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Commit 989c9f20 authored by Howard Chu's avatar Howard Chu
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ITS#5364, #5407 from HEAD

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include/ldap_pvt_thread.h
+ 8
− 0
View file @ 989c9f20
......@@ -243,10 +243,18 @@ ldap_pvt_thread_pool_query LDAP_P((
ldap_pvt_thread_pool_t *pool,
ldap_pvt_thread_pool_param_t param, void *value ));
LDAP_F( int )
ldap_pvt_thread_pool_pausing LDAP_P((
ldap_pvt_thread_pool_t *pool ));
LDAP_F( int )
ldap_pvt_thread_pool_backload LDAP_P((
ldap_pvt_thread_pool_t *pool ));
LDAP_F( int )
ldap_pvt_thread_pool_pausecheck LDAP_P((
ldap_pvt_thread_pool_t *pool ));
LDAP_F( int )
ldap_pvt_thread_pool_pause LDAP_P((
ldap_pvt_thread_pool_t *pool ));
......
libraries/libldap_r/tpool.c
+ 190
− 113
View file @ 989c9f20
......@@ -17,6 +17,7 @@
#include <stdio.h>
#include <ac/signal.h>
#include <ac/stdarg.h>
#include <ac/stdlib.h>
#include <ac/string.h>
......@@ -31,12 +32,6 @@
#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;
......@@ -52,6 +47,9 @@ typedef struct ldap_int_tpool_key_s {
/* 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) */
/* Context: thread ID and thread-specific key/data pairs */
typedef struct ldap_int_thread_userctx_s {
ldap_pvt_thread_t ltu_id;
......@@ -88,6 +86,8 @@ typedef struct ldap_int_thread_task_s {
void *ltt_arg;
} ldap_int_thread_task_t;
typedef LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ldap_int_tpool_plist_t;
struct ldap_int_thread_pool_s {
LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next;
......@@ -100,23 +100,56 @@ struct ldap_int_thread_pool_s {
/* ltp_active_count <= 1 && ltp_pause */
ldap_pvt_thread_cond_t ltp_pcond;
/* ltp_pause == 0 ? &ltp_pending_list : &empty_pending_list,
* maintaned to reduce work for pool_wrapper()
*/
ldap_int_tpool_plist_t *ltp_work_list;
/* pending tasks, and unused task objects */
LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ltp_pending_list;
ldap_int_tpool_plist_t ltp_pending_list;
LDAP_SLIST_HEAD(tcl, ldap_int_thread_task_s) ltp_free_list;
ldap_int_thread_pool_state_t ltp_state;
/* 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.
* Note: Pauses adjust ltp_<open_count/vary_open_count/work_list>,
* so pool_<submit/wrapper>() mostly can avoid testing ltp_pause.
*/
volatile sig_atomic_t ltp_pause;
/* Max number of threads in pool, or 0 for default (LDAP_MAXTHR) */
int ltp_max_count;
/* some active request needs to be the sole active request */
int ltp_pause;
/* Max number of pending + paused requests, negated when ltp_finishing */
int ltp_max_pending;
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 */
int ltp_pending_count; /* Pending or paused requests */
int ltp_active_count; /* Active, not paused requests */
int ltp_open_count; /* Number of threads, negated when ltp_pause */
int ltp_starting; /* Currenlty starting threads */
/* >0 if paused or we may open a thread, <0 if we should close a thread.
* Updated when ltp_<finishing/pause/max_count/open_count> change.
* Maintained to reduce the time ltp_mutex must be locked in
* ldap_pvt_thread_pool_<submit/wrapper>().
*/
int ltp_vary_open_count;
# define SET_VARY_OPEN_COUNT(pool) \
((pool)->ltp_vary_open_count = \
(pool)->ltp_pause ? 1 : \
(pool)->ltp_finishing ? -1 : \
((pool)->ltp_max_count ? (pool)->ltp_max_count : LDAP_MAXTHR) \
- (pool)->ltp_open_count)
};
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 =
......@@ -168,8 +201,8 @@ ldap_pvt_thread_pool_init (
if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR))
max_threads = 0;
if (max_pending < 0)
max_pending = 0;
if (! (1 <= max_pending && max_pending <= MAX_PENDING))
max_pending = MAX_PENDING;
*tpool = NULL;
pool = (ldap_pvt_thread_pool_t) LDAP_CALLOC(1,
......@@ -188,11 +221,15 @@ ldap_pvt_thread_pool_init (
return(rc);
ldap_int_has_thread_pool = 1;
pool->ltp_state = LDAP_INT_THREAD_POOL_RUNNING;
pool->ltp_max_count = max_threads;
SET_VARY_OPEN_COUNT(pool);
pool->ltp_max_pending = max_pending;
LDAP_STAILQ_INIT(&pool->ltp_pending_list);
pool->ltp_work_list = &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);
......@@ -213,6 +250,7 @@ ldap_pvt_thread_pool_init (
* lock the mutex right now, since no threads are running.
*/
pool->ltp_open_count++;
SET_VARY_OPEN_COUNT(pool);
ldap_pvt_thread_t thr;
rc = ldap_pvt_thread_create( &thr, 1, ldap_int_thread_pool_wrapper, pool );
......@@ -256,23 +294,17 @@ ldap_pvt_thread_pool_submit (
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);
}
if (pool->ltp_pending_count >= pool->ltp_max_pending)
goto failed;
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);
}
if (task == NULL)
goto failed;
}
task->ltt_start_routine = start_routine;
......@@ -280,17 +312,18 @@ ldap_pvt_thread_pool_submit (
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)))
/* true if ltp_pause != 0 or we should open (create) a thread */
if (pool->ltp_vary_open_count > 0 &&
pool->ltp_open_count < pool->ltp_active_count+pool->ltp_pending_count)
{
pool->ltp_open_count++;
if (pool->ltp_pause)
goto done;
pool->ltp_starting++;
pool->ltp_open_count++;
SET_VARY_OPEN_COUNT(pool);
if (0 != ldap_pvt_thread_create(
&thr, 1, ldap_int_thread_pool_wrapper, pool))
{
......@@ -299,6 +332,8 @@ ldap_pvt_thread_pool_submit (
*/
pool->ltp_starting--;
pool->ltp_open_count--;
SET_VARY_OPEN_COUNT(pool);
if (pool->ltp_open_count == 0) {
/* no open threads at all?!?
*/
......@@ -314,24 +349,28 @@ ldap_pvt_thread_pool_submit (
* back out of ltp_pending_count, free the task,
* report the error.
*/
pool->ltp_pending_count--;
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);
LDAP_SLIST_INSERT_HEAD(&pool->ltp_free_list, task,
ltt_next.l);
goto failed;
}
}
/* 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_cond_signal(&pool->ltp_cond);
done:
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(0);
failed:
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(-1);
}
/* Set max #threads. value <= 0 means max supported #threads (LDAP_MAXTHR) */
......@@ -354,7 +393,10 @@ ldap_pvt_thread_pool_maxthreads(
return(-1);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
pool->ltp_max_count = max_threads;
SET_VARY_OPEN_COUNT(pool);
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(0);
}
......@@ -387,10 +429,16 @@ ldap_pvt_thread_pool_query(
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_OPEN:
count = pool->ltp_open_count;
if (count < 0)
count = -count;
break;
case LDAP_PVT_THREAD_POOL_PARAM_STARTING:
......@@ -422,32 +470,12 @@ ldap_pvt_thread_pool_query(
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_STATE:
*((char **)value) =
pool->ltp_pause ? "pausing" :
!pool->ltp_finishing ? "running" :
pool->ltp_pending_count ? "finishing" : "stopping";
break;
case LDAP_PVT_THREAD_POOL_PARAM_UNKNOWN:
break;
......@@ -461,6 +489,23 @@ ldap_pvt_thread_pool_query(
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;
}
return rc;
}
/*
* wrapper for ldap_pvt_thread_pool_query(), left around
* for backwards compatibility
......@@ -505,22 +550,25 @@ ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending )
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;
pool->ltp_finishing = 1;
SET_VARY_OPEN_COUNT(pool);
if (pool->ltp_max_pending > 0)
pool->ltp_max_pending = -pool->ltp_max_pending;
if (!run_pending) {
while ((task = LDAP_STAILQ_FIRST(&pool->ltp_pending_list)) != NULL) {
LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltt_next.q);
LDAP_FREE(task);
}
pool->ltp_pending_count = 0;
}
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)
{
......@@ -528,6 +576,7 @@ ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending )
LDAP_FREE(task);
}
ldap_pvt_thread_mutex_unlock(&pool->ltp_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);
......@@ -544,6 +593,7 @@ ldap_int_thread_pool_wrapper (
{
struct ldap_int_thread_pool_s *pool = xpool;
ldap_int_thread_task_t *task;
ldap_int_tpool_plist_t *work_list;
ldap_int_thread_userctx_t ctx, *kctx;
unsigned i, keyslot, hash;
......@@ -578,24 +628,13 @@ ldap_int_thread_pool_wrapper (
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.
work_list = pool->ltp_work_list; /* help the compiler a bit */
task = LDAP_STAILQ_FIRST(work_list);
if (task == NULL) { /* paused or no pending tasks */
if (pool->ltp_vary_open_count < 0) {
/* not paused, and either finishing or too many
* threads running (can happen if ltp_max_count
* was reduced) so let this thread die.
*/
break;
}
......@@ -612,12 +651,11 @@ ldap_int_thread_pool_wrapper (
* 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);
LDAP_STAILQ_REMOVE_HEAD(work_list, ltt_next.q);
pool->ltp_pending_count--;
pool->ltp_active_count++;
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
......@@ -632,6 +670,8 @@ ldap_int_thread_pool_wrapper (
ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
}
assert(!pool->ltp_pause); /* thread_keys writable, ltp_open_count >= 0 */
/* 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);
......@@ -641,8 +681,9 @@ ldap_int_thread_pool_wrapper (
ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
pool->ltp_open_count--;
SET_VARY_OPEN_COUNT(pool);
/* let pool_destroy know we're all done */
if (pool->ltp_open_count < 1)
if (pool->ltp_open_count == 0)
ldap_pvt_thread_cond_signal(&pool->ltp_cond);
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
......@@ -651,10 +692,8 @@ ldap_int_thread_pool_wrapper (
return(NULL);
}
/* Pause the pool. Return when all other threads are paused. */
int
ldap_pvt_thread_pool_pause (
ldap_pvt_thread_pool_t *tpool )
static int
handle_pause( ldap_pvt_thread_pool_t *tpool, int do_pause )
{
struct ldap_int_thread_pool_s *pool;
......@@ -666,6 +705,9 @@ ldap_pvt_thread_pool_pause (
if (pool == NULL)
return(0);
if (! (do_pause || pool->ltp_pause))
return(0);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
/* If someone else has already requested a pause, we have to wait */
......@@ -682,14 +724,41 @@ ldap_pvt_thread_pool_pause (
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);
if (do_pause) {
/* Wait for everyone else to pause or finish */
pool->ltp_pause = 1;
/* Let ldap_pvt_thread_pool_submit() through to its ltp_pause test,
* and do not finish threads in ldap_pvt_thread_pool_wrapper() */
pool->ltp_open_count = -pool->ltp_open_count;
SET_VARY_OPEN_COUNT(pool);
/* Hide pending tasks from ldap_pvt_thread_pool_wrapper() */
pool->ltp_work_list = &empty_pending_list;
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);
return(!do_pause);
}
/*
* If a pause was requested, wait for it. If several threads
* are waiting to pause, let through one or more pauses.
* 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, 0 );
}
/* Pause the pool. Return when all other threads are paused. */
int
ldap_pvt_thread_pool_pause( ldap_pvt_thread_pool_t *tpool )
{
return handle_pause( tpool, 1 );
}
/* End a pause */
......@@ -708,9 +777,17 @@ ldap_pvt_thread_pool_resume (
return(0);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
assert(pool->ltp_pause);
pool->ltp_pause = 0;
if (pool->ltp_state == LDAP_INT_THREAD_POOL_RUNNING)
if (pool->ltp_open_count <= 0) /* true when paused, but be paranoid */
pool->ltp_open_count = -pool->ltp_open_count;
SET_VARY_OPEN_COUNT(pool);
pool->ltp_work_list = &pool->ltp_pending_list;
if (!pool->ltp_finishing)
ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(0);
}
......@@ -846,7 +923,7 @@ 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;
return ctx ? ctx : (void *) &ldap_int_main_thrctx;
}
/*
......
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