diff options
Diffstat (limited to 'mysys/thr_lock.c')
| -rw-r--r-- | mysys/thr_lock.c | 602 |
1 files changed, 255 insertions, 347 deletions
diff --git a/mysys/thr_lock.c b/mysys/thr_lock.c index 97aa51b3ddf..bc2a29b4296 100644 --- a/mysys/thr_lock.c +++ b/mysys/thr_lock.c @@ -1,5 +1,4 @@ -/* - Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. +/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. 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 @@ -12,8 +11,7 @@ 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA -*/ + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ /* Read and write locks for Posix threads. All tread must acquire @@ -31,7 +29,6 @@ TL_READ_WITH_SHARED_LOCKS TL_READ_HIGH_PRIORITY # High priority read TL_READ_NO_INSERT # Read without concurrent inserts TL_WRITE_ALLOW_WRITE # Write lock that allows other writers -TL_WRITE_ALLOW_READ # Write lock, but allow reading TL_WRITE_CONCURRENT_INSERT # Insert that can be mixed when selects TL_WRITE_DELAYED # Used by delayed insert @@ -43,7 +40,7 @@ TL_WRITE_ONLY # High priority write Locks are prioritized according to: -WRITE_ALLOW_WRITE, WRITE_ALLOW_READ, WRITE_CONCURRENT_INSERT, WRITE_DELAYED, +WRITE_ALLOW_WRITE, WRITE_CONCURRENT_INSERT, WRITE_DELAYED, WRITE_LOW_PRIORITY, READ, WRITE, READ_HIGH_PRIORITY and WRITE_ONLY Locks in the same privilege level are scheduled in first-in-first-out order. @@ -66,9 +63,8 @@ get_status: In MyISAM this stores the number of rows and size of the datafile for concurrent reads. -The lock algorithm allows one to have one TL_WRITE_ALLOW_READ, -TL_WRITE_CONCURRENT_INSERT or one TL_WRITE_DELAYED lock at the same time as -multiple read locks. +The lock algorithm allows one to have one TL_WRITE_CONCURRENT_INSERT or +one TL_WRITE_DELAYED lock at the same time as multiple read locks. */ @@ -78,14 +74,12 @@ multiple read locks. #include "mysys_priv.h" -#ifdef THREAD #include "thr_lock.h" #include <m_string.h> #include <errno.h> my_bool thr_lock_inited=0; ulong locks_immediate = 0L, locks_waited = 0L; -ulong table_lock_wait_timeout; enum thr_lock_type thr_upgraded_concurrent_insert_lock = TL_WRITE; /* The following constants are only for debug output */ @@ -96,7 +90,17 @@ enum thr_lock_type thr_upgraded_concurrent_insert_lock = TL_WRITE; LIST *thr_lock_thread_list; /* List of threads in use */ ulong max_write_lock_count= ~(ulong) 0L; -static inline pthread_cond_t *get_cond(void) +static void (*before_lock_wait)(void)= 0; +static void (*after_lock_wait)(void)= 0; + +void thr_set_lock_wait_callback(void (*before_wait)(void), + void (*after_wait)(void)) +{ + before_lock_wait= before_wait; + after_lock_wait= after_wait; +} + +static inline mysql_cond_t *get_cond(void) { return &my_thread_var->suspend; } @@ -112,7 +116,7 @@ my_bool init_thr_lock() } static inline my_bool -thr_lock_owner_equal(THR_LOCK_OWNER *rhs, THR_LOCK_OWNER *lhs) +thr_lock_owner_equal(THR_LOCK_INFO *rhs, THR_LOCK_INFO *lhs) { return rhs == lhs; } @@ -127,7 +131,7 @@ static int check_lock(struct st_lock_list *list, const char* lock_type, { THR_LOCK_DATA *data,**prev; uint count=0; - THR_LOCK_OWNER *UNINIT_VAR(first_owner); + THR_LOCK_INFO *UNINIT_VAR(first_owner); prev= &list->data; if (list->data) @@ -240,7 +244,6 @@ static void check_locks(THR_LOCK *lock, const char *where, (((lock->write_wait.data->type == TL_WRITE_CONCURRENT_INSERT || lock->write_wait.data->type == TL_WRITE_ALLOW_WRITE) && !lock->read_no_write_count) || - lock->write_wait.data->type == TL_WRITE_ALLOW_READ || (lock->write_wait.data->type == TL_WRITE_DELAYED && !lock->read.data))) { @@ -317,16 +320,16 @@ void thr_lock_init(THR_LOCK *lock) { DBUG_ENTER("thr_lock_init"); bzero((char*) lock,sizeof(*lock)); - VOID(pthread_mutex_init(&lock->mutex,MY_MUTEX_INIT_FAST)); + mysql_mutex_init(key_THR_LOCK_mutex, &lock->mutex, MY_MUTEX_INIT_FAST); lock->read.last= &lock->read.data; lock->read_wait.last= &lock->read_wait.data; lock->write_wait.last= &lock->write_wait.data; lock->write.last= &lock->write.data; - pthread_mutex_lock(&THR_LOCK_lock); /* Add to locks in use */ + mysql_mutex_lock(&THR_LOCK_lock); /* Add to locks in use */ lock->list.data=(void*) lock; thr_lock_thread_list=list_add(thr_lock_thread_list,&lock->list); - pthread_mutex_unlock(&THR_LOCK_lock); + mysql_mutex_unlock(&THR_LOCK_lock); DBUG_VOID_RETURN; } @@ -334,10 +337,10 @@ void thr_lock_init(THR_LOCK *lock) void thr_lock_delete(THR_LOCK *lock) { DBUG_ENTER("thr_lock_delete"); - pthread_mutex_lock(&THR_LOCK_lock); + mysql_mutex_lock(&THR_LOCK_lock); thr_lock_thread_list=list_delete(thr_lock_thread_list,&lock->list); - pthread_mutex_unlock(&THR_LOCK_lock); - pthread_mutex_destroy(&lock->mutex); + mysql_mutex_unlock(&THR_LOCK_lock); + mysql_mutex_destroy(&lock->mutex); DBUG_VOID_RETURN; } @@ -347,7 +350,6 @@ void thr_lock_info_init(THR_LOCK_INFO *info) struct st_my_thread_var *tmp= my_thread_var; info->thread= tmp->pthread_self; info->thread_id= tmp->id; - info->n_cursors= 0; } /* Initialize a lock instance */ @@ -363,7 +365,7 @@ void thr_lock_data_init(THR_LOCK *lock,THR_LOCK_DATA *data, void *param) static inline my_bool -have_old_read_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner) +has_old_lock(THR_LOCK_DATA *data, THR_LOCK_INFO *owner) { for ( ; data ; data=data->next) { @@ -390,13 +392,13 @@ static void wake_up_waiters(THR_LOCK *lock); static enum enum_thr_lock_result wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data, - my_bool in_wait_list) + my_bool in_wait_list, ulong lock_wait_timeout) { struct st_my_thread_var *thread_var= my_thread_var; - pthread_cond_t *cond= &thread_var->suspend; + mysql_cond_t *cond= &thread_var->suspend; struct timespec wait_timeout; enum enum_thr_lock_result result= THR_LOCK_ABORTED; - my_bool can_deadlock= test(data->owner->info->n_cursors); + const char *old_proc_info; DBUG_ENTER("wait_for_lock"); /* @@ -435,14 +437,26 @@ wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data, thread_var->current_cond= cond; data->cond= cond; - if (can_deadlock) - set_timespec(wait_timeout, table_lock_wait_timeout); + old_proc_info= proc_info_hook(NULL, "Waiting for table level lock", + __func__, __FILE__, __LINE__); + + /* + Since before_lock_wait potentially can create more threads to + scheduler work for, we don't want to call the before_lock_wait + callback unless it will really start to wait. + + For similar reasons, we do not want to call before_lock_wait and + after_lock_wait for each lap around the loop, so we restrict + ourselves to call it before_lock_wait once before starting to wait + and once after the thread has exited the wait loop. + */ + if ((!thread_var->abort || in_wait_list) && before_lock_wait) + (*before_lock_wait)(); + + set_timespec(wait_timeout, lock_wait_timeout); while (!thread_var->abort || in_wait_list) { - int rc= (can_deadlock ? - pthread_cond_timedwait(cond, &data->lock->mutex, - &wait_timeout) : - pthread_cond_wait(cond, &data->lock->mutex)); + int rc= mysql_cond_timedwait(cond, &data->lock->mutex, &wait_timeout); /* We must break the wait if one of the following occurs: - the connection has been aborted (!thread_var->abort), but @@ -470,6 +484,14 @@ wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data, /* purecov: end */ } } + + /* + We call the after_lock_wait callback once the wait loop has + finished. + */ + if (after_lock_wait) + (*after_lock_wait)(); + DBUG_PRINT("thr_lock", ("aborted: %d in_wait_list: %d", thread_var->abort, in_wait_list)); @@ -498,34 +520,36 @@ wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data, (*data->lock->get_status)(data->status_param, 0); check_locks(data->lock,"got wait_for_lock",0); } - pthread_mutex_unlock(&data->lock->mutex); + mysql_mutex_unlock(&data->lock->mutex); /* The following must be done after unlock of lock->mutex */ - pthread_mutex_lock(&thread_var->mutex); + mysql_mutex_lock(&thread_var->mutex); thread_var->current_mutex= 0; thread_var->current_cond= 0; - pthread_mutex_unlock(&thread_var->mutex); + mysql_mutex_unlock(&thread_var->mutex); + + proc_info_hook(NULL, old_proc_info, __func__, __FILE__, __LINE__); + DBUG_RETURN(result); } enum enum_thr_lock_result -thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, - enum thr_lock_type lock_type) +thr_lock(THR_LOCK_DATA *data, THR_LOCK_INFO *owner, + enum thr_lock_type lock_type, ulong lock_wait_timeout) { THR_LOCK *lock=data->lock; enum enum_thr_lock_result result= THR_LOCK_SUCCESS; struct st_lock_list *wait_queue; - THR_LOCK_DATA *lock_owner; DBUG_ENTER("thr_lock"); data->next=0; data->cond=0; /* safety */ data->type=lock_type; data->owner= owner; /* Must be reset ! */ - VOID(pthread_mutex_lock(&lock->mutex)); + mysql_mutex_lock(&lock->mutex); DBUG_PRINT("lock",("data: 0x%lx thread: 0x%lx lock: 0x%lx type: %d", - (long) data, data->owner->info->thread_id, + (long) data, data->owner->thread_id, (long) lock, (int) lock_type)); check_locks(lock,(uint) lock_type <= (uint) TL_READ_NO_INSERT ? "enter read_lock" : "enter write_lock",0); @@ -534,22 +558,39 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, /* Request for READ lock */ if (lock->write.data) { - /* We can allow a read lock even if there is already a write lock - on the table in one the following cases: - - This thread alread have a write lock on the table - - The write lock is TL_WRITE_ALLOW_READ or TL_WRITE_DELAYED - and the read lock is TL_READ_HIGH_PRIORITY or TL_READ - - The write lock is TL_WRITE_CONCURRENT_INSERT or TL_WRITE_ALLOW_WRITE - and the read lock is not TL_READ_NO_INSERT + /* + We can allow a read lock even if there is already a + write lock on the table if they are owned by the same + thread or if they satisfy the following lock + compatibility matrix: + + Request + /------- + H|++++ WRITE_ALLOW_WRITE + e|+++- WRITE_CONCURRENT_INSERT + l|++++ WRITE_DELAYED + d |||| + |||\= READ_NO_INSERT + ||\ = READ_HIGH_PRIORITY + |\ = READ_WITH_SHARED_LOCKS + \ = READ + + + + = Request can be satisified. + - = Request cannot be satisified. + + READ_NO_INSERT and WRITE_ALLOW_WRITE should in principle + be incompatible. However this will cause starvation of + LOCK TABLE READ in InnoDB under high write load. + See Bug#42147 for more information. */ DBUG_PRINT("lock",("write locked 1 by thread: 0x%lx", - lock->write.data->owner->info->thread_id)); + lock->write.data->owner->thread_id)); if (thr_lock_owner_equal(data->owner, lock->write.data->owner) || (lock->write.data->type <= TL_WRITE_DELAYED && (((int) lock_type <= (int) TL_READ_HIGH_PRIORITY) || - (lock->write.data->type != TL_WRITE_CONCURRENT_INSERT && - lock->write.data->type != TL_WRITE_ALLOW_READ)))) + (lock->write.data->type != TL_WRITE_CONCURRENT_INSERT)))) { /* Already got a write lock */ (*lock->read.last)=data; /* Add to running FIFO */ data->prev=lock->read.last; @@ -573,7 +614,7 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, else if (!lock->write_wait.data || lock->write_wait.data->type <= TL_WRITE_LOW_PRIORITY || lock_type == TL_READ_HIGH_PRIORITY || - have_old_read_lock(lock->read.data, data->owner)) + has_old_lock(lock->read.data, data->owner)) /* Has old read lock */ { /* No important write-locks */ (*lock->read.last)=data; /* Add to running FIFO */ data->prev=lock->read.last; @@ -603,14 +644,7 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, result= THR_LOCK_ABORTED; /* Can't wait for this one */ goto end; } - /* - if there is a TL_WRITE_ALLOW_READ lock, we have to wait for a lock - (TL_WRITE_ALLOW_READ is used for ALTER TABLE in MySQL) - */ - if ((!lock->write.data || - lock->write.data->type != TL_WRITE_ALLOW_READ) && - !have_specific_lock(lock->write_wait.data,TL_WRITE_ALLOW_READ) && - (lock->write.data || lock->read.data)) + if (lock->write.data || lock->read.data) { /* Add delayed write lock to write_wait queue, and return at once */ (*lock->write_wait.last)=data; @@ -632,6 +666,7 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, { if (lock->write.data->type == TL_WRITE_ONLY) { + /* purecov: begin tested */ /* Allow lock owner to bypass TL_WRITE_ONLY. */ if (!thr_lock_owner_equal(data->owner, lock->write.data->owner)) { @@ -640,17 +675,47 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, result= THR_LOCK_ABORTED; /* Can't wait for this one */ goto end; } + /* purecov: end */ } /* - The following test will not work if the old lock was a - TL_WRITE_ALLOW_WRITE, TL_WRITE_ALLOW_READ or TL_WRITE_DELAYED in - the same thread, but this will never happen within MySQL. + The idea is to allow us to get a lock at once if we already have + a write lock or if there is no pending write locks and if all + write locks are of TL_WRITE_ALLOW_WRITE type. + + Note that, since lock requests for the same table are sorted in + such way that requests with higher thr_lock_type value come first + (with one exception (*)), lock being requested usually (**) has + equal or "weaker" type than one which thread might have already + acquired. + *) The only exception to this rule is case when type of old lock + is TL_WRITE_LOW_PRIORITY and type of new lock is changed inside + of thr_lock() from TL_WRITE_CONCURRENT_INSERT to TL_WRITE since + engine turns out to be not supporting concurrent inserts. + Note that since TL_WRITE has the same compatibility rules as + TL_WRITE_LOW_PRIORITY (their only difference is priority), + it is OK to grant new lock without additional checks in such + situation. + **) The exceptions are situations when: + - when old lock type is TL_WRITE_DELAYED + But these should never happen within MySQL. + Therefore it is OK to allow acquiring write lock on the table if + this thread already holds some write lock on it. + + (INSERT INTO t1 VALUES (f1()), where f1() is stored function which + tries to update t1, is an example of statement which requests two + different types of write lock on the same table). */ - if (thr_lock_owner_equal(data->owner, lock->write.data->owner) || - (lock_type == TL_WRITE_ALLOW_WRITE && - !lock->write_wait.data && - lock->write.data->type == TL_WRITE_ALLOW_WRITE)) + DBUG_ASSERT(! has_old_lock(lock->write.data, data->owner) || + ((lock_type <= lock->write.data->type || + (lock_type == TL_WRITE && + lock->write.data->type == TL_WRITE_LOW_PRIORITY)) && + lock->write.data->type != TL_WRITE_DELAYED)); + + if ((lock_type == TL_WRITE_ALLOW_WRITE && + ! lock->write_wait.data && + lock->write.data->type == TL_WRITE_ALLOW_WRITE) || + has_old_lock(lock->write.data, data->owner)) { /* We have already got a write lock or all locks are @@ -670,7 +735,7 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, goto end; } DBUG_PRINT("lock",("write locked 2 by thread: 0x%lx", - lock->write.data->owner->info->thread_id)); + lock->write.data->owner->thread_id)); } else { @@ -706,27 +771,14 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_OWNER *owner, } } DBUG_PRINT("lock",("write locked 3 by thread: 0x%lx type: %d", - lock->read.data->owner->info->thread_id, data->type)); + lock->read.data->owner->thread_id, data->type)); } wait_queue= &lock->write_wait; } - /* - Try to detect a trivial deadlock when using cursors: attempt to - lock a table that is already locked by an open cursor within the - same connection. lock_owner can be zero if we succumbed to a high - priority writer in the write_wait queue. - */ - lock_owner= lock->read.data ? lock->read.data : lock->write.data; - if (lock_owner && lock_owner->owner->info == owner->info) - { - DBUG_PRINT("lock",("deadlock")); - result= THR_LOCK_DEADLOCK; - goto end; - } /* Can't get lock yet; Wait for it */ - DBUG_RETURN(wait_for_lock(wait_queue, data, 0)); + DBUG_RETURN(wait_for_lock(wait_queue, data, 0, lock_wait_timeout)); end: - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_RETURN(result); } @@ -748,7 +800,7 @@ static inline void free_all_read_locks(THR_LOCK *lock, do { - pthread_cond_t *cond=data->cond; + mysql_cond_t *cond= data->cond; if ((int) data->type == (int) TL_READ_NO_INSERT) { if (using_concurrent_insert) @@ -770,10 +822,10 @@ static inline void free_all_read_locks(THR_LOCK *lock, } /* purecov: begin inspected */ DBUG_PRINT("lock",("giving read lock to thread: 0x%lx", - data->owner->info->thread_id)); + data->owner->thread_id)); /* purecov: end */ data->cond=0; /* Mark thread free */ - VOID(pthread_cond_signal(cond)); + mysql_cond_signal(cond); } while ((data=data->next)); *lock->read_wait.last=0; if (!lock->read_wait.data) @@ -789,8 +841,8 @@ void thr_unlock(THR_LOCK_DATA *data) enum thr_lock_type lock_type=data->type; DBUG_ENTER("thr_unlock"); DBUG_PRINT("lock",("data: 0x%lx thread: 0x%lx lock: 0x%lx", - (long) data, data->owner->info->thread_id, (long) lock)); - pthread_mutex_lock(&lock->mutex); + (long) data, data->owner->thread_id, (long) lock)); + mysql_mutex_lock(&lock->mutex); check_locks(lock,"start of release lock",0); if (((*data->prev)=data->next)) /* remove from lock-list */ @@ -822,7 +874,7 @@ void thr_unlock(THR_LOCK_DATA *data) data->type=TL_UNLOCK; /* Mark unlocked */ check_locks(lock,"after releasing lock",1); wake_up_waiters(lock); - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_VOID_RETURN; } @@ -878,12 +930,12 @@ static void wake_up_waiters(THR_LOCK *lock) data->type=TL_WRITE; /* Upgrade lock */ /* purecov: begin inspected */ DBUG_PRINT("lock",("giving write lock of type %d to thread: 0x%lx", - data->type, data->owner->info->thread_id)); + data->type, data->owner->thread_id)); /* purecov: end */ { - pthread_cond_t *cond=data->cond; + mysql_cond_t *cond= data->cond; data->cond=0; /* Mark thread free */ - VOID(pthread_cond_signal(cond)); /* Start waiting thread */ + mysql_cond_signal(cond); /* Start waiting thread */ } if (data->type != TL_WRITE_ALLOW_WRITE || !lock->write_wait.data || @@ -924,7 +976,7 @@ static void wake_up_waiters(THR_LOCK *lock) goto end; } do { - pthread_cond_t *cond=data->cond; + mysql_cond_t *cond= data->cond; if (((*data->prev)=data->next)) /* remove from wait-list */ data->next->prev= data->prev; else @@ -934,7 +986,7 @@ static void wake_up_waiters(THR_LOCK *lock) lock->write.last= &data->next; data->next=0; /* Only one write lock */ data->cond=0; /* Mark thread free */ - VOID(pthread_cond_signal(cond)); /* Start waiting thread */ + mysql_cond_signal(cond); /* Start waiting thread */ } while (lock_type == TL_WRITE_ALLOW_WRITE && (data=lock->write_wait.data) && data->type == TL_WRITE_ALLOW_WRITE); @@ -983,7 +1035,8 @@ static void sort_locks(THR_LOCK_DATA **data,uint count) enum enum_thr_lock_result -thr_multi_lock(THR_LOCK_DATA **data, uint count, THR_LOCK_OWNER *owner) +thr_multi_lock(THR_LOCK_DATA **data, uint count, THR_LOCK_INFO *owner, + ulong lock_wait_timeout) { THR_LOCK_DATA **pos,**end; DBUG_ENTER("thr_multi_lock"); @@ -993,23 +1046,56 @@ thr_multi_lock(THR_LOCK_DATA **data, uint count, THR_LOCK_OWNER *owner) /* lock everything */ for (pos=data,end=data+count; pos < end ; pos++) { - enum enum_thr_lock_result result= thr_lock(*pos, owner, (*pos)->type); + enum enum_thr_lock_result result= thr_lock(*pos, owner, (*pos)->type, + lock_wait_timeout); if (result != THR_LOCK_SUCCESS) { /* Aborted */ thr_multi_unlock(data,(uint) (pos-data)); DBUG_RETURN(result); } + DEBUG_SYNC_C("thr_multi_lock_after_thr_lock"); #ifdef MAIN printf("Thread: %s Got lock: 0x%lx type: %d\n",my_thread_name(), (long) pos[0]->lock, pos[0]->type); fflush(stdout); #endif } - /* - Ensure that all get_locks() have the same status - If we lock the same table multiple times, we must use the same - status_param! - */ + thr_lock_merge_status(data, count); + DBUG_RETURN(THR_LOCK_SUCCESS); +} + + +/** + Ensure that all locks for a given table have the same + status_param. + + This is a MyISAM and possibly Maria specific crutch. MyISAM + engine stores data file length, record count and other table + properties in status_param member of handler. When a table is + locked, connection-local copy is made from a global copy + (myisam_share) by mi_get_status(). When a table is unlocked, + the changed status is transferred back to the global share by + mi_update_status(). + + One thing MyISAM doesn't do is to ensure that when the same + table is opened twice in a connection all instances share the + same status_param. This is necessary, however: for one, to keep + all instances of a connection "on the same page" with regard to + the current state of the table. For other, unless this is done, + myisam_share will always get updated from the last unlocked + instance (in mi_update_status()), and when this instance was not + the one that was used to update data, records may be lost. + + For each table, this function looks up the last lock_data in the + list of acquired locks, and makes sure that all other instances + share status_param with it. +*/ + +void +thr_lock_merge_status(THR_LOCK_DATA **data, uint count) +{ #if !defined(DONT_USE_RW_LOCKS) + THR_LOCK_DATA **pos= data; + THR_LOCK_DATA **end= data + count; if (count > 1) { THR_LOCK_DATA *last_lock= end[-1]; @@ -1051,7 +1137,6 @@ thr_multi_lock(THR_LOCK_DATA **data, uint count, THR_LOCK_OWNER *owner) } while (pos != data); } #endif - DBUG_RETURN(THR_LOCK_SUCCESS); } /* free all locks */ @@ -1074,7 +1159,7 @@ void thr_multi_unlock(THR_LOCK_DATA **data,uint count) else { DBUG_PRINT("lock",("Free lock: data: 0x%lx thread: 0x%lx lock: 0x%lx", - (long) *pos, (*pos)->owner->info->thread_id, + (long) *pos, (*pos)->owner->thread_id, (long) (*pos)->lock)); } } @@ -1090,19 +1175,19 @@ void thr_abort_locks(THR_LOCK *lock, my_bool upgrade_lock) { THR_LOCK_DATA *data; DBUG_ENTER("thr_abort_locks"); - pthread_mutex_lock(&lock->mutex); + mysql_mutex_lock(&lock->mutex); for (data=lock->read_wait.data; data ; data=data->next) { data->type=TL_UNLOCK; /* Mark killed */ /* It's safe to signal the cond first: we're still holding the mutex. */ - pthread_cond_signal(data->cond); + mysql_cond_signal(data->cond); data->cond=0; /* Removed from list */ } for (data=lock->write_wait.data; data ; data=data->next) { data->type=TL_UNLOCK; - pthread_cond_signal(data->cond); + mysql_cond_signal(data->cond); data->cond=0; } lock->read_wait.last= &lock->read_wait.data; @@ -1110,7 +1195,7 @@ void thr_abort_locks(THR_LOCK *lock, my_bool upgrade_lock) lock->read_wait.data=lock->write_wait.data=0; if (upgrade_lock && lock->write.data) lock->write.data->type=TL_WRITE_ONLY; - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_VOID_RETURN; } @@ -1127,16 +1212,16 @@ my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread_id) my_bool found= FALSE; DBUG_ENTER("thr_abort_locks_for_thread"); - pthread_mutex_lock(&lock->mutex); + mysql_mutex_lock(&lock->mutex); for (data= lock->read_wait.data; data ; data= data->next) { - if (data->owner->info->thread_id == thread_id) /* purecov: tested */ + if (data->owner->thread_id == thread_id) /* purecov: tested */ { DBUG_PRINT("info",("Aborting read-wait lock")); data->type= TL_UNLOCK; /* Mark killed */ /* It's safe to signal the cond first: we're still holding the mutex. */ found= TRUE; - pthread_cond_signal(data->cond); + mysql_cond_signal(data->cond); data->cond= 0; /* Removed from list */ if (((*data->prev)= data->next)) @@ -1147,12 +1232,12 @@ my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread_id) } for (data= lock->write_wait.data; data ; data= data->next) { - if (data->owner->info->thread_id == thread_id) /* purecov: tested */ + if (data->owner->thread_id == thread_id) /* purecov: tested */ { DBUG_PRINT("info",("Aborting write-wait lock")); data->type= TL_UNLOCK; found= TRUE; - pthread_cond_signal(data->cond); + mysql_cond_signal(data->cond); data->cond= 0; if (((*data->prev)= data->next)) @@ -1162,7 +1247,7 @@ my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread_id) } } wake_up_waiters(lock); - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_RETURN(found); } @@ -1180,10 +1265,7 @@ my_bool thr_abort_locks_for_thread(THR_LOCK *lock, my_thread_id thread_id) occurs also other waiters, both readers and writers can be allowed to start. The previous lock is often TL_WRITE_ONLY but can also be - TL_WRITE and TL_WRITE_ALLOW_READ. The normal downgrade variants are - TL_WRITE_ONLY => TL_WRITE_ALLOW_READ After a short exclusive lock - TL_WRITE_ALLOW_READ => TL_WRITE_ALLOW_WRITE After discovering that the - operation didn't need such a high lock. + TL_WRITE. The normal downgrade variants are: TL_WRITE_ONLY => TL_WRITE after a short exclusive lock while holding a write table lock TL_WRITE_ONLY => TL_WRITE_ALLOW_WRITE After a short exclusive lock after @@ -1204,194 +1286,31 @@ void thr_downgrade_write_lock(THR_LOCK_DATA *in_data, #ifndef DBUG_OFF enum thr_lock_type old_lock_type= in_data->type; #endif -#ifdef TO_BE_REMOVED - THR_LOCK_DATA *data, *next; - bool start_writers= FALSE; - bool start_readers= FALSE; -#endif DBUG_ENTER("thr_downgrade_write_only_lock"); - pthread_mutex_lock(&lock->mutex); + mysql_mutex_lock(&lock->mutex); DBUG_ASSERT(old_lock_type == TL_WRITE_ONLY); DBUG_ASSERT(old_lock_type > new_lock_type); in_data->type= new_lock_type; check_locks(lock,"after downgrading lock",0); -#if TO_BE_REMOVED - switch (old_lock_type) - { - case TL_WRITE_ONLY: - case TL_WRITE: - case TL_WRITE_LOW_PRIORITY: - /* - Previous lock was exclusive we are now ready to start up most waiting - threads. - */ - switch (new_lock_type) - { - case TL_WRITE_ALLOW_READ: - /* Still cannot start WRITE operations. Can only start readers. */ - start_readers= TRUE; - break; - case TL_WRITE: - case TL_WRITE_LOW_PRIORITY: - /* - Still cannot start anything, but new requests are no longer - aborted. - */ - break; - case TL_WRITE_ALLOW_WRITE: - /* - We can start both writers and readers. - */ - start_writers= TRUE; - start_readers= TRUE; - break; - case TL_WRITE_CONCURRENT_INSERT: - case TL_WRITE_DELAYED: - /* - This routine is not designed for those. Lock will be downgraded - but no start of waiters will occur. This is not the optimal but - should be a correct behaviour. - */ - break; - default: - DBUG_ASSERT(0); - } - break; - case TL_WRITE_DELAYED: - case TL_WRITE_CONCURRENT_INSERT: - /* - This routine is not designed for those. Lock will be downgraded - but no start of waiters will occur. This is not the optimal but - should be a correct behaviour. - */ - break; - case TL_WRITE_ALLOW_READ: - DBUG_ASSERT(new_lock_type == TL_WRITE_ALLOW_WRITE); - /* - Previously writers were not allowed to start, now it is ok to - start them again. Readers are already allowed so no reason to - handle them. - */ - start_writers= TRUE; - break; - default: - DBUG_ASSERT(0); - break; - } - if (start_writers) - { - /* - At this time the only active writer can be ourselves. Thus we need - not worry about that there are other concurrent write operations - active on the table. Thus we only need to worry about starting - waiting operations. - We also only come here with TL_WRITE_ALLOW_WRITE as the new - lock type, thus we can start other writers also of the same type. - If we find a lock at exclusive level >= TL_WRITE_LOW_PRIORITY we - don't start any more operations that would be mean those operations - will have to wait for things started afterwards. - */ - DBUG_ASSERT(new_lock_type == TL_WRITE_ALLOW_WRITE); - for (data=lock->write_wait.data; data ; data= next) - { - /* - All WRITE requests compatible with new lock type are also - started - */ - next= data->next; - if (start_writers && data->type == new_lock_type) - { - pthread_cond_t *cond= data->cond; - /* - It is ok to start this waiter. - Move from being first in wait queue to be last in write queue. - */ - if (((*data->prev)= data->next)) - data->next->prev= data->prev; - else - lock->write_wait.last= data->prev; - data->prev= lock->write.last; - lock->write.last= &data->next; - data->next= 0; - check_locks(lock, "Started write lock after downgrade",0); - data->cond= 0; - pthread_cond_signal(cond); - } - else - { - /* - We found an incompatible lock, we won't start any more write - requests to avoid letting writers pass other writers in the - queue. - */ - start_writers= FALSE; - if (data->type >= TL_WRITE_LOW_PRIORITY) - { - /* - We have an exclusive writer in the queue so we won't start - readers either. - */ - start_readers= FALSE; - } - } - } - } - if (start_readers) - { - DBUG_ASSERT(new_lock_type == TL_WRITE_ALLOW_WRITE || - new_lock_type == TL_WRITE_ALLOW_READ); - /* - When we come here we know that the write locks are - TL_WRITE_ALLOW_WRITE or TL_WRITE_ALLOW_READ. This means that reads - are ok - */ - for (data=lock->read_wait.data; data ; data=next) - { - next= data->next; - /* - All reads are ok to start now except TL_READ_NO_INSERT when - write lock is TL_WRITE_ALLOW_READ. - */ - if (new_lock_type != TL_WRITE_ALLOW_READ || - data->type != TL_READ_NO_INSERT) - { - pthread_cond_t *cond= data->cond; - if (((*data->prev)= data->next)) - data->next->prev= data->prev; - else - lock->read_wait.last= data->prev; - data->prev= lock->read.last; - lock->read.last= &data->next; - data->next= 0; - - if (data->type == TL_READ_NO_INSERT) - lock->read_no_write_count++; - check_locks(lock, "Started read lock after downgrade",0); - data->cond= 0; - pthread_cond_signal(cond); - } - } - } - check_locks(lock,"after starting waiters after downgrading lock",0); -#endif - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_VOID_RETURN; } /* Upgrade a WRITE_DELAY lock to a WRITE_LOCK */ my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data, - enum thr_lock_type new_lock_type) + enum thr_lock_type new_lock_type, + ulong lock_wait_timeout) { THR_LOCK *lock=data->lock; DBUG_ENTER("thr_upgrade_write_delay_lock"); - pthread_mutex_lock(&lock->mutex); + mysql_mutex_lock(&lock->mutex); if (data->type == TL_UNLOCK || data->type >= TL_WRITE_LOW_PRIORITY) { - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_RETURN(data->type == TL_UNLOCK); /* Test if Aborted */ } check_locks(lock,"before upgrading lock",0); @@ -1405,7 +1324,7 @@ my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data, { /* We have the lock */ if (data->lock->get_status) (*data->lock->get_status)(data->status_param, 0); - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_RETURN(0); } @@ -1426,22 +1345,23 @@ my_bool thr_upgrade_write_delay_lock(THR_LOCK_DATA *data, { check_locks(lock,"waiting for lock",0); } - DBUG_RETURN(wait_for_lock(&lock->write_wait,data,1)); + DBUG_RETURN(wait_for_lock(&lock->write_wait,data,1, lock_wait_timeout)); } /* downgrade a WRITE lock to a WRITE_DELAY lock if there is pending locks */ -my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data) +my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data, + ulong lock_wait_timeout) { THR_LOCK *lock=data->lock; enum thr_lock_type write_lock_type; DBUG_ENTER("thr_reschedule_write_lock"); - pthread_mutex_lock(&lock->mutex); + mysql_mutex_lock(&lock->mutex); if (!lock->read_wait.data) /* No waiting read locks */ { - pthread_mutex_unlock(&lock->mutex); + mysql_mutex_unlock(&lock->mutex); DBUG_RETURN(0); } @@ -1463,8 +1383,9 @@ my_bool thr_reschedule_write_lock(THR_LOCK_DATA *data) lock->write_wait.data=data; free_all_read_locks(lock,0); - pthread_mutex_unlock(&lock->mutex); - DBUG_RETURN(thr_upgrade_write_delay_lock(data, write_lock_type)); + mysql_mutex_unlock(&lock->mutex); + DBUG_RETURN(thr_upgrade_write_delay_lock(data, write_lock_type, + lock_wait_timeout)); } @@ -1481,7 +1402,7 @@ static void thr_print_lock(const char* name,struct st_lock_list *list) prev= &list->data; for (data=list->data; data && count++ < MAX_LOCKS ; data=data->next) { - printf("0x%lx (%lu:%d); ", (ulong) data, data->owner->info->thread_id, + printf("0x%lx (%lu:%d); ", (ulong) data, data->owner->thread_id, (int) data->type); if (data->prev != prev) printf("\nWarning: prev didn't point at previous lock\n"); @@ -1498,13 +1419,13 @@ void thr_print_locks(void) LIST *list; uint count=0; - pthread_mutex_lock(&THR_LOCK_lock); + mysql_mutex_lock(&THR_LOCK_lock); puts("Current locks:"); for (list= thr_lock_thread_list; list && count++ < MAX_THREADS; list= list_rest(list)) { THR_LOCK *lock=(THR_LOCK*) list->data; - VOID(pthread_mutex_lock(&lock->mutex)); + mysql_mutex_lock(&lock->mutex); printf("lock: 0x%lx:",(ulong) lock); if ((lock->write_wait.data || lock->read_wait.data) && (! lock->read.data && ! lock->write.data)) @@ -1522,14 +1443,13 @@ void thr_print_locks(void) thr_print_lock("write_wait",&lock->write_wait); thr_print_lock("read",&lock->read); thr_print_lock("read_wait",&lock->read_wait); - VOID(pthread_mutex_unlock(&lock->mutex)); + mysql_mutex_unlock(&lock->mutex); puts(""); } fflush(stdout); - pthread_mutex_unlock(&THR_LOCK_lock); + mysql_mutex_unlock(&THR_LOCK_lock); } -#endif /* THREAD */ /***************************************************************************** ** Test of thread locks @@ -1537,8 +1457,6 @@ void thr_print_locks(void) #ifdef MAIN -#ifdef THREAD - struct st_test { uint lock_nr; enum thr_lock_type lock_type; @@ -1558,15 +1476,14 @@ struct st_test test_8[] = {{1,TL_READ_NO_INSERT},{2,TL_READ_NO_INSERT},{3,TL_REA struct st_test test_9[] = {{4,TL_READ_HIGH_PRIORITY}}; struct st_test test_10[] ={{4,TL_WRITE}}; struct st_test test_11[] = {{0,TL_WRITE_LOW_PRIORITY},{1,TL_WRITE_LOW_PRIORITY},{2,TL_WRITE_LOW_PRIORITY},{3,TL_WRITE_LOW_PRIORITY}}; /* Many writes */ -struct st_test test_12[] = {{0,TL_WRITE_ALLOW_READ},{1,TL_WRITE_ALLOW_READ},{2,TL_WRITE_ALLOW_READ},{3,TL_WRITE_ALLOW_READ}}; /* Many writes */ -struct st_test test_13[] = {{0,TL_WRITE_CONCURRENT_INSERT},{1,TL_WRITE_CONCURRENT_INSERT},{2,TL_WRITE_CONCURRENT_INSERT},{3,TL_WRITE_CONCURRENT_INSERT}}; -struct st_test test_14[] = {{0,TL_WRITE_CONCURRENT_INSERT},{1,TL_READ}}; -struct st_test test_15[] = {{0,TL_WRITE_ALLOW_WRITE},{1,TL_READ}}; -struct st_test test_16[] = {{0,TL_WRITE_ALLOW_WRITE},{1,TL_WRITE_ALLOW_WRITE}}; +struct st_test test_12[] = {{0,TL_WRITE_CONCURRENT_INSERT},{1,TL_WRITE_CONCURRENT_INSERT},{2,TL_WRITE_CONCURRENT_INSERT},{3,TL_WRITE_CONCURRENT_INSERT}}; +struct st_test test_13[] = {{0,TL_WRITE_CONCURRENT_INSERT},{1,TL_READ}}; +struct st_test test_14[] = {{0,TL_WRITE_ALLOW_WRITE},{1,TL_READ}}; +struct st_test test_15[] = {{0,TL_WRITE_ALLOW_WRITE},{1,TL_WRITE_ALLOW_WRITE}}; struct st_test *tests[] = {test_0,test_1,test_2,test_3,test_4,test_5,test_6, test_7,test_8,test_9,test_10,test_11,test_12, - test_13,test_14,test_15,test_16}; + test_13,test_14,test_15}; int lock_counts[]= {sizeof(test_0)/sizeof(struct st_test), sizeof(test_1)/sizeof(struct st_test), sizeof(test_2)/sizeof(struct st_test), @@ -1582,17 +1499,17 @@ int lock_counts[]= {sizeof(test_0)/sizeof(struct st_test), sizeof(test_12)/sizeof(struct st_test), sizeof(test_13)/sizeof(struct st_test), sizeof(test_14)/sizeof(struct st_test), - sizeof(test_15)/sizeof(struct st_test), - sizeof(test_16)/sizeof(struct st_test) + sizeof(test_15)/sizeof(struct st_test) }; -static pthread_cond_t COND_thread_count; -static pthread_mutex_t LOCK_thread_count; +static mysql_cond_t COND_thread_count; +static mysql_mutex_t LOCK_thread_count; static uint thread_count; static ulong sum=0; #define MAX_LOCK_COUNT 8 +#define TEST_TIMEOUT 100000 /* The following functions is for WRITE_CONCURRENT_INSERT */ @@ -1620,7 +1537,6 @@ static void *test_thread(void *arg) { int i,j,param=*((int*) arg); THR_LOCK_DATA data[MAX_LOCK_COUNT]; - THR_LOCK_OWNER owner; THR_LOCK_INFO lock_info; THR_LOCK_DATA *multi_locks[MAX_LOCK_COUNT]; my_thread_init(); @@ -1629,7 +1545,6 @@ static void *test_thread(void *arg) thr_lock_info_init(&lock_info); - thr_lock_owner_init(&owner, &lock_info); for (i=0; i < lock_counts[param] ; i++) thr_lock_data_init(locks+tests[param][i].lock_nr,data+i,NULL); for (j=1 ; j < 10 ; j++) /* try locking 10 times */ @@ -1639,8 +1554,8 @@ static void *test_thread(void *arg) multi_locks[i]= &data[i]; data[i].type= tests[param][i].lock_type; } - thr_multi_lock(multi_locks, lock_counts[param], &owner); - pthread_mutex_lock(&LOCK_thread_count); + thr_multi_lock(multi_locks, lock_counts[param], &lock_info, TEST_TIMEOUT); + mysql_mutex_lock(&LOCK_thread_count); { int tmp=rand() & 7; /* Do something from 0-2 sec */ if (tmp == 0) @@ -1654,16 +1569,16 @@ static void *test_thread(void *arg) sum+=k; } } - pthread_mutex_unlock(&LOCK_thread_count); + mysql_mutex_unlock(&LOCK_thread_count); thr_multi_unlock(multi_locks,lock_counts[param]); } printf("Thread %s (%d) ended\n",my_thread_name(),param); fflush(stdout); thr_print_locks(); - pthread_mutex_lock(&LOCK_thread_count); + mysql_mutex_lock(&LOCK_thread_count); thread_count--; - VOID(pthread_cond_signal(&COND_thread_count)); /* Tell main we are ready */ - pthread_mutex_unlock(&LOCK_thread_count); + mysql_cond_signal(&COND_thread_count); /* Tell main we are ready */ + mysql_mutex_unlock(&LOCK_thread_count); free((uchar*) arg); return 0; } @@ -1680,15 +1595,15 @@ int main(int argc __attribute__((unused)),char **argv __attribute__((unused))) printf("Main thread: %s\n",my_thread_name()); - if ((error=pthread_cond_init(&COND_thread_count,NULL))) + if ((error= mysql_cond_init(0, &COND_thread_count, NULL))) { - fprintf(stderr,"Got error: %d from pthread_cond_init (errno: %d)", + fprintf(stderr, "Got error: %d from mysql_cond_init (errno: %d)", error,errno); exit(1); } - if ((error=pthread_mutex_init(&LOCK_thread_count,MY_MUTEX_INIT_FAST))) + if ((error= mysql_mutex_init(0, &LOCK_thread_count, MY_MUTEX_INIT_FAST))) { - fprintf(stderr,"Got error: %d from pthread_cond_init (errno: %d)", + fprintf(stderr, "Got error: %d from mysql_cond_init (errno: %d)", error,errno); exit(1); } @@ -1723,40 +1638,42 @@ int main(int argc __attribute__((unused)),char **argv __attribute__((unused))) } #endif #ifdef HAVE_THR_SETCONCURRENCY - VOID(thr_setconcurrency(2)); + (void) thr_setconcurrency(2); #endif for (i=0 ; i < (int) array_elements(lock_counts) ; i++) { param=(int*) malloc(sizeof(int)); *param=i; - if ((error=pthread_mutex_lock(&LOCK_thread_count))) + if ((error= mysql_mutex_lock(&LOCK_thread_count))) { - fprintf(stderr,"Got error: %d from pthread_mutex_lock (errno: %d)", - error,errno); + fprintf(stderr, "Got error: %d from mysql_mutex_lock (errno: %d)", + error, errno); exit(1); } - if ((error=pthread_create(&tid,&thr_attr,test_thread,(void*) param))) + if ((error= mysql_thread_create(0, + &tid, &thr_attr, test_thread, + (void*) param))) { - fprintf(stderr,"Got error: %d from pthread_create (errno: %d)\n", - error,errno); - pthread_mutex_unlock(&LOCK_thread_count); + fprintf(stderr, "Got error: %d from mysql_thread_create (errno: %d)\n", + error, errno); + mysql_mutex_unlock(&LOCK_thread_count); exit(1); } thread_count++; - pthread_mutex_unlock(&LOCK_thread_count); + mysql_mutex_unlock(&LOCK_thread_count); } pthread_attr_destroy(&thr_attr); - if ((error=pthread_mutex_lock(&LOCK_thread_count))) - fprintf(stderr,"Got error: %d from pthread_mutex_lock\n",error); + if ((error= mysql_mutex_lock(&LOCK_thread_count))) + fprintf(stderr, "Got error: %d from mysql_mutex_lock\n", error); while (thread_count) { - if ((error=pthread_cond_wait(&COND_thread_count,&LOCK_thread_count))) - fprintf(stderr,"Got error: %d from pthread_cond_wait\n",error); + if ((error= mysql_cond_wait(&COND_thread_count, &LOCK_thread_count))) + fprintf(stderr, "Got error: %d from mysql_cond_wait\n", error); } - if ((error=pthread_mutex_unlock(&LOCK_thread_count))) - fprintf(stderr,"Got error: %d from pthread_mutex_unlock\n",error); + if ((error= mysql_mutex_unlock(&LOCK_thread_count))) + fprintf(stderr, "Got error: %d from mysql_mutex_unlock\n", error); for (i=0 ; i < (int) array_elements(locks) ; i++) thr_lock_delete(locks+i); #ifdef EXTRA_DEBUG @@ -1768,13 +1685,4 @@ int main(int argc __attribute__((unused)),char **argv __attribute__((unused))) return 0; } -#else /* THREAD */ - -int main(int argc __attribute__((unused)),char **argv __attribute__((unused))) -{ - printf("thr_lock disabled because we are not using threads\n"); - exit(1); -} - -#endif /* THREAD */ #endif /* MAIN */ |