[sanitizer] speed up the bitvector-based deadlock detector by ~15% (iterate over the currently held locks using the array, not the bitvector. Bitvector is not the best data structure to iterate over)

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@205168 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 7 deletions

diff --git a/lib/sanitizer_common/sanitizer_deadlock_detector.h b/lib/sanitizer_common/sanitizer_deadlock_detector.h
index a0a03ccbb..e0beb1261 100644
--- a/lib/sanitizer_common/sanitizer_deadlock_detector.h
+++ b/lib/sanitizer_common/sanitizer_deadlock_detector.h
@@ -64,12 +64,10 @@ class DeadlockDetectorTLS {
       recursive_locks[n_recursive_locks++] = lock_id;
       return false;
     }
-    if (stk) {
-      CHECK_LT(n_all_locks_, ARRAY_SIZE(all_locks_with_contexts_));
-      // lock_id < BV::kSize, can cast to a smaller int.
-      u32 lock_id_short = static_cast<u32>(lock_id);
-      all_locks_with_contexts_[n_all_locks_++] = {lock_id_short, stk};
-    }
+    CHECK_LT(n_all_locks_, ARRAY_SIZE(all_locks_with_contexts_));
+    // lock_id < BV::kSize, can cast to a smaller int.
+    u32 lock_id_short = static_cast<u32>(lock_id);
+    all_locks_with_contexts_[n_all_locks_++] = {lock_id_short, stk};
     return true;
   }
 
@@ -109,6 +107,9 @@ class DeadlockDetectorTLS {
     return bv_;
   }
 
+  uptr getNumLocks() const { return n_all_locks_; }
+  uptr getLock(uptr idx) const { return all_locks_with_contexts_[idx].lock; }
+
  private:
   BV bv_;
   uptr epoch_;
@@ -222,7 +223,11 @@ class DeadlockDetector {
     if (cur_node && local_epoch == current_epoch_ &&
         local_epoch == nodeToEpoch(cur_node)) {
       uptr cur_idx = nodeToIndexUnchecked(cur_node);
-      return g_.hasAllEdges(dtls->getLocks(local_epoch), cur_idx);
+      for (uptr i = 0, n = dtls->getNumLocks(); i < n; i++) {
+        if (!g_.hasEdge(dtls->getLock(i), cur_idx))
+          return false;
+      }
+      return true;
     }
     return false;
   }