add apr-util 1.2.8 to in tree libs

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@3734 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/apr-util/misc/apr_queue.c

@@ -0,0 +1,390 @@
+/* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
+ * applicable.
+ *
+ * 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, return APR_EAGAIN.  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;
+    }
+
+    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 */