[x265] [PATCH 1 of 4] improvement by replace lock to atom operator

[Min Chen]

# HG changeset patch
# User Min Chen <chenm003 at 163.com>
# Date 1377155784 -28800
# Node ID 5855cec9604808b34e8cebf7e4a159fbc2977855
# Parent  6fe2b6e1fd6f1c0ed0997a7dd0f0c38a96091f08
improvement by replace lock to atom operator

diff -r 6fe2b6e1fd6f -r 5855cec96048 source/encoder/framefilter.cpp
--- a/source/encoder/framefilter.cpp	Tue Aug 20 08:22:45 2013 -0500
+++ b/source/encoder/framefilter.cpp	Thu Aug 22 15:16:24 2013 +0800
@@ -36,6 +36,7 @@
     : JobProvider(pool)
     , m_cfg(NULL)
     , m_pic(NULL)
+    , active_lft(FALSE)
 {}
 
 void FrameFilter::destroy()
@@ -55,7 +56,9 @@
 
 bool FrameFilter::findJob()
 {
-    ScopedLock self(m_lock);
+    // Check the lock
+    if (ATOMIC_CAS32(&active_lft, FALSE, TRUE) == TRUE)
+        return false;
 
     // NOTE: only one thread can be here
     if (row_done < row_ready)
@@ -63,8 +66,10 @@
         // NOTE: not need atom operator here because we lock before
         row_done++;
         processRow(row_done);
+        active_lft = FALSE;
         return true;
     }
+    active_lft = FALSE;
     return false;
 }
 
@@ -91,6 +96,7 @@
     m_loopFilter.setCfg(pic->getSlice()->getPPS()->getLoopFilterAcrossTilesEnabledFlag());
     row_ready = -1;
     row_done = -1;
+    active_lft = FALSE;
     if (m_cfg->param.bEnableLoopFilter)
     {
         if (m_cfg->param.saoLcuBasedOptimization && m_cfg->param.saoLcuBoundary)
diff -r 6fe2b6e1fd6f -r 5855cec96048 source/encoder/framefilter.h
--- a/source/encoder/framefilter.h	Tue Aug 20 08:22:45 2013 -0500
+++ b/source/encoder/framefilter.h	Thu Aug 22 15:16:24 2013 +0800
@@ -66,7 +66,7 @@
 
     TEncCfg*            m_cfg;
     TComPic*            m_pic;
-    Lock                m_lock;
+    volatile int        active_lft;
 
 public: