QPID-504: Print bound port if --port 0 is specified. Not yet used by tests.

	* qpidd.cpp:
	 - With --port 0 print the bound port number to stdout.
	 - Removed --ppid, --check now prints pid.

	* Daemon.cpp/h: Move pid-file generation to caller (qpidd.cpp)

	* Exception.cpp: Log a debug message in exception constructors.
	  Helps to show what exceptions were thrown even if they aren't
	  logged at a higher level. 

	* daemon_test: Test new daemon options.


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@546180 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 31 insertions, 19 deletions

diff --git a/cpp/src/qpid/broker/Daemon.h b/cpp/src/qpid/broker/Daemon.h
index cf9bf13764..cf7ad37b3a 100644
--- a/cpp/src/qpid/broker/Daemon.h
+++ b/cpp/src/qpid/broker/Daemon.h
@@ -21,6 +21,7 @@
 
 #include <string>
 #include <boost/scoped_ptr.hpp>
+#include <boost/function.hpp>
 
 namespace qpid {
 namespace broker {
@@ -32,24 +33,39 @@ namespace broker {
 class Daemon
 {
   public:
-
-    /** Extract the daemon's name from argv[0] */
-    static std::string nameFromArgv0(const char* argv0);
+    /** Utility function to create pid file name in a standard place
+     * (may require root acces) using identifier as the file name.
+     */
+    static std::string defaultPidFile(const std::string& identifier);
     
     /**
-     * Creating a Daemon instance forks a daemon process.
-     *@param name used to create pid files etc.
-     *@param timeout in seconds for all operations that wait.
+     * Daemon control object.
+     *@param pidFileFn Function that will comupte a PID file name.
+     * Called when pid file is created in ready()
+     *@param timeout in seconds for any operations that wait.
      */
-    Daemon(const std::string& name, int timeout);
+    Daemon(boost::function<std::string()> pidFileFn, int timeout);
 
     ~Daemon();
-    
-    /** Fork the daemon, wait till it signals readiness */
-    pid_t fork();
 
-    /** Child only, send ready signal so parent fork() will return. */
-    void ready();
+    typedef boost::function<void(Daemon&)> Function;
+
+    /** Fork the daemon.
+     *@param parent called in the parent process.
+     *@param child called in the child process.
+     */
+    pid_t fork(Function parent, Function child);
+
+    /** Parent only: wait for child to indicate it is ready.
+     * @return value child passed to ready() */
+    int wait();
+
+    /** Child only. Notify the parent we are ready and write the
+     * PID file.
+     *@param value returned by parent call to wait(). -1 is reserved
+     * for signalling an error.
+     */
+    void ready(int value);
     
     /** Child only, send failed signal so parent fork() will throw. */
     void failed();
@@ -67,18 +83,16 @@ class Daemon
 
     bool isChild() { return pid == 0; }
     
-    std::string getName() const { return name; }
-
     pid_t getPid() const {return pid; }
 
   private:
     class Retval;
 
+    static boost::function<std::string()> pidFileFn;
+    static const char* realPidFileFn();
     void notify(int);
     
-    static std::string name;
-    static std::string pidFile;
-    static const char* getPidFile();
+    static std::string identifier;
     boost::scoped_ptr<Retval> retval;
     pid_t pid;
     int timeout;
@@ -86,6 +100,4 @@ class Daemon
 
 }} // namespace qpid::broker
 
-
-
 #endif  /*!_broker_Daemon_h*/