| /* Copyright 2000-2004 The Apache Software Foundation |
| * |
| * Licensed 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 "apr.h" |
| |
| #if APR_HAVE_STDIO_H |
| #include <stdio.h> |
| #endif |
| #if APR_HAVE_STDLIB_H |
| #include <stdlib.h> |
| #endif |
| #if APR_HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| |
| #include "apu.h" |
| #include "apr_portable.h" |
| #include "apr_thread_mutex.h" |
| #include "apr_thread_cond.h" |
| #include "apr_errno.h" |
| #include "apr_queue.h" |
| |
| #if APR_HAS_THREADS |
| /* |
| * define this to get debug messages |
| * |
| #define QUEUE_DEBUG |
| */ |
| |
| struct apr_queue_t { |
| void **data; |
| unsigned int nelts; /**< # elements */ |
| unsigned int in; /**< next empty location */ |
| unsigned int out; /**< next filled location */ |
| unsigned int bounds;/**< max size of queue */ |
| unsigned int full_waiters; |
| unsigned int empty_waiters; |
| apr_thread_mutex_t *one_big_mutex; |
| apr_thread_cond_t *not_empty; |
| apr_thread_cond_t *not_full; |
| int terminated; |
| }; |
| |
| #ifdef QUEUE_DEBUG |
| static void Q_DBG(char*msg, apr_queue_t *q) { |
| fprintf(stderr, "%ld\t#%d in %d out %d\t%s\n", |
| apr_os_thread_current(), |
| q->nelts, q->in, q->out, |
| msg |
| ); |
| } |
| #else |
| #define Q_DBG(x,y) |
| #endif |
| |
| /** |
| * Detects when the apr_queue_t is full. This utility function is expected |
| * to be called from within critical sections, and is not threadsafe. |
| */ |
| #define apr_queue_full(queue) ((queue)->nelts == (queue)->bounds) |
| |
| /** |
| * Detects when the apr_queue_t is empty. This utility function is expected |
| * to be called from within critical sections, and is not threadsafe. |
| */ |
| #define apr_queue_empty(queue) ((queue)->nelts == 0) |
| |
| /** |
| * Callback routine that is called to destroy this |
| * apr_queue_t when its pool is destroyed. |
| */ |
| static apr_status_t queue_destroy(void *data) |
| { |
| apr_queue_t *queue = data; |
| |
| /* Ignore errors here, we can't do anything about them anyway. */ |
| |
| 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; |
| } |
| |
| /** |
| * Initialize the apr_queue_t. |
| */ |
| APU_DECLARE(apr_status_t) apr_queue_create(apr_queue_t **q, |
| unsigned int queue_capacity, |
| apr_pool_t *a) |
| { |
| apr_status_t rv; |
| apr_queue_t *queue; |
| queue = apr_palloc(a, sizeof(apr_queue_t)); |
| *q = queue; |
| |
| /* nested doesn't work ;( */ |
| rv = apr_thread_mutex_create(&queue->one_big_mutex, |
| APR_THREAD_MUTEX_UNNESTED, |
| a); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| |
| rv = apr_thread_cond_create(&queue->not_empty, a); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| |
| rv = apr_thread_cond_create(&queue->not_full, a); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| |
| /* Set all the data in the queue to NULL */ |
| queue->data = apr_pcalloc(a, queue_capacity * sizeof(void*)); |
| queue->bounds = queue_capacity; |
| queue->nelts = 0; |
| queue->in = 0; |
| queue->out = 0; |
| queue->terminated = 0; |
| queue->full_waiters = 0; |
| queue->empty_waiters = 0; |
| |
| apr_pool_cleanup_register(a, queue, queue_destroy, apr_pool_cleanup_null); |
| |
| return APR_SUCCESS; |
| } |
| |
| /** |
| * Push new data onto the queue. Blocks if the queue is full. Once |
| * the push operation has completed, it signals other threads waiting |
| * in apr_queue_pop() that they may continue consuming sockets. |
| */ |
| APU_DECLARE(apr_status_t) apr_queue_push(apr_queue_t *queue, void *data) |
| { |
| apr_status_t rv; |
| |
| if (queue->terminated) { |
| return APR_EOF; /* no more elements ever again */ |
| } |
| |
| rv = apr_thread_mutex_lock(queue->one_big_mutex); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| |
| if (apr_queue_full(queue)) { |
| if (!queue->terminated) { |
| queue->full_waiters++; |
| rv = apr_thread_cond_wait(queue->not_full, queue->one_big_mutex); |
| queue->full_waiters--; |
| if (rv != APR_SUCCESS) { |
| apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| } |
| /* If we wake up and it's still empty, then we were interrupted */ |
| if (apr_queue_full(queue)) { |
| Q_DBG("queue full (intr)", 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; |
| } |
| } |
| } |
| |
| queue->data[queue->in] = data; |
| queue->in = (queue->in + 1) % queue->bounds; |
| queue->nelts++; |
| |
| if (queue->empty_waiters) { |
| Q_DBG("sig !empty", queue); |
| rv = apr_thread_cond_signal(queue->not_empty); |
| if (rv != APR_SUCCESS) { |
| apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| } |
| |
| rv = apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| |
| /** |
| * Push new data onto the queue. Blocks if the queue is full. Once |
| * the push operation has completed, it signals other threads waiting |
| * in apr_queue_pop() that they may continue consuming sockets. |
| */ |
| APU_DECLARE(apr_status_t) apr_queue_trypush(apr_queue_t *queue, void *data) |
| { |
| apr_status_t rv; |
| |
| if (queue->terminated) { |
| return APR_EOF; /* no more elements ever again */ |
| } |
| |
| rv = apr_thread_mutex_lock(queue->one_big_mutex); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| |
| if (apr_queue_full(queue)) { |
| rv = apr_thread_mutex_unlock(queue->one_big_mutex); |
| return APR_EAGAIN; |
| } |
| |
| queue->data[queue->in] = data; |
| queue->in = (queue->in + 1) % queue->bounds; |
| queue->nelts++; |
| |
| if (queue->empty_waiters) { |
| Q_DBG("sig !empty", queue); |
| rv = apr_thread_cond_signal(queue->not_empty); |
| if (rv != APR_SUCCESS) { |
| apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| } |
| |
| rv = apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| |
| /** |
| * not thread safe |
| */ |
| APU_DECLARE(unsigned int) apr_queue_size(apr_queue_t *queue) { |
| return queue->nelts; |
| } |
| |
| /** |
| * Retrieves the next item from the queue. If there are no |
| * items available, it will block until one becomes available. |
| * Once retrieved, the item is placed into the address specified by |
| * 'data'. |
| */ |
| APU_DECLARE(apr_status_t) apr_queue_pop(apr_queue_t *queue, void **data) |
| { |
| apr_status_t rv; |
| |
| if (queue->terminated) { |
| return APR_EOF; /* no more elements ever again */ |
| } |
| |
| rv = apr_thread_mutex_lock(queue->one_big_mutex); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| |
| /* Keep waiting until we wake up and find that the queue is not empty. */ |
| if (apr_queue_empty(queue)) { |
| if (!queue->terminated) { |
| queue->empty_waiters++; |
| rv = apr_thread_cond_wait(queue->not_empty, queue->one_big_mutex); |
| queue->empty_waiters--; |
| if (rv != APR_SUCCESS) { |
| apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| } |
| /* If we wake up and it's still empty, then we were interrupted */ |
| if (apr_queue_empty(queue)) { |
| Q_DBG("queue empty (intr)", 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; |
| } |
| } |
| } |
| |
| *data = queue->data[queue->out]; |
| queue->nelts--; |
| |
| queue->out = (queue->out + 1) % queue->bounds; |
| if (queue->full_waiters) { |
| Q_DBG("signal !full", queue); |
| rv = apr_thread_cond_signal(queue->not_full); |
| if (rv != APR_SUCCESS) { |
| apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| } |
| |
| rv = apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| |
| /** |
| * Retrieves the next item from the queue. If there are no |
| * items available, it will block until one becomes available. |
| * Once retrieved, the item is placed into the address specified by |
| * 'data'. |
| */ |
| APU_DECLARE(apr_status_t) apr_queue_trypop(apr_queue_t *queue, void **data) |
| { |
| apr_status_t rv; |
| |
| if (queue->terminated) { |
| return APR_EOF; /* no more elements ever again */ |
| } |
| |
| rv = apr_thread_mutex_lock(queue->one_big_mutex); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| |
| /* Keep waiting until we wake up and find that the queue is not empty. */ |
| if (apr_queue_empty(queue)) { |
| rv = apr_thread_mutex_unlock(queue->one_big_mutex); |
| return APR_EAGAIN; |
| } |
| |
| *data = queue->data[queue->out]; |
| queue->nelts--; |
| |
| queue->out = (queue->out + 1) % queue->bounds; |
| if (queue->full_waiters) { |
| Q_DBG("signal !full", queue); |
| rv = apr_thread_cond_signal(queue->not_full); |
| if (rv != APR_SUCCESS) { |
| apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| } |
| |
| rv = apr_thread_mutex_unlock(queue->one_big_mutex); |
| return rv; |
| } |
| |
| APU_DECLARE(apr_status_t) apr_queue_interrupt_all(apr_queue_t *queue) |
| { |
| apr_status_t rv; |
| Q_DBG("intr all", queue); |
| if ((rv = apr_thread_mutex_lock(queue->one_big_mutex)) != APR_SUCCESS) { |
| return rv; |
| } |
| apr_thread_cond_broadcast(queue->not_empty); |
| apr_thread_cond_broadcast(queue->not_full); |
| |
| if ((rv = apr_thread_mutex_unlock(queue->one_big_mutex)) != APR_SUCCESS) { |
| return rv; |
| } |
| |
| return APR_SUCCESS; |
| } |
| |
| APU_DECLARE(apr_status_t) apr_queue_term(apr_queue_t *queue) |
| { |
| 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 |
| */ |
| queue->terminated = 1; |
| if ((rv = apr_thread_mutex_unlock(queue->one_big_mutex)) != APR_SUCCESS) { |
| return rv; |
| } |
| return apr_queue_interrupt_all(queue); |
| } |
| |
| #endif /* APR_HAS_THREADS */ |
