkHeader *next;
-    int result;
-
+    int                result;
     while (head) {
         VALGRIND_MAKE_MEM_DEFINED(head, sizeof(Memento_BlkHeader));
-        VALGRIND_MAKE_MEM_DEFINED(MEMBLK_TOBLK(head), head->rawsize + Memento_PostSize);
+        VALGRIND_MAKE_MEM_DEFINED(MEMBLK_TOBLK(head),
+                                  head->rawsize + Memento_PostSize);
         result = app(head, arg);
         next = head->next;
         VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_POSTPTR(head), Memento_PostSize);
@@ -429,22 +1209,27 @@
     return 0;
 }
 
-static int
-Memento_appBlock(Memento_Blocks *blks, int (*app)(Memento_BlkHeader *, void *), void *arg, Memento_BlkHeader *b)
+#ifndef MEMENTO_LEAKONLY
+/* Distrustful - check the block is a real one */
+static int Memento_appBlockUser(Memento_Blocks    *blks,
+                                int                (*app)(Memento_BlkHeader *,
+                                                          void *),
+                                void              *arg,
+                                Memento_BlkHeader *b)
 {
     Memento_BlkHeader *head = blks->head;
     Memento_BlkHeader *next;
-    int result;
-
+    int                result;
     while (head && head != b) {
         VALGRIND_MAKE_MEM_DEFINED(head, sizeof(Memento_BlkHeader));
         next = head->next;
-        VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_POSTPTR(head), Memento_PostSize);
+       VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_POSTPTR(head), Memento_PostSize);
         head = next;
     }
     if (head == b) {
         VALGRIND_MAKE_MEM_DEFINED(head, sizeof(Memento_BlkHeader));
-        VALGRIND_MAKE_MEM_DEFINED(MEMBLK_TOBLK(head), head->rawsize + Memento_PostSize);
+        VALGRIND_MAKE_MEM_DEFINED(MEMBLK_TOBLK(head),
+                                  head->rawsize + Memento_PostSize);
         result = app(head, arg);
         VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_POSTPTR(head), Memento_PostSize);
         VALGRIND_MAKE_MEM_NOACCESS(head, sizeof(Memento_BlkHeader));
@@ -453,70 +1238,101 @@
     return 0;
 }
 
-static void
-showBlock(Memento_BlkHeader *b, int space)
+static int Memento_appBlock(Memento_Blocks    *blks,
+                            int                (*app)(Memento_BlkHeader *,
+                                                      void *),
+                            void              *arg,
+                            Memento_BlkHeader *b)
 {
-    fprintf(stderr, "0x%p:(size=%d,num=%d)", MEMBLK_TOBLK(b), (int)b->rawsize, b->sequence);
+    int result;
+    VALGRIND_MAKE_MEM_DEFINED(b, sizeof(Memento_BlkHeader));
+    VALGRIND_MAKE_MEM_DEFINED(MEMBLK_TOBLK(b),
+                              b->rawsize + Memento_PostSize);
+    result = app(b, arg);
+    VALGRIND_MAKE_MEM_NOACCESS(MEMBLK_POSTPTR(b), Memento_PostSize);
+    VALGRIND_MAKE_MEM_NOACCESS(b, sizeof(Memento_BlkHeader));
+    return result;
+}
+#endif /* MEMENTO_LEAKONLY */
+
+static void showBlock(Memento_BlkHeader *b, int space)
+{
+    fprintf(stderr, "0x%p:(size=" FMTZ ",num=%d)",
+            MEMBLK_TOBLK(b), (FMTZ_CAST)b->rawsize, b->sequence);
     if (b->label)
         fprintf(stderr, "%c(%s)", space, b->label);
+    if (b->flags & Memento_Flag_KnownLeak)
+        fprintf(stderr, "(Known Leak)");
 }
 
-static void
-blockDisplay(Memento_BlkHeader *b, int n)
+static void blockDisplay(Memento_BlkHeader *b, int n)
 {
     n++;
-    while (n > 0) {
+    while (n > 40)
+    {
+            fprintf(stderr, "*");
+            n -= 40;
+    }
+    while(n > 0)
+    {
         int i = n;
-
         if (i > 32)
             i = 32;
         n -= i;
-        fprintf(stderr, "%s", &"                                "[32 - i]);
+        fprintf(stderr, "%s", &"                                "[32-i]);
     }
     showBlock(b, '\t');
     fprintf(stderr, "\n");
 }
 
-static int
-Memento_listBlock(Memento_BlkHeader *b, void *arg)
+static int Memento_listBlock(Memento_BlkHeader *b,
+                             void              *arg)
 {
-    int *counts = (int *)arg;
-
+    size_t *counts = (size_t *)arg;
     blockDisplay(b, 0);
     counts[0]++;
-    counts[1] += b->rawsize;
+    counts[1]+= b->rawsize;
     return 0;
 }
 
-static void
-doNestedDisplay(Memento_BlkHeader *b, int depth)
+static void doNestedDisplay(Memento_BlkHeader *b,
+                            int depth)
 {
-    blockDisplay(b, depth);
-    for (b = b->child; b; b = b->sibling)
-        doNestedDisplay(b, depth + 1);
+    /* Try and avoid recursion if we can help it */
+    do {
+        blockDisplay(b, depth);
+        if (b->sibling) {
+            if (b->child)
+                doNestedDisplay(b->child, depth+1);
+            b = b->sibling;
+        } else {
+            b = b->child;
+            depth++;
+        }
+    } while (b);
 }
 
-static int
-ptrcmp(const void *a_, const void *b_)
+static int ptrcmp(const void *a_, const void *b_)
 {
     const char **a = (const char **)a_;
     const char **b = (const char **)b_;
-
-    return (int)(*a - *b);
+    return (int)(*a-*b);
 }
 
-static int
-Memento_listBlocksNested(void)
+static
+int Memento_listBlocksNested(void)
 {
-    int count, size, i;
-    Memento_BlkHeader *b;
+    int count, i;
+    size_t size;
+    Memento_BlkHeader *b, *prev;
     void **blocks, *minptr, *maxptr;
-    long mask;
+    intptr_t mask;
 
     /* Count the blocks */
     count = 0;
     size = 0;
-    for (b = globals.used.head; b; b = b->next) {
+    for (b = memento.used.head; b; b = b->next) {
+        VALGRIND_MAKE_MEM_DEFINED(b, sizeof(*b));
         size += b->rawsize;
         count++;
     }
@@ -527,13 +1343,12 @@
         return 1;
 
     /* Populate our block list */
-    b = globals.used.head;
+    b = memento.used.head;
     minptr = maxptr = MEMBLK_TOBLK(b);
-    mask = (long)minptr;
+    mask = (intptr_t)minptr;
     for (i = 0; b; b = b->next, i++) {
         void *p = MEMBLK_TOBLK(b);
-
-        mask &= (long)p;
+        mask &= (intptr_t)p;
         if (p < minptr)
             minptr = p;
         if (p > maxptr)
@@ -540,23 +1355,22 @@
             maxptr = p;
         blocks[i] = p;
         b->flags &= ~Memento_Flag_HasParent;
-        b->child = NULL;
+        b->child   = NULL;
         b->sibling = NULL;
-        b->parent = NULL;
+        b->prev    = NULL; /* parent */
     }
     qsort(blocks, count, sizeof(void *), ptrcmp);
 
     /* Now, calculate tree */
-    for (b = globals.used.head; b; b = b->next) {
+    for (b = memento.used.head; b; b = b->next) {
         char *p = MEMBLK_TOBLK(b);
         int end = (b->rawsize < MEMENTO_PTRSEARCH ? b->rawsize : MEMENTO_PTRSEARCH);
-
         for (i = MEMENTO_SEARCH_SKIP; i < end; i += sizeof(void *)) {
             void *q = *(void **)(&p[i]);
             void **r;
 
             /* Do trivial checks on pointer */
-            if ((mask & (int)q) != mask || q < minptr || q > maxptr)
+            if ((mask & (intptr_t)q) != mask || q < minptr || q > maxptr)
                 continue;
 
             /* Search for pointer */
@@ -568,22 +1382,26 @@
 
                 /* We're assuming tree structure, not graph - ignore second
                  * and subsequent pointers. */
-                if (child->parent != NULL)
+                if (child->prev != NULL) /* parent */
                     continue;
                 if (child->flags & Memento_Flag_HasParent)
                     continue;
 
+                /* Not interested in pointers to ourself! */
+                if (child == b)
+                        continue;
+
                 /* We're also assuming acyclicness here. If this is one of
                  * our parents, ignore it. */
-                parent = b->parent;
+                parent = b->prev; /* parent */
                 while (parent != NULL && parent != child)
-                    parent = parent->parent;
+                    parent = parent->prev; /* parent */
                 if (parent == child)
                     continue;
 
                 child->sibling = b->child;
                 b->child = child;
-                child->parent = b;
+                child->prev = b; /* parent */
                 child->flags |= Memento_Flag_HasParent;
             }
         }
@@ -590,34 +1408,49 @@
     }
 
     /* Now display with nesting */
-    for (b = globals.used.head; b; b = b->next) {
+    for (b = memento.used.head; b; b = b->next) {
         if ((b->flags & Memento_Flag_HasParent) == 0)
             doNestedDisplay(b, 0);
     }
     fprintf(stderr, " Total number of blocks = %d\n", count);
-    fprintf(stderr, " Total size of blocks = %d\n", size);
+    fprintf(stderr, " Total size of blocks = "FMTZ"\n", (FMTZ_CAST)size);
 
     MEMENTO_UNDERLYING_FREE(blocks);
+
+    /* Now put the blocks back for valgrind, and restore the prev
+     * and magic values. */
+    prev = NULL;
+    for (b = memento.used.head; b;) {
+      Memento_BlkHeader *next = b->next;
+      b->prev = prev;
+      b->child = MEMENTO_CHILD_MAGIC;
+      b->sibling = MEMENTO_SIBLING_MAGIC;
+      prev = b;
+      VALGRIND_MAKE_MEM_NOACCESS(b, sizeof(*b));
+      b = next;
+    }
+
     return 0;
 }
 
-void
-Memento_listBlocks(void)
+void Memento_listBlocks(void)
 {
+    MEMENTO_LOCK();
     fprintf(stderr, "Allocated blocks:\n");
-    if (Memento_listBlocksNested()) {
-        int counts[2];
-
+    if (Memento_listBlocksNested())
+    {
+        size_t counts[2];
         counts[0] = 0;
         counts[1] = 0;
-        Memento_appBlocks(&globals.used, Memento_listBlock, &counts[0]);
-        fprintf(stderr, " Total number of blocks = %d\n", counts[0]);
-        fprintf(stderr, " Total size of blocks = %d\n", counts[1]);
+        Memento_appBlocks(&memento.used, Memento_listBlock, &counts[0]);
+        fprintf(stderr, " Total number of blocks = "FMTZ"\n", (FMTZ_CAST)counts[0]);
+        fprintf(stderr, " Total size of blocks = "FMTZ"\n", (FMTZ_CAST)counts[1]);
     }
+    MEMENTO_UNLOCK();
 }
 
-static int
-Memento_listNewBlock(Memento_BlkHeader *b, void *arg)
+static int Memento_listNewBlock(Memento_BlkHeader *b,
+                                void              *arg)
 {
     if (b->flags & Memento_Flag_OldBlock)
         return 0;
@@ -625,111 +1458,216 @@
     return Memento_listBlock(b, arg);
 }
 
-void
-Memento_listNewBlocks(void)
+void Memento_listNewBlocks(void)
 {
-    int counts[2];
-
+    size_t counts[2];
+    MEMENTO_LOCK();
     counts[0] = 0;
     counts[1] = 0;
     fprintf(stderr, "Blocks allocated and still extant since last list:\n");
-    Memento_appBlocks(&globals.used, Memento_listNewBlock, &counts[0]);
-    fprintf(stderr, "  Total number of blocks = %d\n", counts[0]);
-    fprintf(stderr, "  Total size of blocks = %d\n", counts[1]);
+    Memento_appBlocks(&memento.used, Memento_listNewBlock, &counts[0]);
+    fprintf(stderr, "  Total number of blocks = "FMTZ"\n", (FMTZ_CAST)counts[0]);
+    fprintf(stderr, "  Total size of blocks = "FMTZ"\n", (FMTZ_CAST)counts[1]);
+    MEMENTO_UNLOCK();
 }
 
-static void
-Memento_endStats(void)
+static void Memento_endStats(void)
 {
-    fprintf(stderr, "Total memory malloced = %u bytes\n", (unsigned int)globals.totalAlloc);
-    fprintf(stderr, "Peak memory malloced = %u bytes\n", (unsigned int)globals.peakAlloc);
-    fprintf(stderr, "%u mallocs, %u frees, %u reallocs\n", (unsigned int)globals.numMallocs, (unsigned int)globals.numFrees, (unsigned int)globals.numReallocs);
-    fprintf(stderr, "Average allocation size %u bytes\n", (unsigned int)
-            (globals.numMallocs != 0 ? globals.totalAlloc / globals.numMallocs : 0));
+    fprintf(stderr, "Total memory malloced = "FMTZ" bytes\n", (FMTZ_CAST)memento.totalAlloc);
+    fprintf(stderr, "Peak memory malloced = "FMTZ" bytes\n", (FMTZ_CAST)memento.peakAlloc);
+    fprintf(stderr, FMTZ" mallocs, "FMTZ" frees, "FMTZ" reallocs\n", (FMTZ_CAST)memento.numMallocs,
+            (FMTZ_CAST)memento.numFrees, (FMTZ_CAST)memento.numReallocs);
+    fprintf(stderr, "Average allocation size "FMTZ" bytes\n", (FMTZ_CAST)
+            (memento.numMallocs != 0 ? memento.totalAlloc/memento.numMallocs: 0));
 }
 
-void
-Memento_stats(void)
+void Memento_stats(void)
 {
-    fprintf(stderr, "Current memory malloced = %u bytes\n", (unsigned int)globals.alloc);
+    MEMENTO_LOCK();
+    fprintf(stderr, "Current memory malloced = "FMTZ" bytes\n", (FMTZ_CAST)memento.alloc);
     Memento_endStats();
+    MEMENTO_UNLOCK();
 }
 
-static void
-Memento_fin(void)
+#ifdef MEMENTO_DETAILS
+static int showInfo(Memento_BlkHeader *b, void *arg)
 {
+    Memento_BlkDetails *details;
+
+    fprintf(stderr, "0x%p:(size="FMTZ",num=%d)",
+            MEMBLK_TOBLK(b), (FMTZ_CAST)b->rawsize, b->sequence);
+    if (b->label)
+        fprintf(stderr, " (%s)", b->label);
+    fprintf(stderr, "\nEvents:\n");
+
+    details = b->details;
+    while (details)
+    {
+        fprintf(stderr, "  Event %d (%s)\n", details->sequence, eventType[(int)details->type]);
+        Memento_showStacktrace(details->stack, details->count);
+        details = details->next;
+    }
+    return 0;
+}
+#endif
+
+void Memento_listBlockInfo(void)
+{
+#ifdef MEMENTO_DETAILS
+    MEMENTO_LOCK();
+    fprintf(stderr, "Details of allocated blocks:\n");
+    Memento_appBlocks(&memento.used, showInfo, NULL);
+    MEMENTO_UNLOCK();
+#endif
+}
+
+static int Memento_nonLeakBlocksLeaked(void)
+{
+    Memento_BlkHeader *blk = memento.used.head;
+    while (blk)
+    {
+        if ((blk->flags & Memento_Flag_KnownLeak) == 0)
+            return 1;
+        blk = blk->next;
+    }
+    return 0;
+}
+
+void Memento_fin(void)
+{
     Memento_checkAllMemory();
-    Memento_endStats();
-    if (globals.used.head != NULL) {
-        Memento_listBlocks();
-        Memento_breakpoint();
+    if (!memento.segv)
+    {
+        Memento_endStats();
+        if (Memento_nonLeakBlocksLeaked()) {
+            Memento_listBlocks();
+#ifdef MEMENTO_DETAILS
+            fprintf(stderr, "\n");
+            Memento_listBlockInfo();
+#endif
+            Memento_breakpoint();
+        }
     }
-    if (globals.segv) {
-        fprintf(stderr, "Memory dumped on SEGV while squeezing @ %d\n", globals.failAt);
-    } else if (globals.squeezing) {
-        if (globals.pattern == 0)
-            fprintf(stderr, "Memory squeezing @ %d complete\n", globals.squeezeAt);
+    if (memento.squeezing) {
+        if (memento.pattern == 0)
+            fprintf(stderr, "Memory squeezing @ %d complete%s\n", memento.squeezeAt, memento.segv ? " (with SEGV)" : "");
         else
-            fprintf(stderr, "Memory squeezing @ %d (%d) complete\n", globals.squeezeAt, globals.pattern);
+            fprintf(stderr, "Memory squeezing @ %d (%d) complete%s\n", memento.squeezeAt, memento.pattern, memento.segv ? " (with SEGV)" : "");
+    } else if (memento.segv) {
+        fprintf(stderr, "Memento completed (with SEGV)\n");
     }
-    if (globals.failing) {
-        fprintf(stderr, "MEMENTO_FAILAT=%d\n", globals.failAt);
-        fprintf(stderr, "MEMENTO_PATTERN=%d\n", globals.pattern);
+    if (memento.failing)
+    {
+        fprintf(stderr, "MEMENTO_FAILAT=%d\n", memento.failAt);
+        fprintf(stderr, "MEMENTO_PATTERN=%d\n", memento.pattern);
     }
-    if (globals.nextFailAt != 0) {
-        fprintf(stderr, "MEMENTO_NEXTFAILAT=%d\n", globals.nextFailAt);
-        fprintf(stderr, "MEMENTO_NEXTPATTERN=%d\n", globals.nextPattern);
+    if (memento.nextFailAt != 0)
+    {
+        fprintf(stderr, "MEMENTO_NEXTFAILAT=%d\n", memento.nextFailAt);
+        fprintf(stderr, "MEMENTO_NEXTPATTERN=%d\n", memento.nextPattern);
     }
 }
 
-static void
-Memento_inited(void)
+static void Memento_init(void)
 {
-    /* A good place for a breakpoint */
-}
-
-static void
-Memento_init(void)
-{
     char *env;
+    memset(&memento, 0, sizeof(memento));
+    memento.inited    = 1;
+    memento.used.head = NULL;
+    memento.used.tail = NULL;
+    memento.free.head = NULL;
+    memento.free.tail = NULL;
+    memento.sequence  = 0;
+    memento.countdown = 1024;
 
-    memset(&globals, 0, sizeof(globals));
-    globals.inited = 1;
-    globals.used.head = NULL;
-    globals.used.tail = &globals.used.head;
-    globals.free.head = NULL;
-    globals.free.tail = &globals.free.head;
-    globals.sequence = 0;
-    globals.countdown = 1024;
-
     env = getenv("MEMENTO_FAILAT");
-    globals.failAt = (env ? atoi(env) : 0);
+    memento.failAt = (env ? atoi(env) : 0);
 
     env = getenv("MEMENTO_PARANOIA");
-    globals.paranoia = (env ? atoi(env) : 0);
-    if (globals.paranoia == 0)
-        globals.paranoia = 1024;
+    memento.paranoia = (env ? atoi(env) : 0);
+    if (memento.paranoia == 0)
+        memento.paranoia = -1024;
 
     env = getenv("MEMENTO_PARANOIDAT");
-    globals.paranoidAt = (env ? atoi(env) : 0);
+    memento.paranoidAt = (env ? atoi(env) : 0);
 
     env = getenv("MEMENTO_SQUEEZEAT");
-    globals.squeezeAt = (env ? atoi(env) : 0);
+    memento.squeezeAt = (env ? atoi(env) : 0);
 
     env = getenv("MEMENTO_PATTERN");
-    globals.pattern = (env ? atoi(env) : 0);
+    memento.pattern = (env ? atoi(env) : 0);
 
     env = getenv("MEMENTO_MAXMEMORY");
-    globals.maxMemory = (env ? atoi(env) : 0);
+    memento.maxMemory = (env ? atoi(env) : 0);
 
     atexit(Memento_fin);
 
-    Memento_inited();
+    Memento_initMutex(&memento.mutex);
+
+    Memento_initStacktracer();
+
+    Memento_breakpoint();
 }
 
+typedef struct findBlkData {
+    void              *addr;
+    Memento_BlkHeader *blk;
+    int                flags;
+} findBlkData;
+
+static int Memento_containsAddr(Memento_BlkHeader *b,
+                                void *arg)
+{
+    findBlkData *data = (findBlkData *)arg;
+    char *blkend = &((char *)MEMBLK_TOBLK(b))[b->rawsize];
+    if ((MEMBLK_TOBLK(b) <= data->addr) &&
+        ((void *)blkend > data->addr)) {
+        data->blk = b;
+        data->flags = 1;
+        return 1;
+    }
+    if (((void *)b <= data->addr) &&
+        (MEMBLK_TOBLK(b) > data->addr)) {
+        data->blk = b;
+        data->flags = 2;
+        return 1;
+    }
+    if (((void *)blkend <= data->addr) &&
+        ((void *)(blkend + Memento_PostSize) > data->addr)) {
+        data->blk = b;
+        data->flags = 3;
+        return 1;
+    }
+    return 0;
+}
+
+void Memento_info(void *addr)
+{
+#ifdef MEMENTO_DETAILS
+    findBlkData data;
+
+    MEMENTO_LOCK();
+    data.addr  = addr;
+    data.blk   = NULL;
+    data.flags = 0;
+    Memento_appBlocks(&memento.used, Memento_containsAddr, &data);
+    if (data.blk != NULL)
+        showInfo(data.blk, NULL);
+    data.blk   = NULL;
+    data.flags = 0;
+    Memento_appBlocks(&memento.free, Memento_containsAddr, &data);
+    if (data.blk != NULL)
+        showInfo(data.blk, NULL);
+    MEMENTO_UNLOCK();
+#else
+    printf("Memento not compiled with details support\n");
+#endif
+}
+
 #ifdef MEMENTO_HAS_FORK
 #include <unistd.h>
 #include <sys/wait.h>
+#include <time.h>
 #ifdef MEMENTO_STACKTRACE_METHOD
 #if MEMENTO_STACKTRACE_METHOD == 1
 #include <signal.h>
@@ -738,55 +1676,40 @@
 
 /* FIXME: Find some portable way of getting this */
 /* MacOSX has 10240, Ubuntu seems to have 256 */
+#ifndef OPEN_MAX
 #define OPEN_MAX 10240
+#endif
 
 /* stashed_map[j] = i means that file descriptor i-1 was duplicated to j */
 int stashed_map[OPEN_MAX];
 
-extern size_t backtrace(void **, int);
-extern void backtrace_symbols_fd(void **, size_t, int);
-
-static void
-Memento_signal(void)
+static void Memento_signal(int sig)
 {
-    fprintf(stderr, "SEGV after Memory squeezing @ %d\n", globals.squeezeAt);
+    (void)sig;
+    fprintf(stderr, "SEGV at:\n");
+    memento.segv = 1;
+    Memento_bt_internal(0);
 
-#ifdef MEMENTO_STACKTRACE_METHOD
-#if MEMENTO_STACKTRACE_METHOD == 1
-    {
-        void *array[100];
-        size_t size;
-
-        size = backtrace(array, 100);
-        fprintf(stderr, "------------------------------------------------------------------------\n");
-        fprintf(stderr, "Backtrace:\n");
-        backtrace_symbols_fd(array, size, 2);
-        fprintf(stderr, "------------------------------------------------------------------------\n");
-    }
-#endif
-#endif
-
     exit(1);
 }
 
-static int
-squeeze(void)
+static int squeeze(void)
 {
     pid_t pid;
     int i, status;
 
-    if (globals.patternBit < 0)
+    if (memento.patternBit < 0)
         return 1;
-    if (globals.squeezing && globals.patternBit >= MEMENTO_MAXPATTERN)
+    if (memento.squeezing && memento.patternBit >= MEMENTO_MAXPATTERN)
         return 1;
 
-    if (globals.patternBit == 0)
-        globals.squeezeAt = globals.sequence;
+    if (memento.patternBit == 0)
+        memento.squeezeAt = memento.sequence;
 
-    if (!globals.squeezing) {
-        fprintf(stderr, "Memory squeezing @ %d\n", globals.squeezeAt);
+    if (!memento.squeezing) {
+        fprintf(stderr, "Memory squeezing @ %d\n", memento.squeezeAt);
     } else
-        fprintf(stderr, "Memory squeezing @ %d (%x,%x)\n", globals.squeezeAt, globals.pattern, globals.patternBit);
+        fprintf(stderr, "Memory squeezing @ %d (%x,%x)\n", memento.squeezeAt, memento.pattern, memento.patternBit);
 
     /* When we fork below, the child is going to snaffle all our file pointers
      * and potentially corrupt them. Let's make copies of all of them before
@@ -794,31 +1717,49 @@
     for (i = 0; i < OPEN_MAX; i++) {
         if (stashed_map[i] == 0) {
             int j = dup(i);
-
-            stashed_map[j] = i + 1;
+            stashed_map[j] = i+1;
         }
     }
 
+    fprintf(stderr, "Failing at:\n");
+    Memento_bt_internal(2);
     pid = fork();
     if (pid == 0) {
         /* Child */
         signal(SIGSEGV, Memento_signal);
         /* In the child, we always fail the next allocation. */
-        if (globals.patternBit == 0) {
-            globals.patternBit = 1;
+        if (memento.patternBit == 0) {
+            memento.patternBit = 1;
         } else
-            globals.patternBit <<= 1;
-        globals.squeezing = 1;
+            memento.patternBit <<= 1;
+        memento.squeezing = 1;
         return 1;
     }
 
     /* In the parent if we hit another allocation, pass it (and record the
      * fact we passed it in the pattern. */
-    globals.pattern |= globals.patternBit;
-    globals.patternBit <<= 1;
+    memento.pattern |= memento.patternBit;
+    memento.patternBit <<= 1;
 
-    /* Wait for pid to finish */
-    waitpid(pid, &status, 0);
+    /* Wait for pid to finish, with a timeout. */
+    {
+        struct timespec tm = { 0, 10 * 1000 * 1000 }; /* 10ms = 100th sec */
+        int timeout = 30 * 1000 * 1000; /* time out in microseconds! */
+        while (waitpid(pid, &status, WNOHANG) == 0) {
+            nanosleep(&tm, NULL);
+            timeout -= (tm.tv_nsec/1000);
+            tm.tv_nsec *= 2;
+            if (tm.tv_nsec > 999999999)
+                tm.tv_nsec = 999999999;
+            if (timeout <= 0) {
+                char text[32];
+                fprintf(stderr, "Child is taking a long time to die. Killing it.\n");
+                sprintf(text, "kill %d", pid);
+                system(text);
+                break;
+            }
+        }
+    }
 
     if (status != 0) {
         fprintf(stderr, "Child status=%d\n", status);
@@ -827,7 +1768,7 @@
     /* Put the files back */
     for (i = 0; i < OPEN_MAX; i++) {
         if (stashed_map[i] != 0) {
-            dup2(i, stashed_map[i] - 1);
+            dup2(i, stashed_map[i]-1);
             close(i);
             stashed_map[i] = 0;
         }
@@ -838,13 +1779,13 @@
 #else
 #include <signal.h>
 
-static void
-Memento_signal(void)
+static void Memento_signal(int sig)
 {
-    globals.segv = 1;
+    (void)sig;
+    memento.segv = 1;
     /* If we just return from this function the SEGV will be unhandled, and
      * we'll launch into whatever JIT debugging system the OS provides. At
-     * least output something useful first. If MEMENTO_NOJIT is set, then
+     * least fprintf(stderr, something useful first. If MEMENTO_NOJIT is set, then
      * just exit to avoid the JIT (and get the usual atexit handling). */
     if (getenv("MEMENTO_NOJIT"))
         exit(1);
@@ -852,8 +1793,7 @@
         Memento_fin();
 }
 
-int
-squeeze(void)
+static int squeeze(void)
 {
     fprintf(stderr, "Memento memory squeezing disabled as no fork!\n");
     return 0;
@@ -860,108 +1800,179 @@
 }
 #endif
 
-static void
-Memento_startFailing(void)
+static void Memento_startFailing(void)
 {
-    if (!globals.failing) {
+    if (!memento.failing) {
         fprintf(stderr, "Starting to fail...\n");
         fflush(stderr);
-        globals.failing = 1;
-        globals.failAt = globals.sequence;
-        globals.nextFailAt = globals.sequence + 1;
-        globals.pattern = 0;
-        globals.patternBit = 0;
+        memento.failing = 1;
+        memento.failAt = memento.sequence;
+        memento.nextFailAt = memento.sequence+1;
+        memento.pattern = 0;
+        memento.patternBit = 0;
         signal(SIGSEGV, Memento_signal);
         signal(SIGABRT, Memento_signal);
-        Memento_breakpoint();
+        Memento_breakpointLocked();
     }
 }
 
-static void
-Memento_event(void)
+static int Memento_event(void)
 {
-    globals.sequence++;
-    if ((globals.sequence >= globals.paranoidAt) && (globals.paranoidAt != 0)) {
-        globals.paranoia = 1;
-        globals.countdown = 1;
+    memento.sequence++;
+    if ((memento.sequence >= memento.paranoidAt) && (memento.paranoidAt != 0)) {
+        memento.paranoia = 1;
+        memento.countdown = 1;
     }
-    if (--globals.countdown == 0) {
-        Memento_checkAllMemory();
-        globals.countdown = globals.paranoia;
+    if (--memento.countdown == 0) {
+        Memento_checkAllMemoryLocked();
+        if (memento.paranoia > 0)
+            memento.countdown = memento.paranoia;
+        else
+        {
+            memento.countdown = -memento.paranoia;
+            if (memento.paranoia > INT_MIN/2)
+                memento.paranoia *= 2;
+        }
     }
 
-    if (globals.sequence == globals.breakAt) {
-        fprintf(stderr, "Breaking at event %d\n", globals.breakAt);
-        Memento_breakpoint();
+    if (memento.sequence == memento.breakAt) {
+        fprintf(stderr, "Breaking at event %d\n", memento.breakAt);
+        return 1;
     }
+    return 0;
 }
 
-int
-Memento_breakAt(int event)
+int Memento_sequence(void)
 {
-    globals.breakAt = event;
+    return memento.sequence;
+}
+
+int Memento_breakAt(int event)
+{
+    MEMENTO_LOCK();
+    memento.breakAt = event;
+    MEMENTO_UNLOCK();
     return event;
 }
 
-void *
-Memento_label(void *ptr, const char *label)
+static void *safe_find_block(void *ptr)
 {
     Memento_BlkHeader *block;
+    int valid;
 
     if (ptr == NULL)
         return NULL;
+
     block = MEMBLK_FROMBLK(ptr);
-    block->label = label;
+    /* Sometimes wrapping allocators can mean Memento_label
+     * is called with a value within the block, rather than
+     * at the start of the block. If we detect this, find it
+     * the slow way. */
+    VALGRIND_MAKE_MEM_DEFINED(&block->child, sizeof(block->child));
+    VALGRIND_MAKE_MEM_DEFINED(&block->sibling, sizeof(block->sibling));
+    valid = (block->child == MEMENTO_CHILD_MAGIC &&
+             block->sibling == MEMENTO_SIBLING_MAGIC);
+    VALGRIND_MAKE_MEM_NOACCESS(&block->child, sizeof(block->child));
+    VALGRIND_MAKE_MEM_NOACCESS(&block->sibling, sizeof(block->sibling));
+    if (!valid)
+    {
+        findBlkData data;
+
+        data.addr  = ptr;
+        data.blk   = NULL;
+        data.flags = 0;
+        Memento_appBlocks(&memento.used, Memento_containsAddr, &data);
+        if (data.blk == NULL)
+            return NULL;
+        block = data.blk;
+    }
+    return block;
+}
+
+void *Memento_label(void *ptr, const char *label)
+{
+    Memento_BlkHeader *block;
+
+    if (ptr == NULL)
+        return NULL;
+    MEMENTO_LOCK();
+    block = safe_find_block(ptr);
+    if (block != NULL)
+    {
+        VALGRIND_MAKE_MEM_DEFINED(&block->label, sizeof(block->label));
+        block->label = label;
+        VALGRIND_MAKE_MEM_NOACCESS(&block->label, sizeof(block->label));
+    }
+    MEMENTO_UNLOCK();
     return ptr;
 }
 
-int
-Memento_failThisEvent(void)
+void Memento_tick(void)
 {
+    MEMENTO_LOCK();
+    if (Memento_event()) Memento_breakpointLocked();
+    MEMENTO_UNLOCK();
+}
+
+static int Memento_failThisEventLocked(void)
+{
     int failThisOne;
 
-    if (!globals.inited)
-        Memento_init();
+    if (Memento_event()) Memento_breakpointLocked();
 
-    Memento_event();
-
-    if ((globals.sequence >= globals.failAt) && (globals.failAt != 0))
+    if ((memento.sequence >= memento.failAt) && (memento.failAt != 0))
         Memento_startFailing();
-    if ((globals.sequence >= globals.squeezeAt) && (globals.squeezeAt != 0)) {
+    if ((memento.sequence >= memento.squeezeAt) && (memento.squeezeAt != 0)) {
         return squeeze();
     }
 
-    if (!globals.failing)
+    if (!memento.failing)
         return 0;
-    failThisOne = ((globals.patternBit & globals.pattern) == 0);
+    failThisOne = ((memento.patternBit & memento.pattern) == 0);
     /* If we are failing, and we've reached the end of the pattern and we've
      * still got bits available in the pattern word, and we haven't already
      * set a nextPattern, then extend the pattern. */
-    if (globals.failing && ((~(globals.patternBit - 1) & globals.pattern) == 0) && (globals.patternBit != 0) && globals.nextPattern == 0) {
+    if (memento.failing &&
+        ((~(memento.patternBit-1) & memento.pattern) == 0) &&
+        (memento.patternBit != 0) &&
+        memento.nextPattern == 0)
+    {
         /* We'll fail this one, and set the 'next' one to pass it. */
-        globals.nextFailAt = globals.failAt;
-        globals.nextPattern = globals.pattern | globals.patternBit;
+        memento.nextFailAt = memento.failAt;
+        memento.nextPattern = memento.pattern | memento.patternBit;
     }
-    globals.patternBit = (globals.patternBit ? globals.patternBit << 1 : 1);
+    memento.patternBit = (memento.patternBit ? memento.patternBit << 1 : 1);
 
     return failThisOne;
 }
 
-void *
-Memento_malloc(size_t s)
+int Memento_failThisEvent(void)
 {
+    int ret;
+
+    if (!memento.inited)
+        Memento_init();
+
+    MEMENTO_LOCK();
+    ret = Memento_failThisEventLocked();
+    MEMENTO_UNLOCK();
+    return ret;
+}
+
+static void *do_malloc(size_t s, int eventType)
+{
     Memento_BlkHeader *memblk;
-    size_t smem = MEMBLK_SIZE(s);
+    size_t             smem = MEMBLK_SIZE(s);
 
-    if (Memento_failThisEvent())
+    if (Memento_failThisEventLocked())
         return NULL;
 
     if (s == 0)
         return NULL;
 
-    globals.numMallocs++;
+    memento.numMallocs++;
 
-    if (globals.maxMemory != 0 && globals.alloc + s > globals.maxMemory)
+    if (memento.maxMemory != 0 && memento.alloc + s > memento.maxMemory)
         return NULL;
 
     memblk = MEMENTO_UNDERLYING_MALLOC(smem);
@@ -968,47 +1979,361 @@
     if (memblk == NULL)
         return NULL;
 
-    globals.alloc += s;
-    globals.totalAlloc += s;
-    if (globals.peakAlloc < globals.alloc)
-        globals.peakAlloc = globals.alloc;
+    memento.alloc      += s;
+    memento.totalAlloc += s;
+    if (memento.peakAlloc < memento.alloc)
+        memento.peakAlloc = memento.alloc;
 #ifndef MEMENTO_LEAKONLY
     memset(MEMBLK_TOBLK(memblk), MEMENTO_ALLOCFILL, s);
 #endif
-    memblk->rawsize = s;
-    memblk->sequence = globals.sequence;
+    memblk->rawsize       = s;
+    memblk->sequence      = memento.sequence;
     memblk->lastCheckedOK = memblk->sequence;
-    memblk->flags = 0;
-    memblk->label = 0;
-    memblk->child = NULL;
-    memblk->sibling = NULL;
-    Memento_addBlockHead(&globals.used, memblk, 0);
+    memblk->flags         = 0;
+    memblk->label         = 0;
+    memblk->child         = MEMENTO_CHILD_MAGIC;
+    memblk->sibling       = MEMENTO_SIBLING_MAGIC;
+#ifdef MEMENTO_DETAILS
+    memblk->details       = NULL;
+    memblk->details_tail  = &memblk->details;
+    Memento_storeDetails(memblk, Memento_EventType_malloc);
+#endif /* MEMENTO_DETAILS */
+    Memento_addBlockHead(&memento.used, memblk, 0);
+
+    if (memento.leaking > 0)
+        memblk->flags |= Memento_Flag_KnownLeak;
+
     return MEMBLK_TOBLK(memblk);
 }
 
-void *
-Memento_calloc(size_t n, size_t s)
+void *Memento_malloc(size_t s)
 {
-    void *block = Memento_malloc(n * s);
+    void *ret;
 
+    if (!memento.inited)
+        Memento_init();
+
+    MEMENTO_LOCK();
+    ret = do_malloc(s, Memento_EventType_malloc);
+    MEMENTO_UNLOCK();
+    return ret;
+}
+
+void *Memento_calloc(size_t n, size_t s)
+{
+    void *block;
+
+    if (!memento.inited)
+        Memento_init();
+
+    MEMENTO_LOCK();
+    block = do_malloc(n*s, Memento_EventType_calloc);
     if (block)
-        memset(block, 0, n * s);
+        memset(block, 0, n*s);
+    MEMENTO_UNLOCK();
     return block;
 }
 
-static int
-checkBlock(Memento_BlkHeader *memblk, const char *action)
+static void do_reference(Memento_BlkHeader *blk, int event)
 {
+#ifdef MEMENTO_DETAILS
+    Memento_storeDetails(blk, event);
+#endif /* MEMENTO_DETAILS */
+}
+
+int Memento_checkPointerOrNull(void *blk)
+{
+	if (blk == NULL)
+		return 0;
+	if (blk == MEMENTO_PREFILL_PTR)
+		fprintf(stderr, "Prefill value found as pointer - buffer underrun?\n");
+	else if (blk == MEMENTO_POSTFILL_PTR)
+		fprintf(stderr, "Postfill value found as pointer - buffer overrun?\n");
+	else if (blk == MEMENTO_ALLOCFILL_PTR)
+		fprintf(stderr, "Allocfill value found as pointer - use of uninitialised value?\n");
+	else if (blk == MEMENTO_FREEFILL_PTR)
+		fprintf(stderr, "Allocfill value found as pointer - use after free?\n");
+	else
+		return 0;
+#ifdef MEMENTO_DETAILS
+	fprintf(stderr, "Current backtrace:\n");
+	Memento_bt();
+	fprintf(stderr, "History:\n");
+	Memento_info(blk);
+#endif
+	return 1;
+}
+
+int Memento_checkBytePointerOrNull(void *blk)
+{
+	unsigned char i;
+	if (blk == NULL)
+		return 0;
+	Memento_checkPointerOrNull(blk);
+
+	i = *(unsigned int *)blk;
+
+	if (i == MEMENTO_PREFILL_UBYTE)
+		fprintf(stderr, "Prefill value found - buffer underrun?\n");
+	else if (i == MEMENTO_POSTFILL_UBYTE)
+		fprintf(stderr, "Postfill value found - buffer overrun?\n");
+	else if (i == MEMENTO_ALLOCFILL_UBYTE)
+		fprintf(stderr, "Allocfill value found - use of uninitialised value?\n");
+	else if (i == MEMENTO_FREEFILL_UBYTE)
+		fprintf(stderr, "Allocfill value found - use after free?\n");
+	else
+		return 0;
+#ifdef MEMENTO_DETAILS
+	fprintf(stderr, "Current backtrace:\n");
+	Memento_bt();
+	fprintf(stderr, "History:\n");
+	Memento_info(blk);
+#endif
+	Memento_breakpoint();
+	return 1;
+}
+
+int Memento_checkShortPointerOrNull(void *blk)
+{
+	unsigned short i;
+	if (blk == NULL)
+		return 0;
+	Memento_checkPointerOrNull(blk);
+
+	i = *(unsigned short *)blk;
+
+	if (i == MEMENTO_PREFILL_USHORT)
+		fprintf(stderr, "Prefill value found - buffer underrun?\n");
+	else if (i == MEMENTO_POSTFILL_USHORT)
+		fprintf(stderr, "Postfill value found - buffer overrun?\n");
+	else if (i == MEMENTO_ALLOCFILL_USHORT)
+		fprintf(stderr, "Allocfill value found - use of uninitialised value?\n");
+	else if (i == MEMENTO_FREEFILL_USHORT)
+		fprintf(stderr, "Allocfill value found - use after free?\n");
+	else
+		return 0;
+#ifdef MEMENTO_DETAILS
+	fprintf(stderr, "Current backtrace:\n");
+	Memento_bt();
+	fprintf(stderr, "History:\n");
+	Memento_info(blk);
+#endif
+	Memento_breakpoint();
+	return 1;
+}
+
+int Memento_checkIntPointerOrNull(void *blk)
+{
+	unsigned int i;
+	if (blk == NULL)
+		return 0;
+	Memento_checkPointerOrNull(blk);
+
+	i = *(unsigned int *)blk;
+
+	if (i == MEMENTO_PREFILL_UINT)
+		fprintf(stderr, "Prefill value found - buffer underrun?\n");
+	else if (i == MEMENTO_POSTFILL_UINT)
+		fprintf(stderr, "Postfill value found - buffer overrun?\n");
+	else if (i == MEMENTO_ALLOCFILL_UINT)
+		fprintf(stderr, "Allocfill value found - use of uninitialised value?\n");
+	else if (i == MEMENTO_FREEFILL_UINT)
+		fprintf(stderr, "Allocfill value found - use after free?\n");
+	else
+		return 0;
+#ifdef MEMENTO_DETAILS
+	fprintf(stderr, "Current backtrace:\n");
+	Memento_bt();
+	fprintf(stderr, "History:\n");
+	Memento_info(blk);
+#endif
+	Memento_breakpoint();
+	return 1;
+}
+
+static void *do_takeRef(void *blk)
+{
+    MEMENTO_LOCK();
+    do_reference(safe_find_block(blk), Memento_EventType_takeRef);
+    MEMENTO_UNLOCK();
+    return blk;
+}
+
+void *Memento_takeByteRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    (void)Memento_checkBytePointerOrNull(blk);
+
+    return do_takeRef(blk);
+}
+
+void *Memento_takeShortRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    (void)Memento_checkShortPointerOrNull(blk);
+
+    return do_takeRef(blk);
+}
+
+void *Memento_takeIntRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    (void)Memento_checkIntPointerOrNull(blk);
+
+    return do_takeRef(blk);
+}
+
+void *Memento_takeRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    return do_takeRef(blk);
+}
+
+static void *do_dropRef(void *blk)
+{
+    MEMENTO_LOCK();
+    do_reference(safe_find_block(blk), Memento_EventType_dropRef);
+    MEMENTO_UNLOCK();
+    return blk;
+}
+
+void *Memento_dropByteRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    Memento_checkBytePointerOrNull(blk);
+
+    return do_dropRef(blk);
+}
+
+void *Memento_dropShortRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    Memento_checkShortPointerOrNull(blk);
+
+    return do_dropRef(blk);
+}
+
+void *Memento_dropIntRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    Memento_checkIntPointerOrNull(blk);
+
+    return do_dropRef(blk);
+}
+
+void *Memento_dropRef(void *blk)
+{
+    if (!memento.inited)
+        Memento_init();
+
+    if (Memento_event()) Memento_breakpoint();
+
+    if (!blk)
+        return NULL;
+
+    return do_dropRef(blk);
+}
+
+void *Memento_adjustRef(void *blk, int adjust)
+{
+    if (Memento_event()) Memento_breakpoint();
+
+    if (blk == NULL)
+        return NULL;
+
+    while (adjust > 0)
+    {
+        do_takeRef(blk);
+        adjust--;
+    }
+    while (adjust < 0)
+    {
+        do_dropRef(blk);
+        adjust++;
+    }
+
+    return blk;
+ }
+
+void *Memento_reference(void *blk)
+{
+    if (!blk)
+        return NULL;
+
+    if (!memento.inited)
+        Memento_init();
+
+    MEMENTO_LOCK();
+    do_reference(safe_find_block(blk), Memento_EventType_reference);
+    MEMENTO_UNLOCK();
+    return blk;
+}
+
+/* Treat blocks from the user with suspicion, and check them the slow
+ * but safe way. */
+static int checkBlockUser(Memento_BlkHeader *memblk, const char *action)
+{
 #ifndef MEMENTO_LEAKONLY
     BlkCheckData data;
 
     memset(&data, 0, sizeof(data));
-    Memento_appBlock(&globals.used, Memento_Internal_checkAllocedBlock, &data, memblk);
+    Memento_appBlockUser(&memento.used, Memento_Internal_checkAllocedBlock,
+                         &data, memblk);
     if (!data.found) {
         /* Failure! */
         fprintf(stderr, "Attempt to %s block ", action);
         showBlock(memblk, 32);
-        Memento_breakpoint();
+        fprintf(stderr, "\n");
+        Memento_breakpointLocked();
         return 1;
     } else if (data.preCorrupt || data.postCorrupt) {
         fprintf(stderr, "Block ");
@@ -1020,8 +2345,9 @@
         if (data.postCorrupt) {
             fprintf(stderr, "Postguard corrupted\n");
         }
-        fprintf(stderr, "Block last checked OK at allocation %d. Now %d.\n", memblk->lastCheckedOK, globals.sequence);
-        Memento_breakpoint();
+        fprintf(stderr, "Block last checked OK at allocation %d. Now %d.\n",
+                memblk->lastCheckedOK, memento.sequence);
+        Memento_breakpointLocked();
         return 1;
     }
 #endif
@@ -1028,16 +2354,59 @@
     return 0;
 }
 
-void
-Memento_free(void *blk)
+static int checkBlock(Memento_BlkHeader *memblk, const char *action)
 {
-    Memento_BlkHeader *memblk;
+#ifndef MEMENTO_LEAKONLY
+    BlkCheckData data;
+#endif
 
-    if (!globals.inited)
-        Memento_init();
+    if (memblk->child != MEMENTO_CHILD_MAGIC ||
+        memblk->sibling != MEMENTO_SIBLING_MAGIC)
+    {
+        /* Failure! */
+        fprintf(stderr, "Attempt to %s invalid block ", action);
+        showBlock(memblk, 32);
+        fprintf(stderr, "\n");
+        Memento_breakpointLocked();
+        return 1;
+    }
 
-    Memento_event();
+#ifndef MEMENTO_LEAKONLY
+    memset(&data, 0, sizeof(data));
+    Memento_appBlock(&memento.used, Memento_Internal_checkAllocedBlock,
+                     &data, memblk);
+    if (!data.found) {
+        /* Failure! */
+        fprintf(stderr, "Attempt to %s block ", action);
+        showBlock(memblk, 32);
+        fprintf(stderr, "\n");
+        Memento_breakpointLocked();
+        return 1;
+    } else if (data.preCorrupt || data.postCorrupt) {
+        fprintf(stderr, "Block ");
+        showBlock(memblk, ' ');
+        fprintf(stderr, " found to be corrupted on %s!\n", action);
+        if (data.preCorrupt) {
+            fprintf(stderr, "Preguard corrupted\n");
+        }
+        if (data.postCorrupt) {
+            fprintf(stderr, "Postguard corrupted\n");
+        }
+        fprintf(stderr, "Block last checked OK at allocation %d. Now %d.\n",
+                memblk->lastCheckedOK, memento.sequence);
+        Memento_breakpointLocked();
+        return 1;
+    }
+#endif
+    return 0;
+}
 
+static void do_free(void *blk, int eventType)
+{
+    Memento_BlkHeader *memblk;
+
+    if (Memento_event()) Memento_breakpointLocked();
+
     if (blk == NULL)
         return;
 
@@ -1046,102 +2415,154 @@
     if (checkBlock(memblk, "free"))
         return;
 
-    if (memblk->flags & Memento_Flag_BreakOnFree)
-        Memento_breakpoint();
+#ifdef MEMENTO_DETAILS
+    Memento_storeDetails(memblk, Memento_EventType_free);
+#endif
 
     VALGRIND_MAKE_MEM_DEFINED(memblk, sizeof(*memblk));
-    globals.alloc -= memblk->rawsize;
-    globals.numFrees++;
+    if (memblk->flags & Memento_Flag_BreakOnFree)
+        Memento_breakpointLocked();
 
-    Memento_removeBlock(&globals.used, memblk);
+    memento.alloc -= memblk->rawsize;
+    memento.numFrees++;
 
+    Memento_removeBlock(&memento.used, memblk);
+
     VALGRIND_MAKE_MEM_DEFINED(memblk, sizeof(*memblk));
     if (Memento_Internal_makeSpace(MEMBLK_SIZE(memblk->rawsize))) {
         VALGRIND_MAKE_MEM_DEFINED(memblk, sizeof(*memblk));
-        VALGRIND_MAKE_MEM_DEFINED(MEMBLK_TOBLK(memblk), memblk->rawsize + Memento_PostSize);
+        VALGRIND_MAKE_MEM_DEFINED(MEMBLK_TOBLK(memblk),
+                                  memblk->rawsize + Memento_PostSize);
 #ifndef MEMENTO_LEAKONLY
         memset(MEMBLK_TOBLK(memblk), MEMENTO_FREEFILL, memblk->rawsize);
 #endif
-        Memento_addBlockTail(&globals.free, memblk, 1);
+        memblk->flags |= Memento_Flag_Freed;
+        Memento_addBlockTail(&memento.free, memblk, 1);
     } else {
-        MEMENTO_UNDERLYING_FREE(memblk);
+        free_block(memblk);
     }
 }
 
-void *
-Memento_realloc(void *blk, size_t newsize)
+void Memento_free(void *blk)
 {
+    if (!memento.inited)
+        Memento_init();
+
+    MEMENTO_LOCK();
+    do_free(blk, Memento_EventType_free);
+    MEMENTO_UNLOCK();
+}
+
+static void *do_realloc(void *blk, size_t newsize, int type)
+{
     Memento_BlkHeader *memblk, *newmemblk;
-    size_t newsizemem;
-    int flags;
+    size_t             newsizemem;
+    int                flags;
 
-    if (blk == NULL)
-        return Memento_malloc(newsize);
-    if (newsize == 0) {
-        Memento_free(blk);
+    if (Memento_failThisEventLocked())
         return NULL;
-    }
 
-    if (Memento_failThisEvent())
-        return NULL;
-
-    memblk = MEMBLK_FROMBLK(blk);
+    memblk     = MEMBLK_FROMBLK(blk);
+    VALGRIND_MAKE_MEM_DEFINED(memblk, sizeof(*memblk));
     if (checkBlock(memblk, "realloc"))
         return NULL;
 
+#ifdef MEMENTO_DETAILS
+    Memento_storeDetails(memblk, type);
+#endif
+
+    VALGRIND_MAKE_MEM_DEFINED(memblk, sizeof(*memblk));
     if (memblk->flags & Memento_Flag_BreakOnRealloc)
-        Memento_breakpoint();
+        Memento_breakpointLocked();
 
-    if (globals.maxMemory != 0 && globals.alloc - memblk->rawsize + newsize > globals.maxMemory)
+    VALGRIND_MAKE_MEM_DEFINED(memblk, sizeof(*memblk));
+    if (memento.maxMemory != 0 && memento.alloc - memblk->rawsize + newsize > memento.maxMemory)
         return NULL;
 
     newsizemem = MEMBLK_SIZE(newsize);
-    Memento_removeBlock(&globals.used, memblk);
+    Memento_removeBlock(&memento.used, memblk);
+    VALGRIND_MAKE_MEM_DEFINED(memblk, sizeof(*memblk));
     flags = memblk->flags;
-    newmemblk = MEMENTO_UNDERLYING_REALLOC(memblk, newsizemem);
-    if (newmemblk == NULL) {
-        Memento_addBlockHead(&globals.used, memblk, 2);
+    newmemblk  = MEMENTO_UNDERLYING_REALLOC(memblk, newsizemem);
+    if (newmemblk == NULL)
+    {
+        Memento_addBlockHead(&memento.used, memblk, 2);
         return NULL;
     }
-    globals.numReallocs++;
-    globals.totalAlloc += newsize;
-    globals.alloc -= newmemblk->rawsize;
-    globals.alloc += newsize;
-    if (globals.peakAlloc < globals.alloc)
-        globals.peakAlloc = globals.alloc;
+    memento.numReallocs++;
+    memento.totalAlloc += newsize;
+    memento.alloc      -= newmemblk->rawsize;
+    memento.alloc      += newsize;
+    if (memento.peakAlloc < memento.alloc)
+        memento.peakAlloc = memento.alloc;
     newmemblk->flags = flags;
-    if (newmemblk->rawsize < newsize) {
-        char *newbytes = ((char *)MEMBLK_TOBLK(newmemblk)) + newmemblk->rawsize;
-
 #ifndef MEMENTO_LEAKONLY
+    if (newmemblk->rawsize < newsize) {
+        char *newbytes = ((char *)MEMBLK_TOBLK(newmemblk))+newmemblk->rawsize;
+        VALGRIND_MAKE_MEM_DEFINED(newbytes, newsize - newmemblk->rawsize);
         memset(newbytes, MEMENTO_ALLOCFILL, newsize - newmemblk->rawsize);
-#endif
         VALGRIND_MAKE_MEM_UNDEFINED(newbytes, newsize - newmemblk->rawsize);
     }
+#endif
     newmemblk->rawsize = newsize;
 #ifndef MEMENTO_LEAKONLY
+    VALGRIND_MAKE_MEM_DEFINED(newmemblk->preblk, Memento_PreSize);
     memset(newmemblk->preblk, MEMENTO_PREFILL, Memento_PreSize);
+    VALGRIND_MAKE_MEM_UNDEFINED(newmemblk->preblk, Memento_PreSize);
+    VALGRIND_MAKE_MEM_DEFINED(MEMBLK_POSTPTR(newmemblk), Memento_PostSize);
     memset(MEMBLK_POSTPTR(newmemblk), MEMENTO_POSTFILL, Memento_PostSize);
+    VALGRIND_MAKE_MEM_UNDEFINED(MEMBLK_POSTPTR(newmemblk), Memento_PostSize);
 #endif
-    Memento_addBlockHead(&globals.used, newmemblk, 2);
+    Memento_addBlockHead(&memento.used, newmemblk, 2);
     return MEMBLK_TOBLK(newmemblk);
 }
 
-int
-Memento_checkBlock(void *blk)
+void *Memento_realloc(void *blk, size_t newsize)
 {
+    void *ret;
+
+    if (!memento.inited)
+        Memento_init();
+
+    if (blk == NULL)
+    {
+        MEMENTO_LOCK();
+        ret = do_malloc(newsize, Memento_EventType_realloc);
+        MEMENTO_UNLOCK();
+        return ret;
+    }
+    if (newsize == 0) {
+        MEMENTO_LOCK();
+        do_free(blk, Memento_EventType_realloc);
+        MEMENTO_UNLOCK();
+        return NULL;
+    }
+
+    MEMENTO_LOCK();
+    ret = do_realloc(blk, newsize, Memento_EventType_realloc);
+    MEMENTO_UNLOCK();
+    return ret;
+}
+
+int Memento_checkBlock(void *blk)
+{
     Memento_BlkHeader *memblk;
+    int ret;
 
     if (blk == NULL)
         return 0;
+
+    MEMENTO_LOCK();
     memblk = MEMBLK_FROMBLK(blk);
-    return checkBlock(memblk, "check");
+    ret = checkBlockUser(memblk, "check");
+    MEMENTO_UNLOCK();
+    return ret;
 }
 
-static int
-Memento_Internal_checkAllAlloced(Memento_BlkHeader *memblk, void *arg)
+#ifndef MEMENTO_LEAKONLY
+static int Memento_Internal_checkAllAlloced(Memento_BlkHeader *memblk, void *arg)
 {
-    BlkCheckData *data = (BlkCheckData *) arg;
+    BlkCheckData *data = (BlkCheckData *)arg;
 
     Memento_Internal_checkAllocedBlock(memblk, data);
     if (data->preCorrupt || data->postCorrupt) {
@@ -1155,21 +2576,24 @@
             fprintf(stderr, " Preguard ");
         }
         if (data->postCorrupt) {
-            fprintf(stderr, "%s Postguard ", (data->preCorrupt ? "&" : ""));
+            fprintf(stderr, "%s Postguard ",
+                    (data->preCorrupt ? "&" : ""));
         }
-        fprintf(stderr, "corrupted.\n    " "Block last checked OK at allocation %d. Now %d.\n", memblk->lastCheckedOK, globals.sequence);
-        data->preCorrupt = 0;
+        fprintf(stderr, "corrupted.\n    "
+                "Block last checked OK at allocation %d. Now %d.\n",
+                memblk->lastCheckedOK, memento.sequence);
+        data->preCorrupt  = 0;
         data->postCorrupt = 0;
         data->freeCorrupt = 0;
-    } else
-        memblk->lastCheckedOK = globals.sequence;
+    }
+    else
+        memblk->lastCheckedOK = memento.sequence;
     return 0;
 }
 
-static int
-Memento_Internal_checkAllFreed(Memento_BlkHeader *memblk, void *arg)
+static int Memento_Internal_checkAllFreed(Memento_BlkHeader *memblk, void *arg)
 {
-    BlkCheckData *data = (BlkCheckData *) arg;
+    BlkCheckData *data = (BlkCheckData *)arg;
 
     Memento_Internal_checkFreedBlock(memblk, data);
     if (data->preCorrupt || data->postCorrupt || data->freeCorrupt) {
@@ -1180,7 +2604,8 @@
         fprintf(stderr, "  ");
         showBlock(memblk, ' ');
         if (data->freeCorrupt) {
-            fprintf(stderr, " index %d (address 0x%p) onwards", data->index, &((char *)MEMBLK_TOBLK(memblk))[data->index]);
+            fprintf(stderr, " index %d (address 0x%p) onwards", (int)data->index,
+                    &((char *)MEMBLK_TOBLK(memblk))[data->index]);
             if (data->preCorrupt) {
                 fprintf(stderr, "+ preguard");
             }
@@ -1192,55 +2617,72 @@
                 fprintf(stderr, " preguard");
             }
             if (data->postCorrupt) {
-                fprintf(stderr, "%s Postguard", (data->preCorrupt ? "+" : ""));
+                fprintf(stderr, "%s Postguard",
+                        (data->preCorrupt ? "+" : ""));
             }
         }
-        fprintf(stderr, " corrupted.\n" "    Block last checked OK at allocation %d. Now %d.\n", memblk->lastCheckedOK, globals.sequence);
-        data->preCorrupt = 0;
+        fprintf(stderr, " corrupted.\n"
+                "    Block last checked OK at allocation %d. Now %d.\n",
+                memblk->lastCheckedOK, memento.sequence);
+        data->preCorrupt  = 0;
         data->postCorrupt = 0;
         data->freeCorrupt = 0;
-    } else
-        memblk->lastCheckedOK = globals.sequence;
+    }
+    else
+        memblk->lastCheckedOK = memento.sequence;
     return 0;
 }
+#endif /* MEMENTO_LEAKONLY */
 
-int
-Memento_checkAllMemory(void)
+static int Memento_checkAllMemoryLocked(void)
 {
 #ifndef MEMENTO_LEAKONLY
     BlkCheckData data;
 
     memset(&data, 0, sizeof(data));
-    Memento_appBlocks(&globals.used, Memento_Internal_checkAllAlloced, &data);
-    Memento_appBlocks(&globals.free, Memento_Internal_checkAllFreed, &data);
-    if (data.found & 6) {
+    Memento_appBlocks(&memento.used, Memento_Internal_checkAllAlloced, &data);
+    Memento_appBlocks(&memento.free, Memento_Internal_checkAllFreed, &data);
+    return data.found;
+#else
+    return 0;
+#endif
+}
+
+int Memento_checkAllMemory(void)
+{
+#ifndef MEMENTO_LEAKONLY
+    int ret;
+
+    MEMENTO_LOCK();
+    ret = Memento_checkAllMemoryLocked();
+    MEMENTO_UNLOCK();
+    if (ret & 6) {
         Memento_breakpoint();
         return 1;
     }
-#endif
     return 0;
+#endif
 }
 
-int
-Memento_setParanoia(int i)
+int Memento_setParanoia(int i)
 {
-    globals.paranoia = i;
-    globals.countdown = globals.paranoia;
+    memento.paranoia = i;
+    if (memento.paranoia > 0)
+        memento.countdown = memento.paranoia;
+    else
+        memento.countdown = -memento.paranoia;
     return i;
 }
 
-int
-Memento_paranoidAt(int i)
+int Memento_paranoidAt(int i)
 {
-    globals.paranoidAt = i;
+    memento.paranoidAt = i;
     return i;
 }
 
-int
-Memento_getBlockNum(void *b)
+int Memento_getBlockNum(void *b)
 {
     Memento_BlkHeader *memblk;
-
     if (b == NULL)
         return 0;
     memblk = MEMBLK_FROMBLK(b);
@@ -1247,8 +2689,7 @@
     return (memblk->sequence);
 }
 
-int
-Memento_check(void)
+int Memento_check(void)
 {
     int result;
 
@@ -1258,139 +2699,197 @@
     return result;
 }
 
-typedef struct findBlkData {
-    void *addr;
-    Memento_BlkHeader *blk;
-    int flags;
-} findBlkData;
-
-static int
-Memento_containsAddr(Memento_BlkHeader *b, void *arg)
+int Memento_find(void *a)
 {
-    findBlkData *data = (findBlkData *) arg;
-    char *blkend = &((char *)MEMBLK_TOBLK(b))[b->rawsize];
-
-    if ((MEMBLK_TOBLK(b) <= data->addr) && ((void *)blkend > data->addr)) {
-        data->blk = b;
-        data->flags = 1;
-        return 1;
-    }
-    if (((void *)b <= data->addr) && (MEMBLK_TOBLK(b) > data->addr)) {
-        data->blk = b;
-        data->flags = 2;
-        return 1;
-    }
-    if (((void *)blkend <= data->addr) && ((void *)(blkend + Memento_PostSize) > data->addr)) {
-        data->blk = b;
-        data->flags = 3;
-        return 1;
-    }
-    return 0;
-}
-
-int
-Memento_find(void *a)
-{
     findBlkData data;
 
-    data.addr = a;
-    data.blk = NULL;
+    MEMENTO_LOCK();
+    data.addr  = a;
+    data.blk   = NULL;
     data.flags = 0;
-    Memento_appBlocks(&globals.used, Memento_containsAddr, &data);
+    Memento_appBlocks(&memento.used, Memento_containsAddr, &data);
     if (data.blk != NULL) {
-        fprintf(stderr, "Address 0x%p is in %sallocated block ", data.addr, (data.flags == 1 ? "" : (data.flags == 2 ? "preguard of " : "postguard of ")));
+        fprintf(stderr, "Address 0x%p is in %sallocated block ",
+                data.addr,
+                (data.flags == 1 ? "" : (data.flags == 2 ?
+                                         "preguard of " : "postguard of ")));
         showBlock(data.blk, ' ');
         fprintf(stderr, "\n");
+        MEMENTO_UNLOCK();
         return data.blk->sequence;
     }
-    data.blk = NULL;
+    data.blk   = NULL;
     data.flags = 0;
-    Memento_appBlocks(&globals.free, Memento_containsAddr, &data);
+    Memento_appBlocks(&memento.free, Memento_containsAddr, &data);
     if (data.blk != NULL) {
-        fprintf(stderr, "Address 0x%p is in %sfreed block ", data.addr, (data.flags == 1 ? "" : (data.flags == 2 ? "preguard of " : "postguard of ")));
+        fprintf(stderr, "Address 0x%p is in %sfreed block ",
+                data.addr,
+                (data.flags == 1 ? "" : (data.flags == 2 ?
+                                         "preguard of " : "postguard of ")));
         showBlock(data.blk, ' ');
         fprintf(stderr, "\n");
+        MEMENTO_UNLOCK();
         return data.blk->sequence;
     }
+    MEMENTO_UNLOCK();
     return 0;
 }
 
-void
-Memento_breakOnFree(void *a)
+void Memento_breakOnFree(void *a)
 {
     findBlkData data;
 
-    data.addr = a;
-    data.blk = NULL;
+    MEMENTO_LOCK();
+    data.addr  = a;
+    data.blk   = NULL;
     data.flags = 0;
-    Memento_appBlocks(&globals.used, Memento_containsAddr, &data);
+    Memento_appBlocks(&memento.used, Memento_containsAddr, &data);
     if (data.blk != NULL) {
         fprintf(stderr, "Will stop when address 0x%p (in %sallocated block ",
-                data.addr, (data.flags == 1 ? "" : (data.flags == 2 ? "preguard of " : "postguard of ")));
+                data.addr,
+                (data.flags == 1 ? "" : (data.flags == 2 ?
+                                         "preguard of " : "postguard of ")));
         showBlock(data.blk, ' ');
         fprintf(stderr, ") is freed\n");
         data.blk->flags |= Memento_Flag_BreakOnFree;
+        MEMENTO_UNLOCK();
         return;
     }
-    data.blk = NULL;
+    data.blk   = NULL;
     data.flags = 0;
-    Memento_appBlocks(&globals.free, Memento_containsAddr, &data);
+    Memento_appBlocks(&memento.free, Memento_containsAddr, &data);
     if (data.blk != NULL) {
         fprintf(stderr, "Can't stop on free; address 0x%p is in %sfreed block ",
-                data.addr, (data.flags == 1 ? "" : (data.flags == 2 ? "preguard of " : "postguard of ")));
+                data.addr,
+                (data.flags == 1 ? "" : (data.flags == 2 ?
+                                         "preguard of " : "postguard of ")));
         showBlock(data.blk, ' ');
         fprintf(stderr, "\n");
+        MEMENTO_UNLOCK();
         return;
     }
     fprintf(stderr, "Can't stop on free; address 0x%p is not in a known block.\n", a);
+    MEMENTO_UNLOCK();
 }
 
-void
-Memento_breakOnRealloc(void *a)
+void Memento_breakOnRealloc(void *a)
 {
     findBlkData data;
 
-    data.addr = a;
-    data.blk = NULL;
+    MEMENTO_LOCK();
+    data.addr  = a;
+    data.blk   = NULL;
     data.flags = 0;
-    Memento_appBlocks(&globals.used, Memento_containsAddr, &data);
+    Memento_appBlocks(&memento.used, Memento_containsAddr, &data);
     if (data.blk != NULL) {
         fprintf(stderr, "Will stop when address 0x%p (in %sallocated block ",
-                data.addr, (data.flags == 1 ? "" : (data.flags == 2 ? "preguard of " : "postguard of ")));
+                data.addr,
+                (data.flags == 1 ? "" : (data.flags == 2 ?
+                                         "preguard of " : "postguard of ")));
         showBlock(data.blk, ' ');
         fprintf(stderr, ") is freed (or realloced)\n");
         data.blk->flags |= Memento_Flag_BreakOnFree | Memento_Flag_BreakOnRealloc;
+        MEMENTO_UNLOCK();
         return;
     }
-    data.blk = NULL;
+    data.blk   = NULL;
     data.flags = 0;
-    Memento_appBlocks(&globals.free, Memento_containsAddr, &data);
+    Memento_appBlocks(&memento.free, Memento_containsAddr, &data);
     if (data.blk != NULL) {
         fprintf(stderr, "Can't stop on free/realloc; address 0x%p is in %sfreed block ",
-                data.addr, (data.flags == 1 ? "" : (data.flags == 2 ? "preguard of " : "postguard of ")));
+                data.addr,
+                (data.flags == 1 ? "" : (data.flags == 2 ?
+                                         "preguard of " : "postguard of ")));
         showBlock(data.blk, ' ');
         fprintf(stderr, "\n");
+        MEMENTO_UNLOCK();
         return;
     }
     fprintf(stderr, "Can't stop on free/realloc; address 0x%p is not in a known block.\n", a);
+    MEMENTO_UNLOCK();
 }
 
-int
-Memento_failAt(int i)
+int Memento_failAt(int i)
 {
-    globals.failAt = i;
-    if ((globals.sequence > globals.failAt) && (globals.failing != 0))
+    memento.failAt = i;
+    if ((memento.sequence > memento.failAt) &&
+        (memento.failing != 0))
         Memento_startFailing();
     return i;
 }
 
-size_t
-Memento_setMax(size_t max)
+size_t Memento_setMax(size_t max)
 {
-    globals.maxMemory = max;
+    memento.maxMemory = max;
     return max;
 }
 
+void Memento_startLeaking(void)
+{
+    memento.leaking++;
+}
+
+void Memento_stopLeaking(void)
+{
+    memento.leaking--;
+}
+
+#endif /* MEMENTO_CPP_EXTRAS_ONLY */
+
+#ifdef __cplusplus
+/* Dumb overrides for the new and delete operators */
+
+void *operator new(size_t size)
+{
+    void *ret;
+
+    if (!memento.inited)
+        Memento_init();
+
+    if (size == 0)
+        size = 1;
+    MEMENTO_LOCK();
+    ret = do_malloc(size, Memento_EventType_new);
+    MEMENTO_UNLOCK();
+    return ret;
+}
+
+void  operator delete(void *pointer)
+{
+    if (!pointer)
+        return;
+
+    MEMENTO_LOCK();
+    do_free(pointer, Memento_EventType_delete);
+    MEMENTO_UNLOCK();
+}
+
+/* Some C++ systems (apparently) don't provide new[] or delete[]
+ * operators. Provide a way to cope with this */
+#ifndef MEMENTO_CPP_NO_ARRAY_CONSTRUCTORS
+void *operator new[](size_t size)
+{
+    void *ret;
+    if (!memento.inited)
+        Memento_init();
+
+    if (size == 0)
+        size = 1;
+    MEMENTO_LOCK();
+    ret = do_malloc(size, Memento_EventType_newArray);
+    MEMENTO_UNLOCK();
+    return ret;
+}
+
+void  operator delete[](void *pointer)
+{
+    MEMENTO_LOCK();
+    do_free(pointer, Memento_EventType_deleteArray);
+    MEMENTO_UNLOCK();
+}
+#endif /* MEMENTO_CPP_NO_ARRAY_CONSTRUCTORS */
+#endif /* __cplusplus */
+
 #else
 
 /* Just in case anyone has left some debugging code in... */
@@ -1428,7 +2927,7 @@
     return 0;
 }
 
-int (Memento_getBlockNum)(void *i)
+int  (Memento_getBlockNum)(void *i)
 {
     return 0;
 }
@@ -1451,31 +2950,47 @@
 {
 }
 
+void *(Memento_takeRef)(void *a)
+{
+    return a;
+}
+
+void *(Memento_dropRef)(void *a)
+{
+    return a;
+}
+
+void *(Memento_adjustRef)(void *a, int adjust)
+{
+    return a;
+}
+
+void *(Memento_reference)(void *a)
+{
+    return a;
+}
+
 #undef Memento_malloc
 #undef Memento_free
 #undef Memento_realloc
 #undef Memento_calloc
 
-void *
-Memento_malloc(size_t size)
+void *Memento_malloc(size_t size)
 {
     return MEMENTO_UNDERLYING_MALLOC(size);
 }
 
-void
-Memento_free(void *b)
+void Memento_free(void *b)
 {
     MEMENTO_UNDERLYING_FREE(b);
 }
 
-void *
-Memento_realloc(void *b, size_t s)
+void *Memento_realloc(void *b, size_t s)
 {
     return MEMENTO_UNDERLYING_REALLOC(b, s);
 }
 
-void *
-Memento_calloc(size_t n, size_t s)
+void *Memento_calloc(size_t n, size_t s)
 {
     return MEMENTO_UNDERLYING_CALLOC(n, s);
 }
@@ -1488,7 +3003,7 @@
 {
 }
 
-size_t(Memento_setMax)(size_t max)
+size_t (Memento_setMax)(size_t max)
 {
     return 0;
 }
@@ -1500,6 +3015,22 @@
 void *(Memento_label)(void *ptr, const char *label)
 {
     return ptr;
+}
+
+void (Memento_info)(void *addr)
+{
+}
+
+void (Memento_listBlockInfo)(void)
+{
+}
+
+void (Memento_startLeaking)(void)
+{
+}
+
+void (Memento_stopLeaking)(void)
+{
 }
 
 #endif
--- a/memento.h
+++ b/memento.h
@@ -1,21 +1,19 @@
-/* Copyright (C) 2001-2018 Artifex Software, Inc.
+/* Copyright (C) 2009-2018 Artifex Software, Inc.
    All Rights Reserved.
 
    This software is provided AS-IS with no warranty, either express or
    implied.
 
-   This software is distributed under license and may not be copied,
-   modified or distributed except as expressly authorized under the terms
-   of the license contained in the file LICENSE in this distribution.
-
-   Refer to licensing information at http://www.artifex.com or contact
-   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
-   CA 94945, U.S.A., +1(415)492-9861, for further information.
+   This software is distributed under license and may not be copied, modified
+   or distributed except as expressly authorized under the terms of that
+   license. Refer to licensing information at http://www.artifex.com
+   or contact Artifex Software, Inc.,  1305 Grant Avenue - Suite 200,
+   Novato, CA 94945, U.S.A., +1(415)492-9861, for further information.
 */
 
 /* Memento: A library to aid debugging of memory leaks/heap corruption.
  *
- * Usage:
+ * Usage (with C):
  *    First, build your project with MEMENTO defined, and include this
  *    header file wherever you use malloc, realloc or free.
  *    This header file will use macros to point malloc, realloc and free to
@@ -31,11 +29,15 @@
  *    On each event Memento increments a counter. Every block is tagged with
  *    the current counter on allocation. Every so often during program
  *    execution, the heap is checked for consistency. By default this happens
- *    every 1024 events. This can be changed at runtime by using
- *    Memento_setParanoia(int level). 0 turns off such checking, 1 sets
- *    checking to happen on every event, any other number n sets checking to
- *    happen once every n events.
+ *    after 1024 events, then after 2048 events, then after 4096 events, etc.
+ *    This can be changed at runtime by using Memento_setParanoia(int level).
+ *    0 turns off such checking, 1 sets checking to happen on every event,
+ *    any positive number n sets checking to happen once every n events,
+ *    and any negative number n sets checking to happen after -n events, then
+ *    after -2n events etc.
  *
+ *    The default paranoia level is therefore -1024.
+ *
  *    Memento keeps blocks around for a while after they have been freed, and
  *    checks them as part of these heap checks to see if they have been
  *    written to (or are freed twice etc).
@@ -57,7 +59,7 @@
  *    it last passed a check for correctness.
  *
  *    If you rerun, and call Memento_paranoidAt(int event); with this number
- *    the the code will wait until it reaches that event and then start
+ *    the code will wait until it reaches that event and then start
  *    checking the heap after every allocation event. Assuming it is a
  *    deterministic failure, you should then find out where in your program
  *    the error is occurring (between event x-1 and event x).
@@ -132,11 +134,34 @@
  *      then more useful features can be used; firstly memory squeezing will
  *      work, and secondly, Memento will have a "finer grained" paranoia
  *      available to it.
+ *
+ * Usage with C++:
+ *
+ *    Memento has some experimental code in it to trap new/delete (and
+ *    new[]/delete[] if required) calls.
+ *
+ *    In order for this to work, either:
+ *
+ *    1) Build memento.c with the c++ compiler.
+ *
+ *    or
+ *
+ *    2) Build memento.c as normal with the C compiler, then from any
+ *       one of your .cpp files, do:
+ *
+ *       #define MEMENTO_CPP_EXTRAS_ONLY
+ *       #include "memento.c"
+ *
+ *       In the case where MEMENTO is not defined, this will not do anything.
+ *
+ *    Both Windows and GCC provide separate new[] and delete[] operators
+ *    for arrays. Apparently some systems do not. If this is the case for
+ *    your system, define MEMENTO_CPP_NO_ARRAY_CONSTRUCTORS.
  */
 
 #ifndef MEMENTO_H
 
-#include <memory.h>
+#include <stdlib.h>
 
 #define MEMENTO_H
 
@@ -183,12 +208,40 @@
 size_t Memento_setMax(size_t);
 void Memento_stats(void);
 void *Memento_label(void *, const char *);
+void Memento_tick(void);
 
 void *Memento_malloc(size_t s);
 void *Memento_realloc(void *, size_t s);
-void Memento_free(void *);
+void  Memento_free(void *);
 void *Memento_calloc(size_t, size_t);
 
+void Memento_info(void *addr);
+void Memento_listBlockInfo(void);
+void *Memento_takeByteRef(void *blk);
+void *Memento_dropByteRef(void *blk);
+void *Memento_takeShortRef(void *blk);
+void *Memento_dropShortRef(void *blk);
+void *Memento_takeIntRef(void *blk);
+void *Memento_dropIntRef(void *blk);
+void *Memento_takeRef(void *blk);
+void *Memento_dropRef(void *blk);
+void *Memento_adjustRef(void *blk, int adjust);
+void *Memento_reference(void *blk);
+
+int Memento_checkPointerOrNull(void *blk);
+int Memento_checkBytePointerOrNull(void *blk);
+int Memento_checkShortPointerOrNull(void *blk);
+int Memento_checkIntPointerOrNull(void *blk);
+
+void Memento_startLeaking(void);
+void Memento_stopLeaking(void);
+
+int Memento_sequence(void);
+
+void Memento_fin(void);
+
+void Memento_bt(void);
+
 #ifdef MEMENTO
 
 #ifndef COMPILING_MEMENTO_C
@@ -205,24 +258,47 @@
 #define Memento_realloc MEMENTO_UNDERLYING_REALLOC
 #define Memento_calloc  MEMENTO_UNDERLYING_CALLOC
 
-#define Memento_checkBlock(A)     0
-#define Memento_checkAllMemory()  0
-#define Memento_check()           0
-#define Memento_setParanoia(A)    0
-#define Memento_paranoidAt(A)     0
-#define Memento_breakAt(A)        0
-#define Memento_breakOnFree(A)    0
-#define Memento_breakOnRealloc(A) 0
-#define Memento_getBlockNum(A)    0
-#define Memento_find(A)           0
-#define Memento_breakpoint()      do {} while (0)
-#define Memento_failAt(A)         0
-#define Memento_failThisEvent()   0
-#define Memento_listBlocks()      do {} while (0)
-#define Memento_listNewBlocks()   do {} while (0)
-#define Memento_setMax(A)         0
-#define Memento_stats()           do {} while (0)
-#define Memento_label(A,B)        (A)
+#define Memento_checkBlock(A)              0
+#define Memento_checkAllMemory()           0
+#define Memento_check()                    0
+#define Memento_setParanoia(A)             0
+#define Memento_paranoidAt(A)              0
+#define Memento_breakAt(A)                 0
+#define Memento_breakOnFree(A)             0
+#define Memento_breakOnRealloc(A)          0
+#define Memento_getBlockNum(A)             0
+#define Memento_find(A)                    0
+#define Memento_breakpoint()               do {} while (0)
+#define Memento_failAt(A)                  0
+#define Memento_failThisEvent()            0
+#define Memento_listBlocks()               do {} while (0)
+#define Memento_listNewBlocks()            do {} while (0)
+#define Memento_setMax(A)                  0
+#define Memento_stats()                    do {} while (0)
+#define Memento_label(A,B)                 (A)
+#define Memento_info(A)                    do {} while (0)
+#define Memento_listBlockInfo()            do {} while (0)
+#define Memento_takeByteRef(A)             (A)
+#define Memento_dropByteRef(A)             (A)
+#define Memento_takeShortRef(A)            (A)
+#define Memento_dropShortRef(A)            (A)
+#define Memento_takeIntRef(A)              (A)
+#define Memento_dropIntRef(A)              (A)
+#define Memento_takeRef(A)                 (A)
+#define Memento_dropRef(A)                 (A)
+#define Memento_adjustRef(A,V)             (A)
+#define Memento_reference(A)               (A)
+#define Memento_checkPointerOrNull(A)      0
+#define Memento_checkBytePointerOrNull(A)  0
+#define Memento_checkShortPointerOrNull(A) 0
+#define Memento_checkIntPointerOrNull(A)   0
+
+#define Memento_tick()                     do {} while (0)
+#define Memento_startLeaking()             do {} while (0)
+#define Memento_stopLeaking()              do {} while (0)
+#define Memento_fin()                      do {} while (0)
+#define Memento_bt()                       do {} while (0)
+#define Memento_sequence()                 (0)
 
 #endif /* MEMENTO */