Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdemultimedia@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 74 insertions, 0 deletions

diff --git a/mpeglib/lib/util/abstract/threadQueue.h b/mpeglib/lib/util/abstract/threadQueue.h
new file mode 100644
index 00000000..4c650e21
--- /dev/null
+++ b/mpeglib/lib/util/abstract/threadQueue.h
@@ -0,0 +1,74 @@
+/*
+  fifo waitqueue for threads.(Multi-in, single out)
+  Copyright (C) 2000  Martin Vogt
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Library General Public License as published by
+  the Free Software Foundation.
+
+  For more information look at the file COPYRIGHT in this package
+
+ */
+
+
+#ifndef __THREADQUEUE_H
+#define __THREADQUEUE_H
+
+
+#include "abs_thread.h"
+
+class  WaitThreadEntry {
+ public:
+  WaitThreadEntry();
+  ~WaitThreadEntry();
+
+  abs_thread_cond_t waitCond;
+};
+
+/**
+   This class can be used as a general purpuse wrapper to
+   make C++ classes thread safe.
+   Mpeglib uses for every decoder a single thread which
+   reads from the input and write to one output type (video/audio)
+   To make the input and output classes thread safe you have
+   two solutions. First you can try to do it in every class
+   itsself, this is much work and needs understanding of
+   threads or you can use this wrapper class.
+   Normally you don't need two threads in one class, only
+   for the audio/video sync this is necessary, but for
+   the inputstream (file,http,..) this not necessary.
+   For the output this is the same.
+   This class offers two methods. waitForExclusiceAcess()
+   and releaseExlusiveAcess. Internally the thread who
+   calls waitFor.. in enqueued (if it does not get the exclusive
+   access) the thread who have the exclusive access calls
+   sometimes release.. with then pass the exclusive access
+   to the next thread. 
+   Why it is needed?
+   Because we access the input/output streams from different
+   threads. A user of mpeglib may want to set mpeg video
+   in fullscreen mode, this means two threads call
+   methods in the output classes including: closing windows,
+   resizing windows ... now this is safley possible when
+   the threadSafeInputStream / threadSafeoutputStream wrappers
+   are used, which forward the calls to the real classes.
+*/
+
+class ThreadQueue {
+
+  abs_thread_mutex_t queueMut; 
+  int insertPos;
+  int removePos;
+  int size;
+  WaitThreadEntry** waitThreadEntries;
+
+ public:
+  ThreadQueue();
+  ~ThreadQueue();
+
+  void waitForExclusiveAccess();
+  void releaseExclusiveAccess();
+
+};
+
+#endif