Adding upstream version 1.7.2.upstream/1.7.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 165 insertions, 0 deletions

diff --git a/locks/win32/thread_rwlock.c b/locks/win32/thread_rwlock.c
new file mode 100644
index 0000000..fd9d579
--- /dev/null
+++ b/locks/win32/thread_rwlock.c
@@ -0,0 +1,165 @@
+/* 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 "apr.h"
+#include "apr_private.h"
+#include "apr_general.h"
+#include "apr_strings.h"
+#include "apr_arch_thread_rwlock.h"
+#include "apr_portable.h"
+
+static apr_status_t thread_rwlock_cleanup(void *data)
+{
+    apr_thread_rwlock_t *rwlock = data;
+    
+    if (! CloseHandle(rwlock->read_event))
+        return apr_get_os_error();
+
+    if (! CloseHandle(rwlock->write_mutex))
+        return apr_get_os_error();
+    
+    return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_status_t)apr_thread_rwlock_create(apr_thread_rwlock_t **rwlock,
+                                                  apr_pool_t *pool)
+{
+    *rwlock = apr_palloc(pool, sizeof(**rwlock));
+
+    (*rwlock)->pool        = pool;
+    (*rwlock)->readers     = 0;
+
+    if (! ((*rwlock)->read_event = CreateEvent(NULL, TRUE, FALSE, NULL))) {
+        *rwlock = NULL;
+        return apr_get_os_error();
+    }
+
+    if (! ((*rwlock)->write_mutex = CreateMutex(NULL, FALSE, NULL))) {
+        CloseHandle((*rwlock)->read_event);
+        *rwlock = NULL;
+        return apr_get_os_error();
+    }
+
+    apr_pool_cleanup_register(pool, *rwlock, thread_rwlock_cleanup,
+                              apr_pool_cleanup_null);
+
+    return APR_SUCCESS;
+}
+
+static apr_status_t apr_thread_rwlock_rdlock_core(apr_thread_rwlock_t *rwlock,
+                                                  DWORD  milliseconds)
+{
+    DWORD   code = WaitForSingleObject(rwlock->write_mutex, milliseconds);
+
+    if (code == WAIT_FAILED || code == WAIT_TIMEOUT)
+        return APR_FROM_OS_ERROR(code);
+
+    /* We've successfully acquired the writer mutex, we can't be locked
+     * for write, so it's OK to add the reader lock.  The writer mutex
+     * doubles as race condition protection for the readers counter.   
+     */
+    InterlockedIncrement(&rwlock->readers);
+    
+    if (! ResetEvent(rwlock->read_event))
+        return apr_get_os_error();
+    
+    if (! ReleaseMutex(rwlock->write_mutex))
+        return apr_get_os_error();
+    
+    return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_status_t) apr_thread_rwlock_rdlock(apr_thread_rwlock_t *rwlock)
+{
+    return apr_thread_rwlock_rdlock_core(rwlock, INFINITE);
+}
+
+APR_DECLARE(apr_status_t) 
+apr_thread_rwlock_tryrdlock(apr_thread_rwlock_t *rwlock)
+{
+    return apr_thread_rwlock_rdlock_core(rwlock, 0);
+}
+
+static apr_status_t 
+apr_thread_rwlock_wrlock_core(apr_thread_rwlock_t *rwlock, DWORD milliseconds)
+{
+    DWORD   code = WaitForSingleObject(rwlock->write_mutex, milliseconds);
+
+    if (code == WAIT_FAILED || code == WAIT_TIMEOUT)
+        return APR_FROM_OS_ERROR(code);
+
+    /* We've got the writer lock but we have to wait for all readers to
+     * unlock before it's ok to use it.
+     */
+    if (rwlock->readers) {
+        /* Must wait for readers to finish before returning, unless this
+         * is an trywrlock (milliseconds == 0):
+         */
+        code = milliseconds
+          ? WaitForSingleObject(rwlock->read_event, milliseconds)
+          : WAIT_TIMEOUT;
+        
+        if (code == WAIT_FAILED || code == WAIT_TIMEOUT) {
+            /* Unable to wait for readers to finish, release write lock: */
+            if (! ReleaseMutex(rwlock->write_mutex))
+                return apr_get_os_error();
+            
+            return APR_FROM_OS_ERROR(code);
+        }
+    }
+
+    return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_status_t) apr_thread_rwlock_wrlock(apr_thread_rwlock_t *rwlock)
+{
+    return apr_thread_rwlock_wrlock_core(rwlock, INFINITE);
+}
+
+APR_DECLARE(apr_status_t)apr_thread_rwlock_trywrlock(apr_thread_rwlock_t *rwlock)
+{
+    return apr_thread_rwlock_wrlock_core(rwlock, 0);
+}
+
+APR_DECLARE(apr_status_t) apr_thread_rwlock_unlock(apr_thread_rwlock_t *rwlock)
+{
+    apr_status_t rv = 0;
+
+    /* First, guess that we're unlocking a writer */
+    if (! ReleaseMutex(rwlock->write_mutex))
+        rv = apr_get_os_error();
+    
+    if (rv == APR_FROM_OS_ERROR(ERROR_NOT_OWNER)) {
+        /* Nope, we must have a read lock */
+        if (rwlock->readers &&
+            ! InterlockedDecrement(&rwlock->readers) &&
+            ! SetEvent(rwlock->read_event)) {
+            rv = apr_get_os_error();
+        }
+        else {
+            rv = 0;
+        }
+    }
+
+    return rv;
+}
+
+APR_DECLARE(apr_status_t) apr_thread_rwlock_destroy(apr_thread_rwlock_t *rwlock)
+{
+    return apr_pool_cleanup_run(rwlock->pool, rwlock, thread_rwlock_cleanup);
+}
+
+APR_POOL_IMPLEMENT_ACCESSOR(thread_rwlock)