QPID-1148 - from Manuel Tiera

Lock file abstraction in sys/ with implementation portable to Linux and Solaris.

Changes by myself:
 - Makefile.am - must be updated for any new/renamed/removed source files.
 - Exception.h, Daemon.h, LockFile.h: Replaced throwIf() with if (...) throw ErrnoException(...)

The idiom throwIf(call-system-function(), "msg", errno) is incorret
(my fault, not Manuels). It assumes the first argument that makes a
system call call will be evaluated before the last one which fetches
errno. This may not be true on some compilers/platforms.


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@674865 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 58 insertions, 0 deletions

diff --git a/cpp/src/qpid/sys/posix/LockFile.h b/cpp/src/qpid/sys/posix/LockFile.h
new file mode 100644
index 0000000000..a8fbb678b8
--- /dev/null
+++ b/cpp/src/qpid/sys/posix/LockFile.h
@@ -0,0 +1,58 @@
+#ifndef _sys_posix_LockFile_h
+#define _sys_posix_LockFile_h
+
+#include "check.h"
+
+#include <boost/noncopyable.hpp>
+#include <string>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+/*
+ *
+ * Copyright (c) 2008 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.
+ *
+ */
+namespace qpid {
+namespace sys {
+    
+class LockFile : private boost::noncopyable {
+public:
+    LockFile(const std::string& path_, bool create):
+        path(path_), fd(-1), created(create) {
+        errno = 0;
+        int flags=create ? O_WRONLY|O_CREAT|O_NOFOLLOW : O_RDWR;
+        fd = ::open(path.c_str(), flags, 0644);
+        if (fd < 0) throw ErrnoException("Cannot open " + path, errno);
+        if (::lockf(fd, F_TLOCK, 0) < 0) throw ErrnoException("Cannot lock " + path, errno);
+    }
+
+    ~LockFile() {
+        if (fd >= 0) {
+            ::lockf(fd, F_ULOCK, 0);
+            ::close(fd);
+        }
+    }
+
+    std::string path;
+    int fd;
+    bool created;
+};
+ 
+}
+}
+#endif /*!_sys_posix_LockFile_h*/