Here is the long awaited optimized version of the S_LOCK patch.
This incorporates all the precedeing patches and emailed suggestions and the results of the performance testing I posted last week. I would like to get this tested on as many platforms as possible so I can verify it went in correctly (as opposed to the horrorshow last time I sent in a patch). Once this is confirmed, I will make a tarball of files that can be dropped into a 6.3.2 source tree as a few people have asked for this in 6.3.2 as well. David Gould
This commit is contained in:
Bruce Momjian
parent
7784312f99
commit
0d8e7f6381
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@ -4,7 +4,7 @@
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# Makefile for storage/buffer
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#
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# IDENTIFICATION
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# $Header: /cvsroot/pgsql/src/backend/storage/buffer/Makefile,v 1.10 1998/05/04 16:58:37 scrappy Exp $
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# $Header: /cvsroot/pgsql/src/backend/storage/buffer/Makefile,v 1.11 1998/06/16 07:18:15 momjian Exp $
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#
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#-------------------------------------------------------------------------
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@ -27,7 +27,7 @@ clean:
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rm -f SUBSYS.o $(OBJS) s_lock_test
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s_lock_test: s_lock.c
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$(CC) $(CFLAGS) -DS_LOCK_TEST=1 -g s_lock.c -o s_lock_test
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$(CC) $(CFLAGS) -DS_LOCK_TEST=1 s_lock.c -o s_lock_test
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./s_lock_test
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ifeq (depend,$(wildcard depend))
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@ -7,12 +7,13 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/storage/buffer/Attic/s_lock.c,v 1.7 1998/05/04 23:49:09 scrappy Exp $
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* $Header: /cvsroot/pgsql/src/backend/storage/buffer/Attic/s_lock.c,v 1.8 1998/06/16 07:18:15 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include <stdio.h>
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#include <sys/time.h>
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#include "config.h"
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#include "c.h"
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@ -22,50 +23,24 @@
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/*
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* Each time we busy spin we select the next element of this array as the
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* number of microseconds to wait. This accomplishes pseudo random back-off.
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* Values are not critical and are weighted to the low end of the range. They
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* were chosen to work even with different select() timer resolutions on
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* different platforms.
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* note: total time to cycle through all 16 entries might be about .1 second.
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* Values are not critical but 10 milliseconds is a common platform
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* granularity.
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* note: total time to cycle through all 16 entries might be about .07 sec.
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*/
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int s_spincycle[S_NSPINCYCLE] =
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{0, 0, 0, 1000, 5000, 0, 10000, 3000,
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0, 10000, 0, 15000, 9000, 21000, 6000, 30000
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#define S_NSPINCYCLE 20
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#define S_MAX_BUSY 500 * S_NSPINCYCLE
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int s_spincycle[S_NSPINCYCLE] =
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{ 0, 0, 0, 0, 10000, 0, 0, 0, 10000, 0,
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0, 10000, 0, 0, 10000, 0, 10000, 0, 10000, 10000
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};
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#if defined(S_LOCK_DEBUG)
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/*
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* s_lock(lock) - take a spinlock
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* add intrumentation code to this and define S_LOCK_DEBUG
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* instead of hacking up the macro in s_lock.h
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* s_lock_stuck(lock) - complain about a stuck spinlock
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*/
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void
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s_lock(slock_t *lock, char *file, int line)
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{
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int spins = 0;
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while (TAS(lock))
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{
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struct timeval delay;
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delay.tv_sec = 0;
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delay.tv_usec = s_spincycle[spins++ % S_NSPINCYCLE];
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(void) select(0, NULL, NULL, NULL, &delay);
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if (spins > S_MAX_BUSY)
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{
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/* It's been well over a minute... */
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s_lock_stuck(lock, file, line);
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}
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}
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}
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#endif /* S_LOCK_DEBUG */
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/*
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* s_lock_stuck(lock) - deal with stuck spinlock
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*/
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void
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s_lock_stuck(slock_t *lock, char *file, int line)
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static void
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s_lock_stuck(volatile slock_t *lock, const char *file, const int line)
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{
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fprintf(stderr,
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"\nFATAL: s_lock(%08x) at %s:%d, stuck spinlock. Aborting.\n",
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@ -79,84 +54,51 @@ s_lock_stuck(slock_t *lock, char *file, int line)
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/*
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* Various TAS implementations moved from s_lock.h to avoid redundant
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* definitions of the same routine.
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* RESOLVE: move this to tas.c. Alternatively get rid of tas.[cso] and fold
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* all that into this file.
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* s_lock(lock) - take a spinlock with backoff
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*/
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void
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s_lock(volatile slock_t *lock, const char *file, const int line)
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{
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int spins = 0;
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while (TAS(lock))
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{
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struct timeval delay;
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delay.tv_sec = 0;
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delay.tv_usec = s_spincycle[spins % S_NSPINCYCLE];
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(void) select(0, NULL, NULL, NULL, &delay);
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if (++spins > S_MAX_BUSY)
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{
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/* It's been over a minute... */
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s_lock_stuck(lock, file, line);
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}
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}
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}
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/*
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* Various TAS implementations that cannot live in s_lock.h as no inline
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* definition exists (yet).
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* In the future, get rid of tas.[cso] and fold it into this file.
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*/
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#if defined(linux)
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#if defined(__GNUC__)
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/*************************************************************************
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* All the Linux flavors
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* All the gcc flavors that are not inlined
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*/
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#if defined(__alpha)
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int
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tas(slock_t *lock)
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{
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slock_t _res;
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__asm__(" ldq $0, %0 \n\
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bne $0, already_set \n\
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ldq_l $0, %0 \n\
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bne $0, already_set \n\
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or $31, 1, $0 \n\
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stq_c $0, %0 \n\
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beq $0, stqc_fail \n\
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success: bis $31, $31, %1 \n\
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mb \n\
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jmp $31, end \n\
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stqc_fail: or $31, 1, $0 \n\
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already_set: bis $0, $0, %1 \n\
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end: nop ": "=m"(*lock), "=r"(_res): :"0");
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return (_res != 0);
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}
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#endif /* __alpha */
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#if defined(i386)
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int
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tas(slock_t *lock)
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{
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slock_t _res = 1;
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__asm__("lock; xchgb %0,%1": "=q"(_res), "=m"(*lock):"0"(0x1));
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return (_res != 0);
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}
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#endif /* i386 */
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#if defined(sparc)
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int
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tas(slock_t *lock)
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{
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slock_t _res;
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slock_t *tmplock = lock;
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__asm__("ldstub [%1], %0" \
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: "=&r"(_res), "=r"(tmplock) \
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: "1"(tmplock));
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return (_res != 0);
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}
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#endif /* sparc */
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#if defined(PPC)
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static int
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tas_dummy()
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/* Note: need a nice gcc constrained asm version so it can be inlined */
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int
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tas(volatile slock_t *lock)
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{
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__asm__(" \n\
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tas: \n\
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lwarx 5,0,3 \n\
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__asm__("lwarx 5,0,3 \n\
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cmpwi 5,0 \n\
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bne fail \n\
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addi 5,5,1 \n\
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@ -169,21 +111,20 @@ success: \n\
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blr \n\
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");
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}
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#endif /* PPC */
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#else /* defined(linux) */
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#else /* defined(__GNUC__) */
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/***************************************************************************
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* All Non-Linux
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* All non gcc
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*/
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#if defined(sun3)
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static void
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tas_dummy() /* really means: extern int tas(slock_t *lock); */
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tas_dummy() /* really means: extern int tas(slock_t *lock); */
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{
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asm("LLA0:");
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asm(" .data");
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@ -208,26 +149,18 @@ tas_dummy() /* really means: extern int tas(slock_t *lock); */
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#if defined(NEED_SPARC_TAS_ASM)
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/*
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* bsd and bsdi sparc machines
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* sparc machines not using gcc
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*/
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/* if we're using -ansi w/ gcc, use __asm__ instead of asm */
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#if defined(__STRICT_ANSI__)
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#define asm(x) __asm__(x)
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#endif /* __STRICT_ANSI__ */
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static void
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tas_dummy() /* really means: extern int tas(slock_t *lock); */
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tas_dummy() /* really means: extern int tas(slock_t *lock); */
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{
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asm(".seg \"data\"");
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asm(".seg \"text\"");
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asm("_tas:");
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/*
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* Sparc atomic test and set (sparc calls it "atomic load-store")
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*/
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asm("ldstub [%r8], %r8");
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asm("retl");
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asm("nop");
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}
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@ -237,76 +170,25 @@ tas_dummy() /* really means: extern int tas(slock_t *lock); */
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#if defined(NEED_VAX_TAS_ASM)
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/*
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* VAXen -- even multiprocessor ones
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* (thanks to Tom Ivar Helbekkmo)
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*/
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typedef unsigned char slock_t;
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int
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tas(slock_t *lock)
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{
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register ret;
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asm(" movl $1, r0
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bbssi $0, (%1), 1f
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clrl r0
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1: movl r0, %0 "
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: "=r"(ret) /* return value, in register */
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: "r"(lock) /* argument, 'lock pointer', in register */
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: "r0"); /* inline code uses this register */
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return ret;
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}
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#endif /* NEED_VAX_TAS_ASM */
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#if defined(NEED_I386_TAS_ASM)
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/*
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* i386 based things
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*/
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#if defined(USE_UNIVEL_CC)
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asm int
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tas(slock_t *s_lock)
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{
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%lab locked;
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/* Upon entry, %eax will contain the pointer to the lock byte */
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pushl % ebx
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xchgl % eax, %ebx
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xor % eax, %eax
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movb $255, %al
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lock
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xchgb % al, (%ebx)
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popl % ebx
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}
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#else /* USE_UNIVEL_CC */
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int
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tas(slock_t *lock)
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{
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slock_t _res = 1;
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__asm__("lock; xchgb %0,%1": "=q"(_res), "=m"(*lock):"0"(0x1));
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return (_res != 0);
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}
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#endif /* USE_UNIVEL_CC */
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/* non gcc i386 based things */
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#endif /* NEED_I386_TAS_ASM */
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#endif /* linux */
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#endif /* not __GNUC__ */
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/*****************************************************************************/
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#if defined(S_LOCK_TEST)
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slock_t test_lock;
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/*
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* test program for verifying a port.
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*/
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volatile slock_t test_lock;
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void
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main()
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@ -330,7 +212,7 @@ main()
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printf("S_LOCK_TEST: this will hang for a few minutes and then abort\n");
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printf(" with a 'stuck spinlock' message if S_LOCK()\n");
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printf(" and TAS() are working.\n");
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S_LOCK(&test_lock);
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s_lock(&test_lock, __FILE__, __LINE__);
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printf("S_LOCK_TEST: failed, lock not locked~\n");
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exit(3);
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@ -338,3 +220,4 @@ main()
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}
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#endif /* S_LOCK_TEST */
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@ -7,13 +7,14 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/include/storage/s_lock.h,v 1.35 1998/06/15 18:40:04 momjian Exp $
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* $Header: /cvsroot/pgsql/src/include/storage/s_lock.h,v 1.36 1998/06/16 07:18:16 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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/*
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* DESCRIPTION
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* The public functions that must be provided are:
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* The public macros that must be provided are:
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*
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* void S_INIT_LOCK(slock_t *lock)
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*
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@ -45,11 +46,15 @@
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* #define TAS(lock) tas(lock)
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* int tas(slock_t *lock) // True if lock already set
|
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*
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* There are default implementations for all these macros at the bottom
|
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* of this file. Check if your platform can use these or needs to
|
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* override them.
|
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*
|
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* NOTES
|
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* If none of this can be done, POSTGRES will default to using
|
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* System V semaphores (and take a large performance hit -- around 40%
|
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* of its time on a DS5000/240 is spent in semop(3)...).
|
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*
|
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* NOTES
|
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* AIX has a test-and-set but the recommended interface is the cs(3)
|
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* system call. This provides an 8-instruction (plus system call
|
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* overhead) uninterruptible compare-and-set operation. True
|
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|
|
@ -57,10 +62,6 @@
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* regression test suite by about 25%. I don't have an assembler
|
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* manual for POWER in any case.
|
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*
|
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* There are default implementations for all these macros at the bottom
|
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* of this file. Check if your platform can use these or needs to
|
||||
* override them.
|
||||
*
|
||||
*/
|
||||
#if !defined(S_LOCK_H)
|
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#define S_LOCK_H
|
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|
|
@ -69,23 +70,104 @@
|
|||
|
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#if defined(HAS_TEST_AND_SET)
|
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|
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#if defined(linux)
|
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/***************************************************************************
|
||||
* All Linux
|
||||
|
||||
#if defined(__GNUC__)
|
||||
/*************************************************************************
|
||||
* All the gcc inlines
|
||||
*/
|
||||
|
||||
#if defined(__alpha)
|
||||
|
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#define TAS(lock) tas(lock)
|
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#define S_UNLOCK(lock) { __asm__("mb"); *(lock) = 0; }
|
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|
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static __inline__ int
|
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tas(volatile slock_t *lock)
|
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{
|
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register slock_t _res;
|
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|
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__asm__(" ldq $0, %0 \n\
|
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bne $0, already_set \n\
|
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ldq_l $0, %0 \n\
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bne $0, already_set \n\
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or $31, 1, $0 \n\
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stq_c $0, %0 \n\
|
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beq $0, stqc_fail \n\
|
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success: bis $31, $31, %1 \n\
|
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mb \n\
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jmp $31, end \n\
|
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stqc_fail: or $31, 1, $0 \n\
|
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already_set: bis $0, $0, %1 \n\
|
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end: nop " : "=m"(*lock), "=r"(_res) : : "0");
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||||
|
||||
return (int) _res;
|
||||
}
|
||||
#endif /* __alpha */
|
||||
|
||||
|
||||
|
||||
#if defined(i386)
|
||||
#define TAS(lock) tas(lock)
|
||||
|
||||
#else /* linux */
|
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static __inline__ int
|
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tas(volatile slock_t *lock)
|
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{
|
||||
register slock_t _res = 1;
|
||||
|
||||
__asm__("lock; xchgb %0,%1" : "=q"(_res), "=m"(*lock) : "0"(_res) );
|
||||
return (int) _res;
|
||||
}
|
||||
#endif /* i386 */
|
||||
|
||||
|
||||
|
||||
#if defined(sparc)
|
||||
#define TAS(lock) tas(lock)
|
||||
|
||||
static __inline__ int
|
||||
tas(volatile slock_t *lock)
|
||||
{
|
||||
register slock_t _res = 1;
|
||||
|
||||
__asm__("ldstub [%1], %0" \
|
||||
: "=r"(_res), "=m"(*lock) \
|
||||
: "1"(lock));
|
||||
return (int) _res;
|
||||
}
|
||||
#endif /* sparc */
|
||||
|
||||
|
||||
|
||||
#if defined(NEED_VAX_TAS_ASM)
|
||||
/*
|
||||
* VAXen -- even multiprocessor ones
|
||||
* (thanks to Tom Ivar Helbekkmo)
|
||||
*/
|
||||
#define TAS(lock) tas(lock)
|
||||
|
||||
typedef unsigned char slock_t;
|
||||
|
||||
static __inline__ int
|
||||
tas(volatile slock_t *lock)
|
||||
{
|
||||
register _res;
|
||||
|
||||
__asm__(" movl $1, r0
|
||||
bbssi $0, (%1), 1f
|
||||
clrl r0
|
||||
1: movl r0, %0 "
|
||||
: "=r"(_res) /* return value, in register */
|
||||
: "r"(lock) /* argument, 'lock pointer', in register */
|
||||
: "r0"); /* inline code uses this register */
|
||||
return (int) _res;
|
||||
}
|
||||
#endif /* NEED_VAX_TAS_ASM */
|
||||
|
||||
|
||||
|
||||
|
||||
#else /* __GNUC__ */
|
||||
/***************************************************************************
|
||||
* All non Linux
|
||||
* All non gcc
|
||||
*/
|
||||
|
||||
#if defined (nextstep)
|
||||
|
|
@ -95,14 +177,10 @@
|
|||
*/
|
||||
|
||||
#define S_LOCK(lock) mutex_lock(lock)
|
||||
|
||||
#define S_UNLOCK(lock) mutex_unlock(lock)
|
||||
|
||||
#define S_INIT_LOCK(lock) mutex_init(lock)
|
||||
|
||||
/* For Mach, we have to delve inside the entrails of `struct mutex'. Ick! */
|
||||
#define S_LOCK_FREE(alock) ((alock)->lock == 0)
|
||||
|
||||
#endif /* nextstep */
|
||||
|
||||
|
||||
|
|
@ -118,13 +196,9 @@
|
|||
* for the R3000 chips out there.
|
||||
*/
|
||||
#define TAS(lock) (!acquire_lock(lock))
|
||||
|
||||
#define S_UNLOCK(lock) release_lock(lock)
|
||||
|
||||
#define S_INIT_LOCK(lock) init_lock(lock)
|
||||
|
||||
#define S_LOCK_FREE(lock) (stat_lock(lock) == UNLOCKED)
|
||||
|
||||
#endif /* __sgi */
|
||||
|
||||
|
||||
|
|
@ -137,13 +211,9 @@
|
|||
* (see storage/ipc.h).
|
||||
*/
|
||||
#define TAS(lock) (msem_lock((lock), MSEM_IF_NOWAIT) < 0)
|
||||
|
||||
#define S_UNLOCK(lock) msem_unlock((lock), 0)
|
||||
|
||||
#define S_INIT_LOCK(lock) msem_init((lock), MSEM_UNLOCKED)
|
||||
|
||||
#define S_LOCK_FREE(lock) (!(lock)->msem_state)
|
||||
|
||||
#endif /* __alpha */
|
||||
|
||||
|
||||
|
|
@ -156,7 +226,6 @@
|
|||
* (see storage/ipc.h).
|
||||
*/
|
||||
#define TAS(lock) cs((int *) (lock), 0, 1)
|
||||
|
||||
#endif /* _AIX */
|
||||
|
||||
|
||||
|
|
@ -175,14 +244,38 @@ static slock_t clear_lock =
|
|||
{-1, -1, -1, -1};
|
||||
|
||||
#define S_UNLOCK(lock) (*(lock) = clear_lock) /* struct assignment */
|
||||
|
||||
#define S_LOCK_FREE(lock) ( *(int *) (((long) (lock) + 15) & ~15) != 0)
|
||||
|
||||
#endif /* __hpux */
|
||||
|
||||
|
||||
|
||||
#endif /* else defined(linux) */
|
||||
#if defined(NEED_I386_TAS_ASM)
|
||||
/* non gcc i386 based things */
|
||||
|
||||
|
||||
#if defined(USE_UNIVEL_CC)
|
||||
#define TAS(lock) tas(lock)
|
||||
|
||||
asm int
|
||||
tas(slock_t *s_lock)
|
||||
{
|
||||
%lab locked;
|
||||
/* Upon entry, %eax will contain the pointer to the lock byte */
|
||||
pushl % ebx
|
||||
xchgl % eax, %ebx
|
||||
xor % eax, %eax
|
||||
movb $255, %al
|
||||
lock
|
||||
xchgb % al, (%ebx)
|
||||
popl % ebx
|
||||
}
|
||||
#endif /* USE_UNIVEL_CC */
|
||||
|
||||
|
||||
#endif /* NEED_I386_TAS_ASM */
|
||||
|
||||
|
||||
#endif /* else defined(__GNUC__) */
|
||||
|
||||
|
||||
|
||||
|
|
@ -192,47 +285,15 @@ static slock_t clear_lock =
|
|||
*/
|
||||
|
||||
#if !defined(S_LOCK)
|
||||
|
||||
#include <sys/time.h>
|
||||
|
||||
#define S_NSPINCYCLE 16
|
||||
#define S_MAX_BUSY 1000 * S_NSPINCYCLE
|
||||
|
||||
extern int s_spincycle[];
|
||||
extern void s_lock_stuck(slock_t *lock, char *file, int line);
|
||||
|
||||
#if defined(S_LOCK_DEBUG)
|
||||
|
||||
extern void s_lock(slock_t *lock);
|
||||
|
||||
#define S_LOCK(lock) s_lock(lock, __FILE__, __LINE__)
|
||||
|
||||
#else /* S_LOCK_DEBUG */
|
||||
|
||||
extern void s_lock(volatile slock_t *lock, const char *file, const int line);
|
||||
#define S_LOCK(lock) \
|
||||
do { \
|
||||
int spins = 0; \
|
||||
while (TAS(lock)) \
|
||||
{ \
|
||||
struct timeval delay; \
|
||||
delay.tv_sec = 0; \
|
||||
delay.tv_usec = s_spincycle[spins++ % S_NSPINCYCLE]; \
|
||||
(void) select(0, NULL, NULL, NULL, &delay); \
|
||||
if (spins > S_MAX_BUSY) \
|
||||
{ \
|
||||
/* It's been well over a minute... */ \
|
||||
s_lock_stuck(lock, __FILE__, __LINE__); \
|
||||
} \
|
||||
} \
|
||||
} while(0)
|
||||
|
||||
#endif /* S_LOCK_DEBUG */
|
||||
if (TAS((volatile slock_t *) lock)) {\
|
||||
s_lock((volatile slock_t *) lock, __FILE__, __LINE__); \
|
||||
} else
|
||||
#endif /* S_LOCK */
|
||||
|
||||
|
||||
|
||||
#if !defined(S_LOCK_FREE)
|
||||
#define S_LOCK_FREE(lock) ((*lock) == 0)
|
||||
#define S_LOCK_FREE(lock) (*(lock) == 0)
|
||||
#endif /* S_LOCK_FREE */
|
||||
|
||||
#if !defined(S_UNLOCK)
|
||||
|
|
@ -244,12 +305,11 @@ do { \
|
|||
#endif /* S_INIT_LOCK */
|
||||
|
||||
#if !defined(TAS)
|
||||
int tas(slock_t *lock); /* port/.../tas.s, or s_lock.c */
|
||||
|
||||
#define TAS(lock) tas(lock)
|
||||
int tas(volatile slock_t *lock); /* port/.../tas.s, or s_lock.c */
|
||||
#define TAS(lock) tas((volatile slock_t *) lock)
|
||||
#endif /* TAS */
|
||||
|
||||
|
||||
#endif /* HAS_TEST_AND_SET */
|
||||
|
||||
#endif /* S_LOCK_H */
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue