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libc: change tas/sleep locks to cas/semacquire/semrelease locks (from sources)

spinlocks have been changed to use the new semacquire/semrelease
syscalls in combination with atomic compare and swap operations.

--- a/sys/include/libc.h

+++ b/sys/include/libc.h

@@ -410,11 +410,18 @@

 extern	void	prof(void (*fn)(void*), void *arg, int entries, int what);

 /*

+ *  atomic

+ */

+extern	long	ainc(long*);

+extern	long	adec(long*);

+

+/*

  *  synchronization

  */

 typedef

 struct Lock {

-	int	val;

+	long	key;

+	long	sem;

 } Lock;

 extern int	_tas(int*);

@@ -700,9 +707,6 @@

 extern	char*	sysname(void);

 extern	void	werrstr(char*, ...);

 #pragma	varargck	argpos	werrstr	1

-

-extern	long	ainc(long*);

-extern	long	adec(long*);

 extern char *argv0;

 #define	ARGBEGIN	for((argv0||(argv0=*argv)),argv++,argc--;\

--- a/sys/src/libc/68000/cycles.c

+++ /dev/null

@@ -1,7 +1,0 @@

-#include <u.h>

-#include <libc.h>

-

-void	cycles(uvlong*u)

-{

-	*u = 0LL;

-}

--- a/sys/src/libc/68000/mkfile

+++ b/sys/src/libc/68000/mkfile

@@ -24,7 +24,6 @@

 	strlen.s\

 CFILES=\

-	cycles.c\

 	notejmp.c\

 	vlrt.c\

--- /dev/null

+++ b/sys/src/libc/68020/lock.c

@@ -1,0 +1,41 @@

+#include <u.h>

+#include <libc.h>

+

+void

+lock(Lock *lk)

+{

+	int i;

+

+	/* once fast */

+	if(!_tas((int*)&lk->key))

+		return;

+	/* a thousand times pretty fast */

+	for(i=0; i<1000; i++){

+		if(!_tas((int*)&lk->key))

+			return;

+		sleep(0);

+	}

+	/* now nice and slow */

+	for(i=0; i<1000; i++){

+		if(!_tas((int*)&lk->key))

+			return;

+		sleep(100);

+	}

+	/* take your time */

+	while(_tas((int*)&lk->key))

+		sleep(1000);

+}

+

+int

+canlock(Lock *lk)

+{

+	if(_tas((int*)&lk->key))

+		return 0;

+	return 1;

+}

+

+void

+unlock(Lock *lk)

+{

+	lk->key = 0;

+}

--- a/sys/src/libc/68020/mkfile

+++ b/sys/src/libc/68020/mkfile

@@ -26,7 +26,7 @@

 	vlop.s\

 CFILES=\

-	cycles.c\

+	lock.c\

 	notejmp.c\

 	vlrt.c\

--- a/sys/src/libc/alpha/cycles.c

+++ /dev/null

@@ -1,7 +1,0 @@

-#include <u.h>

-#include <libc.h>

-

-void	cycles(uvlong*u)

-{

-	*u = 0LL;

-}

--- /dev/null

+++ b/sys/src/libc/alpha/lock.c

@@ -1,0 +1,41 @@

+#include <u.h>

+#include <libc.h>

+

+void

+lock(Lock *lk)

+{

+	int i;

+

+	/* once fast */

+	if(!_tas((int*)&lk->key))

+		return;

+	/* a thousand times pretty fast */

+	for(i=0; i<1000; i++){

+		if(!_tas((int*)&lk->key))

+			return;

+		sleep(0);

+	}

+	/* now nice and slow */

+	for(i=0; i<1000; i++){

+		if(!_tas((int*)&lk->key))

+			return;

+		sleep(100);

+	}

+	/* take your time */

+	while(_tas((int*)&lk->key))

+		sleep(1000);

+}

+

+int

+canlock(Lock *lk)

+{

+	if(_tas((int*)&lk->key))

+		return 0;

+	return 1;

+}

+

+void

+unlock(Lock *lk)

+{

+	lk->key = 0;

+}

--- a/sys/src/libc/alpha/mkfile

+++ b/sys/src/libc/alpha/mkfile

@@ -18,7 +18,7 @@

 CFILES=\

 	_seek.c\

-	cycles.c\

+	lock.c\

 	notejmp.c\

 HFILES=/sys/include/libc.h

--- a/sys/src/libc/arm/cycles.c

+++ /dev/null

@@ -1,10 +1,0 @@

-#include <u.h>

-#include <libc.h>

-

-#pragma profile off

-

-void

-cycles(uvlong*u)

-{

-	*u = 0LL;

-}

--- a/sys/src/libc/arm/mkfile

+++ b/sys/src/libc/arm/mkfile

@@ -20,7 +20,6 @@

 	vlop.s\

 CFILES=\

-	cycles.c\

 	notejmp.c\

 	vlrt.c\

--- a/sys/src/libc/mips/atom.s

+++ b/sys/src/libc/mips/atom.s

@@ -12,7 +12,8 @@

 loop:	MOVW	$1, R3

 	LL(2, 1)

 	NOOP

-	ADD	R1,R3,R3

+	ADDU	R1, R3

+	MOVW	R3, R1			/* return new value */

 	SC(2, 3)

 	NOOP

 	BEQ	R3,loop

@@ -24,8 +25,8 @@

 loop1:	MOVW	$-1, R3

 	LL(2, 1)

 	NOOP

-	ADD	R1,R3,R3

-	MOVW	R3, R1

+	ADDU	R1, R3

+	MOVW	R3, R1			/* return new value */

 	SC(2, 3)

 	NOOP

 	BEQ	R3,loop1

@@ -48,10 +49,4 @@

 	RET

 fail:

 	MOVW	$0, R1

-	RET

-

-/* general-purpose abort */

-_trap:

-	MOVD	$0, R0

-	MOVD	0(R0), R0

 	RET

--- a/sys/src/libc/mips/lock.c

+++ /dev/null

@@ -1,171 +1,0 @@

-#include <u.h>

-#include <libc.h>

-

-enum

-{

-	Pagesize	= 4096,

-	Semperpg	= Pagesize/(16*sizeof(uint)),

-	Lockaddr	= 0x60000000,

-

-	POWER		= 0x320,

-	MAGNUM		= 0x330,

-	MAGNUMII	= 0x340,

-	R4K		= 0x500,

-};

-

-static	int arch;

-extern	int C_3ktas(int*);

-extern	int C_4ktas(int*);

-extern	int C_fcr0(void);

-

-static void

-lockinit(void)

-{

-	void *v;

-

-	if(arch != 0)

-		return;	/* allow multiple calls */

-	arch = C_fcr0();

-	switch(arch) {

-	case POWER:

-		v = (void*)Lockaddr;

-		if(segattach(SG_CEXEC, "lock", v, Pagesize) == (void*)-1) {

-			arch = MAGNUM;

-			break;

-		}

-		memset(v, 0, Pagesize);

-		break;

-	case MAGNUM:

-	case MAGNUMII:

-	case R4K:

-		break;

-	default:

-		arch = R4K;

-		break;

-	}

-}

-

-void

-lock(Lock *lk)

-{

-	int *hwsem;

-	int hash;

-

-retry:

-	switch(arch) {

-	case 0:

-		lockinit();

-		goto retry;

-	case MAGNUM:

-	case MAGNUMII:

-		while(C_3ktas(&lk->val))

-			sleep(0);

-		return;

-	case R4K:

-		for(;;){

-			while(lk->val)

-				;

-			if(C_4ktas(&lk->val) == 0)

-				return;

-		}

-		break;

-	case POWER:

-		/* Use low order lock bits to generate hash */

-		hash = ((int)lk/sizeof(int)) & (Semperpg-1);

-		hwsem = (int*)Lockaddr+hash;

-

-		for(;;) {

-			if((*hwsem & 1) == 0) {

-				if(lk->val)

-					*hwsem = 0;

-				else {

-					lk->val = 1;

-					*hwsem = 0;

-					return;

-				}

-			}

-			while(lk->val)

-				;

-		}

-	}

-}

-

-int

-canlock(Lock *lk)

-{

-	int *hwsem;

-	int hash;

-

-retry:

-	switch(arch) {

-	case 0:

-		lockinit();

-		goto retry;

-	case MAGNUM:

-	case MAGNUMII:

-		if(C_3ktas(&lk->val))

-			return 0;

-		return 1;

-	case R4K:

-		if(C_4ktas(&lk->val))

-			return 0;

-		return 1;

-	case POWER:

-		/* Use low order lock bits to generate hash */

-		hash = ((int)lk/sizeof(int)) & (Semperpg-1);

-		hwsem = (int*)Lockaddr+hash;

-

-		if((*hwsem & 1) == 0) {

-			if(lk->val)

-				*hwsem = 0;

-			else {

-				lk->val = 1;

-				*hwsem = 0;

-				return 1;

-			}

-		}

-		break;

-	}

-	return 0;

-}

-

-void

-unlock(Lock *lk)

-{

-	lk->val = 0;

-}

-

-int

-_tas(int *p)

-{

-	int *hwsem;

-	int hash;

-

-retry:

-	switch(arch) {

-	case 0:

-		lockinit();

-		goto retry;

-	case MAGNUM:

-	case MAGNUMII:

-		return C_3ktas(p);

-	case R4K:

-		return C_4ktas(p);

-	case POWER:

-		/* Use low order lock bits to generate hash */

-		hash = ((int)p/sizeof(int)) & (Semperpg-1);

-		hwsem = (int*)Lockaddr+hash;

-

-		if((*hwsem & 1) == 0) {

-			if(*p)

-				*hwsem = 0;

-			else {

-				*p = 1;

-				*hwsem = 0;

-				return 0;

-			}

-		}

-		break;

-	}

-	return 1;

-}

--- a/sys/src/libc/mips/mkfile

+++ b/sys/src/libc/mips/mkfile

@@ -23,7 +23,6 @@

 CFILES=\

 	cycles.c\

-	lock.c\

 	notejmp.c\

 	sqrt.c\

 	vlrt.c\

--- a/sys/src/libc/mips/tas.s

+++ b/sys/src/libc/mips/tas.s

@@ -17,6 +17,7 @@

 	BLTZ	R1, btas

 	RET

+	TEXT	_tas(SB),$0

 	TEXT	C_4ktas(SB), $0

 	MOVW	R1, R2		/* address of key */

 tas1:

--- a/sys/src/libc/mkfile

+++ b/sys/src/libc/mkfile

@@ -37,7 +37,7 @@

 		cd $i

 		mk $MKFLAGS update

 	}

-	update $UPDATEFLAGS /386/lib/libc.a

+	update $UPDATEFLAGS /$objtype/lib/libc.a

 installall:V:

 	for(objtype in $CPUS) mk $MKFLAGS install

--- /dev/null

+++ b/sys/src/libc/port/cycles.c

@@ -1,0 +1,7 @@

+#include <u.h>

+#include <libc.h>

+

+void	cycles(uvlong*u)

+{

+	*u = 0LL;

+}

--- a/sys/src/libc/port/lock.c

+++ b/sys/src/libc/port/lock.c

@@ -2,40 +2,32 @@

 #include <libc.h>

 void

-lock(Lock *lk)

+lock(Lock *l)

 {

-	int i;

-

-	/* once fast */

-	if(!_tas(&lk->val))

-		return;

-	/* a thousand times pretty fast */

-	for(i=0; i<1000; i++){

-		if(!_tas(&lk->val))

-			return;

-		sleep(0);

+	if(ainc(&l->key) == 1)

+		return;	/* changed from 0 -> 1: we hold lock */

+	/* otherwise wait in kernel */

+	while(semacquire(&l->sem, 1) < 0){

+		/* interrupted; try again */

 	}

-	/* now nice and slow */

-	for(i=0; i<1000; i++){

-		if(!_tas(&lk->val))

-			return;

-		sleep(100);

-	}

-	/* take your time */

-	while(_tas(&lk->val))

-		sleep(1000);

 }

-int

-canlock(Lock *lk)

+void

+unlock(Lock *l)

 {

-	if(_tas(&lk->val))

-		return 0;

-	return 1;

+	if(adec(&l->key) == 0)

+		return;	/* changed from 1 -> 0: no contention */

+	semrelease(&l->sem, 1);

 }

-void

-unlock(Lock *lk)

+int

+canlock(Lock *l)

 {

-	lk->val = 0;

+	if(ainc(&l->key) == 1)

+		return 1;	/* changed from 0 -> 1: success */

+	/* Undo increment (but don't miss wakeup) */

+	if(adec(&l->key) == 0)

+		return 0;	/* changed from 1 -> 0: no contention */

+	semrelease(&l->sem, 1);

+	return 0;

 }

--- a/sys/src/libc/port/malloc.acid

+++ b/sys/src/libc/port/malloc.acid

@@ -122,16 +122,18 @@

 Profkernel = 2;

 Proftime = 3;

 Profsample = 4;

-sizeofLock = 4;

+sizeofLock = 8;

 aggr Lock

 {

-	'D' 0 val;

+	'D' 0 key;

+	'D' 4 sem;

 };

 defn

 Lock(addr) {

 	complex Lock addr;

-	print("	val	", addr.val, "\n");

+	print("	key	", addr.key, "\n");

+	print("	sem	", addr.sem, "\n");

 };

 sizeofQLp = 12;

@@ -150,13 +152,13 @@

 	print("	state	", addr.state, "\n");

 };

-sizeofQLock = 16;

+sizeofQLock = 20;

 aggr QLock

 {

 	Lock 0 lock;

-	'D' 4 locked;

-	'A' QLp 8 $head;

-	'A' QLp 12 $tail;

+	'D' 8 locked;

+	'A' QLp 12 $head;

+	'A' QLp 16 $tail;

 };

 defn

@@ -170,14 +172,14 @@

 	print("	$tail	", addr.$tail\X, "\n");

 };

-sizeofRWLock = 20;

+sizeofRWLock = 24;

 aggr RWLock

 {

 	Lock 0 lock;

-	'D' 4 readers;

-	'D' 8 writer;

-	'A' QLp 12 $head;

-	'A' QLp 16 $tail;

+	'D' 8 readers;

+	'D' 12 writer;

+	'A' QLp 16 $head;

+	'A' QLp 20 $tail;

 };

 defn

@@ -438,12 +440,12 @@

 };

 complex Tos _tos;

-sizeofPrivate = 12;

+sizeofPrivate = 16;

 aggr Private

 {

 	Lock 0 lk;

-	'D' 4 pid;

-	'D' 8 printfd;

+	'D' 8 pid;

+	'D' 12 printfd;

 };

 defn

--- a/sys/src/libc/port/mkfile

+++ b/sys/src/libc/port/mkfile

@@ -19,6 +19,7 @@

 	cleanname.c\

 	crypt.c\

 	ctype.c\

+	cycles.c\

 	encodefmt.c\

 	execl.c\

 	exp.c\

--- a/sys/src/libc/port/pool.acid

+++ b/sys/src/libc/port/pool.acid

@@ -122,16 +122,18 @@

 Profkernel = 2;

 Proftime = 3;

 Profsample = 4;

-sizeofLock = 4;

+sizeofLock = 8;

 aggr Lock

 {

-	'D' 0 val;

+	'D' 0 key;

+	'D' 4 sem;

 };

 defn

 Lock(addr) {

 	complex Lock addr;

-	print("	val	", addr.val, "\n");

+	print("	key	", addr.key, "\n");

+	print("	sem	", addr.sem, "\n");

 };

 sizeofQLp = 12;

@@ -150,13 +152,13 @@

 	print("	state	", addr.state, "\n");

 };

-sizeofQLock = 16;

+sizeofQLock = 20;

 aggr QLock

 {

 	Lock 0 lock;

-	'D' 4 locked;

-	'A' QLp 8 $head;

-	'A' QLp 12 $tail;

+	'D' 8 locked;

+	'A' QLp 12 $head;

+	'A' QLp 16 $tail;

 };

 defn

@@ -170,14 +172,14 @@

 	print("	$tail	", addr.$tail\X, "\n");

 };

-sizeofRWLock = 20;

+sizeofRWLock = 24;

 aggr RWLock

 {

 	Lock 0 lock;

-	'D' 4 readers;

-	'D' 8 writer;

-	'A' QLp 12 $head;

-	'A' QLp 16 $tail;

+	'D' 8 readers;

+	'D' 12 writer;

+	'A' QLp 16 $head;

+	'A' QLp 20 $tail;

 };

 defn

@@ -504,34 +506,20 @@

 complex Free checklist:t;

 complex Free checklist:q;

 complex Free checktree:t;

-complex Free ltreewalk:t;

-complex Free ltreewalk:f;

-complex Free treeinsert:tree;

-complex Free treeinsert:node;

-complex Free treeinsert:loc;

-complex Free treeinsert:repl;

-complex Free treedelete:tree;

-complex Free treedelete:node;

-complex Free treedelete:loc;

-complex Free treedelete:lsucc;

-complex Free treedelete:succ;

 complex Free treelookupgt:t;

 complex Free treelookupgt:lastgood;

-complex Free listadd:list;

-complex Free listadd:node;

-complex Free listdelete:list;

-complex Free listdelete:node;

+complex Free treesplay:t;

+complex Free treesplay:N;

+complex Free treesplay:l;

+complex Free treesplay:r;

+complex Free treesplay:y;

 complex Pool pooladd:p;

 complex Alloc pooladd:anode;

-complex Free pooladd:lst;

-complex Free pooladd:olst;

 complex Free pooladd:node;

-complex Free pooladd:parent;

+complex Free pooladd:root;

 complex Pool pooldel:p;

 complex Free pooldel:node;

-complex Free pooldel:lst;

-complex Free pooldel:olst;

-complex Free pooldel:parent;

+complex Free pooldel:root;

 complex Pool dsize2bsize:p;

 complex Pool bsize2asize:p;

 complex Pool blockmerge:pool;

--- /dev/null

+++ b/sys/src/libc/sparc/lock.c

@@ -1,0 +1,41 @@

+#include <u.h>

+#include <libc.h>

+

+void

+lock(Lock *lk)

+{

+	int i;

+

+	/* once fast */

+	if(!_tas((int*)&lk->key))

+		return;

+	/* a thousand times pretty fast */

+	for(i=0; i<1000; i++){

+		if(!_tas((int*)&lk->key))

+			return;

+		sleep(0);

+	}

+	/* now nice and slow */

+	for(i=0; i<1000; i++){

+		if(!_tas((int*)&lk->key))

+			return;

+		sleep(100);

+	}

+	/* take your time */

+	while(_tas((int*)&lk->key))

+		sleep(1000);

+}

+

+int

+canlock(Lock *lk)

+{

+	if(_tas((int*)&lk->key))

+		return 0;

+	return 1;

+}

+

+void

+unlock(Lock *lk)

+{

+	lk->key = 0;

+}

--- a/sys/src/libc/sparc/mkfile

+++ b/sys/src/libc/sparc/mkfile

@@ -22,7 +22,7 @@

 	vlop.s

 CFILES=\

-	cycles.c\

+	lock.c\

 	notejmp.c\

 	sqrt.c\

 	vlrt.c\