Removed the "not_full" condition variable and associated conditional

logic from the file descriptor queue, now that we can rely on the
idle worker reference count to keep the listener from trying to
push connections into a full queue
Reviewed by:	Aaron Bannert (concept)

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94845 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/server/mpm/worker/fdqueue.c b/server/mpm/worker/fdqueue.c
index 362583986e136cdd4aa5d83d37c0bd5fbe7c2835..14c17e7ecf05924ff986f2822ad385c4beeed2e5 100644 (file)
--- a/server/mpm/worker/fdqueue.c
+++ b/server/mpm/worker/fdqueue.c
@@ -214,7 +214,6 @@ static apr_status_t ap_queue_destroy(void *data)
      * 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_cond_destroy(queue->not_full);
     apr_thread_mutex_destroy(queue->one_big_mutex);
 
     return APR_SUCCESS;
@@ -235,11 +234,7 @@ apr_status_t ap_queue_init(fd_queue_t *queue, int queue_capacity, apr_pool_t *a)
     if ((rv = apr_thread_cond_create(&queue->not_empty, a)) != APR_SUCCESS) {
         return rv;
     }
-    if ((rv = apr_thread_cond_create(&queue->not_full, a)) != APR_SUCCESS) {
-        return rv;
-    }
 
-    queue->head = queue->tail = 0;
     queue->data = apr_palloc(a, queue_capacity * sizeof(fd_queue_elem_t));
     queue->bounds = queue_capacity;
     queue->nelts = 0;
@@ -268,13 +263,9 @@ apr_status_t ap_queue_push(fd_queue_t *queue, apr_socket_t *sd, apr_pool_t *p)
     }
 
     AP_DEBUG_ASSERT(!queue->terminated);
-    
-    while (ap_queue_full(queue)) {
-        apr_thread_cond_wait(queue->not_full, queue->one_big_mutex);
-    }
+    AP_DEBUG_ASSERT(!ap_queue_full(queue));
 
-    elem = &queue->data[queue->tail];
-    queue->tail = (queue->tail + 1) % queue->bounds;
+    elem = &queue->data[queue->nelts];
     elem->sd = sd;
     elem->p = p;
     queue->nelts++;
@@ -323,18 +314,11 @@ apr_status_t ap_queue_pop(fd_queue_t *queue, apr_socket_t **sd, apr_pool_t **p)
         }
     } 
 
-    elem = &queue->data[queue->head];
-    queue->head = (queue->head + 1) % queue->bounds;
+    elem = &queue->data[--queue->nelts];
     *sd = elem->sd;
     *p = elem->p;
     elem->sd = NULL;
     elem->p = NULL;
-    queue->nelts--;
-
-    /* signal not_full if we were full before this pop */
-    if (queue->nelts == queue->bounds - 1) {
-        apr_thread_cond_signal(queue->not_full);
-    }
 
     rv = apr_thread_mutex_unlock(queue->one_big_mutex);
     return rv;
@@ -348,9 +332,6 @@ apr_status_t ap_queue_interrupt_all(fd_queue_t *queue)
         return rv;
     }
     apr_thread_cond_broadcast(queue->not_empty);
-    /* We shouldn't have multiple threads sitting in not_full, but
-     * broadcast just in case. */
-    apr_thread_cond_broadcast(queue->not_full);
     if ((rv = apr_thread_mutex_unlock(queue->one_big_mutex)) != APR_SUCCESS) {
         return rv;
     }

diff --git a/server/mpm/worker/fdqueue.h b/server/mpm/worker/fdqueue.h
index 4e72358188fd494a751f4ddad2975638ca4a4131..de76921f01e294a0fbd2a54f37e5b3bc0abd2050 100644 (file)
--- a/server/mpm/worker/fdqueue.h
+++ b/server/mpm/worker/fdqueue.h
@@ -88,14 +88,11 @@ struct fd_queue_elem_t {
 typedef struct fd_queue_elem_t fd_queue_elem_t;
 
 struct fd_queue_t {
-    int                 head;
-    int                 tail;
     fd_queue_elem_t    *data;
     int                 nelts;
     int                 bounds;
     apr_thread_mutex_t *one_big_mutex;
     apr_thread_cond_t  *not_empty;
-    apr_thread_cond_t  *not_full;
     int                 terminated;
 };
 typedef struct fd_queue_t fd_queue_t;