/* $OpenLDAP: pkg/ldap/libraries/libldap_r/tpool.c,v 1.52.2.8 2007/11/07 20:58:37 quanah Exp $ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 1998-2007 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
* <http://www.OpenLDAP.org/license.html>.
*/
#include "portable.h"
#include <stdio.h>
#include <ac/stdarg.h>
#include <ac/stdlib.h>
#include <ac/string.h>
#include <ac/time.h>
#include <ac/errno.h>
#include "ldap-int.h"
#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
typedef enum ldap_int_thread_pool_state_e {
LDAP_INT_THREAD_POOL_RUNNING,
LDAP_INT_THREAD_POOL_FINISHING,
LDAP_INT_THREAD_POOL_STOPPING
} ldap_int_thread_pool_state_t;
/* 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 */
/* Context: thread ID and thread-specific key/data pairs */
typedef struct ldap_int_thread_userctx_s {
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 except during pauses,
* when it is read-only (used by pool_purgekey and pool_context).
* Protected by tpool->ltp_mutex during pauses.
*/
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;
} ldap_int_thread_task_t;
struct ldap_int_thread_pool_s {
LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next;
/* protect members below, and protect thread_keys[] during pauses */
ldap_pvt_thread_mutex_t ltp_mutex;
/* not paused and something to do for pool_<wrapper/pause/destroy>() */
ldap_pvt_thread_cond_t ltp_cond;
/* ltp_active_count <= 1 && ltp_pause */
ldap_pvt_thread_cond_t ltp_pcond;
/* pending tasks, and unused task objects */
LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ltp_pending_list;
LDAP_SLIST_HEAD(tcl, ldap_int_thread_task_s) ltp_free_list;
ldap_int_thread_pool_state_t ltp_state;
/* some active request needs to be the sole active request */
int ltp_pause;
long ltp_max_count; /* max number of threads in pool, or 0 */
long ltp_max_pending; /* max pending or paused requests, or 0 */
long ltp_pending_count; /* pending or paused requests */
long ltp_active_count; /* active, not paused requests */
long ltp_open_count; /* number of threads */
long ltp_starting; /* currenlty starting threads */
};
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 (
ldap_pvt_thread_pool_t *tpool,
int max_threads,
int max_pending )
{
ldap_pvt_thread_pool_t pool;
int rc;
/* 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 (max_pending < 0)
max_pending = 0;
*tpool = NULL;
pool = (ldap_pvt_thread_pool_t) LDAP_CALLOC(1,
sizeof(struct ldap_int_thread_pool_s));
if (pool == NULL) return(-1);
rc = ldap_pvt_thread_mutex_init(&pool->ltp_mutex);
if (rc != 0)
return(rc);
rc = ldap_pvt_thread_cond_init(&pool->ltp_cond);
if (rc != 0)
return(rc);
rc = ldap_pvt_thread_cond_init(&pool->ltp_pcond);
if (rc != 0)
return(rc);
ldap_int_has_thread_pool = 1;
pool->ltp_state = LDAP_INT_THREAD_POOL_RUNNING;
pool->ltp_max_count = max_threads;
pool->ltp_max_pending = max_pending;
LDAP_STAILQ_INIT(&pool->ltp_pending_list);
LDAP_SLIST_INIT(&pool->ltp_free_list);
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);
#if 0
/* THIS WILL NOT WORK on some systems. If the process
* forks after starting a thread, there is no guarantee
* that the thread will survive the fork. For example,
* slapd forks in order to daemonize, and does so after
* calling ldap_pvt_thread_pool_init. On some systems,
* this initial thread does not run in the child process,
* but ltp_open_count == 1, so two things happen:
* 1) the first client connection fails, and 2) when
* slapd is kill'ed, it never terminates since it waits
* for all worker threads to exit. */
/* start up one thread, just so there is one. no need to
* lock the mutex right now, since no threads are running.
*/
pool->ltp_open_count++;
ldap_pvt_thread_t thr;
rc = ldap_pvt_thread_create( &thr, 1, ldap_int_thread_pool_wrapper, pool );
if( rc != 0) {
/* couldn't start one? then don't start any */
ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
LDAP_STAILQ_REMOVE(ldap_int_thread_pool_list, pool,
ldap_int_thread_pool_s, ltp_next);
ldap_int_has_thread_pool = 0;
ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
ldap_pvt_thread_cond_destroy(&pool->ltp_pcond);
ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
LDAP_FREE(pool);
return(-1);
}
#endif
*tpool = pool;
return(0);
}
/* 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 )
{
struct ldap_int_thread_pool_s *pool;
ldap_int_thread_task_t *task;
ldap_pvt_thread_t thr;
if (tpool == NULL)
return(-1);
pool = *tpool;
if (pool == NULL)
return(-1);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
if (pool->ltp_state != LDAP_INT_THREAD_POOL_RUNNING
|| (pool->ltp_max_pending
&& pool->ltp_pending_count >= pool->ltp_max_pending))
{
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(-1);
}
task = LDAP_SLIST_FIRST(&pool->ltp_free_list);
if (task) {
LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltt_next.l);
} else {
task = (ldap_int_thread_task_t *) LDAP_MALLOC(sizeof(*task));
if (task == NULL) {
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(-1);
}
}
task->ltt_start_routine = start_routine;
task->ltt_arg = arg;
pool->ltp_pending_count++;
LDAP_STAILQ_INSERT_TAIL(&pool->ltp_pending_list, task, ltt_next.q);
if (pool->ltp_pause) {
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(0);
}
ldap_pvt_thread_cond_signal(&pool->ltp_cond);
if (pool->ltp_open_count < pool->ltp_active_count + pool->ltp_pending_count
&& (pool->ltp_open_count <
(pool->ltp_max_count ? pool->ltp_max_count : LDAP_MAXTHR)))
{
pool->ltp_open_count++;
pool->ltp_starting++;
if (0 != ldap_pvt_thread_create(
&thr, 1, ldap_int_thread_pool_wrapper, pool))
{
/* couldn't create thread. back out of
* ltp_open_count and check for even worse things.
*/
pool->ltp_starting--;
pool->ltp_open_count--;
if (pool->ltp_open_count == 0) {
/* no open threads at all?!?
*/
ldap_int_thread_task_t *ptr;
/* let pool_destroy know there are no more threads */
ldap_pvt_thread_cond_signal(&pool->ltp_cond);
LDAP_STAILQ_FOREACH(ptr, &pool->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.
*/
LDAP_STAILQ_REMOVE(&pool->ltp_pending_list, task,
ldap_int_thread_task_s, ltt_next.q);
pool->ltp_pending_count--;
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
LDAP_FREE(task);
return(-1);
}
}
/* there is another open thread, so this
* task will be handled eventually.
* continue on, we have signalled that
* the task is waiting.
*/
}
}
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
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;
if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR))
max_threads = 0;
if (tpool == NULL)
return(-1);
pool = *tpool;
if (pool == NULL)
return(-1);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
pool->ltp_max_count = max_threads;
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
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;
}
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
switch ( param ) {
case LDAP_PVT_THREAD_POOL_PARAM_MAX:
count = pool->ltp_max_count;
break;
case LDAP_PVT_THREAD_POOL_PARAM_MAX_PENDING:
count = pool->ltp_max_pending;
break;
case LDAP_PVT_THREAD_POOL_PARAM_OPEN:
count = pool->ltp_open_count;
break;
case LDAP_PVT_THREAD_POOL_PARAM_STARTING:
count = pool->ltp_starting;
break;
case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE:
count = pool->ltp_active_count;
break;
case LDAP_PVT_THREAD_POOL_PARAM_PAUSING:
count = pool->ltp_pause;
break;
case LDAP_PVT_THREAD_POOL_PARAM_PENDING:
count = pool->ltp_pending_count;
break;
case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD:
count = pool->ltp_pending_count + pool->ltp_active_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: {
static struct {
char *name;
ldap_int_thread_pool_state_t state;
} str2state[] = {
{ "running", LDAP_INT_THREAD_POOL_RUNNING },
{ "finishing", LDAP_INT_THREAD_POOL_FINISHING },
{ "stopping", LDAP_INT_THREAD_POOL_STOPPING },
{ NULL }
};
int i;
if ( pool->ltp_pause ) {
*((char **)value) = "pausing";
} else {
for ( i = 0; str2state[ i ].name != NULL; i++ ) {
if ( str2state[ i ].state == pool->ltp_state ) {
break;
}
}
*((char **)value) = str2state[ i ].name;
}
if ( *((char **)value) != NULL ) {
count = -2;
}
} break;
case LDAP_PVT_THREAD_POOL_PARAM_UNKNOWN:
break;
}
ldap_pvt_thread_mutex_unlock( &pool->ltp_mutex );
if ( count > -1 ) {
*((int *)value) = count;
}
return ( count == -1 ? -1 : 0 );
}
/*
* 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;
}
/* Destroy the pool after making its threads finish */
int
ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending )
{
struct ldap_int_thread_pool_s *pool, *pptr;
ldap_int_thread_task_t *task;
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_mutex_lock(&pool->ltp_mutex);
pool->ltp_state = run_pending
? LDAP_INT_THREAD_POOL_FINISHING
: LDAP_INT_THREAD_POOL_STOPPING;
while (pool->ltp_open_count) {
if (!pool->ltp_pause)
ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
}
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
while ((task = LDAP_STAILQ_FIRST(&pool->ltp_pending_list)) != NULL)
{
LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltt_next.q);
LDAP_FREE(task);
}
while ((task = LDAP_SLIST_FIRST(&pool->ltp_free_list)) != NULL)
{
LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltt_next.l);
LDAP_FREE(task);
}
ldap_pvt_thread_cond_destroy(&pool->ltp_pcond);
ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
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_pool_s *pool = xpool;
ldap_int_thread_task_t *task;
ldap_int_thread_userctx_t ctx, *kctx;
unsigned i, keyslot, hash;
assert(pool != NULL);
for ( i=0; i<MAXKEYS; i++ ) {
ctx.ltu_key[i].ltk_key = NULL;
}
ctx.ltu_id = ldap_pvt_thread_self();
TID_HASH(ctx.ltu_id, hash);
ldap_pvt_thread_key_setdata( ldap_tpool_key, &ctx );
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);
/* 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);
pool->ltp_starting--;
for (;;) {
while (pool->ltp_pause)
ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
if (pool->ltp_state == LDAP_INT_THREAD_POOL_STOPPING)
break;
task = LDAP_STAILQ_FIRST(&pool->ltp_pending_list);
if (task == NULL) {
if (pool->ltp_state == LDAP_INT_THREAD_POOL_FINISHING)
break;
if (pool->ltp_open_count >
(pool->ltp_max_count ? pool->ltp_max_count : LDAP_MAXTHR))
{
/* too many threads running (can happen if the
* maximum threads value is set during ongoing
* operation using ldap_pvt_thread_pool_maxthreads)
* so let this thread die.
*/
break;
}
/* 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 (break;)
*
* Just use pthread_cond_timedwait if we want to
* check idle time.
*/
assert(pool->ltp_state == LDAP_INT_THREAD_POOL_RUNNING);
ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
continue;
}
LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltt_next.q);
pool->ltp_pending_count--;
pool->ltp_active_count++;
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
task->ltt_start_routine(&ctx, task->ltt_arg);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
LDAP_SLIST_INSERT_HEAD(&pool->ltp_free_list, task, ltt_next.l);
pool->ltp_active_count--;
/* let pool_pause know when it is the sole active thread */
if (pool->ltp_active_count < 2)
ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
}
/* The ltp_mutex lock protects ctx->ltu_key from pool_purgekey()
* during this call, since it prevents new pauses. */
ldap_pvt_thread_pool_context_reset(&ctx);
ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
thread_keys[keyslot].ctx = DELETED_THREAD_CTX;
ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
pool->ltp_open_count--;
/* let pool_destroy know we're all done */
if (pool->ltp_open_count < 1)
ldap_pvt_thread_cond_signal(&pool->ltp_cond);
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
ldap_pvt_thread_exit(NULL);
return(NULL);
}
/* Pause the pool. Return when all other threads are paused. */
int
ldap_pvt_thread_pool_pause (
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);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
/* If someone else has already requested a pause, we have to wait */
if (pool->ltp_pause) {
pool->ltp_pending_count++;
pool->ltp_active_count--;
/* let the other pool_pause() know when it can proceed */
if (pool->ltp_active_count < 2)
ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
do {
ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
} while (pool->ltp_pause);
pool->ltp_pending_count--;
pool->ltp_active_count++;
}
/* Wait for everyone else to pause or finish */
pool->ltp_pause = 1;
while (pool->ltp_active_count > 1) {
ldap_pvt_thread_cond_wait(&pool->ltp_pcond, &pool->ltp_mutex);
}
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(0);
}
/* End a pause */
int
ldap_pvt_thread_pool_resume (
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);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
pool->ltp_pause = 0;
if (pool->ltp_state == LDAP_INT_THREAD_POOL_RUNNING)
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; i<MAXKEYS && ctx->ltu_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 )
{
ldap_int_thread_userctx_t *ctx = xctx;
int i, found;
if ( !ctx || !key ) return EINVAL;
for ( i=found=0; i<MAXKEYS; i++ ) {
if ( ctx->ltu_key[i].ltk_key == key ) {
found = 1;
break;
} else if ( !ctx->ltu_key[i].ltk_key ) {
break;
}
}
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 );
for ( i=0; i<LDAP_MAXTHR; i++ ) {
ctx = thread_keys[i].ctx;
if ( ctx && ctx != DELETED_THREAD_CTX ) {
for ( j=0; j<MAXKEYS && ctx->ltu_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;
}
}
}
}
}
/*
* 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 : &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 */
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