Improve collecting malloc stats in ASan

Summary:
This change makes races between updates of thread-local stats and
merging all the thread-local stats together less harmful.

Reviewers: kcc

Reviewed By: kcc

CC: dvyukov, llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1572

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@189744 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 7 deletions

diff --git a/lib/asan/asan_stats.h b/lib/asan/asan_stats.h
index 68495fb3..e3030e88 100644
--- a/lib/asan/asan_stats.h
+++ b/lib/asan/asan_stats.h
@@ -52,18 +52,16 @@ struct AsanStats {
   // Default ctor for thread-local stats.
   AsanStats();
 
-  // Prints formatted stats to stderr.
-  void Print();
+  void Print();  // Prints formatted stats to stderr.
+  void Clear();
+  void MergeFrom(const AsanStats *stats);
 };
 
 // Returns stats for GetCurrentThread(), or stats for fake "unknown thread"
 // if GetCurrentThread() returns 0.
 AsanStats &GetCurrentThreadStats();
-// Flushes all thread-local stats to accumulated stats, and makes
-// a copy of accumulated stats.
-void GetAccumulatedStats(AsanStats *stats);
-// Flushes a given stats into accumulated stats.
-void FlushToAccumulatedStats(AsanStats *stats);
+// Flushes a given stats into accumulated stats of dead threads.
+void FlushToDeadThreadStats(AsanStats *stats);
 
 // A cross-platform equivalent of malloc_statistics_t on Mac OS.
 struct AsanMallocStats {