tsan: dynamic history size

introduces history_size parameter that can be used to control trace size at startup

llvm-svn: 168786

1 files changed, 6 insertions, 0 deletions

diff --git a/compiler-rt/lib/tsan/rtl/tsan_flags.h b/compiler-rt/lib/tsan/rtl/tsan_flags.h
index 895cef8a38f..06c3d0d1eb1 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_flags.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_flags.h
@@ -66,6 +66,12 @@ struct Flags {
   bool running_on_valgrind;
   // Path to external symbolizer.
   const char *external_symbolizer_path;
+  // Per-thread history size, controls how many previous memory accesses
+  // is remembered per thread.  Possible values are [0..7].
+  // history_size=0 amounts to 32K memory accesses.  Each next value doubles
+  // the amount of memory accesses, up to history_size=7 that amounts to
+  // 4M memory accesses.  The default value is 2 (128K memory accesses).
+  int history_size;
 };
 
 Flags *flags();