[compiler-rt] r204227 - tsan: fix large stack frame in deadlock detector

[Dmitry Vyukov]

Author: dvyukov
Date: Wed Mar 19 07:49:46 2014
New Revision: 204227

URL: http://llvm.org/viewvc/llvm-project?rev=204227&view=rev
Log:
tsan: fix large stack frame in deadlock detector

In member function 'virtual void __sanitizer::DD::MutexBeforeLock(__sanitizer::DDCallback*, __sanitizer::DDMutex*, bool)':
error: the frame size of 544 bytes is larger than 512 bytes [-Werror=frame-larger-than=]

The code is now [arguably] better as well.



Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector1.cc

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector1.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector1.cc?rev=204227&r1=204226&r2=204227&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector1.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_deadlock_detector1.cc Wed Mar 19 07:49:46 2014
@@ -54,6 +54,7 @@ struct DD : public DDetector {
   DDReport *GetReport(DDCallback *cb);
 
   void MutexEnsureID(DDLogicalThread *lt, DDMutex *m);
+  void ReportDeadlock(DDCallback *cb, DDMutex *m);
 };
 
 DDetector *DDetector::Create(const DDFlags *flags) {
@@ -109,28 +110,33 @@ void DD::MutexBeforeLock(DDCallback *cb,
   if (dd.onLockBefore(&lt->dd, m->id)) {
     // Actually add this edge now so that we have all the stack traces.
     dd.addEdges(&lt->dd, m->id, cb->Unwind());
-    uptr path[10];
-    uptr len = dd.findPathToLock(&lt->dd, m->id, path, ARRAY_SIZE(path));
-    CHECK_GT(len, 0U);  // Hm.. cycle of 10 locks? I'd like to see that.
-    CHECK_EQ(m->id, path[0]);
-    lt->report_pending = true;
-    DDReport *rep = &lt->rep;
-    rep->n = len;
-    for (uptr i = 0; i < len; i++) {
-      uptr from = path[i];
-      uptr to = path[(i + 1) % len];
-      DDMutex *m0 = (DDMutex*)dd.getData(from);
-      DDMutex *m1 = (DDMutex*)dd.getData(to);
-
-      u32 stk_from = 0, stk_to = 0;
-      dd.findEdge(from, to, &stk_from, &stk_to);
-      // Printf("Edge: %zd=>%zd: %u/%u\n", from, to, stk_from, stk_to);
-      rep->loop[i].thr_ctx = 0;  // don't know
-      rep->loop[i].mtx_ctx0 = m0->ctx;
-      rep->loop[i].mtx_ctx1 = m1->ctx;
-      rep->loop[i].stk[0] = stk_from;
-      rep->loop[i].stk[1] = stk_to;
-    }
+    ReportDeadlock(cb, m);
+  }
+}
+
+void DD::ReportDeadlock(DDCallback *cb, DDMutex *m) {
+  DDLogicalThread *lt = cb->lt;
+  uptr path[10];
+  uptr len = dd.findPathToLock(&lt->dd, m->id, path, ARRAY_SIZE(path));
+  CHECK_GT(len, 0U);  // Hm.. cycle of 10 locks? I'd like to see that.
+  CHECK_EQ(m->id, path[0]);
+  lt->report_pending = true;
+  DDReport *rep = &lt->rep;
+  rep->n = len;
+  for (uptr i = 0; i < len; i++) {
+    uptr from = path[i];
+    uptr to = path[(i + 1) % len];
+    DDMutex *m0 = (DDMutex*)dd.getData(from);
+    DDMutex *m1 = (DDMutex*)dd.getData(to);
+
+    u32 stk_from = 0, stk_to = 0;
+    dd.findEdge(from, to, &stk_from, &stk_to);
+    // Printf("Edge: %zd=>%zd: %u/%u\n", from, to, stk_from, stk_to);
+    rep->loop[i].thr_ctx = 0;  // don't know
+    rep->loop[i].mtx_ctx0 = m0->ctx;
+    rep->loop[i].mtx_ctx1 = m1->ctx;
+    rep->loop[i].stk[0] = stk_from;
+    rep->loop[i].stk[1] = stk_to;
   }
 }