Once SSLMutex allowed for the setting of both the

locking method and the lockfile location, I never
liked how AcceptMutex was linked to LockFile. This
seemed unnecessary. Much better to have AcceptMutex
do both as well. Plus, now that we will likely see
other modules require a "standard" way of setting
mutexes, why not have Apache provide that as
an API of sorts.

Anyway, LockFile is now depreciated and AcceptMutex
is now SSLMutex-like. We also provide a short
function that "parses" out a mutex parameter
and strips out the mechanism and lockfile location.
AcceptMutex and SSLMutex is this capability.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@467326 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 167 insertions, 0 deletions

diff --git a/server/util_mutex.c b/server/util_mutex.c
new file mode 100644
index 0000000000..c8017b6ddc
--- /dev/null
+++ b/server/util_mutex.c
@@ -0,0 +1,167 @@
+/* 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.
+ */
+
+/*
+ * util_mutex.c: Useful functions for determining allowable
+ *               mutexes and mutex settings
+ */
+
+
+#include "apr.h"
+#include "apr_strings.h"
+#include "apr_lib.h"
+
+#define APR_WANT_STRFUNC
+#include "apr_want.h"
+
+#define CORE_PRIVATE
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_main.h"
+#include "http_config.h"
+#include "util_mutex.h"
+
+AP_DECLARE_DATA const char ap_all_available_mutexes_string[] =
+    "Mutex mechanisms are: `none', `default'"
+#if APR_HAS_FLOCK_SERIALIZE
+    ", `flock:/path/to/file'"
+#endif
+#if APR_HAS_FCNTL_SERIALIZE
+    ", `fcntl:/path/to/file'"
+#endif
+#if APR_HAS_SYSVSEM_SERIALIZE && !defined(PERCHILD_MPM)
+    ", `sysvsem'"
+#endif
+#if APR_HAS_POSIXSEM_SERIALIZE
+    ", `posixsem'"
+#endif
+#if APR_HAS_PROC_PTHREAD_SERIALIZE
+    ", `pthread'"
+#endif
+#if APR_HAS_FLOCK_SERIALIZE || APR_HAS_FCNTL_SERIALIZE
+    ", `file:/path/to/file'"
+#endif
+#if (APR_HAS_SYSVSEM_SERIALIZE && !defined(PERCHILD_MPM)) || APR_HAS_POSIXSEM_SERIALIZE
+    ", `sem'"
+#endif
+    " ";
+
+AP_DECLARE_DATA const char ap_available_mutexes_string[] =
+    "Mutex mechanisms are: `default'"
+#if APR_HAS_FLOCK_SERIALIZE
+    ", `flock:/path/to/file'"
+#endif
+#if APR_HAS_FCNTL_SERIALIZE
+    ", `fcntl:/path/to/file'"
+#endif
+#if APR_HAS_SYSVSEM_SERIALIZE && !defined(PERCHILD_MPM)
+    ", `sysvsem'"
+#endif
+#if APR_HAS_POSIXSEM_SERIALIZE
+    ", `posixsem'"
+#endif
+#if APR_HAS_PROC_PTHREAD_SERIALIZE
+    ", `pthread'"
+#endif
+#if APR_HAS_FLOCK_SERIALIZE || APR_HAS_FCNTL_SERIALIZE
+    ", `file:/path/to/file'"
+#endif
+#if (APR_HAS_SYSVSEM_SERIALIZE && !defined(PERCHILD_MPM)) || APR_HAS_POSIXSEM_SERIALIZE
+    ", `sem'"
+#endif
+    " ";
+
+
+AP_DECLARE(apr_status_t) ap_parse_mutex(const char *arg, apr_pool_t *pool,
+                                        apr_lockmech_e *mutexmech,
+                                        const char **mutexfile)
+{
+    /* Split arg into meth and file */
+    char *meth = apr_pstrdup(pool, arg);
+    char *file = strchr(meth, ':');
+    if (file) {
+        *(file++) = '\0';
+        if (!*file) {
+            file = NULL;
+        }
+    }
+
+    if (!strcasecmp(meth, "none") || !strcasecmp(meth, "no")) {
+        return APR_ENOLOCK;
+    }
+
+    /* APR determines temporary filename unless overridden below,
+     * we presume file indicates an mutexfile is a file path
+     * unless the method sets mutexfile=file and NULLs file
+     */
+    *mutexfile = NULL;
+
+    /* NOTE: previously, 'yes' implied 'sem' */
+    if (!strcasecmp(meth, "default") || !strcasecmp(meth, "yes")) {
+        *mutexmech = APR_LOCK_DEFAULT;
+    }
+#if APR_HAS_FCNTL_SERIALIZE
+    else if (!strcasecmp(meth, "fcntl") || !strcasecmp(meth, "file")) {
+        *mutexmech = APR_LOCK_FCNTL;
+    }
+#endif
+#if APR_HAS_FLOCK_SERIALIZE
+    else if (!strcasecmp(meth, "flock") || !strcasecmp(meth, "file")) {
+        *mutexmech = APR_LOCK_FLOCK;
+    }
+#endif
+#if APR_HAS_POSIXSEM_SERIALIZE
+    else if (!strcasecmp(meth, "posixsem") || !strcasecmp(meth, "sem")) {
+        *mutexmech = APR_LOCK_POSIXSEM;
+        /* Posix/SysV semaphores aren't file based, use the literal name
+         * if provided and fall back on APR's default if not.  Today, APR
+         * will ignore it, but once supported it has an absurdly short limit.
+         */
+        if (file) {
+            *mutexfile = apr_pstrdup(pool, file);
+
+            file = NULL;
+        }
+    }
+#endif
+#if APR_HAS_SYSVSEM_SERIALIZE && !defined(PERCHILD_MPM)
+    else if (!strcasecmp(meth, "sysvsem") || !strcasecmp(meth, "sem")) {
+        *mutexmech = APR_LOCK_SYSVSEM;
+    }
+#endif
+#if APR_HAS_PROC_PTHREAD_SERIALIZE
+    else if (!strcasecmp(meth, "pthread")) {
+        *mutexmech = APR_LOCK_PROC_PTHREAD;
+    }
+#endif
+    else {
+        return APR_ENOTIMPL;
+    }
+
+    /* Unless the method above assumed responsibility for setting up
+     * mutexfile and NULLing out file, presume it is a file we
+     * are looking to use
+     */
+    if (file) {
+        *mutexfile = ap_server_root_relative(pool, file);
+        if (!*mutexfile) {
+            return APR_BADARG;
+        }
+    }
+
+    return APR_SUCCESS;
+}