[DPL] FileLock

[Issue#]   N_SE-55833
[Problem]  There is no file locking wrapper
[Cause]    This is needs in depending repos.
[Solution] Introduce file lock.

[Verification] N/A
    - build repository,
    - verification should be done by reviewers based on wrt-installer changes,

Change-Id: I27cdfb5ea168b62ad5430585785599f3e65c53e1

diff --git a/modules/core/config.cmake b/modules/core/config.cmake
index 1a8625e..6e665d4 100644 (file)
--- a/modules/core/config.cmake
+++ b/modules/core/config.cmake
@@ -36,6 +36,7 @@ SET(DPL_CORE_SOURCES
     ${PROJECT_SOURCE_DIR}/modules/core/src/exception.cpp
     ${PROJECT_SOURCE_DIR}/modules/core/src/fast_delegate.cpp
     ${PROJECT_SOURCE_DIR}/modules/core/src/file_input.cpp
+    ${PROJECT_SOURCE_DIR}/modules/core/src/file_lock.cpp
     ${PROJECT_SOURCE_DIR}/modules/core/src/file_output.cpp
     ${PROJECT_SOURCE_DIR}/modules/core/src/lexical_cast.cpp
     ${PROJECT_SOURCE_DIR}/modules/core/src/mutable_task_list.cpp
@@ -95,6 +96,7 @@ SET(DPL_CORE_HEADERS
     ${PROJECT_SOURCE_DIR}/modules/core/include/dpl/exception.h
     ${PROJECT_SOURCE_DIR}/modules/core/include/dpl/fast_delegate.h
     ${PROJECT_SOURCE_DIR}/modules/core/include/dpl/file_input.h
+    ${PROJECT_SOURCE_DIR}/modules/core/include/dpl/file_lock.h
     ${PROJECT_SOURCE_DIR}/modules/core/include/dpl/file_output.h
     ${PROJECT_SOURCE_DIR}/modules/core/include/dpl/foreach.h
     ${PROJECT_SOURCE_DIR}/modules/core/include/dpl/generic_event.h

diff --git a/modules/core/include/dpl/file_lock.h b/modules/core/include/dpl/file_lock.h
new file mode 100644 (file)
index 0000000..4771d89
--- /dev/null
+++ b/modules/core/include/dpl/file_lock.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd All Rights Reserved
+ *
+ *    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.
+ */
+/*
+ * @file        file_lock.h
+ * @author      Tomasz Iwanek (t.iwanek@samsung.com)
+ * @version     1.0
+ * @brief       This implementation fo file locking
+ */
+#ifndef DPL_FILE_LOCK_H
+#define DPL_FILE_LOCK_H
+
+#include <string>
+#include <cstddef>
+
+#include <dpl/exception.h>
+#include <dpl/noncopyable.h>
+
+namespace DPL {
+class FileLock : private Noncopyable
+{
+  protected:
+    int m_fd;
+    std::string m_filename;
+    size_t m_mode;
+
+  public:
+    FileLock(const std::string & filename, bool blocking = true, size_t mode = 0666);
+    ~FileLock();
+
+    bool lock(bool blocking = true);
+    bool unlock();
+    bool isHoldingLock() const;
+    int getFd() const;
+};
+
+class FileBasedMutex : public FileLock
+{
+public:
+    FileBasedMutex(const std::string & id, bool blocking = true);
+};
+
+} // namespace DPL
+
+#endif // DPL_FILE_LOCK_H

diff --git a/modules/core/src/file_lock.cpp b/modules/core/src/file_lock.cpp
new file mode 100644 (file)
index 0000000..0106df4
--- /dev/null
+++ b/modules/core/src/file_lock.cpp
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd All Rights Reserved
+ *
+ *    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.
+ */
+/*
+ * @file        file_input.cpp
+ * @author      Przemyslaw Dobrowolski (p.dobrowolsk@samsung.com)
+ * @version     1.0
+ * @brief       This file is the implementation file of named input pipe
+ */
+
+#include <dpl/file_lock.h>
+
+#include <sys/file.h>
+
+namespace DPL {
+
+FileLock::FileLock(const std::string & filename, bool blocking, size_t mode) : m_filename(filename), m_mode(mode)
+{
+    lock(blocking);
+}
+
+FileLock::~FileLock()
+{
+    if(isHoldingLock())
+    {
+        unlock();
+    }
+}
+
+bool FileLock::lock(bool blocking)
+{
+    if(isHoldingLock()) return true;
+
+    int ret = 0;
+
+    m_fd = open(m_filename.c_str(), O_RDONLY | O_CREAT, m_mode);
+
+    if (m_fd == -1) {
+        return false;
+    }
+
+    if(blocking)
+    {
+        ret = flock(m_fd, LOCK_EX);
+    }
+    else
+    {
+        ret = flock(m_fd, LOCK_EX | LOCK_NB);
+    }
+
+    if (ret == -1) {
+        close(m_fd);
+        m_fd = -1;
+        return false;
+    }
+
+    return true;
+}
+
+bool FileLock::unlock()
+{
+    if(!isHoldingLock()) return true;
+
+    int ret = 0;
+    ret = flock(m_fd, LOCK_UN);
+    if(ret == -1)
+    {
+        return false;
+    }
+    close(m_fd);
+    m_fd = -1;
+    return true;
+}
+
+bool FileLock::isHoldingLock() const
+{
+    return (m_fd > 0);
+}
+
+int FileLock::getFd() const
+{
+    return m_fd;
+}
+
+FileBasedMutex::FileBasedMutex(const std::string & id, bool blocking) : FileLock(std::string("/tmp/.dpl_lock.") + id, blocking)
+{
+}
+
+} // namespace DPL
+