From 1c5106c6bff9faf73654282d7727f1af3f1186a3 Mon Sep 17 00:00:00 2001
From: Yann Ylavic <ylavic@apache.org>
Date: Thu, 18 Jan 2018 17:45:40 +0000
Subject: [PATCH] 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
---
server/mpm/event/config3.m4 | 2 +-
server/mpm/event/event.c | 2 +-
server/mpm/event/fdqueue.c | 524 ---------------------
server/mpm_unix.c | 515 ++++++++++++++++++++
server/{mpm/event/fdqueue.h => mpm_unix.h} | 0
5 files changed, 517 insertions(+), 526 deletions(-)
delete mode 100644 server/mpm/event/fdqueue.c
rename server/{mpm/event/fdqueue.h => mpm_unix.h} (100%)
diff --git a/server/mpm/event/config3.m4 b/server/mpm/event/config3.m4
index e15f235314..b4dc5e38bc 100644
--- a/server/mpm/event/config3.m4
+++ b/server/mpm/event/config3.m4
@@ -8,7 +8,7 @@ if test "$ac_cv_serf" = yes ; then
fi
APACHE_SUBST(MOD_MPM_EVENT_LDADD)
-APACHE_MPM_MODULE(event, $enable_mpm_event, event.lo fdqueue.lo,[
+APACHE_MPM_MODULE(event, $enable_mpm_event, event.lo,[
AC_CHECK_FUNCS(pthread_kill)
], , [\$(MOD_MPM_EVENT_LDADD)])
diff --git a/server/mpm/event/event.c b/server/mpm/event/event.c
index 8065ae287c..55a7e562d5 100644
--- a/server/mpm/event/event.c
+++ b/server/mpm/event/event.c
@@ -91,7 +91,7 @@
#include "mpm_common.h"
#include "ap_listen.h"
#include "scoreboard.h"
-#include "fdqueue.h"
+#include "mpm_unix.h"
#include "mpm_default.h"
#include "http_vhost.h"
#include "unixd.h"
diff --git a/server/mpm/event/fdqueue.c b/server/mpm/event/fdqueue.c
deleted file mode 100644
index 5b0192b2ee..0000000000
--- a/server/mpm/event/fdqueue.c
+++ /dev/null
@@ -1,524 +0,0 @@
-/* Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "fdqueue.h"
-#include "apr_atomic.h"
-
-static const apr_uint32_t zero_pt = APR_UINT32_MAX/2;
-
-struct recycled_pool
-{
- apr_pool_t *pool;
- struct recycled_pool *next;
-};
-
-struct fd_queue_info_t
-{
- apr_uint32_t volatile idlers; /**
- * >= zero_pt: number of idle worker threads
- * < zero_pt: number of threads blocked,
- * waiting for an idle worker
- */
- apr_thread_mutex_t *idlers_mutex;
- apr_thread_cond_t *wait_for_idler;
- int terminated;
- int max_idlers;
- int max_recycled_pools;
- apr_uint32_t recycled_pools_count;
- struct recycled_pool *volatile recycled_pools;
-};
-
-static apr_status_t queue_info_cleanup(void *data_)
-{
- fd_queue_info_t *qi = data_;
- apr_thread_cond_destroy(qi->wait_for_idler);
- apr_thread_mutex_destroy(qi->idlers_mutex);
-
- /* Clean up any pools in the recycled list */
- for (;;) {
- struct recycled_pool *first_pool = qi->recycled_pools;
- if (first_pool == NULL) {
- break;
- }
- if (apr_atomic_casptr
- ((void*) &(qi->recycled_pools), first_pool->next,
- first_pool) == first_pool) {
- apr_pool_destroy(first_pool->pool);
- }
- }
-
- return APR_SUCCESS;
-}
-
-apr_status_t ap_queue_info_create(fd_queue_info_t ** queue_info,
- apr_pool_t * pool, int max_idlers,
- int max_recycled_pools)
-{
- apr_status_t rv;
- fd_queue_info_t *qi;
-
- qi = apr_pcalloc(pool, sizeof(*qi));
-
- rv = apr_thread_mutex_create(&qi->idlers_mutex, APR_THREAD_MUTEX_DEFAULT,
- pool);
- if (rv != APR_SUCCESS) {
- return rv;
- }
- rv = apr_thread_cond_create(&qi->wait_for_idler, pool);
- if (rv != APR_SUCCESS) {
- return rv;
- }
- qi->recycled_pools = NULL;
- qi->max_recycled_pools = max_recycled_pools;
- qi->max_idlers = max_idlers;
- qi->idlers = zero_pt;
- apr_pool_cleanup_register(pool, qi, queue_info_cleanup,
- apr_pool_cleanup_null);
-
- *queue_info = qi;
-
- return APR_SUCCESS;
-}
-
-apr_status_t ap_queue_info_set_idle(fd_queue_info_t * queue_info,
- apr_pool_t * pool_to_recycle)
-{
- apr_status_t rv;
-
- ap_push_pool(queue_info, pool_to_recycle);
-
- /* If other threads are waiting on a worker, wake one up */
- if (apr_atomic_inc32(&queue_info->idlers) < zero_pt) {
- rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
- if (rv != APR_SUCCESS) {
- AP_DEBUG_ASSERT(0);
- return rv;
- }
- rv = apr_thread_cond_signal(queue_info->wait_for_idler);
- if (rv != APR_SUCCESS) {
- apr_thread_mutex_unlock(queue_info->idlers_mutex);
- return rv;
- }
- rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
- if (rv != APR_SUCCESS) {
- return rv;
- }
- }
-
- return APR_SUCCESS;
-}
-
-apr_status_t ap_queue_info_try_get_idler(fd_queue_info_t * queue_info)
-{
- /* Don't block if there isn't any idle worker. */
- for (;;) {
- apr_uint32_t idlers = queue_info->idlers;
- if (idlers <= zero_pt) {
- return APR_EAGAIN;
- }
- if (apr_atomic_cas32(&queue_info->idlers, idlers - 1,
- idlers) == idlers) {
- return APR_SUCCESS;
- }
- }
-}
-
-apr_status_t ap_queue_info_wait_for_idler(fd_queue_info_t * queue_info,
- int *had_to_block)
-{
- apr_status_t rv;
-
- /* Block if there isn't any idle worker.
- * apr_atomic_add32(x, -1) does the same as dec32(x), except
- * that it returns the previous value (unlike dec32's bool).
- */
- if (apr_atomic_add32(&queue_info->idlers, -1) <= zero_pt) {
- rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
- if (rv != APR_SUCCESS) {
- AP_DEBUG_ASSERT(0);
- apr_atomic_inc32(&(queue_info->idlers)); /* back out dec */
- return rv;
- }
- /* Re-check the idle worker count to guard against a
- * race condition. Now that we're in the mutex-protected
- * region, one of two things may have happened:
- * - If the idle worker count is still negative, the
- * workers are all still busy, so it's safe to
- * block on a condition variable.
- * - If the idle worker count is non-negative, then a
- * worker has become idle since the first check
- * of queue_info->idlers above. It's possible
- * that the worker has also signaled the condition
- * variable--and if so, the listener missed it
- * because it wasn't yet blocked on the condition
- * variable. But if the idle worker count is
- * now non-negative, it's safe for this function to
- * return immediately.
- *
- * A "negative value" (relative to zero_pt) in
- * queue_info->idlers tells how many
- * threads are waiting on an idle worker.
- */
- if (queue_info->idlers < zero_pt) {
- *had_to_block = 1;
- rv = apr_thread_cond_wait(queue_info->wait_for_idler,
- queue_info->idlers_mutex);
- if (rv != APR_SUCCESS) {
- apr_status_t rv2;
- AP_DEBUG_ASSERT(0);
- rv2 = apr_thread_mutex_unlock(queue_info->idlers_mutex);
- if (rv2 != APR_SUCCESS) {
- return rv2;
- }
- return rv;
- }
- }
- rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
- if (rv != APR_SUCCESS) {
- return rv;
- }
- }
-
- if (queue_info->terminated) {
- return APR_EOF;
- }
- else {
- return APR_SUCCESS;
- }
-}
-
-apr_uint32_t ap_queue_info_get_idlers(fd_queue_info_t * queue_info)
-{
- apr_uint32_t val;
- val = apr_atomic_read32(&queue_info->idlers);
- if (val <= zero_pt)
- return 0;
- return val - zero_pt;
-}
-
-void ap_push_pool(fd_queue_info_t * queue_info,
- apr_pool_t * pool_to_recycle)
-{
- struct recycled_pool *new_recycle;
- /* If we have been given a pool to recycle, atomically link
- * it into the queue_info's list of recycled pools
- */
- if (!pool_to_recycle)
- return;
-
- if (queue_info->max_recycled_pools >= 0) {
- apr_uint32_t cnt = apr_atomic_read32(&queue_info->recycled_pools_count);
- if (cnt >= queue_info->max_recycled_pools) {
- apr_pool_destroy(pool_to_recycle);
- return;
- }
- apr_atomic_inc32(&queue_info->recycled_pools_count);
- }
-
- apr_pool_clear(pool_to_recycle);
- new_recycle = (struct recycled_pool *) apr_palloc(pool_to_recycle,
- sizeof (*new_recycle));
- new_recycle->pool = pool_to_recycle;
- for (;;) {
- /*
- * Save queue_info->recycled_pool in local variable next because
- * new_recycle->next can be changed after apr_atomic_casptr
- * function call. For gory details see PR 44402.
- */
- struct recycled_pool *next = queue_info->recycled_pools;
- new_recycle->next = next;
- if (apr_atomic_casptr((void*) &(queue_info->recycled_pools),
- new_recycle, next) == next)
- break;
- }
-}
-
-void ap_pop_pool(apr_pool_t ** recycled_pool, fd_queue_info_t * queue_info)
-{
- /* Atomically pop a pool from the recycled list */
-
- /* This function is safe only as long as it is single threaded because
- * it reaches into the queue and accesses "next" which can change.
- * We are OK today because it is only called from the listener thread.
- * cas-based pushes do not have the same limitation - any number can
- * happen concurrently with a single cas-based pop.
- */
-
- *recycled_pool = NULL;
-
-
- /* Atomically pop a pool from the recycled list */
- for (;;) {
- struct recycled_pool *first_pool = queue_info->recycled_pools;
- if (first_pool == NULL) {
- break;
- }
- if (apr_atomic_casptr
- ((void*) &(queue_info->recycled_pools),
- first_pool->next, first_pool) == first_pool) {
- *recycled_pool = first_pool->pool;
- if (queue_info->max_recycled_pools >= 0)
- apr_atomic_dec32(&queue_info->recycled_pools_count);
- break;
- }
- }
-}
-
-void ap_free_idle_pools(fd_queue_info_t *queue_info)
-{
- apr_pool_t *p;
-
- queue_info->max_recycled_pools = 0;
- do {
- ap_pop_pool(&p, queue_info);
- if (p != NULL)
- apr_pool_destroy(p);
- } while (p != NULL);
-}
-
-
-apr_status_t ap_queue_info_term(fd_queue_info_t * queue_info)
-{
- apr_status_t rv;
- rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
- if (rv != APR_SUCCESS) {
- return rv;
- }
- queue_info->terminated = 1;
- apr_thread_cond_broadcast(queue_info->wait_for_idler);
- return apr_thread_mutex_unlock(queue_info->idlers_mutex);
-}
-
-/**
- * Detects when the fd_queue_t is full. This utility function is expected
- * to be called from within critical sections, and is not threadsafe.
- */
-#define ap_queue_full(queue) ((queue)->nelts == (queue)->bounds)
-
-/**
- * Detects when the fd_queue_t is empty. This utility function is expected
- * to be called from within critical sections, and is not threadsafe.
- */
-#define ap_queue_empty(queue) ((queue)->nelts == 0 && APR_RING_EMPTY(&queue->timers ,timer_event_t, link))
-
-/**
- * Callback routine that is called to destroy this
- * fd_queue_t when its pool is destroyed.
- */
-static apr_status_t ap_queue_destroy(void *data)
-{
- fd_queue_t *queue = data;
-
- /* Ignore errors here, we can't do anything about them anyway.
- * XXX: We should at least try to signal an error here, it is
- * indicative of a programmer error. -aaron */
- apr_thread_cond_destroy(queue->not_empty);
- apr_thread_mutex_destroy(queue->one_big_mutex);
-
- return APR_SUCCESS;
-}
-
-/**
- * Initialize the fd_queue_t.
- */
-apr_status_t ap_queue_init(fd_queue_t * queue, int queue_capacity,
- apr_pool_t * a)
-{
- int i;
- apr_status_t rv;
-
- if ((rv = apr_thread_mutex_create(&queue->one_big_mutex,
- APR_THREAD_MUTEX_DEFAULT,
- a)) != APR_SUCCESS) {
- return rv;
- }
- if ((rv = apr_thread_cond_create(&queue->not_empty, a)) != APR_SUCCESS) {
- return rv;
- }
-
- APR_RING_INIT(&queue->timers, timer_event_t, link);
-
- queue->data = apr_palloc(a, queue_capacity * sizeof(fd_queue_elem_t));
- queue->bounds = queue_capacity;
- queue->nelts = 0;
- queue->in = 0;
- queue->out = 0;
-
- /* Set all the sockets in the queue to NULL */
- for (i = 0; i < queue_capacity; ++i)
- queue->data[i].sd = NULL;
-
- apr_pool_cleanup_register(a, queue, ap_queue_destroy,
- apr_pool_cleanup_null);
-
- return APR_SUCCESS;
-}
-
-/**
- * Push a new socket onto the queue.
- *
- * precondition: ap_queue_info_wait_for_idler has already been called
- * to reserve an idle worker thread
- */
-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;
- apr_status_t rv;
-
- if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
- return rv;
- }
-
- AP_DEBUG_ASSERT(!queue->terminated);
- AP_DEBUG_ASSERT(!ap_queue_full(queue));
-
- elem = &queue->data[queue->in];
- queue->in++;
- if (queue->in >= queue->bounds)
- queue->in -= queue->bounds;
- elem->sd = sd;
- elem->ecs = ecs;
- elem->p = p;
- queue->nelts++;
-
- 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);
-}
diff --git a/server/mpm_unix.c b/server/mpm_unix.c
index 29bc3a2b00..2aa2d3bbe3 100644
--- a/server/mpm_unix.c
+++ b/server/mpm_unix.c
@@ -36,6 +36,7 @@
#include "apr_getopt.h"
#include "apr_optional.h"
#include "apr_allocator.h"
+#include "apr_atomic.h"
#include "httpd.h"
#include "http_config.h"
@@ -48,6 +49,8 @@
#include "scoreboard.h"
#include "util_mutex.h"
+#include "mpm_unix.h"
+
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
@@ -1104,4 +1107,516 @@ AP_DECLARE(apr_status_t) ap_fatal_signal_setup(server_rec *s,
return APR_SUCCESS;
}
+
+/*
+ * fdqueue code used by MPMs event and worker.
+ * Not part of the API, so not AP_DECLARE()d.
+ */
+
+static const apr_uint32_t zero_pt = APR_UINT32_MAX/2;
+
+struct recycled_pool
+{
+ apr_pool_t *pool;
+ struct recycled_pool *next;
+};
+
+struct fd_queue_info_t
+{
+ apr_uint32_t volatile idlers; /**
+ * >= zero_pt: number of idle worker threads
+ * < zero_pt: number of threads blocked,
+ * waiting for an idle worker
+ */
+ apr_thread_mutex_t *idlers_mutex;
+ apr_thread_cond_t *wait_for_idler;
+ int terminated;
+ int max_idlers;
+ int max_recycled_pools;
+ apr_uint32_t recycled_pools_count;
+ struct recycled_pool *volatile recycled_pools;
+};
+
+static apr_status_t queue_info_cleanup(void *data_)
+{
+ fd_queue_info_t *qi = data_;
+ apr_thread_cond_destroy(qi->wait_for_idler);
+ apr_thread_mutex_destroy(qi->idlers_mutex);
+
+ /* Clean up any pools in the recycled list */
+ for (;;) {
+ struct recycled_pool *first_pool = qi->recycled_pools;
+ if (first_pool == NULL) {
+ break;
+ }
+ if (apr_atomic_casptr
+ ((void*) &(qi->recycled_pools), first_pool->next,
+ first_pool) == first_pool) {
+ apr_pool_destroy(first_pool->pool);
+ }
+ }
+
+ return APR_SUCCESS;
+}
+
+apr_status_t ap_queue_info_create(fd_queue_info_t ** queue_info,
+ apr_pool_t * pool, int max_idlers,
+ int max_recycled_pools)
+{
+ apr_status_t rv;
+ fd_queue_info_t *qi;
+
+ qi = apr_pcalloc(pool, sizeof(*qi));
+
+ rv = apr_thread_mutex_create(&qi->idlers_mutex, APR_THREAD_MUTEX_DEFAULT,
+ pool);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ rv = apr_thread_cond_create(&qi->wait_for_idler, pool);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ qi->recycled_pools = NULL;
+ qi->max_recycled_pools = max_recycled_pools;
+ qi->max_idlers = max_idlers;
+ qi->idlers = zero_pt;
+ apr_pool_cleanup_register(pool, qi, queue_info_cleanup,
+ apr_pool_cleanup_null);
+
+ *queue_info = qi;
+
+ return APR_SUCCESS;
+}
+
+apr_status_t ap_queue_info_set_idle(fd_queue_info_t * queue_info,
+ apr_pool_t * pool_to_recycle)
+{
+ apr_status_t rv;
+
+ ap_push_pool(queue_info, pool_to_recycle);
+
+ /* If other threads are waiting on a worker, wake one up */
+ if (apr_atomic_inc32(&queue_info->idlers) < zero_pt) {
+ rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
+ if (rv != APR_SUCCESS) {
+ AP_DEBUG_ASSERT(0);
+ return rv;
+ }
+ rv = apr_thread_cond_signal(queue_info->wait_for_idler);
+ if (rv != APR_SUCCESS) {
+ apr_thread_mutex_unlock(queue_info->idlers_mutex);
+ return rv;
+ }
+ rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ }
+
+ return APR_SUCCESS;
+}
+
+apr_status_t ap_queue_info_try_get_idler(fd_queue_info_t * queue_info)
+{
+ /* Don't block if there isn't any idle worker. */
+ for (;;) {
+ apr_uint32_t idlers = queue_info->idlers;
+ if (idlers <= zero_pt) {
+ return APR_EAGAIN;
+ }
+ if (apr_atomic_cas32(&queue_info->idlers, idlers - 1,
+ idlers) == idlers) {
+ return APR_SUCCESS;
+ }
+ }
+}
+
+apr_status_t ap_queue_info_wait_for_idler(fd_queue_info_t * queue_info,
+ int *had_to_block)
+{
+ apr_status_t rv;
+
+ /* Block if there isn't any idle worker.
+ * apr_atomic_add32(x, -1) does the same as dec32(x), except
+ * that it returns the previous value (unlike dec32's bool).
+ */
+ if (apr_atomic_add32(&queue_info->idlers, -1) <= zero_pt) {
+ rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
+ if (rv != APR_SUCCESS) {
+ AP_DEBUG_ASSERT(0);
+ apr_atomic_inc32(&(queue_info->idlers)); /* back out dec */
+ return rv;
+ }
+ /* Re-check the idle worker count to guard against a
+ * race condition. Now that we're in the mutex-protected
+ * region, one of two things may have happened:
+ * - If the idle worker count is still negative, the
+ * workers are all still busy, so it's safe to
+ * block on a condition variable.
+ * - If the idle worker count is non-negative, then a
+ * worker has become idle since the first check
+ * of queue_info->idlers above. It's possible
+ * that the worker has also signaled the condition
+ * variable--and if so, the listener missed it
+ * because it wasn't yet blocked on the condition
+ * variable. But if the idle worker count is
+ * now non-negative, it's safe for this function to
+ * return immediately.
+ *
+ * A "negative value" (relative to zero_pt) in
+ * queue_info->idlers tells how many
+ * threads are waiting on an idle worker.
+ */
+ if (queue_info->idlers < zero_pt) {
+ *had_to_block = 1;
+ rv = apr_thread_cond_wait(queue_info->wait_for_idler,
+ queue_info->idlers_mutex);
+ if (rv != APR_SUCCESS) {
+ apr_status_t rv2;
+ AP_DEBUG_ASSERT(0);
+ rv2 = apr_thread_mutex_unlock(queue_info->idlers_mutex);
+ if (rv2 != APR_SUCCESS) {
+ return rv2;
+ }
+ return rv;
+ }
+ }
+ rv = apr_thread_mutex_unlock(queue_info->idlers_mutex);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ }
+
+ if (queue_info->terminated) {
+ return APR_EOF;
+ }
+ else {
+ return APR_SUCCESS;
+ }
+}
+
+apr_uint32_t ap_queue_info_get_idlers(fd_queue_info_t * queue_info)
+{
+ apr_uint32_t val;
+ val = apr_atomic_read32(&queue_info->idlers);
+ if (val <= zero_pt)
+ return 0;
+ return val - zero_pt;
+}
+
+void ap_push_pool(fd_queue_info_t * queue_info,
+ apr_pool_t * pool_to_recycle)
+{
+ struct recycled_pool *new_recycle;
+ /* If we have been given a pool to recycle, atomically link
+ * it into the queue_info's list of recycled pools
+ */
+ if (!pool_to_recycle)
+ return;
+
+ if (queue_info->max_recycled_pools >= 0) {
+ apr_uint32_t cnt = apr_atomic_read32(&queue_info->recycled_pools_count);
+ if (cnt >= queue_info->max_recycled_pools) {
+ apr_pool_destroy(pool_to_recycle);
+ return;
+ }
+ apr_atomic_inc32(&queue_info->recycled_pools_count);
+ }
+
+ apr_pool_clear(pool_to_recycle);
+ new_recycle = (struct recycled_pool *) apr_palloc(pool_to_recycle,
+ sizeof (*new_recycle));
+ new_recycle->pool = pool_to_recycle;
+ for (;;) {
+ /*
+ * Save queue_info->recycled_pool in local variable next because
+ * new_recycle->next can be changed after apr_atomic_casptr
+ * function call. For gory details see PR 44402.
+ */
+ struct recycled_pool *next = queue_info->recycled_pools;
+ new_recycle->next = next;
+ if (apr_atomic_casptr((void*) &(queue_info->recycled_pools),
+ new_recycle, next) == next)
+ break;
+ }
+}
+
+void ap_pop_pool(apr_pool_t ** recycled_pool, fd_queue_info_t * queue_info)
+{
+ /* Atomically pop a pool from the recycled list */
+
+ /* This function is safe only as long as it is single threaded because
+ * it reaches into the queue and accesses "next" which can change.
+ * We are OK today because it is only called from the listener thread.
+ * cas-based pushes do not have the same limitation - any number can
+ * happen concurrently with a single cas-based pop.
+ */
+
+ *recycled_pool = NULL;
+
+
+ /* Atomically pop a pool from the recycled list */
+ for (;;) {
+ struct recycled_pool *first_pool = queue_info->recycled_pools;
+ if (first_pool == NULL) {
+ break;
+ }
+ if (apr_atomic_casptr
+ ((void*) &(queue_info->recycled_pools),
+ first_pool->next, first_pool) == first_pool) {
+ *recycled_pool = first_pool->pool;
+ if (queue_info->max_recycled_pools >= 0)
+ apr_atomic_dec32(&queue_info->recycled_pools_count);
+ break;
+ }
+ }
+}
+
+void ap_free_idle_pools(fd_queue_info_t *queue_info)
+{
+ apr_pool_t *p;
+
+ queue_info->max_recycled_pools = 0;
+ do {
+ ap_pop_pool(&p, queue_info);
+ if (p != NULL)
+ apr_pool_destroy(p);
+ } while (p != NULL);
+}
+
+
+apr_status_t ap_queue_info_term(fd_queue_info_t * queue_info)
+{
+ apr_status_t rv;
+ rv = apr_thread_mutex_lock(queue_info->idlers_mutex);
+ if (rv != APR_SUCCESS) {
+ return rv;
+ }
+ queue_info->terminated = 1;
+ apr_thread_cond_broadcast(queue_info->wait_for_idler);
+ return apr_thread_mutex_unlock(queue_info->idlers_mutex);
+}
+
+/**
+ * Detects when the fd_queue_t is full. This utility function is expected
+ * to be called from within critical sections, and is not threadsafe.
+ */
+#define ap_queue_full(queue) ((queue)->nelts == (queue)->bounds)
+
+/**
+ * Detects when the fd_queue_t is empty. This utility function is expected
+ * to be called from within critical sections, and is not threadsafe.
+ */
+#define ap_queue_empty(queue) ((queue)->nelts == 0 && APR_RING_EMPTY(&queue->timers ,timer_event_t, link))
+
+/**
+ * Callback routine that is called to destroy this
+ * fd_queue_t when its pool is destroyed.
+ */
+static apr_status_t ap_queue_destroy(void *data)
+{
+ fd_queue_t *queue = data;
+
+ /* Ignore errors here, we can't do anything about them anyway.
+ * XXX: We should at least try to signal an error here, it is
+ * indicative of a programmer error. -aaron */
+ apr_thread_cond_destroy(queue->not_empty);
+ apr_thread_mutex_destroy(queue->one_big_mutex);
+
+ return APR_SUCCESS;
+}
+
+/**
+ * Initialize the fd_queue_t.
+ */
+apr_status_t ap_queue_init(fd_queue_t * queue, int queue_capacity,
+ apr_pool_t * a)
+{
+ int i;
+ apr_status_t rv;
+
+ if ((rv = apr_thread_mutex_create(&queue->one_big_mutex,
+ APR_THREAD_MUTEX_DEFAULT,
+ a)) != APR_SUCCESS) {
+ return rv;
+ }
+ if ((rv = apr_thread_cond_create(&queue->not_empty, a)) != APR_SUCCESS) {
+ return rv;
+ }
+
+ APR_RING_INIT(&queue->timers, timer_event_t, link);
+
+ queue->data = apr_palloc(a, queue_capacity * sizeof(fd_queue_elem_t));
+ queue->bounds = queue_capacity;
+ queue->nelts = 0;
+ queue->in = 0;
+ queue->out = 0;
+
+ /* Set all the sockets in the queue to NULL */
+ for (i = 0; i < queue_capacity; ++i)
+ queue->data[i].sd = NULL;
+
+ apr_pool_cleanup_register(a, queue, ap_queue_destroy,
+ apr_pool_cleanup_null);
+
+ return APR_SUCCESS;
+}
+
+/**
+ * Push a new socket onto the queue.
+ *
+ * precondition: ap_queue_info_wait_for_idler has already been called
+ * to reserve an idle worker thread
+ */
+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;
+ apr_status_t rv;
+
+ if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) {
+ return rv;
+ }
+
+ AP_DEBUG_ASSERT(!queue->terminated);
+ AP_DEBUG_ASSERT(!ap_queue_full(queue));
+
+ elem = &queue->data[queue->in];
+ queue->in++;
+ if (queue->in >= queue->bounds)
+ queue->in -= queue->bounds;
+ elem->sd = sd;
+ elem->ecs = ecs;
+ elem->p = p;
+ queue->nelts++;
+
+ 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 */
diff --git a/server/mpm/event/fdqueue.h b/server/mpm_unix.h
similarity index 100%
rename from server/mpm/event/fdqueue.h
rename to server/mpm_unix.h
--
2.40.0