tsan: fix vector clocks

the new optimizations break when thread ids gets reused (clocks go backwards)
add the necessary tests as well



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@206035 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 4 deletions

diff --git a/lib/sanitizer_common/sanitizer_thread_registry.cc b/lib/sanitizer_common/sanitizer_thread_registry.cc
index ed5ed711b..ed2c6019d 100644
--- a/lib/sanitizer_common/sanitizer_thread_registry.cc
+++ b/lib/sanitizer_common/sanitizer_thread_registry.cc
@@ -17,8 +17,9 @@
 namespace __sanitizer {
 
 ThreadContextBase::ThreadContextBase(u32 tid)
-    : tid(tid), unique_id(0), os_id(0), user_id(0), status(ThreadStatusInvalid),
-      detached(false), reuse_count(0), parent_tid(0), next(0) {
+    : tid(tid), unique_id(0), reuse_count(), os_id(0), user_id(0),
+      status(ThreadStatusInvalid),
+      detached(false), parent_tid(0), next(0) {
   name[0] = '\0';
 }
 
@@ -78,7 +79,6 @@ void ThreadContextBase::SetCreated(uptr _user_id, u64 _unique_id,
 
 void ThreadContextBase::Reset() {
   status = ThreadStatusInvalid;
-  reuse_count++;
   SetName(0);
   OnReset();
 }
@@ -88,10 +88,11 @@ void ThreadContextBase::Reset() {
 const u32 ThreadRegistry::kUnknownTid = ~0U;
 
 ThreadRegistry::ThreadRegistry(ThreadContextFactory factory, u32 max_threads,
-                               u32 thread_quarantine_size)
+                               u32 thread_quarantine_size, u32 max_reuse)
     : context_factory_(factory),
       max_threads_(max_threads),
       thread_quarantine_size_(thread_quarantine_size),
+      max_reuse_(max_reuse),
       mtx_(),
       n_contexts_(0),
       total_threads_(0),
@@ -282,6 +283,9 @@ void ThreadRegistry::QuarantinePush(ThreadContextBase *tctx) {
   dead_threads_.pop_front();
   CHECK_EQ(tctx->status, ThreadStatusDead);
   tctx->Reset();
+  tctx->reuse_count++;
+  if (max_reuse_ > 0 && tctx->reuse_count >= max_reuse_)
+    return;
   invalid_threads_.push_back(tctx);
 }