1 files changed, 97 insertions, 0 deletions
diff --git a/src/lib/util/pid_file.h b/src/lib/util/pid_file.h
new file mode 100644
index 0000000..a30640d
--- /dev/null
+++ b/src/lib/util/pid_file.h
@@ -0,0 +1,97 @@
+// Copyright (C) 2015 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef PID_FILE_H
+#define PID_FILE_H
+
+#include <exceptions/exceptions.h>
+#include <boost/shared_ptr.hpp>
+#include <fstream>
+#include <ostream>
+#include <string>
+
+namespace isc {
+namespace util {
+
+/// @brief Exception thrown when an error occurs during PID file processing.
+class PIDFileError : public Exception {
+public:
+    PIDFileError(const char* file, size_t line, const char* what) :
+        isc::Exception(file, line, what) { };
+};
+
+/// @brief Exception thrown when an error occurs trying to read a PID
+/// from an opened file.
+class PIDCantReadPID : public Exception {
+public:
+    PIDCantReadPID(const char* file, size_t line, const char* what) :
+        isc::Exception(file, line, what) { };
+};
+
+/// @brief Class to help with processing PID files
+///
+/// This is a utility class to manipulate PID file. It provides
+/// functions for writing and deleting a file containing a PID as
+/// well as for extracting a PID from a file and checking if the
+/// process is still running.
+class PIDFile {
+public:
+    /// @brief Constructor
+    ///
+    /// @param filename PID filename.
+    PIDFile(const std::string& filename);
+
+    /// @brief Destructor
+    ~PIDFile();
+
+    /// @brief Read the PID in from the file and check it.
+    ///
+    /// Read the PID in from the file then use it to see if
+    /// a process with that PID exists. If the file doesn't
+    /// exist treat it as the process not being there.
+    /// If the file exists but can't be read or it doesn't have
+    /// the proper format treat it as the process existing.
+    ///
+    /// @return returns the PID if it is in, 0 otherwise.
+    ///
+    /// @throw throws PIDCantReadPID if it was able to open the file
+    /// but was unable to read the PID from it.
+    int check() const;
+
+    /// @brief Write the PID to the file.
+    ///
+    /// @param pid the pid to write to the file.
+    ///
+    /// @throw throws PIDFileError if it can't open or write to the PID file.
+    void write(int) const;
+
+    /// @brief Get PID of the current process and write it to the file.
+    ///
+    /// @throw throws PIDFileError if it can't open or write to the PID file.
+    void write() const;
+
+    /// @brief Delete the PID file.
+    ///
+    /// @throw throws PIDFileError if it can't delete the PID file
+    void deleteFile() const;
+
+    /// @brief Returns the path to the PID file.
+    std::string getFilename() const {
+        return (filename_);
+    }
+
+private:
+    /// @brief PID filename
+    std::string filename_;
+};
+
+/// @brief Defines a shared pointer to a PIDFile
+typedef boost::shared_ptr<PIDFile> PIDFilePtr;
+
+} // namespace isc::util
+} // namespace isc
+
+#endif // PID_FILE_H