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_PAUSING
+ LDAP_INT_THREAD_POOL_STOPPING
} ldap_int_thread_pool_state_t;
-typedef struct ldap_int_thread_key_s {
+/* 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_thread_key_t;
+} 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_thread_key_t ltu_key[MAXKEYS];
+ ldap_int_tpool_key_t ltu_key[MAXKEYS];
} ldap_int_thread_userctx_t;
-static ldap_pvt_thread_t tid_zero;
+/* 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_pvt_thread_t id;
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];
-
-typedef struct ldap_int_thread_ctx_s {
+#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_ctx_s) q;
- LDAP_SLIST_ENTRY(ldap_int_thread_ctx_s) l;
- LDAP_SLIST_ENTRY(ldap_int_thread_ctx_s) al;
- } ltc_next;
- ldap_pvt_thread_start_t *ltc_start_routine;
- void *ltc_arg;
-} ldap_int_thread_ctx_t;
+ 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;
- LDAP_STAILQ_HEAD(tcq, ldap_int_thread_ctx_s) ltp_pending_list;
- LDAP_SLIST_HEAD(tcl, ldap_int_thread_ctx_s) ltp_free_list;
- LDAP_SLIST_HEAD(tclq, ldap_int_thread_ctx_s) ltp_active_list;
+
+ /* 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;
- long ltp_max_count;
- long ltp_max_pending;
- long ltp_pending_count;
- long ltp_active_count;
- long ltp_open_count;
- long ltp_starting;
+
+ /* 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 void *ldap_int_thread_pool_wrapper( void *pool );
-static ldap_pvt_thread_t ldap_int_main_tid;
+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_tid = ldap_pvt_thread_self();
- ldap_int_main_thrctx.ltu_id = ldap_int_main_tid;
-
+ 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);
}
(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);
}
-typedef struct ldap_lazy_sem_t {
- ldap_pvt_thread_mutex_t ls_mutex;
- ldap_pvt_thread_cond_t ls_cond;
- int ls_sem_value;
- /*
- * when more than ls_lazy_count number of resources
- * becmoes available, the thread wating for the resources will
- * be waken up in order to prevent frequent blocking/waking-up
- */
- unsigned int ls_lazy_count;
- /*
- * only one thread(listener) will wait on this semaphore
- * using a flag instead of a list
- */
- int ls_wait;
-} ldap_lazy_sem_t;
-
-ldap_lazy_sem_t* thread_pool_sem = NULL;
-
-int
-ldap_lazy_sem_init( unsigned int value, unsigned int lazyness )
-{
- thread_pool_sem = (ldap_lazy_sem_t*) LDAP_CALLOC(1,
- sizeof( ldap_lazy_sem_t ));
-
- if( thread_pool_sem == NULL ) return -1;
-
- ldap_pvt_thread_mutex_init( &thread_pool_sem->ls_mutex );
- ldap_pvt_thread_cond_init( &thread_pool_sem->ls_cond );
- thread_pool_sem->ls_sem_value = value;
- thread_pool_sem->ls_lazy_count = lazyness;
- thread_pool_sem->ls_wait = 0;
-
- return 0;
-}
-
-/* FIXME: move to some approprite header */
-int ldap_lazy_sem_dec( ldap_lazy_sem_t* ls );
-int ldap_lazy_sem_wait ( ldap_lazy_sem_t* ls );
-
-/*
- * ldap_lazy_sem_wait is used if a caller is blockable(listener).
- * Otherwise use ldap_lazy_sem_dec (worker)
- */
-int
-ldap_lazy_sem_op_submit( ldap_lazy_sem_t* ls )
-{
- if ( ls == NULL ) return -1;
-
- /* only worker thread has its thread ctx */
- if ( ldap_pvt_thread_pool_context() ) {
- /* worker thread */
- return ldap_lazy_sem_dec( ls );
- } else {
- /* listener */
- return ldap_lazy_sem_wait( ls );
- }
-}
-
-/*
- * test if given semaphore's count is zero.
- * If 0, the caller is blocked
- * If not, the count is decremented.
- */
-int
-ldap_lazy_sem_wait ( ldap_lazy_sem_t* ls )
-{
- ldap_pvt_thread_mutex_lock( &ls->ls_mutex );
-
-lazy_sem_retry:
- if ( ls->ls_sem_value <= 0 ) {
- /* no more avaliable resources */
- ls->ls_wait = 1;
- ldap_pvt_thread_cond_wait( &ls->ls_cond, &ls->ls_mutex );
- goto lazy_sem_retry;
- } else {
- /* avaliable resources */
- ls->ls_sem_value--;
- }
-
- ldap_pvt_thread_mutex_unlock( &ls->ls_mutex );
-
- return 0;
-}
-
-/*
- * decrement the count without blocking
- * even when the count becomes less than or equal to 0
- */
-int
-ldap_lazy_sem_dec( ldap_lazy_sem_t* ls )
-{
- ldap_pvt_thread_mutex_lock( &ls->ls_mutex );
-
- ls->ls_sem_value--;
-
- ldap_pvt_thread_mutex_unlock( &ls->ls_mutex );
-
- return 0;
-}
-
-/*
- * Increment the count by one and test if it is greater or
- * equal to lazyness. If it is, wake up a blocked thread.
- */
-int
-ldap_lazy_sem_post( ldap_lazy_sem_t* ls )
-{
- if( ls == NULL ) return (-1);
-
- ldap_pvt_thread_mutex_lock( &ls->ls_mutex );
-
- ls->ls_sem_value++;
- if ( ls->ls_wait ) {
- if ( ls->ls_sem_value >= ls->ls_lazy_count ) {
- ls->ls_wait = 0;
- ldap_pvt_thread_cond_signal( &ls->ls_cond );
- }
- }
-
- ldap_pvt_thread_mutex_unlock( &ls->ls_mutex );
-
- return 0;
-}
+/* Create a thread pool */
int
ldap_pvt_thread_pool_init (
ldap_pvt_thread_pool_t *tpool,
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));
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_SLIST_INIT(&pool->ltp_active_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);
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);
return(0);
}
-#define TID_HASH(tid, hash) do { unsigned i; \
- unsigned char *ptr = (unsigned char *)&(tid); \
- for (i=0, hash=0; i<sizeof(tid); i++) hash += ptr[i]; } while(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_ctx_t *ctx;
- int need_thread = 0;
+ ldap_int_thread_task_t *task;
ldap_pvt_thread_t thr;
if (tpool == NULL)
return(-1);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
- if ((pool->ltp_state != LDAP_INT_THREAD_POOL_RUNNING &&
- pool->ltp_state != LDAP_INT_THREAD_POOL_PAUSING)
- || (pool->ltp_max_pending > 0
+ 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);
}
- ctx = LDAP_SLIST_FIRST(&pool->ltp_free_list);
- if (ctx) {
- LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltc_next.l);
+
+ task = LDAP_SLIST_FIRST(&pool->ltp_free_list);
+ if (task) {
+ LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltt_next.l);
} else {
- ctx = (ldap_int_thread_ctx_t *) LDAP_MALLOC(
- sizeof(ldap_int_thread_ctx_t));
- if (ctx == NULL) {
+ task = (ldap_int_thread_task_t *) LDAP_MALLOC(sizeof(*task));
+ if (task == NULL) {
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
return(-1);
}
}
- ctx->ltc_start_routine = start_routine;
- ctx->ltc_arg = arg;
+ task->ltt_start_routine = start_routine;
+ task->ltt_arg = arg;
pool->ltp_pending_count++;
- LDAP_STAILQ_INSERT_TAIL(&pool->ltp_pending_list, ctx, ltc_next.q);
- if (pool->ltp_state == LDAP_INT_THREAD_POOL_PAUSING) {
+ 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 <= 0 ))
+ && (pool->ltp_open_count <
+ (pool->ltp_max_count ? pool->ltp_max_count : LDAP_MAXTHR)))
{
pool->ltp_open_count++;
pool->ltp_starting++;
- need_thread = 1;
- }
- ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
-
-#ifdef LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL
- ldap_lazy_sem_op_submit( thread_pool_sem );
-#endif
-
- if (need_thread) {
- int rc;
-
- ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
-
- rc = ldap_pvt_thread_create( &thr, 1,
- ldap_int_thread_pool_wrapper, pool );
- if (rc == 0) {
- int hash;
- pool->ltp_starting--;
-
- /* assign this thread ID to a key slot; start
- * at the thread ID itself (mod LDAP_MAXTHR) and
- * look for an empty slot.
- */
- TID_HASH(thr, hash);
- for (rc = hash & (LDAP_MAXTHR-1);
- !ldap_pvt_thread_equal(thread_keys[rc].id, tid_zero);
- rc = (rc+1) & (LDAP_MAXTHR-1));
- thread_keys[rc].id = thr;
- } else {
+ 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_open_count--;
pool->ltp_starting--;
+ pool->ltp_open_count--;
if (pool->ltp_open_count == 0) {
/* no open threads at all?!?
*/
- ldap_int_thread_ctx_t *ptr;
- LDAP_STAILQ_FOREACH(ptr, &pool->ltp_pending_list, ltc_next.q)
- if (ptr == ctx) break;
- if (ptr == ctx) {
- /* no open threads, context not handled, so
- * back out of ltp_pending_count, free the context,
+ 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, ctx,
- ldap_int_thread_ctx_s, ltc_next.q);
- 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(ctx);
+ LDAP_FREE(task);
return(-1);
}
}
/* there is another open thread, so this
- * context will be handled eventually.
- * continue on and signal that the context
- * is waiting.
+ * task will be handled eventually.
+ * continue on, we have signalled that
+ * the task is waiting.
*/
}
- ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
}
+ 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 )
+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);
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 )
+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;
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;
{ "running", LDAP_INT_THREAD_POOL_RUNNING },
{ "finishing", LDAP_INT_THREAD_POOL_FINISHING },
{ "stopping", LDAP_INT_THREAD_POOL_STOPPING },
- { "pausing", LDAP_INT_THREAD_POOL_PAUSING },
{ NULL }
};
int i;
- for ( i = 0; str2state[ i ].name != NULL; i++ ) {
- if ( str2state[ i ].state == pool->ltp_state ) {
- break;
+ 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;
}
- *((char **)value) = str2state[ i ].name;
- if ( str2state[ i ].name != NULL ) {
+ if ( *((char **)value) != NULL ) {
count = -2;
}
} break;
+
+ case LDAP_PVT_THREAD_POOL_PARAM_UNKNOWN:
+ break;
}
ldap_pvt_thread_mutex_unlock( &pool->ltp_mutex );
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_ctx_t *ctx;
+ ldap_int_thread_task_t *task;
if (tpool == NULL)
return(-1);
? LDAP_INT_THREAD_POOL_FINISHING
: LDAP_INT_THREAD_POOL_STOPPING;
- if ( pool->ltp_open_count ) {
- ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
+ 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 ((ctx = LDAP_STAILQ_FIRST(&pool->ltp_pending_list)) != NULL)
+ while ((task = LDAP_STAILQ_FIRST(&pool->ltp_pending_list)) != NULL)
{
- LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltc_next.q);
- LDAP_FREE(ctx);
+ LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltt_next.q);
+ LDAP_FREE(task);
}
- while ((ctx = LDAP_SLIST_FIRST(&pool->ltp_free_list)) != NULL)
+ while ((task = LDAP_SLIST_FIRST(&pool->ltp_free_list)) != NULL)
{
- LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltc_next.l);
- LDAP_FREE(ctx);
+ 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);
-#ifdef LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL
- if ( thread_pool_sem ) {
- LDAP_FREE( thread_pool_sem );
- }
-#endif
+ *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_ctx_t *ctx;
- ldap_int_thread_userctx_t uctx;
- int i, keyslot, hash;
+ ldap_int_thread_task_t *task;
+ ldap_int_thread_userctx_t ctx, *kctx;
+ unsigned i, keyslot, hash;
- if (pool == NULL)
- return NULL;
+ assert(pool != NULL);
for ( i=0; i<MAXKEYS; i++ ) {
- uctx.ltu_key[i].ltk_key = NULL;
+ ctx.ltu_key[i].ltk_key = NULL;
}
- uctx.ltu_id = ldap_pvt_thread_self();
+ 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);
- /* store pointer to our keys */
- TID_HASH(uctx.ltu_id, hash);
- for (i = hash & (LDAP_MAXTHR-1);
- !ldap_pvt_thread_equal(thread_keys[i].id, uctx.ltu_id);
- i = (i+1) & (LDAP_MAXTHR-1));
- thread_keys[i].ctx = &uctx;
- keyslot = i;
-
- while (pool->ltp_state != LDAP_INT_THREAD_POOL_STOPPING) {
- ctx = LDAP_STAILQ_FIRST(&pool->ltp_pending_list);
- if (ctx) {
- LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltc_next.q);
- } else {
+ /* 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_max_count > 0
- && pool->ltp_open_count > pool->ltp_max_count)
+
+ 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
* 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, leave thread (break;)
+ * check timer, wait if ltp_pause, leave thread (break;)
*
* Just use pthread_cond_timedwait if we want to
* check idle time.
*/
- if (pool->ltp_state == LDAP_INT_THREAD_POOL_RUNNING
- || pool->ltp_state == LDAP_INT_THREAD_POOL_PAUSING)
- {
- ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
- }
-
+ 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--;
-
- LDAP_SLIST_INSERT_HEAD(&pool->ltp_active_list, ctx, ltc_next.al);
pool->ltp_active_count++;
ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
- ctx->ltc_start_routine(&uctx, ctx->ltc_arg);
+ task->ltt_start_routine(&ctx, task->ltt_arg);
-#ifdef LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL
- ldap_lazy_sem_post( thread_pool_sem );
-#endif
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
- LDAP_SLIST_REMOVE(&pool->ltp_active_list, ctx,
- ldap_int_thread_ctx_s, ltc_next.al);
- LDAP_SLIST_INSERT_HEAD(&pool->ltp_free_list, ctx, ltc_next.l);
+ LDAP_SLIST_INSERT_HEAD(&pool->ltp_free_list, task, ltt_next.l);
pool->ltp_active_count--;
-
- if (pool->ltp_state == LDAP_INT_THREAD_POOL_PAUSING) {
- if (pool->ltp_active_count < 2) {
- ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
- }
- ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
- }
+ /* 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);
}
- ldap_pvt_thread_pool_context_reset(&uctx);
+ /* 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);
- thread_keys[keyslot].ctx = NULL;
- thread_keys[keyslot].id = tid_zero;
+ 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);
return(NULL);
}
+/* Pause the pool. Return when all other threads are paused. */
int
ldap_pvt_thread_pool_pause (
ldap_pvt_thread_pool_t *tpool )
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
/* If someone else has already requested a pause, we have to wait */
- while (pool->ltp_state == LDAP_INT_THREAD_POOL_PAUSING) {
+ if (pool->ltp_pause) {
pool->ltp_pending_count++;
pool->ltp_active_count--;
- ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
+ /* 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 finish */
- pool->ltp_state = LDAP_INT_THREAD_POOL_PAUSING;
+
+ /* 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 )
return(0);
ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
-
- pool->ltp_state = LDAP_INT_THREAD_POOL_RUNNING;
- ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
+ 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,
ldap_int_thread_userctx_t *ctx = xctx;
int i;
- if ( !ctx || !data ) return EINVAL;
+ 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 ) {
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,
ldap_pvt_thread_pool_keyfree_t *kfree )
{
ldap_int_thread_userctx_t *ctx = xctx;
- int i;
+ int i, found;
if ( !ctx || !key ) return EINVAL;
- for ( i=0; i<MAXKEYS; i++ ) {
- if ( !ctx->ltu_key[i].ltk_key || ctx->ltu_key[i].ltk_key == key ) {
- ctx->ltu_key[i].ltk_key = key;
- ctx->ltu_key[i].ltk_data = data;
- ctx->ltu_key[i].ltk_free = kfree;
- return 0;
+ 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;
}
}
- return ENOMEM;
+
+ 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.
int i, j;
ldap_int_thread_userctx_t *ctx;
+ assert ( key != NULL );
+
for ( i=0; i<LDAP_MAXTHR; i++ ) {
- if ( thread_keys[i].ctx ) {
- ctx = thread_keys[i].ctx;
- for ( j=0; j<MAXKEYS; j++ ) {
+ 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 );
- ctx->ltu_key[j].ltk_key = NULL;
- ctx->ltu_key[j].ltk_free = NULL;
+ 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 to
+ * 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( )
{
- ldap_pvt_thread_t tid;
- int i, hash;
+ void *ctx = NULL;
- tid = ldap_pvt_thread_self();
- if ( ldap_pvt_thread_equal( tid, ldap_int_main_tid ))
- return &ldap_int_main_thrctx;
-
- TID_HASH( tid, hash );
- for (i = hash & (LDAP_MAXTHR-1);
- !ldap_pvt_thread_equal(thread_keys[i].id, tid_zero) &&
- !ldap_pvt_thread_equal(thread_keys[i].id, tid);
- i = (i+1) & (LDAP_MAXTHR-1));
-
- return thread_keys[i].ctx;
+ 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;
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