commit c98882dcd380002bcd0db7cc115acd1bbae227fe
author pbos@webrtc.org <pbos@webrtc.org@4adac7df-926f-26a2-2b94-8c16560cd09d> Mon Jan 27 09:11:10 2014
committer pbos@webrtc.org <pbos@webrtc.org@4adac7df-926f-26a2-2b94-8c16560cd09d> Mon Jan 27 09:11:10 2014
tree effedc6be1cb015d3b9c71a84858c900fd0262a3
parent 37c29765118a52b6011ac94a978a1a53ef573ece

Always initialize Trace in Call TraceDispatcher.

Prevents violation of lock order occuring previously when
RegisterCallback called SetTraceCallback while holding its lock, which
called Print back (which acquires the lock).

BUG=
R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/7559004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5433 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/video/call.cc

diff --git a/webrtc/video/call.cc b/webrtc/video/call.cc
index baa2d40..ff7a05f 100644
--- a/webrtc/video/call.cc
+++ b/webrtc/video/call.cc
@@ -91,21 +91,22 @@
 class TraceDispatcher : public TraceCallback {
  public:
   TraceDispatcher()
-      : crit_(CriticalSectionWrapper::CreateCriticalSection()),
-        initialized_(false),
-        filter_(kTraceNone) {}
+      : lock_(CriticalSectionWrapper::CreateCriticalSection()),
+        filter_(kTraceNone) {
+    Trace::CreateTrace();
+    VideoEngine::SetTraceCallback(this);
+    VideoEngine::SetTraceFilter(kTraceNone);
+  }
 
   ~TraceDispatcher() {
-    if (initialized_) {
-      Trace::ReturnTrace();
-      VideoEngine::SetTraceCallback(NULL);
-    }
+    Trace::ReturnTrace();
+    VideoEngine::SetTraceCallback(NULL);
   }
 
   virtual void Print(TraceLevel level,
                      const char* message,
                      int length) OVERRIDE {
-    CriticalSectionScoped lock(crit_.get());
+    CriticalSectionScoped crit(lock_.get());
     for (std::map<Call*, Call::Config*>::iterator it = callbacks_.begin();
          it != callbacks_.end();
          ++it) {
@@ -118,20 +119,15 @@
     if (config->trace_callback == NULL)
       return;
 
-    CriticalSectionScoped lock(crit_.get());
+    CriticalSectionScoped crit(lock_.get());
     callbacks_[call] = config;
 
     filter_ |= config->trace_filter;
-    if (filter_ != kTraceNone && !initialized_) {
-      initialized_ = true;
-      Trace::CreateTrace();
-      VideoEngine::SetTraceCallback(this);
-    }
     VideoEngine::SetTraceFilter(filter_);
   }
 
   void DeregisterCallback(Call* call) {
-    CriticalSectionScoped lock(crit_.get());
+    CriticalSectionScoped crit(lock_.get());
     callbacks_.erase(call);
 
     filter_ = kTraceNone;
@@ -145,8 +141,7 @@
   }
 
  private:
-  scoped_ptr<CriticalSectionWrapper> crit_;
-  bool initialized_;
+  scoped_ptr<CriticalSectionWrapper> lock_;
   unsigned int filter_;
   std::map<Call*, Call::Config*> callbacks_;
 };