diff options
Diffstat (limited to 'externals/mysql/mysys/thr_mutex.c')
| -rw-r--r-- | externals/mysql/mysys/thr_mutex.c | 875 |
1 files changed, 0 insertions, 875 deletions
diff --git a/externals/mysql/mysys/thr_mutex.c b/externals/mysql/mysys/thr_mutex.c deleted file mode 100644 index 9c7eb714326..00000000000 --- a/externals/mysql/mysys/thr_mutex.c +++ /dev/null @@ -1,875 +0,0 @@ -/* Copyright (C) 2000-2008 MySQL AB, 2008 Sun Microsystems, Inc - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; version 2 of the License. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ - -/* This makes a wrapper for mutex handling to make it easier to debug mutex */ - -#include <my_global.h> -#if defined(TARGET_OS_LINUX) && !defined (__USE_UNIX98) -#define __USE_UNIX98 /* To get rw locks under Linux */ -#endif -#if defined(THREAD) && defined(SAFE_MUTEX) -#undef SAFE_MUTEX /* Avoid safe_mutex redefinitions */ -#include "mysys_priv.h" -#include "my_static.h" -#include <m_string.h> -#include <hash.h> - -#ifndef DO_NOT_REMOVE_THREAD_WRAPPERS -/* Remove wrappers */ -#undef pthread_mutex_t -#undef pthread_mutex_init -#undef pthread_mutex_lock -#undef pthread_mutex_unlock -#undef pthread_mutex_destroy -#undef pthread_cond_wait -#undef pthread_cond_timedwait -#ifdef HAVE_NONPOSIX_PTHREAD_MUTEX_INIT -#define pthread_mutex_init(a,b) my_pthread_noposix_mutex_init((a),(b)) -#endif -#endif /* DO_NOT_REMOVE_THREAD_WRAPPERS */ - -static pthread_mutex_t THR_LOCK_mutex; -static ulong safe_mutex_count= 0; /* Number of mutexes created */ -static ulong safe_mutex_id= 0; -my_bool safe_mutex_deadlock_detector= 1; /* On by default */ - -#ifdef SAFE_MUTEX_DETECT_DESTROY -static struct st_safe_mutex_create_info_t *safe_mutex_create_root= NULL; -#endif - -static my_bool add_used_to_locked_mutex(safe_mutex_t *used_mutex, - safe_mutex_deadlock_t *locked_mutex); -static my_bool add_to_locked_mutex(safe_mutex_deadlock_t *locked_mutex, - safe_mutex_t *current_mutex); -static my_bool remove_from_locked_mutex(safe_mutex_t *mp, - safe_mutex_t *delete_mutex); -static my_bool remove_from_used_mutex(safe_mutex_deadlock_t *locked_mutex, - safe_mutex_t *mutex); -static void print_deadlock_warning(safe_mutex_t *new_mutex, - safe_mutex_t *conflicting_mutex); - -void safe_mutex_global_init(void) -{ - pthread_mutex_init(&THR_LOCK_mutex,MY_MUTEX_INIT_FAST); - safe_mutex_id= safe_mutex_count= 0; - safe_mutex_deadlock_detector= 1; - -#ifdef SAFE_MUTEX_DETECT_DESTROY - safe_mutex_create_root= 0; -#endif -} - -static inline void remove_from_active_list(safe_mutex_t *mp) -{ - if (!(mp->active_flags & (MYF_NO_DEADLOCK_DETECTION | MYF_TRY_LOCK))) - { - /* Remove mutex from active mutex linked list */ - if (mp->next) - mp->next->prev= mp->prev; - if (mp->prev) - mp->prev->next= mp->next; - else - *my_thread_var_mutex_in_use()= mp->next; - } - mp->prev= mp->next= 0; -} - - -int safe_mutex_init(safe_mutex_t *mp, - const pthread_mutexattr_t *attr __attribute__((unused)), - const char *name, - myf my_flags, - const char *file, - uint line) -{ - DBUG_ENTER("safe_mutex_init"); - DBUG_PRINT("enter",("mutex: 0x%lx name: %s", (ulong) mp, name)); - bzero((char*) mp,sizeof(*mp)); - pthread_mutex_init(&mp->global,MY_MUTEX_INIT_ERRCHK); - pthread_mutex_init(&mp->mutex,attr); - /* Mark that mutex is initialized */ - mp->file= file; - mp->line= line; - /* Skip the very common '&' prefix from the autogenerated name */ - mp->name= name[0] == '&' ? name + 1 : name; - - if (safe_mutex_deadlock_detector && !( my_flags & MYF_NO_DEADLOCK_DETECTION)) - { - if (!my_multi_malloc(MY_FAE | MY_WME, - &mp->locked_mutex, sizeof(*mp->locked_mutex), - &mp->used_mutex, sizeof(*mp->used_mutex), NullS)) - { - /* Disable deadlock handling for this mutex */ - my_flags|= MYF_NO_DEADLOCK_DETECTION; - } - else - { - pthread_mutex_lock(&THR_LOCK_mutex); - mp->id= ++safe_mutex_id; - pthread_mutex_unlock(&THR_LOCK_mutex); - my_hash_init(mp->locked_mutex, &my_charset_bin, - 1000, - offsetof(safe_mutex_deadlock_t, id), - sizeof(mp->id), - 0, 0, HASH_UNIQUE); - my_hash_init(mp->used_mutex, &my_charset_bin, - 1000, - offsetof(safe_mutex_t, id), - sizeof(mp->id), - 0, 0, HASH_UNIQUE); - } - } - else - my_flags|= MYF_NO_DEADLOCK_DETECTION; - mp->create_flags= my_flags; - -#ifdef SAFE_MUTEX_DETECT_DESTROY - /* - Monitor the freeing of mutexes. This code depends on single thread init - and destroy - */ - if ((mp->info= (safe_mutex_info_t *) malloc(sizeof(safe_mutex_info_t)))) - { - struct st_safe_mutex_info_t *info= mp->info; - - info->init_file= file; - info->init_line= line; - info->prev= NULL; - info->next= NULL; - - pthread_mutex_lock(&THR_LOCK_mutex); - if ((info->next= safe_mutex_create_root)) - safe_mutex_create_root->prev= info; - safe_mutex_create_root= info; - safe_mutex_count++; - pthread_mutex_unlock(&THR_LOCK_mutex); - } -#else - thread_safe_increment(safe_mutex_count, &THR_LOCK_mutex); -#endif /* SAFE_MUTEX_DETECT_DESTROY */ - DBUG_RETURN(0); -} - - -int safe_mutex_lock(safe_mutex_t *mp, myf my_flags, const char *file, - uint line) -{ - int error; - DBUG_PRINT("mutex", ("%s (0x%lx) locking", mp->name ? mp->name : "Null", - (ulong) mp)); - if (!mp->file) - { - fprintf(stderr, - "safe_mutex: Trying to lock unitialized mutex at %s, line %d\n", - file, line); - fflush(stderr); - abort(); - } - - pthread_mutex_lock(&mp->global); - if (mp->count > 0) - { - /* - Check that we are not trying to lock mutex twice. This is an error - even if we are using 'try_lock' as it's not portably what happens - if you lock the mutex many times and this is in any case bad - behaviour that should not be encouraged - */ - if (pthread_equal(pthread_self(),mp->thread)) - { - fprintf(stderr, - "safe_mutex: Trying to lock mutex at %s, line %d, when the" - " mutex was already locked at %s, line %d in thread %s\n", - file,line,mp->file, mp->line, my_thread_name()); - fflush(stderr); - abort(); - } - } - pthread_mutex_unlock(&mp->global); - - /* - If we are imitating trylock(), we need to take special - precautions. - - - We cannot use pthread_mutex_lock() only since another thread can - overtake this thread and take the lock before this thread - causing pthread_mutex_trylock() to hang. In this case, we should - just return EBUSY. Hence, we use pthread_mutex_trylock() to be - able to return immediately. - - - We cannot just use trylock() and continue execution below, since - this would generate an error and abort execution if the thread - was overtaken and trylock() returned EBUSY . In this case, we - instead just return EBUSY, since this is the expected behaviour - of trylock(). - */ - if (my_flags & MYF_TRY_LOCK) - { - error= pthread_mutex_trylock(&mp->mutex); - if (error == EBUSY) - return error; - } - else - error= pthread_mutex_lock(&mp->mutex); - - if (error || (error=pthread_mutex_lock(&mp->global))) - { - fprintf(stderr,"Got error %d when trying to lock mutex %s at %s, line %d\n", - error, mp->name, file, line); - fflush(stderr); - abort(); - } - mp->thread= pthread_self(); - if (mp->count++) - { - fprintf(stderr,"safe_mutex: Error in thread libray: Got mutex %s at %s, " - "line %d more than 1 time\n", mp->name, file,line); - fflush(stderr); - abort(); - } - mp->file= file; - mp->line= line; - mp->active_flags= mp->create_flags | my_flags; - pthread_mutex_unlock(&mp->global); - - /* Deadlock detection */ - - mp->prev= mp->next= 0; - if (!(mp->active_flags & (MYF_TRY_LOCK | MYF_NO_DEADLOCK_DETECTION))) - { - safe_mutex_t **mutex_in_use= my_thread_var_mutex_in_use(); - - if (!mutex_in_use) - { - /* thread has not called my_thread_init() */ - mp->active_flags|= MYF_NO_DEADLOCK_DETECTION; - } - else - { - safe_mutex_t *mutex_root; - if ((mutex_root= *mutex_in_use)) /* If not first locked */ - { - /* - Protect locked_mutex against changes if a mutex is deleted - */ - pthread_mutex_lock(&THR_LOCK_mutex); - - if (! my_hash_search(mutex_root->locked_mutex, (uchar*) &mp->id, 0)) - { - safe_mutex_deadlock_t *deadlock; - safe_mutex_t *mutex; - - /* Create object to store mutex info */ - if (!(deadlock= my_malloc(sizeof(*deadlock), - MYF(MY_ZEROFILL | MY_WME | MY_FAE)))) - goto abort_loop; - deadlock->name= mp->name; - deadlock->id= mp->id; - deadlock->mutex= mp; - /* The following is useful for debugging wrong mutex usage */ - deadlock->file= file; - deadlock->line= line; - - /* Check if potential deadlock */ - mutex= mutex_root; - do - { - if (my_hash_search(mp->locked_mutex, (uchar*) &mutex->id, 0)) - { - print_deadlock_warning(mp, mutex); - /* Mark wrong usage to avoid future warnings for same error */ - deadlock->warning_only= 1; - add_to_locked_mutex(deadlock, mutex_root); - DBUG_ASSERT(deadlock->count > 0); - goto abort_loop; - } - } - while ((mutex= mutex->next)); - - /* - Copy current mutex and all mutex that has been locked - after current mutex (mp->locked_mutex) to all mutex that - was locked before previous mutex (mutex_root->used_mutex) - - For example if A->B would have been done before and we - are now locking (C) in B->C, then we would add C into - B->locked_mutex and A->locked_mutex - */ - my_hash_iterate(mutex_root->used_mutex, - (my_hash_walk_action) add_used_to_locked_mutex, - deadlock); - - /* - Copy all current mutex and all mutex locked after current one - into the prev mutex - */ - add_used_to_locked_mutex(mutex_root, deadlock); - DBUG_ASSERT(deadlock->count > 0); - } - abort_loop: - pthread_mutex_unlock(&THR_LOCK_mutex); - } - /* Link mutex into mutex_in_use list */ - if ((mp->next= *mutex_in_use)) - (*mutex_in_use)->prev= mp; - *mutex_in_use= mp; - } - } - - DBUG_PRINT("mutex", ("%s (0x%lx) locked", mp->name, (ulong) mp)); - return error; -} - - -int safe_mutex_unlock(safe_mutex_t *mp,const char *file, uint line) -{ - int error; - DBUG_PRINT("mutex", ("%s (0x%lx) unlocking", mp->name, (ulong) mp)); - pthread_mutex_lock(&mp->global); - if (mp->count == 0) - { - fprintf(stderr, - "safe_mutex: Trying to unlock mutex %s that wasn't locked at " - "%s, line %d\n" - "Last used at %s, line: %d\n", - mp->name ? mp->name : "Null", file, line, - mp->file ? mp->file : "Null", mp->line); - fflush(stderr); - abort(); - } - if (!pthread_equal(pthread_self(),mp->thread)) - { - fprintf(stderr, - "safe_mutex: Trying to unlock mutex %s at %s, line %d that was " - "locked by " - "another thread at: %s, line: %d\n", - mp->name, file, line, mp->file, mp->line); - fflush(stderr); - abort(); - } - mp->thread= 0; - mp->count--; - - remove_from_active_list(mp); - -#ifdef __WIN__ - pthread_mutex_unlock(&mp->mutex); - error=0; -#else - error=pthread_mutex_unlock(&mp->mutex); - if (error) - { - fprintf(stderr, - "safe_mutex: Got error: %d (%d) when trying to unlock mutex " - "%s at %s, line %d\n", error, errno, mp->name, file, line); - fflush(stderr); - abort(); - } -#endif /* __WIN__ */ - pthread_mutex_unlock(&mp->global); - return error; -} - - -int safe_cond_wait(pthread_cond_t *cond, safe_mutex_t *mp, const char *file, - uint line) -{ - int error; - safe_mutex_t save_state; - - pthread_mutex_lock(&mp->global); - if (mp->count == 0) - { - fprintf(stderr, - "safe_mutex: Trying to cond_wait on a unlocked mutex %s at %s, " - "line %d\n", - mp->name ? mp->name : "Null", file, line); - fflush(stderr); - abort(); - } - if (!pthread_equal(pthread_self(),mp->thread)) - { - fprintf(stderr, - "safe_mutex: Trying to cond_wait on a mutex %s at %s, line %d " - "that was locked by another thread at: %s, line: %d\n", - mp->name, file, line, mp->file, mp->line); - fflush(stderr); - abort(); - } - - if (mp->count-- != 1) - { - fprintf(stderr, - "safe_mutex: Count was %d on locked mutex %s at %s, line %d\n", - mp->count+1, mp->name, file, line); - fflush(stderr); - abort(); - } - save_state= *mp; - remove_from_active_list(mp); - pthread_mutex_unlock(&mp->global); - error=pthread_cond_wait(cond,&mp->mutex); - pthread_mutex_lock(&mp->global); - - if (error) - { - fprintf(stderr, - "safe_mutex: Got error: %d (%d) when doing a safe_mutex_wait on " - "%s at %s, line %d\n", error, errno, mp->name, file, line); - fflush(stderr); - abort(); - } - /* Restore state as it was before */ - mp->thread= save_state.thread; - mp->active_flags= save_state.active_flags; - mp->next= save_state.next; - mp->prev= save_state.prev; - - if (mp->count++) - { - fprintf(stderr, - "safe_mutex: Count was %d in thread 0x%lx when locking mutex %s " - "at %s, line %d\n", - mp->count-1, my_thread_dbug_id(), mp->name, file, line); - fflush(stderr); - abort(); - } - mp->file= file; - mp->line=line; - pthread_mutex_unlock(&mp->global); - return error; -} - - -int safe_cond_timedwait(pthread_cond_t *cond, safe_mutex_t *mp, - struct timespec *abstime, - const char *file, uint line) -{ - int error; - safe_mutex_t save_state; - - pthread_mutex_lock(&mp->global); - if (mp->count != 1 || !pthread_equal(pthread_self(),mp->thread)) - { - fprintf(stderr, - "safe_mutex: Trying to cond_wait at %s, line %d on a not hold " - "mutex %s\n", - file, line, mp->name ? mp->name : "Null"); - fflush(stderr); - abort(); - } - mp->count--; /* Mutex will be released */ - save_state= *mp; - remove_from_active_list(mp); - pthread_mutex_unlock(&mp->global); - error=pthread_cond_timedwait(cond,&mp->mutex,abstime); -#ifdef EXTRA_DEBUG - if (error && (error != EINTR && error != ETIMEDOUT && error != ETIME)) - { - fprintf(stderr, - "safe_mutex: Got error: %d (%d) when doing a safe_mutex_timedwait " - "on %s at %s, line %d\n", - error, errno, mp->name, file, line); - } -#endif - pthread_mutex_lock(&mp->global); - /* Restore state as it was before */ - mp->thread= save_state.thread; - mp->active_flags= save_state.active_flags; - mp->next= save_state.next; - mp->prev= save_state.prev; - - if (mp->count++) - { - fprintf(stderr, - "safe_mutex: Count was %d in thread 0x%lx when locking mutex " - "%s at %s, line %d (error: %d (%d))\n", - mp->count-1, my_thread_dbug_id(), mp->name, file, line, - error, error); - fflush(stderr); - abort(); - } - mp->file= file; - mp->line=line; - pthread_mutex_unlock(&mp->global); - return error; -} - - -int safe_mutex_destroy(safe_mutex_t *mp, const char *file, uint line) -{ - int error=0; - DBUG_ENTER("safe_mutex_destroy"); - DBUG_PRINT("enter", ("mutex: 0x%lx name: %s", (ulong) mp, mp->name)); - if (!mp->file) - { - fprintf(stderr, - "safe_mutex: Trying to destroy unitialized mutex at %s, line %d\n", - file, line); - fflush(stderr); - abort(); - } - if (mp->count != 0) - { - fprintf(stderr, - "safe_mutex: Trying to destroy a mutex %s that was locked at %s, " - "line %d at %s, line %d\n", - mp->name, mp->file, mp->line, file, line); - fflush(stderr); - abort(); - } - - /* Free all entries that points to this one */ - safe_mutex_free_deadlock_data(mp); - -#ifdef __WIN__ - pthread_mutex_destroy(&mp->global); - pthread_mutex_destroy(&mp->mutex); -#else - if (pthread_mutex_destroy(&mp->global)) - error=1; - if (pthread_mutex_destroy(&mp->mutex)) - error=1; -#endif - mp->file= 0; /* Mark destroyed */ - -#ifdef SAFE_MUTEX_DETECT_DESTROY - if (mp->info) - { - struct st_safe_mutex_info_t *info= mp->info; - pthread_mutex_lock(&THR_LOCK_mutex); - - if (info->prev) - info->prev->next = info->next; - else - safe_mutex_create_root = info->next; - if (info->next) - info->next->prev = info->prev; - safe_mutex_count--; - - pthread_mutex_unlock(&THR_LOCK_mutex); - free(info); - mp->info= NULL; /* Get crash if double free */ - } -#else - thread_safe_sub(safe_mutex_count, 1, &THR_LOCK_mutex); -#endif /* SAFE_MUTEX_DETECT_DESTROY */ - DBUG_RETURN(error); -} - - -/** - Free all data related to deadlock detection - - This is also useful together with safemalloc when you don't want to - have reports of not freed memory for mysys mutexes. -*/ - -void safe_mutex_free_deadlock_data(safe_mutex_t *mp) -{ - /* Free all entries that points to this one */ - if (!(mp->create_flags & MYF_NO_DEADLOCK_DETECTION)) - { - pthread_mutex_lock(&THR_LOCK_mutex); - my_hash_iterate(mp->used_mutex, - (my_hash_walk_action) remove_from_locked_mutex, - mp); - my_hash_iterate(mp->locked_mutex, - (my_hash_walk_action) remove_from_used_mutex, - mp); - pthread_mutex_unlock(&THR_LOCK_mutex); - - my_hash_free(mp->used_mutex); - my_hash_free(mp->locked_mutex); - my_free(mp->locked_mutex, 0); - mp->create_flags|= MYF_NO_DEADLOCK_DETECTION; - } -} - -/* - Free global resources and check that all mutex has been destroyed - - SYNOPSIS - safe_mutex_end() - file Print errors on this file - - NOTES - We can't use DBUG_PRINT() here as we have in my_end() disabled - DBUG handling before calling this function. - - In MySQL one may get one warning for a mutex created in my_thr_init.c - This is ok, as this thread may not yet have been exited. -*/ - -void safe_mutex_end(FILE *file __attribute__((unused))) -{ - if (!safe_mutex_count) /* safetly */ - pthread_mutex_destroy(&THR_LOCK_mutex); -#ifdef SAFE_MUTEX_DETECT_DESTROY - if (!file) - return; - - if (safe_mutex_count) - { - fprintf(file, "Warning: Not destroyed mutex: %lu\n", safe_mutex_count); - (void) fflush(file); - } - { - struct st_safe_mutex_info_t *ptr; - for (ptr= safe_mutex_create_root ; ptr ; ptr= ptr->next) - { - fprintf(file, "\tMutex %s initiated at line %4u in '%s'\n", - ptr->name, ptr->init_line, ptr->init_file); - (void) fflush(file); - } - } -#endif /* SAFE_MUTEX_DETECT_DESTROY */ -} - - -static my_bool add_used_to_locked_mutex(safe_mutex_t *used_mutex, - safe_mutex_deadlock_t *locked_mutex) -{ - /* Add mutex to all parent of the current mutex */ - if (!locked_mutex->warning_only) - { - (void) my_hash_iterate(locked_mutex->mutex->locked_mutex, - (my_hash_walk_action) add_to_locked_mutex, - used_mutex); - /* mark that locked_mutex is locked after used_mutex */ - (void) add_to_locked_mutex(locked_mutex, used_mutex); - } - return 0; -} - - -/** - register that locked_mutex was locked after current_mutex -*/ - -static my_bool add_to_locked_mutex(safe_mutex_deadlock_t *locked_mutex, - safe_mutex_t *current_mutex) -{ - DBUG_ENTER("add_to_locked_mutex"); - DBUG_PRINT("info", ("inserting 0x%lx into 0x%lx (id: %lu -> %lu)", - (ulong) locked_mutex, (long) current_mutex, - locked_mutex->id, current_mutex->id)); - if (my_hash_insert(current_mutex->locked_mutex, (uchar*) locked_mutex)) - { - /* Got mutex through two paths; ignore */ - DBUG_RETURN(0); - } - locked_mutex->count++; - if (my_hash_insert(locked_mutex->mutex->used_mutex, - (uchar*) current_mutex)) - { - DBUG_ASSERT(0); - } - DBUG_RETURN(0); -} - - -/** - Remove mutex from the locked mutex hash - @fn remove_from_used_mutex() - @param mp Mutex that has delete_mutex in it's locked_mutex hash - @param delete_mutex Mutex should be removed from the hash - - @notes - safe_mutex_deadlock_t entries in the locked hash are shared. - When counter goes to 0, we delete the safe_mutex_deadlock_t entry. -*/ - -static my_bool remove_from_locked_mutex(safe_mutex_t *mp, - safe_mutex_t *delete_mutex) -{ - safe_mutex_deadlock_t *found; - DBUG_ENTER("remove_from_locked_mutex"); - DBUG_PRINT("enter", ("delete_mutex: 0x%lx mutex: 0x%lx (id: %lu <- %lu)", - (ulong) delete_mutex, (ulong) mp, - delete_mutex->id, mp->id)); - - found= (safe_mutex_deadlock_t*) my_hash_search(mp->locked_mutex, - (uchar*) &delete_mutex->id, 0); - DBUG_ASSERT(found); - if (found) - { - if (my_hash_delete(mp->locked_mutex, (uchar*) found)) - { - DBUG_ASSERT(0); - } - if (!--found->count) - my_free(found, MYF(0)); - } - DBUG_RETURN(0); -} - -static my_bool remove_from_used_mutex(safe_mutex_deadlock_t *locked_mutex, - safe_mutex_t *mutex) -{ - DBUG_ENTER("remove_from_used_mutex"); - DBUG_PRINT("enter", ("delete_mutex: 0x%lx mutex: 0x%lx (id: %lu <- %lu)", - (ulong) mutex, (ulong) locked_mutex, - mutex->id, locked_mutex->id)); - if (my_hash_delete(locked_mutex->mutex->used_mutex, (uchar*) mutex)) - { - DBUG_ASSERT(0); - } - if (!--locked_mutex->count) - my_free(locked_mutex, MYF(0)); - DBUG_RETURN(0); -} - - -static void print_deadlock_warning(safe_mutex_t *new_mutex, - safe_mutex_t *parent_mutex) -{ - safe_mutex_t *mutex_root; - DBUG_ENTER("print_deadlock_warning"); - DBUG_PRINT("enter", ("mutex: %s parent: %s", - new_mutex->name, parent_mutex->name)); - - fprintf(stderr, "safe_mutex: Found wrong usage of mutex " - "'%s' and '%s'\n", - parent_mutex->name, new_mutex->name); - DBUG_PRINT("info", ("safe_mutex: Found wrong usage of mutex " - "'%s' and '%s'", - parent_mutex->name, new_mutex->name)); - fprintf(stderr, "Mutex currently locked (in reverse order):\n"); - DBUG_PRINT("info", ("Mutex currently locked (in reverse order):")); - fprintf(stderr, "%-32.32s %s line %u\n", new_mutex->name, new_mutex->file, - new_mutex->line); - DBUG_PRINT("info", ("%-32.32s %s line %u\n", new_mutex->name, - new_mutex->file, new_mutex->line)); - for (mutex_root= *my_thread_var_mutex_in_use() ; - mutex_root; - mutex_root= mutex_root->next) - { - fprintf(stderr, "%-32.32s %s line %u\n", mutex_root->name, - mutex_root->file, mutex_root->line); - DBUG_PRINT("info", ("%-32.32s %s line %u", mutex_root->name, - mutex_root->file, mutex_root->line)); - } - fflush(stderr); - DBUG_VOID_RETURN; -} - - -#endif /* THREAD && SAFE_MUTEX */ - -#if defined(THREAD) && defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX) - -#include "mysys_priv.h" -#include "my_static.h" -#include <m_string.h> - -#include <m_ctype.h> -#include <hash.h> -#include <myisampack.h> -#include <mysys_err.h> -#include <my_sys.h> - -#undef pthread_mutex_t -#undef pthread_mutex_init -#undef pthread_mutex_lock -#undef pthread_mutex_trylock -#undef pthread_mutex_unlock -#undef pthread_mutex_destroy -#undef pthread_cond_wait -#undef pthread_cond_timedwait - -ulong mutex_delay(ulong delayloops) -{ - ulong i; - volatile ulong j; - - j = 0; - - for (i = 0; i < delayloops * 50; i++) - j += i; - - return(j); -} - -#define MY_PTHREAD_FASTMUTEX_SPINS 8 -#define MY_PTHREAD_FASTMUTEX_DELAY 4 - -static int cpu_count= 0; - -int my_pthread_fastmutex_init(my_pthread_fastmutex_t *mp, - const pthread_mutexattr_t *attr) -{ - if ((cpu_count > 1) && (attr == MY_MUTEX_INIT_FAST)) - mp->spins= MY_PTHREAD_FASTMUTEX_SPINS; - else - mp->spins= 0; - mp->rng_state= 1; - return pthread_mutex_init(&mp->mutex, attr); -} - -/** - Park-Miller random number generator. A simple linear congruential - generator that operates in multiplicative group of integers modulo n. - - x_{k+1} = (x_k g) mod n - - Popular pair of parameters: n = 2^32 − 5 = 4294967291 and g = 279470273. - The period of the generator is about 2^31. - Largest value that can be returned: 2147483646 (RAND_MAX) - - Reference: - - S. K. Park and K. W. Miller - "Random number generators: good ones are hard to find" - Commun. ACM, October 1988, Volume 31, No 10, pages 1192-1201. -*/ - -static double park_rng(my_pthread_fastmutex_t *mp) -{ - mp->rng_state= ((my_ulonglong)mp->rng_state * 279470273U) % 4294967291U; - return (mp->rng_state / 2147483647.0); -} - -int my_pthread_fastmutex_lock(my_pthread_fastmutex_t *mp) -{ - int res; - uint i; - uint maxdelay= MY_PTHREAD_FASTMUTEX_DELAY; - - for (i= 0; i < mp->spins; i++) - { - res= pthread_mutex_trylock(&mp->mutex); - - if (res == 0) - return 0; - - if (res != EBUSY) - return res; - - mutex_delay(maxdelay); - maxdelay += park_rng(mp) * MY_PTHREAD_FASTMUTEX_DELAY + 1; - } - return pthread_mutex_lock(&mp->mutex); -} - - -void fastmutex_global_init(void) -{ -#ifdef _SC_NPROCESSORS_CONF - cpu_count= sysconf(_SC_NPROCESSORS_CONF); -#endif -} - -#endif /* defined(THREAD) && defined(MY_PTHREAD_FASTMUTEX) && !defined(SAFE_MUTEX) */ |