From 5ea77a75dd2d2158401331879f3c8f47940a732c Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:35:32 +0200 Subject: Adding upstream version 2.5.13+dfsg. Signed-off-by: Daniel Baumann --- libraries/libldap/tpool.c | 1474 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1474 insertions(+) create mode 100644 libraries/libldap/tpool.c (limited to 'libraries/libldap/tpool.c') diff --git a/libraries/libldap/tpool.c b/libraries/libldap/tpool.c new file mode 100644 index 0000000..797d59e --- /dev/null +++ b/libraries/libldap/tpool.c @@ -0,0 +1,1474 @@ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software . + * + * Copyright 1998-2022 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_pausecheck( ldap_pvt_thread_pool_t *tpool ) +{ + return handle_pause(tpool, PAUSE_ARG(CHECK_PAUSE)); +} + +/* + * 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 */ -- cgit v1.2.3