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Share fdqueue code between MPMs event and worker.
This first step moves the content of server/mpm/event/fdqueue.c to the existing server/mpm_unix.c file, and the server/mpm/event/fdqueue.h file to trunk/server/mpm_unix.h (untouched for now, simple svn move). Will follow up with the necessary changes to mpm_unix.* for common code. [Reverted by r1821619] git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1821526 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Yann Ylavic
@@ -36,6 +36,7 @@
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#include "apr_getopt.h"
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#include "apr_optional.h"
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#include "apr_allocator.h"
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#include "apr_atomic.h"
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#include "httpd.h"
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#include "http_config.h"
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@@ -48,6 +49,8 @@
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#include "scoreboard.h"
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#include "util_mutex.h"
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#include "mpm_unix.h"
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#ifdef HAVE_PWD_H
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#include <pwd.h>
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#endif
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@@ -1104,4 +1107,516 @@ AP_DECLARE(apr_status_t) ap_fatal_signal_setup(server_rec *s,
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return APR_SUCCESS;
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}
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/*
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* fdqueue code used by MPMs event and worker.
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* Not part of the API, so not AP_DECLARE()d.
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*/
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static const apr_uint32_t zero_pt = APR_UINT32_MAX/2;
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struct recycled_pool
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{
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apr_pool_t *pool;
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struct recycled_pool *next;
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};
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struct fd_queue_info_t
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{
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apr_uint32_t volatile idlers; /**
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* >= zero_pt: number of idle worker threads
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* < zero_pt: number of threads blocked,
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* waiting for an idle worker
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*/
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apr_thread_mutex_t *idlers_mutex;
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apr_thread_cond_t *wait_for_idler;
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int terminated;
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int max_idlers;
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int max_recycled_pools;
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apr_uint32_t recycled_pools_count;
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struct recycled_pool *volatile recycled_pools;
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};
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static apr_status_t queue_info_cleanup(void *data_)
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{
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fd_queue_info_t *qi = data_;
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apr_thread_cond_destroy(qi->wait_for_idler);
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apr_thread_mutex_destroy(qi->idlers_mutex);
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/* Clean up any pools in the recycled list */
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for (;;) {
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struct recycled_pool *first_pool = qi->recycled_pools;
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if (first_pool == NULL) {
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break;
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}
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if (apr_atomic_casptr
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((void*) &(qi->recycled_pools), first_pool->next,
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first_pool) == first_pool) {
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apr_pool_destroy(first_pool->pool);
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}
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}
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return APR_SUCCESS;
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}
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apr_status_t ap_queue_info_create(fd_queue_info_t ** queue_info,
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apr_pool_t * pool, int max_idlers,
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int max_recycled_pools)
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{
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apr_status_t rv;
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fd_queue_info_t *qi;
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qi = apr_pcalloc(pool, sizeof(*qi));
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rv = apr_thread_mutex_create(&qi->idlers_mutex, APR_THREAD_MUTEX_DEFAULT,
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pool);
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if (rv != APR_SUCCESS) {
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return rv;
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}
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rv = apr_thread_cond_create(&qi->wait_for_idler, pool);
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if (rv != APR_SUCCESS) {
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return rv;
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}
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qi->recycled_pools = NULL;
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qi->max_recycled_pools = max_recycled_pools;
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qi->max_idlers = max_idlers;
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qi->idlers = zero_pt;
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apr_pool_cleanup_register(pool, qi, queue_info_cleanup,
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apr_pool_cleanup_null);
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*queue_info = qi;
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return APR_SUCCESS;
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}
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apr_status_t ap_queue_info_set_idle(fd_queue_info_t * queue_info,
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apr_pool_t * pool_to_recycle)
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{
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apr_status_t rv;
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ap_push_pool(queue_info, pool_to_recycle);
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/* If other threads are waiting on a worker, wake one up */
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if (apr_atomic_inc32(&queue_info->idlers) < zero_pt) {
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rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
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if (rv != APR_SUCCESS) {
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AP_DEBUG_ASSERT(0);
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return rv;
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}
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rv = apr_thread_cond_signal(queue_info->wait_for_idler);
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if (rv != APR_SUCCESS) {
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apr_thread_mutex_unlock(queue_info->idlers_mutex);
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return rv;
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}
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rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
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if (rv != APR_SUCCESS) {
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return rv;
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}
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}
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return APR_SUCCESS;
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}
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apr_status_t ap_queue_info_try_get_idler(fd_queue_info_t * queue_info)
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{
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/* Don't block if there isn't any idle worker. */
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for (;;) {
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apr_uint32_t idlers = queue_info->idlers;
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if (idlers <= zero_pt) {
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return APR_EAGAIN;
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}
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if (apr_atomic_cas32(&queue_info->idlers, idlers - 1,
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idlers) == idlers) {
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return APR_SUCCESS;
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}
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}
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}
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apr_status_t ap_queue_info_wait_for_idler(fd_queue_info_t * queue_info,
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int *had_to_block)
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{
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apr_status_t rv;
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/* Block if there isn't any idle worker.
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* apr_atomic_add32(x, -1) does the same as dec32(x), except
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* that it returns the previous value (unlike dec32's bool).
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*/
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if (apr_atomic_add32(&queue_info->idlers, -1) <= zero_pt) {
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rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
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if (rv != APR_SUCCESS) {
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AP_DEBUG_ASSERT(0);
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apr_atomic_inc32(&(queue_info->idlers)); /* back out dec */
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return rv;
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}
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/* Re-check the idle worker count to guard against a
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* race condition. Now that we're in the mutex-protected
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* region, one of two things may have happened:
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* - If the idle worker count is still negative, the
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* workers are all still busy, so it's safe to
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* block on a condition variable.
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* - If the idle worker count is non-negative, then a
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* worker has become idle since the first check
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* of queue_info->idlers above. It's possible
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* that the worker has also signaled the condition
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* variable--and if so, the listener missed it
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* because it wasn't yet blocked on the condition
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* variable. But if the idle worker count is
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* now non-negative, it's safe for this function to
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* return immediately.
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*
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* A "negative value" (relative to zero_pt) in
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* queue_info->idlers tells how many
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* threads are waiting on an idle worker.
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*/
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if (queue_info->idlers < zero_pt) {
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*had_to_block = 1;
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rv = apr_thread_cond_wait(queue_info->wait_for_idler,
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queue_info->idlers_mutex);
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if (rv != APR_SUCCESS) {
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apr_status_t rv2;
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AP_DEBUG_ASSERT(0);
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rv2 = apr_thread_mutex_unlock(queue_info->idlers_mutex);
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if (rv2 != APR_SUCCESS) {
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return rv2;
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}
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return rv;
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}
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}
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rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
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if (rv != APR_SUCCESS) {
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return rv;
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}
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}
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if (queue_info->terminated) {
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return APR_EOF;
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}
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else {
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return APR_SUCCESS;
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}
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}
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apr_uint32_t ap_queue_info_get_idlers(fd_queue_info_t * queue_info)
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{
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apr_uint32_t val;
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val = apr_atomic_read32(&queue_info->idlers);
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if (val <= zero_pt)
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return 0;
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return val - zero_pt;
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}
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void ap_push_pool(fd_queue_info_t * queue_info,
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apr_pool_t * pool_to_recycle)
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{
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struct recycled_pool *new_recycle;
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/* If we have been given a pool to recycle, atomically link
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* it into the queue_info's list of recycled pools
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*/
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if (!pool_to_recycle)
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return;
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if (queue_info->max_recycled_pools >= 0) {
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apr_uint32_t cnt = apr_atomic_read32(&queue_info->recycled_pools_count);
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if (cnt >= queue_info->max_recycled_pools) {
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apr_pool_destroy(pool_to_recycle);
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return;
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}
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apr_atomic_inc32(&queue_info->recycled_pools_count);
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}
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apr_pool_clear(pool_to_recycle);
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new_recycle = (struct recycled_pool *) apr_palloc(pool_to_recycle,
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sizeof (*new_recycle));
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new_recycle->pool = pool_to_recycle;
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for (;;) {
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/*
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* Save queue_info->recycled_pool in local variable next because
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* new_recycle->next can be changed after apr_atomic_casptr
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* function call. For gory details see PR 44402.
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*/
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struct recycled_pool *next = queue_info->recycled_pools;
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new_recycle->next = next;
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if (apr_atomic_casptr((void*) &(queue_info->recycled_pools),
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new_recycle, next) == next)
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break;
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}
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}
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void ap_pop_pool(apr_pool_t ** recycled_pool, fd_queue_info_t * queue_info)
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{
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/* Atomically pop a pool from the recycled list */
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/* This function is safe only as long as it is single threaded because
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* it reaches into the queue and accesses "next" which can change.
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* We are OK today because it is only called from the listener thread.
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* cas-based pushes do not have the same limitation - any number can
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* happen concurrently with a single cas-based pop.
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*/
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*recycled_pool = NULL;
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/* Atomically pop a pool from the recycled list */
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for (;;) {
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struct recycled_pool *first_pool = queue_info->recycled_pools;
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if (first_pool == NULL) {
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break;
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}
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if (apr_atomic_casptr
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((void*) &(queue_info->recycled_pools),
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first_pool->next, first_pool) == first_pool) {
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*recycled_pool = first_pool->pool;
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if (queue_info->max_recycled_pools >= 0)
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apr_atomic_dec32(&queue_info->recycled_pools_count);
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break;
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}
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}
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}
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void ap_free_idle_pools(fd_queue_info_t *queue_info)
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{
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apr_pool_t *p;
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queue_info->max_recycled_pools = 0;
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do {
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ap_pop_pool(&p, queue_info);
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if (p != NULL)
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apr_pool_destroy(p);
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} while (p != NULL);
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}
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apr_status_t ap_queue_info_term(fd_queue_info_t * queue_info)
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{
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apr_status_t rv;
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rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
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if (rv != APR_SUCCESS) {
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return rv;
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}
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queue_info->terminated = 1;
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apr_thread_cond_broadcast(queue_info->wait_for_idler);
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return apr_thread_mutex_unlock(queue_info->idlers_mutex);
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}
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/**
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* Detects when the fd_queue_t is full. This utility function is expected
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* to be called from within critical sections, and is not threadsafe.
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*/
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#define ap_queue_full(queue) ((queue)->nelts == (queue)->bounds)
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/**
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* Detects when the fd_queue_t is empty. This utility function is expected
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* to be called from within critical sections, and is not threadsafe.
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*/
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#define ap_queue_empty(queue) ((queue)->nelts == 0 && APR_RING_EMPTY(&queue->timers ,timer_event_t, link))
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/**
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* Callback routine that is called to destroy this
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* fd_queue_t when its pool is destroyed.
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*/
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static apr_status_t ap_queue_destroy(void *data)
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{
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fd_queue_t *queue = data;
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/* Ignore errors here, we can't do anything about them anyway.
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* XXX: We should at least try to signal an error here, it is
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* indicative of a programmer error. -aaron */
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apr_thread_cond_destroy(queue->not_empty);
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apr_thread_mutex_destroy(queue->one_big_mutex);
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return APR_SUCCESS;
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}
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/**
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* Initialize the fd_queue_t.
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*/
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apr_status_t ap_queue_init(fd_queue_t * queue, int queue_capacity,
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apr_pool_t * a)
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{
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int i;
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apr_status_t rv;
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if ((rv = apr_thread_mutex_create(&queue->one_big_mutex,
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APR_THREAD_MUTEX_DEFAULT,
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a)) != APR_SUCCESS) {
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return rv;
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}
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if ((rv = apr_thread_cond_create(&queue->not_empty, a)) != APR_SUCCESS) {
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return rv;
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}
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APR_RING_INIT(&queue->timers, timer_event_t, link);
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queue->data = apr_palloc(a, queue_capacity * sizeof(fd_queue_elem_t));
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queue->bounds = queue_capacity;
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queue->nelts = 0;
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queue->in = 0;
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queue->out = 0;
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/* Set all the sockets in the queue to NULL */
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for (i = 0; i < queue_capacity; ++i)
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queue->data[i].sd = NULL;
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apr_pool_cleanup_register(a, queue, ap_queue_destroy,
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apr_pool_cleanup_null);
|
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|
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return APR_SUCCESS;
|
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}
|
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|
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/**
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* Push a new socket onto the queue.
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*
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* precondition: ap_queue_info_wait_for_idler has already been called
|
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* to reserve an idle worker thread
|
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*/
|
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apr_status_t ap_queue_push(fd_queue_t * queue, apr_socket_t * sd,
|
||||
event_conn_state_t * ecs, apr_pool_t * p)
|
||||
{
|
||||
fd_queue_elem_t *elem;
|
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apr_status_t rv;
|
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|
||||
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
|
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return rv;
|
||||
}
|
||||
|
||||
AP_DEBUG_ASSERT(!queue->terminated);
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AP_DEBUG_ASSERT(!ap_queue_full(queue));
|
||||
|
||||
elem = &queue->data[queue->in];
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||||
queue->in++;
|
||||
if (queue->in >= queue->bounds)
|
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queue->in -= queue->bounds;
|
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elem->sd = sd;
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||||
elem->ecs = ecs;
|
||||
elem->p = p;
|
||||
queue->nelts++;
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||||
|
||||
apr_thread_cond_signal(queue->not_empty);
|
||||
|
||||
if ((rv = apr_thread_mutex_unlock(queue->one_big_mutex)) != APR_SUCCESS) {
|
||||
return rv;
|
||||
}
|
||||
|
||||
return APR_SUCCESS;
|
||||
}
|
||||
|
||||
apr_status_t ap_queue_push_timer(fd_queue_t * queue, timer_event_t *te)
|
||||
{
|
||||
apr_status_t rv;
|
||||
|
||||
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
|
||||
return rv;
|
||||
}
|
||||
|
||||
AP_DEBUG_ASSERT(!queue->terminated);
|
||||
|
||||
APR_RING_INSERT_TAIL(&queue->timers, te, timer_event_t, link);
|
||||
|
||||
apr_thread_cond_signal(queue->not_empty);
|
||||
|
||||
if ((rv = apr_thread_mutex_unlock(queue->one_big_mutex)) != APR_SUCCESS) {
|
||||
return rv;
|
||||
}
|
||||
|
||||
return APR_SUCCESS;
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves the next available socket from the queue. If there are no
|
||||
* sockets available, it will block until one becomes available.
|
||||
* Once retrieved, the socket is placed into the address specified by
|
||||
* 'sd'.
|
||||
*/
|
||||
apr_status_t ap_queue_pop_something(fd_queue_t * queue, apr_socket_t ** sd,
|
||||
event_conn_state_t ** ecs, apr_pool_t ** p,
|
||||
timer_event_t ** te_out)
|
||||
{
|
||||
fd_queue_elem_t *elem;
|
||||
apr_status_t rv;
|
||||
|
||||
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
|
||||
return rv;
|
||||
}
|
||||
|
||||
/* Keep waiting until we wake up and find that the queue is not empty. */
|
||||
if (ap_queue_empty(queue)) {
|
||||
if (!queue->terminated) {
|
||||
apr_thread_cond_wait(queue->not_empty, queue->one_big_mutex);
|
||||
}
|
||||
/* If we wake up and it's still empty, then we were interrupted */
|
||||
if (ap_queue_empty(queue)) {
|
||||
rv = apr_thread_mutex_unlock(queue->one_big_mutex);
|
||||
if (rv != APR_SUCCESS) {
|
||||
return rv;
|
||||
}
|
||||
if (queue->terminated) {
|
||||
return APR_EOF; /* no more elements ever again */
|
||||
}
|
||||
else {
|
||||
return APR_EINTR;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
*te_out = NULL;
|
||||
|
||||
if (!APR_RING_EMPTY(&queue->timers, timer_event_t, link)) {
|
||||
*te_out = APR_RING_FIRST(&queue->timers);
|
||||
APR_RING_REMOVE(*te_out, link);
|
||||
}
|
||||
else {
|
||||
elem = &queue->data[queue->out];
|
||||
queue->out++;
|
||||
if (queue->out >= queue->bounds)
|
||||
queue->out -= queue->bounds;
|
||||
queue->nelts--;
|
||||
*sd = elem->sd;
|
||||
*ecs = elem->ecs;
|
||||
*p = elem->p;
|
||||
#ifdef AP_DEBUG
|
||||
elem->sd = NULL;
|
||||
elem->p = NULL;
|
||||
#endif /* AP_DEBUG */
|
||||
}
|
||||
|
||||
rv = apr_thread_mutex_unlock(queue->one_big_mutex);
|
||||
return rv;
|
||||
}
|
||||
|
||||
static apr_status_t queue_interrupt(fd_queue_t *queue, int all, int term)
|
||||
{
|
||||
apr_status_t rv;
|
||||
|
||||
if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
|
||||
return rv;
|
||||
}
|
||||
/* we must hold one_big_mutex when setting this... otherwise,
|
||||
* we could end up setting it and waking everybody up just after a
|
||||
* would-be popper checks it but right before they block
|
||||
*/
|
||||
if (term) {
|
||||
queue->terminated = 1;
|
||||
}
|
||||
if (all)
|
||||
apr_thread_cond_broadcast(queue->not_empty);
|
||||
else
|
||||
apr_thread_cond_signal(queue->not_empty);
|
||||
return apr_thread_mutex_unlock(queue->one_big_mutex);
|
||||
}
|
||||
|
||||
apr_status_t ap_queue_interrupt_all(fd_queue_t * queue)
|
||||
{
|
||||
return queue_interrupt(queue, 1, 0);
|
||||
}
|
||||
|
||||
apr_status_t ap_queue_interrupt_one(fd_queue_t * queue)
|
||||
{
|
||||
return queue_interrupt(queue, 0, 0);
|
||||
}
|
||||
|
||||
apr_status_t ap_queue_term(fd_queue_t * queue)
|
||||
{
|
||||
return queue_interrupt(queue, 1, 1);
|
||||
}
|
||||
|
||||
#endif /* WIN32 */
|
||||
|
||||
Reference in New Issue
Block a user