ref: ada1920a0e4787d46402dcdc3e9f3ad3ddae7f0e
dir: /sys/src/libventi/mem.c/
#include <u.h> #include <libc.h> #include <venti.h> enum { IdealAlignment = 32, ChunkSize = 128*1024 }; void vtfree(void *p) { free(p); } void * vtmalloc(ulong size) { void *p = mallocz(size, 0); if(p == nil){ fprint(2, "vtmalloc: out of memory allocating %lud", size); abort(); } setmalloctag(p, getcallerpc(&size)); return p; } void * vtmallocz(ulong size) { void *p = mallocz(size, 1); if(p == nil){ fprint(2, "vtmallocz: out of memory allocating %lud", size); abort(); } setmalloctag(p, getcallerpc(&size)); return p; } void * vtrealloc(void *p, ulong size) { p = realloc(p, size); if(p == 0 && size != 0){ fprint(2, "vtrealloc: out of memory allocating %lud", size); abort(); } setrealloctag(p, getcallerpc(&size)); return p; } void * vtbrk(ulong n) { static Lock lk; static uchar *buf; static ulong nbuf, nchunk; ulong align, pad; void *p; if(n >= IdealAlignment) align = IdealAlignment; else if(n > 8) align = 8; else align = 4; if(n > ChunkSize){ p = sbrk(n); if(p == (void*)-1) sysfatal("Failed to allocate permanent chunk size %lud", n); memset(p, 0, n); return (uchar*)p; } lock(&lk); pad = (align - (uintptr)buf) & (align-1); if(n + pad > nbuf) { buf = sbrk(ChunkSize); if(buf == (void*)-1) sysfatal("Failed to allocate permanent chunk size %ud", ChunkSize); memset(buf, 0, ChunkSize); nbuf = ChunkSize; pad = (align - (uintptr)buf) & (align-1); nchunk++; } assert(n + pad <= nbuf); p = buf + pad; buf += pad + n; nbuf -= pad + n; unlock(&lk); return p; }