2 files changed, 17 insertions, 7 deletions

diff --git a/system_wrappers/source/trace_posix.cc b/system_wrappers/source/trace_posix.cc
index 49659690..d0ab45b7 100644
--- a/system_wrappers/source/trace_posix.cc
+++ b/system_wrappers/source/trace_posix.cc
@@ -38,13 +38,15 @@
 
 namespace webrtc {
 
-TracePosix::TracePosix() {
+TracePosix::TracePosix()
+    : crit_sect_(*CriticalSectionWrapper::CreateCriticalSection()) {
   struct timeval system_time_high_res;
   gettimeofday(&system_time_high_res, 0);
   prev_api_tick_count_ = prev_tick_count_ = system_time_high_res.tv_sec;
 }
 
 TracePosix::~TracePosix() {
+  delete &crit_sect_;
   StopThread();
 }
 
@@ -60,13 +62,17 @@ WebRtc_Word32 TracePosix::AddTime(char* trace_message,
 
   const WebRtc_UWord32 ms_time = system_time_high_res.tv_usec / 1000;
   WebRtc_UWord32 prev_tickCount = 0;
-  if (level == kTraceApiCall) {
-    prev_tickCount = prev_tick_count_;
-    prev_tick_count_ = ms_time;
-  } else {
-    prev_tickCount = prev_api_tick_count_;
-    prev_api_tick_count_ = ms_time;
+  {
+    CriticalSectionScoped lock(&crit_sect_);
+    if (level == kTraceApiCall) {
+      prev_tickCount = prev_tick_count_;
+      prev_tick_count_ = ms_time;
+    } else {
+      prev_tickCount = prev_api_tick_count_;
+      prev_api_tick_count_ = ms_time;
+    }
   }
+
   WebRtc_UWord32 dw_delta_time = ms_time - prev_tickCount;
   if (prev_tickCount == 0) {
     dw_delta_time = 0;
diff --git a/system_wrappers/source/trace_posix.h b/system_wrappers/source/trace_posix.h
index 76df1b16..1c446b1f 100644
--- a/system_wrappers/source/trace_posix.h
+++ b/system_wrappers/source/trace_posix.h
@@ -21,6 +21,8 @@ class TracePosix : public TraceImpl {
   TracePosix();
   virtual ~TracePosix();
 
+  // This method can be called on several different threads different from
+  // the creating thread.
   virtual WebRtc_Word32 AddTime(char* trace_message,
                                 const TraceLevel level) const;
 
@@ -30,6 +32,8 @@ class TracePosix : public TraceImpl {
  private:
   volatile mutable WebRtc_UWord32  prev_api_tick_count_;
   volatile mutable WebRtc_UWord32  prev_tick_count_;
+
+  CriticalSectionWrapper& crit_sect_;
 };
 
 }  // namespace webrtc