diff options
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/storage/s_lock.h | 194 |
1 files changed, 127 insertions, 67 deletions
diff --git a/src/include/storage/s_lock.h b/src/include/storage/s_lock.h index 369a3d8724..4808d3d493 100644 --- a/src/include/storage/s_lock.h +++ b/src/include/storage/s_lock.h @@ -7,13 +7,14 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/include/storage/s_lock.h,v 1.35 1998/06/15 18:40:04 momjian Exp $ + * $Header: /cvsroot/pgsql/src/include/storage/s_lock.h,v 1.36 1998/06/16 07:18:16 momjian Exp $ * *------------------------------------------------------------------------- */ + /* * DESCRIPTION - * The public functions that must be provided are: + * The public macros that must be provided are: * * void S_INIT_LOCK(slock_t *lock) * @@ -45,11 +46,15 @@ * #define TAS(lock) tas(lock) * int tas(slock_t *lock) // True if lock already set * + * There are default implementations for all these macros at the bottom + * of this file. Check if your platform can use these or needs to + * override them. + * + * NOTES * If none of this can be done, POSTGRES will default to using * System V semaphores (and take a large performance hit -- around 40% * of its time on a DS5000/240 is spent in semop(3)...). * - * NOTES * AIX has a test-and-set but the recommended interface is the cs(3) * system call. This provides an 8-instruction (plus system call * overhead) uninterruptible compare-and-set operation. True @@ -57,10 +62,6 @@ * regression test suite by about 25%. I don't have an assembler * manual for POWER in any case. * - * There are default implementations for all these macros at the bottom - * of this file. Check if your platform can use these or needs to - * override them. - * */ #if !defined(S_LOCK_H) #define S_LOCK_H @@ -69,23 +70,104 @@ #if defined(HAS_TEST_AND_SET) -#if defined(linux) -/*************************************************************************** - * All Linux + +#if defined(__GNUC__) +/************************************************************************* + * All the gcc inlines */ #if defined(__alpha) - +#define TAS(lock) tas(lock) #define S_UNLOCK(lock) { __asm__("mb"); *(lock) = 0; } +static __inline__ int +tas(volatile slock_t *lock) +{ + register slock_t _res; + + __asm__(" ldq $0, %0 \n\ + bne $0, already_set \n\ + ldq_l $0, %0 \n\ + bne $0, already_set \n\ + or $31, 1, $0 \n\ + stq_c $0, %0 \n\ + beq $0, stqc_fail \n\ + success: bis $31, $31, %1 \n\ + mb \n\ + jmp $31, end \n\ + stqc_fail: or $31, 1, $0 \n\ + already_set: bis $0, $0, %1 \n\ + end: nop " : "=m"(*lock), "=r"(_res) : : "0"); + + return (int) _res; +} #endif /* __alpha */ +#if defined(i386) +#define TAS(lock) tas(lock) + +static __inline__ int +tas(volatile slock_t *lock) +{ + 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 /* linux */ + +#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 */ @@ -175,64 +244,56 @@ 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) -/**************************************************************************** - * Default Definitions - override these above as needed. - */ +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 */ -#if !defined(S_LOCK) -#include <sys/time.h> +#endif /* NEED_I386_TAS_ASM */ -#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); +#endif /* else defined(__GNUC__) */ -#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 */ +/**************************************************************************** + * Default Definitions - override these above as needed. + */ +#if !defined(S_LOCK) +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 */ + |