- Added pthread_once wrapper

diff --git a/zypp/thread/Makefile.am b/zypp/thread/Makefile.am
index 9309ef4..501c004 100644 (file)
--- a/zypp/thread/Makefile.am
+++ b/zypp/thread/Makefile.am
@@ -10,7 +10,8 @@ threadincludedir = $(pkgincludedir)/thread
 threadinclude_HEADERS =        \
        MutexException.h        \
        Mutex.h                 \
-       MutexLock.h
+       MutexLock.h             \
+       Once.h
 
 noinst_LTLIBRARIES =   lib@PACKAGE@_thread.la
 

diff --git a/zypp/thread/Once.h b/zypp/thread/Once.h
new file mode 100644 (file)
index 0000000..036cf58
--- /dev/null
+++ b/zypp/thread/Once.h
@@ -0,0 +1,65 @@
+/*---------------------------------------------------------------------\
+|                          ____ _   __ __ ___                          |
+|                         |__  / \ / / . \ . \                         |
+|                           / / \ V /|  _/  _/                         |
+|                          / /__ | | | | | |                           |
+|                         /_____||_| |_| |_|                           |
+|                                                                      |
+\---------------------------------------------------------------------*/
+/** \file zypp/thread/Once.h
+ *
+*/
+#ifndef   ZYPP_THREAD_ONCE_H
+#define   ZYPP_THREAD_ONCE_H
+
+#include <pthread.h>
+
+
+//////////////////////////////////////////////////////////////////////
+namespace zypp
+{ ////////////////////////////////////////////////////////////////////
+  ////////////////////////////////////////////////////////////////////
+  namespace thread
+  { //////////////////////////////////////////////////////////////////
+
+
+    /** The initialization value for OnceFlag variables. */
+    #define ZYPP_ONCE_INIT  PTHREAD_ONCE_INIT
+
+
+    /** The OnceFlag variable type.
+     */
+    typedef pthread_once_t OnceFlag;
+
+
+    /**
+     * Call once function.
+     *
+     * The purpose of callOnce is to ensure that a piece of initialization
+     * code is executed at most once.
+     * The OnceFlag \p flag has to point to a static or extern variable,
+     * that was statically initialized to ZYPP_ONCE_INIT.
+     *
+     * The first time callOnce is called with a given \p onceFlag argument,
+     * it calls \p fuct with no argument and changes the value of \p flag
+     * to indicate that the function has been run.
+     * Subsequent calls with the same once flag does nothing.
+     */
+    void callOnce(OnceFlag& flag, void (*func)());
+
+    inline void callOnce(OnceFlag& flag, void (*func)())
+    {
+      pthread_once(&flag, func);
+    }
+
+    //////////////////////////////////////////////////////////////////
+  } // namespace thread
+  ////////////////////////////////////////////////////////////////////
+  ////////////////////////////////////////////////////////////////////
+} // namespace zypp
+//////////////////////////////////////////////////////////////////////
+
+#endif // ZYPP_THREAD_ONCE_H
+/*
+** vim: set ts=2 sts=2 sw=2 ai et:
+*/