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author | Ulrich Drepper <drepper@redhat.com> | 2000-01-02 06:01:06 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2000-01-02 06:01:06 +0000 |
commit | 8d6f1731fcd082e4f744ba9cb4bde4be7c08f1b3 (patch) | |
tree | 099a250d7366aef2ab028fdb24f0d692cd784b4a /db2/mutex/mutex.c | |
parent | 9a6450d578556c11e7c173d2f28362345b8f1258 (diff) | |
download | glibc-8d6f1731fcd082e4f744ba9cb4bde4be7c08f1b3.tar.gz glibc-8d6f1731fcd082e4f744ba9cb4bde4be7c08f1b3.tar.xz glibc-8d6f1731fcd082e4f744ba9cb4bde4be7c08f1b3.zip |
Update.
* Makeconfig (all-subdirs): Remove db and db2. * db/*: Removed. * db2/*: Removed.
Diffstat (limited to 'db2/mutex/mutex.c')
-rw-r--r-- | db2/mutex/mutex.c | 318 |
1 files changed, 0 insertions, 318 deletions
diff --git a/db2/mutex/mutex.c b/db2/mutex/mutex.c deleted file mode 100644 index 2fac14cf3d..0000000000 --- a/db2/mutex/mutex.c +++ /dev/null @@ -1,318 +0,0 @@ -/*- - * See the file LICENSE for redistribution information. - * - * Copyright (c) 1996, 1997, 1998 - * Sleepycat Software. All rights reserved. - */ - -#include "config.h" - -#ifndef lint -static const char sccsid[] = "@(#)mutex.c 10.52 (Sleepycat) 11/8/98"; -#endif /* not lint */ - -#ifndef NO_SYSTEM_INCLUDES -#include <sys/types.h> - -#include <errno.h> -#include <fcntl.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#endif - -#include "db_int.h" - -#ifdef HAVE_SPINLOCKS - -#ifdef HAVE_FUNC_AIX -#define TSL_INIT(x) -#define TSL_SET(x) (!_check_lock(x, 0, 1)) -#define TSL_UNSET(x) _clear_lock(x, 0) -#endif - -#ifdef HAVE_ASSEM_MC68020_GCC -#include "68020.gcc" -#endif - -#if defined(HAVE_FUNC_MSEM) -/* - * !!! - * Do not remove the MSEM_IF_NOWAIT flag. The problem is that if a single - * process makes two msem_lock() calls in a row, the second one returns an - * error. We depend on the fact that we can lock against ourselves in the - * locking subsystem, where we set up a mutex so that we can block ourselves. - * Tested on OSF1 v4.0. - */ -#define TSL_INIT(x) (msem_init(x, MSEM_UNLOCKED) == NULL) -#define TSL_INIT_ERROR 1 -#define TSL_SET(x) (!msem_lock(x, MSEM_IF_NOWAIT)) -#define TSL_UNSET(x) msem_unlock(x, 0) -#endif - -#ifdef HAVE_FUNC_RELIANT -#define TSL_INIT(x) initspin(x, 1) -#define TSL_SET(x) (cspinlock(x) == 0) -#define TSL_UNSET(x) spinunlock(x) -#endif - -#ifdef HAVE_FUNC_SGI -#define TSL_INIT(x) (init_lock(x) != 0) -#define TSL_INIT_ERROR 1 -#define TSL_SET(x) (!acquire_lock(x)) -#define TSL_UNSET(x) release_lock(x) -#endif - -#ifdef HAVE_FUNC_SOLARIS -/* - * Semaphore calls don't work on Solaris 5.5. - * - * #define TSL_INIT(x) (sema_init(x, 1, USYNC_PROCESS, NULL) != 0) - * #define TSL_INIT_ERROR 1 - * #define TSL_SET(x) (sema_wait(x) == 0) - * #define TSL_UNSET(x) sema_post(x) - */ -#define TSL_INIT(x) -#define TSL_SET(x) (_lock_try(x)) -#define TSL_UNSET(x) _lock_clear(x) -#endif - -#ifdef HAVE_FUNC_VMS -#include <builtins.h> -#ifdef __ALPHA -#define TSL_SET(tsl) (!__TESTBITSSI(tsl, 0)) -#else /* __VAX */ -#define TSL_SET(tsl) (!(int)_BBSSI(0, tsl)) -#endif -#define TSL_UNSET(tsl) (*(tsl) = 0) -#define TSL_INIT(tsl) TSL_UNSET(tsl) -#endif - -#ifdef HAVE_ASSEM_PARISC_GCC -#include "parisc.gcc" -#endif - -#ifdef HAVE_ASSEM_SCO_CC -#include "sco.cc" -#endif - -#ifdef HAVE_ASSEM_SPARC_GCC -#include "sparc.gcc" -#endif - -#ifdef HAVE_ASSEM_UTS4_CC -#define TSL_INIT(x) -#define TSL_SET(x) (!uts_lock(x, 1)) -#define TSL_UNSET(x) (*(x) = 0) -#endif - -#ifdef HAVE_ASSEM_X86_GCC -#include "x86.gcc" -#endif - -#ifdef HAVE_ASSEM_ALPHA -#include "alpha.h" -#endif - -#ifdef WIN16 -/* Win16 spinlocks are simple because we cannot possibly be preempted. */ -#define TSL_INIT(tsl) -#define TSL_SET(tsl) (*(tsl) = 1) -#define TSL_UNSET(tsl) (*(tsl) = 0) -#endif - -#if defined(_WIN32) -/* - * XXX - * DBDB this needs to be byte-aligned!! - */ -#define TSL_INIT(tsl) -#define TSL_SET(tsl) (!InterlockedExchange((PLONG)tsl, 1)) -#define TSL_UNSET(tsl) (*(tsl) = 0) -#endif - -#endif /* HAVE_SPINLOCKS */ - -/* - * __db_mutex_init -- - * Initialize a DB mutex structure. - * - * PUBLIC: int __db_mutex_init __P((db_mutex_t *, u_int32_t)); - */ -int -__db_mutex_init(mp, off) - db_mutex_t *mp; - u_int32_t off; -{ -#ifdef DIAGNOSTIC - if ((ALIGNTYPE)mp & (MUTEX_ALIGNMENT - 1)) { - (void)fprintf(stderr, - "MUTEX ERROR: mutex NOT %d-byte aligned!\n", - MUTEX_ALIGNMENT); - abort(); - } -#endif - memset(mp, 0, sizeof(db_mutex_t)); - -#ifdef HAVE_SPINLOCKS - COMPQUIET(off, 0); - -#ifdef TSL_INIT_ERROR - if (TSL_INIT(&mp->tsl_resource)) - return (errno); -#else - TSL_INIT(&mp->tsl_resource); -#endif - mp->spins = __os_spin(); -#else - mp->off = off; -#endif - return (0); -} - -#define MS(n) ((n) * 1000) /* Milliseconds to micro-seconds. */ -#define SECOND (MS(1000)) /* A second's worth of micro-seconds. */ - -/* - * __db_mutex_lock - * Lock on a mutex, logically blocking if necessary. - * - * PUBLIC: int __db_mutex_lock __P((db_mutex_t *, int)); - */ -int -__db_mutex_lock(mp, fd) - db_mutex_t *mp; - int fd; -{ - u_long usecs; -#ifdef HAVE_SPINLOCKS - int nspins; -#else - struct flock k_lock; - pid_t mypid; - int locked; -#endif - - if (!DB_GLOBAL(db_mutexlocks)) - return (0); - -#ifdef HAVE_SPINLOCKS - COMPQUIET(fd, 0); - - for (usecs = MS(1);;) { - /* Try and acquire the uncontested resource lock for N spins. */ - for (nspins = mp->spins; nspins > 0; --nspins) - if (TSL_SET(&mp->tsl_resource)) { -#ifdef DIAGNOSTIC - if (mp->pid != 0) { - (void)fprintf(stderr, - "MUTEX ERROR: __db_mutex_lock: lock currently locked\n"); - abort(); - } - mp->pid = getpid(); -#endif - if (usecs == MS(1)) - ++mp->mutex_set_nowait; - else - ++mp->mutex_set_wait; - return (0); - } - - /* Yield the processor; wait 1ms initially, up to 1 second. */ - __os_yield(usecs); - if ((usecs <<= 1) > SECOND) - usecs = SECOND; - } - /* NOTREACHED */ - -#else /* !HAVE_SPINLOCKS */ - - /* Initialize the lock. */ - k_lock.l_whence = SEEK_SET; - k_lock.l_start = mp->off; - k_lock.l_len = 1; - - for (locked = 0, mypid = getpid();;) { - /* - * Wait for the lock to become available; wait 1ms initially, - * up to 1 second. - */ - for (usecs = MS(1); mp->pid != 0;) { - __os_yield(usecs); - if ((usecs <<= 1) > SECOND) - usecs = SECOND; - } - - /* Acquire an exclusive kernel lock. */ - k_lock.l_type = F_WRLCK; - if (fcntl(fd, F_SETLKW, &k_lock)) - return (errno); - - /* If the resource tsl is still available, it's ours. */ - if (mp->pid == 0) { - locked = 1; - mp->pid = mypid; - } - - /* Release the kernel lock. */ - k_lock.l_type = F_UNLCK; - if (fcntl(fd, F_SETLK, &k_lock)) - return (errno); - - /* - * If we got the resource tsl we're done. - * - * !!! - * We can't check to see if the lock is ours, because we may - * be trying to block ourselves in the lock manager, and so - * the holder of the lock that's preventing us from getting - * the lock may be us! (Seriously.) - */ - if (locked) - break; - } - return (0); -#endif /* !HAVE_SPINLOCKS */ -} - -/* - * __db_mutex_unlock -- - * Release a lock. - * - * PUBLIC: int __db_mutex_unlock __P((db_mutex_t *, int)); - */ -int -__db_mutex_unlock(mp, fd) - db_mutex_t *mp; - int fd; -{ - if (!DB_GLOBAL(db_mutexlocks)) - return (0); - -#ifdef DIAGNOSTIC - if (mp->pid == 0) { - (void)fprintf(stderr, - "MUTEX ERROR: __db_mutex_unlock: lock already unlocked\n"); - abort(); - } -#endif - -#ifdef HAVE_SPINLOCKS - COMPQUIET(fd, 0); - -#ifdef DIAGNOSTIC - mp->pid = 0; -#endif - - /* Release the resource tsl. */ - TSL_UNSET(&mp->tsl_resource); -#else - /* - * Release the resource tsl. We don't have to acquire any locks - * because processes trying to acquire the lock are checking for - * a pid of 0, not a specific value. - */ - mp->pid = 0; -#endif - return (0); -} |