/* $OpenLDAP$ */ /* This work is part of OpenLDAP Software . * * Copyright 1998-2021 The OpenLDAP Foundation. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted only as authorized by the OpenLDAP * Public License. * * A copy of this license is available in file LICENSE in the * top-level directory of the distribution or, alternatively, at * . */ #include "portable.h" #include #include #include #include #include #include #include #include "ldap-int.h" #ifdef LDAP_R_COMPILE #include "ldap_pvt_thread.h" /* Get the thread interface */ #include "ldap_queue.h" #define LDAP_THREAD_POOL_IMPLEMENTATION #include "ldap_thr_debug.h" /* May rename symbols defined below */ #ifndef LDAP_THREAD_HAVE_TPOOL #ifndef CACHELINE #define CACHELINE 64 #endif /* Thread-specific key with data and optional free function */ typedef struct ldap_int_tpool_key_s { void *ltk_key; void *ltk_data; ldap_pvt_thread_pool_keyfree_t *ltk_free; } ldap_int_tpool_key_t; /* Max number of thread-specific keys we store per thread. * We don't expect to use many... */ #define MAXKEYS 32 /* Max number of threads */ #define LDAP_MAXTHR 1024 /* must be a power of 2 */ /* (Theoretical) max number of pending requests */ #define MAX_PENDING (INT_MAX/2) /* INT_MAX - (room to avoid overflow) */ /* pool->ltp_pause values */ enum { NOT_PAUSED = 0, WANT_PAUSE = 1, PAUSED = 2 }; /* Context: thread ID and thread-specific key/data pairs */ typedef struct ldap_int_thread_userctx_s { struct ldap_int_thread_poolq_s *ltu_pq; ldap_pvt_thread_t ltu_id; ldap_int_tpool_key_t ltu_key[MAXKEYS]; } ldap_int_thread_userctx_t; /* Simple {thread ID -> context} hash table; key=ctx->ltu_id. * Protected by ldap_pvt_thread_pool_mutex. */ static struct { ldap_int_thread_userctx_t *ctx; /* ctx is valid when not NULL or DELETED_THREAD_CTX */ # define DELETED_THREAD_CTX (&ldap_int_main_thrctx + 1) /* dummy addr */ } thread_keys[LDAP_MAXTHR]; #define TID_HASH(tid, hash) do { \ unsigned const char *ptr_ = (unsigned const char *)&(tid); \ unsigned i_; \ for (i_ = 0, (hash) = ptr_[0]; ++i_ < sizeof(tid);) \ (hash) += ((hash) << 5) ^ ptr_[i_]; \ } while(0) /* Task for a thread to perform */ typedef struct ldap_int_thread_task_s { union { LDAP_STAILQ_ENTRY(ldap_int_thread_task_s) q; LDAP_SLIST_ENTRY(ldap_int_thread_task_s) l; } ltt_next; ldap_pvt_thread_start_t *ltt_start_routine; void *ltt_arg; struct ldap_int_thread_poolq_s *ltt_queue; } ldap_int_thread_task_t; typedef LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ldap_int_tpool_plist_t; struct ldap_int_thread_poolq_s { void *ltp_free; struct ldap_int_thread_pool_s *ltp_pool; /* protect members below */ ldap_pvt_thread_mutex_t ltp_mutex; /* not paused and something to do for pool_() * Used for normal pool operation, to synch between submitter and * worker threads. Not used for pauses. In normal operation multiple * queues can rendezvous without acquiring the main pool lock. */ ldap_pvt_thread_cond_t ltp_cond; /* ltp_pause == 0 ? <p_pending_list : &empty_pending_list, * maintained to reduce work for pool_wrapper() */ ldap_int_tpool_plist_t *ltp_work_list; /* pending tasks, and unused task objects */ ldap_int_tpool_plist_t ltp_pending_list; LDAP_SLIST_HEAD(tcl, ldap_int_thread_task_s) ltp_free_list; /* Max number of threads in this queue */ int ltp_max_count; /* Max pending + paused + idle tasks, negated when ltp_finishing */ int ltp_max_pending; int ltp_pending_count; /* Pending + paused + idle tasks */ int ltp_active_count; /* Active, not paused/idle tasks */ int ltp_open_count; /* Number of threads */ int ltp_starting; /* Currently starting threads */ }; struct ldap_int_thread_pool_s { LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next; struct ldap_int_thread_poolq_s **ltp_wqs; /* number of poolqs */ int ltp_numqs; /* protect members below */ ldap_pvt_thread_mutex_t ltp_mutex; /* paused and waiting for resume * When a pause is in effect all workers switch to waiting on * this cond instead of their per-queue cond. */ ldap_pvt_thread_cond_t ltp_cond; /* ltp_active_queues < 1 && ltp_pause */ ldap_pvt_thread_cond_t ltp_pcond; /* number of active queues */ int ltp_active_queues; /* The pool is finishing, waiting for its threads to close. * They close when ltp_pending_list is done. pool_submit() * rejects new tasks. ltp_max_pending = -(its old value). */ int ltp_finishing; /* Some active task needs to be the sole active task. * Atomic variable so ldap_pvt_thread_pool_pausing() can read it. */ volatile sig_atomic_t ltp_pause; /* Max number of threads in pool */ int ltp_max_count; /* Configured max number of threads in pool, 0 for default (LDAP_MAXTHR) */ int ltp_conf_max_count; /* Max pending + paused + idle tasks, negated when ltp_finishing */ int ltp_max_pending; }; static ldap_int_tpool_plist_t empty_pending_list = LDAP_STAILQ_HEAD_INITIALIZER(empty_pending_list); static int ldap_int_has_thread_pool = 0; static LDAP_STAILQ_HEAD(tpq, ldap_int_thread_pool_s) ldap_int_thread_pool_list = LDAP_STAILQ_HEAD_INITIALIZER(ldap_int_thread_pool_list); static ldap_pvt_thread_mutex_t ldap_pvt_thread_pool_mutex; static void *ldap_int_thread_pool_wrapper( void *pool ); static ldap_pvt_thread_key_t ldap_tpool_key; /* Context of the main thread */ static ldap_int_thread_userctx_t ldap_int_main_thrctx; int ldap_int_thread_pool_startup ( void ) { ldap_int_main_thrctx.ltu_id = ldap_pvt_thread_self(); ldap_pvt_thread_key_create( &ldap_tpool_key ); return ldap_pvt_thread_mutex_init(&ldap_pvt_thread_pool_mutex); } int ldap_int_thread_pool_shutdown ( void ) { struct ldap_int_thread_pool_s *pool; while ((pool = LDAP_STAILQ_FIRST(&ldap_int_thread_pool_list)) != NULL) { (ldap_pvt_thread_pool_destroy)(&pool, 0); /* ignore thr_debug macro */ } ldap_pvt_thread_mutex_destroy(&ldap_pvt_thread_pool_mutex); ldap_pvt_thread_key_destroy( ldap_tpool_key ); return(0); } /* Create a thread pool */ int ldap_pvt_thread_pool_init_q ( ldap_pvt_thread_pool_t *tpool, int max_threads, int max_pending, int numqs ) { ldap_pvt_thread_pool_t pool; struct ldap_int_thread_poolq_s *pq; int i, rc, rem_thr, rem_pend; /* multiple pools are currently not supported (ITS#4943) */ assert(!ldap_int_has_thread_pool); if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR)) max_threads = 0; if (! (1 <= max_pending && max_pending <= MAX_PENDING)) max_pending = MAX_PENDING; *tpool = NULL; pool = (ldap_pvt_thread_pool_t) LDAP_CALLOC(1, sizeof(struct ldap_int_thread_pool_s)); if (pool == NULL) return(-1); pool->ltp_wqs = LDAP_MALLOC(numqs * sizeof(struct ldap_int_thread_poolq_s *)); if (pool->ltp_wqs == NULL) { LDAP_FREE(pool); return(-1); } for (i=0; i=0; i--) LDAP_FREE(pool->ltp_wqs[i]->ltp_free); LDAP_FREE(pool->ltp_wqs); LDAP_FREE(pool); return(-1); } pool->ltp_wqs[i] = (struct ldap_int_thread_poolq_s *)(((size_t)ptr + CACHELINE-1) & ~(CACHELINE-1)); pool->ltp_wqs[i]->ltp_free = ptr; } pool->ltp_numqs = numqs; pool->ltp_conf_max_count = max_threads; if ( !max_threads ) max_threads = LDAP_MAXTHR; rc = ldap_pvt_thread_mutex_init(&pool->ltp_mutex); if (rc != 0) { fail: for (i=0; iltp_wqs[i]->ltp_free); LDAP_FREE(pool->ltp_wqs); LDAP_FREE(pool); return(rc); } rc = ldap_pvt_thread_cond_init(&pool->ltp_cond); if (rc != 0) goto fail; rc = ldap_pvt_thread_cond_init(&pool->ltp_pcond); if (rc != 0) goto fail; rem_thr = max_threads % numqs; rem_pend = max_pending % numqs; for ( i=0; iltp_wqs[i]; pq->ltp_pool = pool; rc = ldap_pvt_thread_mutex_init(&pq->ltp_mutex); if (rc != 0) return(rc); rc = ldap_pvt_thread_cond_init(&pq->ltp_cond); if (rc != 0) return(rc); LDAP_STAILQ_INIT(&pq->ltp_pending_list); pq->ltp_work_list = &pq->ltp_pending_list; LDAP_SLIST_INIT(&pq->ltp_free_list); pq->ltp_max_count = max_threads / numqs; if ( rem_thr ) { pq->ltp_max_count++; rem_thr--; } pq->ltp_max_pending = max_pending / numqs; if ( rem_pend ) { pq->ltp_max_pending++; rem_pend--; } } ldap_int_has_thread_pool = 1; pool->ltp_max_count = max_threads; pool->ltp_max_pending = max_pending; ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex); LDAP_STAILQ_INSERT_TAIL(&ldap_int_thread_pool_list, pool, ltp_next); ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex); /* Start no threads just yet. That can break if the process forks * later, as slapd does in order to daemonize. On at least POSIX, * only the forking thread would survive in the child. Yet fork() * can't unlock/clean up other threads' locks and data structures, * unless pthread_atfork() handlers have been set up to do so. */ *tpool = pool; return(0); } int ldap_pvt_thread_pool_init ( ldap_pvt_thread_pool_t *tpool, int max_threads, int max_pending ) { return ldap_pvt_thread_pool_init_q( tpool, max_threads, max_pending, 1 ); } /* Submit a task to be performed by the thread pool */ int ldap_pvt_thread_pool_submit ( ldap_pvt_thread_pool_t *tpool, ldap_pvt_thread_start_t *start_routine, void *arg ) { return ldap_pvt_thread_pool_submit2( tpool, start_routine, arg, NULL ); } /* Submit a task to be performed by the thread pool */ int ldap_pvt_thread_pool_submit2 ( ldap_pvt_thread_pool_t *tpool, ldap_pvt_thread_start_t *start_routine, void *arg, void **cookie ) { struct ldap_int_thread_pool_s *pool; struct ldap_int_thread_poolq_s *pq; ldap_int_thread_task_t *task; ldap_pvt_thread_t thr; int i, j; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(-1); if ( pool->ltp_numqs > 1 ) { int min = pool->ltp_wqs[0]->ltp_max_pending + pool->ltp_wqs[0]->ltp_max_count; int min_x = 0, cnt; for ( i = 0; i < pool->ltp_numqs; i++ ) { /* take first queue that has nothing active */ if ( !pool->ltp_wqs[i]->ltp_active_count ) { min_x = i; break; } cnt = pool->ltp_wqs[i]->ltp_active_count + pool->ltp_wqs[i]->ltp_pending_count; if ( cnt < min ) { min = cnt; min_x = i; } } i = min_x; } else i = 0; j = i; while(1) { ldap_pvt_thread_mutex_lock(&pool->ltp_wqs[i]->ltp_mutex); if (pool->ltp_wqs[i]->ltp_pending_count < pool->ltp_wqs[i]->ltp_max_pending) { break; } ldap_pvt_thread_mutex_unlock(&pool->ltp_wqs[i]->ltp_mutex); i++; i %= pool->ltp_numqs; if ( i == j ) return -1; } pq = pool->ltp_wqs[i]; task = LDAP_SLIST_FIRST(&pq->ltp_free_list); if (task) { LDAP_SLIST_REMOVE_HEAD(&pq->ltp_free_list, ltt_next.l); } else { task = (ldap_int_thread_task_t *) LDAP_MALLOC(sizeof(*task)); if (task == NULL) goto failed; } task->ltt_start_routine = start_routine; task->ltt_arg = arg; task->ltt_queue = pq; if ( cookie ) *cookie = task; pq->ltp_pending_count++; LDAP_STAILQ_INSERT_TAIL(&pq->ltp_pending_list, task, ltt_next.q); if (pool->ltp_pause) goto done; /* should we open (create) a thread? */ if (pq->ltp_open_count < pq->ltp_active_count+pq->ltp_pending_count && pq->ltp_open_count < pq->ltp_max_count) { pq->ltp_starting++; pq->ltp_open_count++; if (0 != ldap_pvt_thread_create( &thr, 1, ldap_int_thread_pool_wrapper, pq)) { /* couldn't create thread. back out of * ltp_open_count and check for even worse things. */ pq->ltp_starting--; pq->ltp_open_count--; if (pq->ltp_open_count == 0) { /* no open threads at all?!? */ ldap_int_thread_task_t *ptr; /* let pool_close know there are no more threads */ ldap_pvt_thread_cond_signal(&pq->ltp_cond); LDAP_STAILQ_FOREACH(ptr, &pq->ltp_pending_list, ltt_next.q) if (ptr == task) break; if (ptr == task) { /* no open threads, task not handled, so * back out of ltp_pending_count, free the task, * report the error. */ pq->ltp_pending_count--; LDAP_STAILQ_REMOVE(&pq->ltp_pending_list, task, ldap_int_thread_task_s, ltt_next.q); LDAP_SLIST_INSERT_HEAD(&pq->ltp_free_list, task, ltt_next.l); goto failed; } } /* there is another open thread, so this * task will be handled eventually. */ } } ldap_pvt_thread_cond_signal(&pq->ltp_cond); done: ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); return(0); failed: ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); return(-1); } static void * no_task( void *ctx, void *arg ) { return NULL; } /* Cancel a pending task that was previously submitted. * Return 1 if the task was successfully cancelled, 0 if * not found, -1 for invalid parameters */ int ldap_pvt_thread_pool_retract ( void *cookie ) { ldap_int_thread_task_t *task, *ttmp; struct ldap_int_thread_poolq_s *pq; if (cookie == NULL) return(-1); ttmp = cookie; pq = ttmp->ltt_queue; if (pq == NULL) return(-1); ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); LDAP_STAILQ_FOREACH(task, &pq->ltp_pending_list, ltt_next.q) if (task == ttmp) { /* Could LDAP_STAILQ_REMOVE the task, but that * walks ltp_pending_list again to find it. */ task->ltt_start_routine = no_task; task->ltt_arg = NULL; break; } ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); return task != NULL; } /* Walk the pool and allow tasks to be retracted, only to be called while the * pool is paused */ int ldap_pvt_thread_pool_walk( ldap_pvt_thread_pool_t *tpool, ldap_pvt_thread_start_t *start, ldap_pvt_thread_walk_t *cb, void *arg ) { struct ldap_int_thread_pool_s *pool; struct ldap_int_thread_poolq_s *pq; ldap_int_thread_task_t *task; int i; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(-1); ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); assert(pool->ltp_pause == PAUSED); ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); for (i=0; iltp_numqs; i++) { pq = pool->ltp_wqs[i]; LDAP_STAILQ_FOREACH(task, &pq->ltp_pending_list, ltt_next.q) { if ( task->ltt_start_routine == start ) { if ( cb( task->ltt_start_routine, task->ltt_arg, arg ) ) { /* retract */ task->ltt_start_routine = no_task; task->ltt_arg = NULL; } } } } return 0; } /* Set number of work queues in this pool. Should not be * more than the number of CPUs. */ int ldap_pvt_thread_pool_queues( ldap_pvt_thread_pool_t *tpool, int numqs ) { struct ldap_int_thread_pool_s *pool; struct ldap_int_thread_poolq_s *pq; int i, rc, rem_thr, rem_pend; if (numqs < 1 || tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(-1); if (numqs < pool->ltp_numqs) { for (i=numqs; iltp_numqs; i++) pool->ltp_wqs[i]->ltp_max_count = 0; } else if (numqs > pool->ltp_numqs) { struct ldap_int_thread_poolq_s **wqs; wqs = LDAP_REALLOC(pool->ltp_wqs, numqs * sizeof(struct ldap_int_thread_poolq_s *)); if (wqs == NULL) return(-1); pool->ltp_wqs = wqs; for (i=pool->ltp_numqs; iltp_wqs[i] = NULL; return(-1); } pq = (struct ldap_int_thread_poolq_s *)(((size_t)ptr + CACHELINE-1) & ~(CACHELINE-1)); pq->ltp_free = ptr; pool->ltp_wqs[i] = pq; pq->ltp_pool = pool; rc = ldap_pvt_thread_mutex_init(&pq->ltp_mutex); if (rc != 0) return(rc); rc = ldap_pvt_thread_cond_init(&pq->ltp_cond); if (rc != 0) return(rc); LDAP_STAILQ_INIT(&pq->ltp_pending_list); pq->ltp_work_list = &pq->ltp_pending_list; LDAP_SLIST_INIT(&pq->ltp_free_list); } } rem_thr = pool->ltp_max_count % numqs; rem_pend = pool->ltp_max_pending % numqs; for ( i=0; iltp_wqs[i]; pq->ltp_max_count = pool->ltp_max_count / numqs; if ( rem_thr ) { pq->ltp_max_count++; rem_thr--; } pq->ltp_max_pending = pool->ltp_max_pending / numqs; if ( rem_pend ) { pq->ltp_max_pending++; rem_pend--; } } pool->ltp_numqs = numqs; return 0; } /* Set max #threads. value <= 0 means max supported #threads (LDAP_MAXTHR) */ int ldap_pvt_thread_pool_maxthreads( ldap_pvt_thread_pool_t *tpool, int max_threads ) { struct ldap_int_thread_pool_s *pool; struct ldap_int_thread_poolq_s *pq; int remthr, i; if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR)) max_threads = 0; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(-1); pool->ltp_conf_max_count = max_threads; if ( !max_threads ) max_threads = LDAP_MAXTHR; pool->ltp_max_count = max_threads; remthr = max_threads % pool->ltp_numqs; max_threads /= pool->ltp_numqs; for (i=0; iltp_numqs; i++) { pq = pool->ltp_wqs[i]; pq->ltp_max_count = max_threads; if (remthr) { pq->ltp_max_count++; remthr--; } } return(0); } /* Inspect the pool */ int ldap_pvt_thread_pool_query( ldap_pvt_thread_pool_t *tpool, ldap_pvt_thread_pool_param_t param, void *value ) { struct ldap_int_thread_pool_s *pool; int count = -1; if ( tpool == NULL || value == NULL ) { return -1; } pool = *tpool; if ( pool == NULL ) { return 0; } switch ( param ) { case LDAP_PVT_THREAD_POOL_PARAM_MAX: count = pool->ltp_conf_max_count; break; case LDAP_PVT_THREAD_POOL_PARAM_MAX_PENDING: count = pool->ltp_max_pending; if (count < 0) count = -count; if (count == MAX_PENDING) count = 0; break; case LDAP_PVT_THREAD_POOL_PARAM_PAUSING: ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); count = (pool->ltp_pause != 0); ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); break; case LDAP_PVT_THREAD_POOL_PARAM_OPEN: case LDAP_PVT_THREAD_POOL_PARAM_STARTING: case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE: case LDAP_PVT_THREAD_POOL_PARAM_PENDING: case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD: { int i; count = 0; for (i=0; iltp_numqs; i++) { struct ldap_int_thread_poolq_s *pq = pool->ltp_wqs[i]; ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); switch(param) { case LDAP_PVT_THREAD_POOL_PARAM_OPEN: count += pq->ltp_open_count; break; case LDAP_PVT_THREAD_POOL_PARAM_STARTING: count += pq->ltp_starting; break; case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE: count += pq->ltp_active_count; break; case LDAP_PVT_THREAD_POOL_PARAM_PENDING: count += pq->ltp_pending_count; break; case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD: count += pq->ltp_pending_count + pq->ltp_active_count; break; default: break; } ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); } if (count < 0) count = -count; } break; case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE_MAX: break; case LDAP_PVT_THREAD_POOL_PARAM_PENDING_MAX: break; case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD_MAX: break; case LDAP_PVT_THREAD_POOL_PARAM_STATE: if (pool->ltp_pause) *((char **)value) = "pausing"; else if (!pool->ltp_finishing) *((char **)value) = "running"; else { int i; for (i=0; iltp_numqs; i++) if (pool->ltp_wqs[i]->ltp_pending_count) break; if (iltp_numqs) *((char **)value) = "finishing"; else *((char **)value) = "stopping"; } break; case LDAP_PVT_THREAD_POOL_PARAM_UNKNOWN: break; } if ( count > -1 ) { *((int *)value) = count; } return ( count == -1 ? -1 : 0 ); } /* * true if pool is pausing; does not lock any mutex to check. * 0 if not pause, 1 if pause, -1 if error or no pool. */ int ldap_pvt_thread_pool_pausing( ldap_pvt_thread_pool_t *tpool ) { int rc = -1; struct ldap_int_thread_pool_s *pool; if ( tpool != NULL && (pool = *tpool) != NULL ) { rc = (pool->ltp_pause != 0); } return rc; } /* * wrapper for ldap_pvt_thread_pool_query(), left around * for backwards compatibility */ int ldap_pvt_thread_pool_backload ( ldap_pvt_thread_pool_t *tpool ) { int rc, count; rc = ldap_pvt_thread_pool_query( tpool, LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD, (void *)&count ); if ( rc == 0 ) { return count; } return rc; } /* * wrapper for ldap_pvt_thread_pool_close+free(), left around * for backwards compatibility */ int ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending ) { int rc; if ( (rc = ldap_pvt_thread_pool_close( tpool, run_pending )) ) { return rc; } return ldap_pvt_thread_pool_free( tpool ); } /* Shut down the pool making its threads finish */ int ldap_pvt_thread_pool_close ( ldap_pvt_thread_pool_t *tpool, int run_pending ) { struct ldap_int_thread_pool_s *pool, *pptr; struct ldap_int_thread_poolq_s *pq; ldap_int_thread_task_t *task; int i; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(-1); ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex); LDAP_STAILQ_FOREACH(pptr, &ldap_int_thread_pool_list, ltp_next) if (pptr == pool) break; ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex); if (pool != pptr) return(-1); ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); pool->ltp_finishing = 1; if (pool->ltp_max_pending > 0) pool->ltp_max_pending = -pool->ltp_max_pending; ldap_pvt_thread_cond_broadcast(&pool->ltp_cond); ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); for (i=0; iltp_numqs; i++) { pq = pool->ltp_wqs[i]; ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); if (pq->ltp_max_pending > 0) pq->ltp_max_pending = -pq->ltp_max_pending; if (!run_pending) { while ((task = LDAP_STAILQ_FIRST(&pq->ltp_pending_list)) != NULL) { LDAP_STAILQ_REMOVE_HEAD(&pq->ltp_pending_list, ltt_next.q); LDAP_FREE(task); } pq->ltp_pending_count = 0; } while (pq->ltp_open_count) { ldap_pvt_thread_cond_broadcast(&pq->ltp_cond); ldap_pvt_thread_cond_wait(&pq->ltp_cond, &pq->ltp_mutex); } while ((task = LDAP_SLIST_FIRST(&pq->ltp_free_list)) != NULL) { LDAP_SLIST_REMOVE_HEAD(&pq->ltp_free_list, ltt_next.l); LDAP_FREE(task); } ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); } return(0); } /* Destroy the pool, everything must have already shut down */ int ldap_pvt_thread_pool_free ( ldap_pvt_thread_pool_t *tpool ) { struct ldap_int_thread_pool_s *pool, *pptr; struct ldap_int_thread_poolq_s *pq; int i; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(-1); ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex); LDAP_STAILQ_FOREACH(pptr, &ldap_int_thread_pool_list, ltp_next) if (pptr == pool) break; if (pptr == pool) LDAP_STAILQ_REMOVE(&ldap_int_thread_pool_list, pool, ldap_int_thread_pool_s, ltp_next); ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex); if (pool != pptr) return(-1); ldap_pvt_thread_cond_destroy(&pool->ltp_pcond); ldap_pvt_thread_cond_destroy(&pool->ltp_cond); ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex); for (i=0; iltp_numqs; i++) { pq = pool->ltp_wqs[i]; assert( !pq->ltp_open_count ); assert( LDAP_SLIST_EMPTY(&pq->ltp_free_list) ); ldap_pvt_thread_cond_destroy(&pq->ltp_cond); ldap_pvt_thread_mutex_destroy(&pq->ltp_mutex); if (pq->ltp_free) { LDAP_FREE(pq->ltp_free); } } LDAP_FREE(pool->ltp_wqs); LDAP_FREE(pool); *tpool = NULL; ldap_int_has_thread_pool = 0; return(0); } /* Thread loop. Accept and handle submitted tasks. */ static void * ldap_int_thread_pool_wrapper ( void *xpool ) { struct ldap_int_thread_poolq_s *pq = xpool; struct ldap_int_thread_pool_s *pool = pq->ltp_pool; ldap_int_thread_task_t *task; ldap_int_tpool_plist_t *work_list; ldap_int_thread_userctx_t ctx, *kctx; unsigned i, keyslot, hash; int pool_lock = 0, freeme = 0; assert(pool != NULL); for ( i=0; iltp_pause) { ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); /* thread_keys[] is read-only when paused */ while (pool->ltp_pause) ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex); ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); } /* find a key slot to give this thread ID and store a * pointer to our keys there; start at the thread ID * itself (mod LDAP_MAXTHR) and look for an empty slot. */ ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex); for (keyslot = hash & (LDAP_MAXTHR-1); (kctx = thread_keys[keyslot].ctx) && kctx != DELETED_THREAD_CTX; keyslot = (keyslot+1) & (LDAP_MAXTHR-1)); thread_keys[keyslot].ctx = &ctx; ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex); ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); pq->ltp_starting--; pq->ltp_active_count++; for (;;) { work_list = pq->ltp_work_list; /* help the compiler a bit */ task = LDAP_STAILQ_FIRST(work_list); if (task == NULL) { /* paused or no pending tasks */ if (--(pq->ltp_active_count) < 1) { if (pool->ltp_pause) { ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); pool_lock = 1; if (--(pool->ltp_active_queues) < 1) { /* Notify pool_pause it is the sole active thread. */ ldap_pvt_thread_cond_signal(&pool->ltp_pcond); } } } do { if (pool->ltp_finishing || pq->ltp_open_count > pq->ltp_max_count) { /* Not paused, and either finishing or too many * threads running (can happen if ltp_max_count * was reduced). Let this thread die. */ goto done; } /* We could check an idle timer here, and let the * thread die if it has been inactive for a while. * Only die if there are other open threads (i.e., * always have at least one thread open). * The check should be like this: * if (pool->ltp_open_count>1 && pool->ltp_starting==0) * check timer, wait if ltp_pause, leave thread; * * Just use pthread_cond_timedwait() if we want to * check idle time. */ if (pool_lock) { ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex); if (!pool->ltp_pause) { ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); pool_lock = 0; } } else ldap_pvt_thread_cond_wait(&pq->ltp_cond, &pq->ltp_mutex); work_list = pq->ltp_work_list; task = LDAP_STAILQ_FIRST(work_list); } while (task == NULL); if (pool_lock) { ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); pool_lock = 0; } pq->ltp_active_count++; } LDAP_STAILQ_REMOVE_HEAD(work_list, ltt_next.q); pq->ltp_pending_count--; ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); task->ltt_start_routine(&ctx, task->ltt_arg); ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); LDAP_SLIST_INSERT_HEAD(&pq->ltp_free_list, task, ltt_next.l); } done: ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex); /* The pool_mutex lock protects ctx->ltu_key from pool_purgekey() * during this call, since it prevents new pauses. */ ldap_pvt_thread_pool_context_reset(&ctx); thread_keys[keyslot].ctx = DELETED_THREAD_CTX; ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex); pq->ltp_open_count--; if (pq->ltp_open_count == 0) { if (pool->ltp_finishing) /* let pool_destroy know we're all done */ ldap_pvt_thread_cond_signal(&pq->ltp_cond); else freeme = 1; } if (pool_lock) ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); else ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); if (freeme) { ldap_pvt_thread_cond_destroy(&pq->ltp_cond); ldap_pvt_thread_mutex_destroy(&pq->ltp_mutex); LDAP_FREE(pq->ltp_free); pq->ltp_free = NULL; } ldap_pvt_thread_exit(NULL); return(NULL); } /* Arguments > ltp_pause to handle_pause(,PAUSE_ARG()). arg=PAUSE_ARG * ensures (arg-ltp_pause) sets GO_* at need and keeps DO_PAUSE/GO_*. */ #define GO_IDLE 8 #define GO_UNIDLE 16 #define CHECK_PAUSE 32 /* if ltp_pause: GO_IDLE; wait; GO_UNIDLE */ #define DO_PAUSE 64 /* CHECK_PAUSE; pause the pool */ #define PAUSE_ARG(a) \ ((a) | ((a) & (GO_IDLE|GO_UNIDLE) ? GO_IDLE-1 : CHECK_PAUSE)) static int handle_pause( ldap_pvt_thread_pool_t *tpool, int pause_type ) { struct ldap_int_thread_pool_s *pool; struct ldap_int_thread_poolq_s *pq; int ret = 0, pause, max_ltp_pause; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(0); if (pause_type == CHECK_PAUSE && !pool->ltp_pause) return(0); { ldap_int_thread_userctx_t *ctx = ldap_pvt_thread_pool_context(); pq = ctx->ltu_pq; if ( !pq ) return(-1); } /* Let pool_unidle() ignore requests for new pauses */ max_ltp_pause = pause_type==PAUSE_ARG(GO_UNIDLE) ? WANT_PAUSE : NOT_PAUSED; ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); pause = pool->ltp_pause; /* NOT_PAUSED, WANT_PAUSE or PAUSED */ /* If ltp_pause and not GO_IDLE|GO_UNIDLE: Set GO_IDLE,GO_UNIDLE */ pause_type -= pause; if (pause_type & GO_IDLE) { int do_pool = 0; ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); pq->ltp_pending_count++; pq->ltp_active_count--; if (pause && pq->ltp_active_count < 1) { do_pool = 1; } ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); if (do_pool) { pool->ltp_active_queues--; if (pool->ltp_active_queues < 1) /* Tell the task waiting to DO_PAUSE it can proceed */ ldap_pvt_thread_cond_signal(&pool->ltp_pcond); } } if (pause_type & GO_UNIDLE) { /* Wait out pause if any, then cancel GO_IDLE */ if (pause > max_ltp_pause) { ret = 1; do { ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex); } while (pool->ltp_pause > max_ltp_pause); } ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); pq->ltp_pending_count--; pq->ltp_active_count++; ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); } if (pause_type & DO_PAUSE) { int i, j; /* Tell everyone else to pause or finish, then await that */ ret = 0; assert(!pool->ltp_pause); pool->ltp_pause = WANT_PAUSE; pool->ltp_active_queues = 0; for (i=0; iltp_numqs; i++) if (pool->ltp_wqs[i] == pq) break; ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); /* temporarily remove ourself from active count */ pq->ltp_active_count--; j=i; do { pq = pool->ltp_wqs[j]; if (j != i) ldap_pvt_thread_mutex_lock(&pq->ltp_mutex); /* Hide pending tasks from ldap_pvt_thread_pool_wrapper() */ pq->ltp_work_list = &empty_pending_list; if (pq->ltp_active_count > 0) pool->ltp_active_queues++; ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex); if (pool->ltp_numqs > 1) { j++; j %= pool->ltp_numqs; } } while (j != i); /* Wait for this task to become the sole active task */ while (pool->ltp_active_queues > 0) ldap_pvt_thread_cond_wait(&pool->ltp_pcond, &pool->ltp_mutex); /* restore us to active count */ pool->ltp_wqs[i]->ltp_active_count++; assert(pool->ltp_pause == WANT_PAUSE); pool->ltp_pause = PAUSED; } ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); return(ret); } /* Consider this task idle: It will not block pool_pause() in other tasks. */ void ldap_pvt_thread_pool_idle( ldap_pvt_thread_pool_t *tpool ) { handle_pause(tpool, PAUSE_ARG(GO_IDLE)); } /* Cancel pool_idle(). If the pool is paused, wait it out first. */ void ldap_pvt_thread_pool_unidle( ldap_pvt_thread_pool_t *tpool ) { handle_pause(tpool, PAUSE_ARG(GO_UNIDLE)); } /* * If a pause was requested, wait for it. If several threads * are waiting to pause, let through one or more pauses. * The calling task must be active, not idle. * Return 1 if we waited, 0 if not, -1 at parameter error. */ int ldap_pvt_thread_pool_pausewait( ldap_pvt_thread_pool_t *tpool ) { return handle_pause(tpool, PAUSE_ARG(CHECK_PAUSE)); } /* Return 1 if a pause has been requested */ int ldap_pvt_thread_pool_pausequery( ldap_pvt_thread_pool_t *tpool ) { struct ldap_int_thread_pool_s *pool; if ( !tpool ) return -1; pool = *tpool; if ( !pool ) return 0; return pool->ltp_pause != 0; } /* * Wait for a pause, from a non-pooled thread. */ int ldap_pvt_thread_pool_pausecheck_native( ldap_pvt_thread_pool_t *tpool ) { struct ldap_int_thread_pool_s *pool; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(0); if (!pool->ltp_pause) return(0); ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); while (pool->ltp_pause) ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex); ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); return 1; } /* * Pause the pool. The calling task must be active, not idle. * Return when all other tasks are paused or idle. */ int ldap_pvt_thread_pool_pause( ldap_pvt_thread_pool_t *tpool ) { return handle_pause(tpool, PAUSE_ARG(DO_PAUSE)); } /* End a pause */ int ldap_pvt_thread_pool_resume ( ldap_pvt_thread_pool_t *tpool ) { struct ldap_int_thread_pool_s *pool; struct ldap_int_thread_poolq_s *pq; int i; if (tpool == NULL) return(-1); pool = *tpool; if (pool == NULL) return(0); ldap_pvt_thread_mutex_lock(&pool->ltp_mutex); assert(pool->ltp_pause == PAUSED); pool->ltp_pause = 0; for (i=0; iltp_numqs; i++) { pq = pool->ltp_wqs[i]; pq->ltp_work_list = &pq->ltp_pending_list; ldap_pvt_thread_cond_broadcast(&pq->ltp_cond); } ldap_pvt_thread_cond_broadcast(&pool->ltp_cond); ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex); return(0); } /* * Get the key's data and optionally free function in the given context. */ int ldap_pvt_thread_pool_getkey( void *xctx, void *key, void **data, ldap_pvt_thread_pool_keyfree_t **kfree ) { ldap_int_thread_userctx_t *ctx = xctx; int i; if ( !ctx || !key || !data ) return EINVAL; for ( i=0; iltu_key[i].ltk_key; i++ ) { if ( ctx->ltu_key[i].ltk_key == key ) { *data = ctx->ltu_key[i].ltk_data; if ( kfree ) *kfree = ctx->ltu_key[i].ltk_free; return 0; } } return ENOENT; } static void clear_key_idx( ldap_int_thread_userctx_t *ctx, int i ) { for ( ; i < MAXKEYS-1 && ctx->ltu_key[i+1].ltk_key; i++ ) ctx->ltu_key[i] = ctx->ltu_key[i+1]; ctx->ltu_key[i].ltk_key = NULL; } /* * Set or remove data for the key in the given context. * key can be any unique pointer. * kfree() is an optional function to free the data (but not the key): * pool_context_reset() and pool_purgekey() call kfree(key, data), * but pool_setkey() does not. For pool_setkey() it is the caller's * responsibility to free any existing data with the same key. * kfree() must not call functions taking a tpool argument. */ int ldap_pvt_thread_pool_setkey( void *xctx, void *key, void *data, ldap_pvt_thread_pool_keyfree_t *kfree, void **olddatap, ldap_pvt_thread_pool_keyfree_t **oldkfreep ) { ldap_int_thread_userctx_t *ctx = xctx; int i, found; if ( !ctx || !key ) return EINVAL; for ( i=found=0; iltu_key[i].ltk_key == key ) { found = 1; break; } else if ( !ctx->ltu_key[i].ltk_key ) { break; } } if ( olddatap ) { if ( found ) { *olddatap = ctx->ltu_key[i].ltk_data; } else { *olddatap = NULL; } } if ( oldkfreep ) { if ( found ) { *oldkfreep = ctx->ltu_key[i].ltk_free; } else { *oldkfreep = 0; } } if ( data || kfree ) { if ( i>=MAXKEYS ) return ENOMEM; ctx->ltu_key[i].ltk_key = key; ctx->ltu_key[i].ltk_data = data; ctx->ltu_key[i].ltk_free = kfree; } else if ( found ) { clear_key_idx( ctx, i ); } return 0; } /* Free all elements with this key, no matter which thread they're in. * May only be called while the pool is paused. */ void ldap_pvt_thread_pool_purgekey( void *key ) { int i, j; ldap_int_thread_userctx_t *ctx; assert ( key != NULL ); ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex); for ( i=0; iltu_key[j].ltk_key; j++ ) { if ( ctx->ltu_key[j].ltk_key == key ) { if (ctx->ltu_key[j].ltk_free) ctx->ltu_key[j].ltk_free( ctx->ltu_key[j].ltk_key, ctx->ltu_key[j].ltk_data ); clear_key_idx( ctx, j ); break; } } } } ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex); } /* * Find the context of the current thread. * This is necessary if the caller does not have access to the * thread context handle (for example, a slapd plugin calling * slapi_search_internal()). No doubt it is more efficient * for the application to keep track of the thread context * handles itself. */ void *ldap_pvt_thread_pool_context( ) { void *ctx = NULL; ldap_pvt_thread_key_getdata( ldap_tpool_key, &ctx ); return ctx ? ctx : (void *) &ldap_int_main_thrctx; } /* * Free the context's keys. * Must not call functions taking a tpool argument (because this * thread already holds ltp_mutex when called from pool_wrapper()). */ void ldap_pvt_thread_pool_context_reset( void *vctx ) { ldap_int_thread_userctx_t *ctx = vctx; int i; for ( i=MAXKEYS-1; i>=0; i--) { if ( !ctx->ltu_key[i].ltk_key ) continue; if ( ctx->ltu_key[i].ltk_free ) ctx->ltu_key[i].ltk_free( ctx->ltu_key[i].ltk_key, ctx->ltu_key[i].ltk_data ); ctx->ltu_key[i].ltk_key = NULL; } } ldap_pvt_thread_t ldap_pvt_thread_pool_tid( void *vctx ) { ldap_int_thread_userctx_t *ctx = vctx; return ctx->ltu_id; } #endif /* LDAP_THREAD_HAVE_TPOOL */ #endif /* LDAP_R_COMPILE */