1 files changed, 89 insertions, 0 deletions
diff --git a/lib/tsan/rtl/tsan_mutexset.cc b/lib/tsan/rtl/tsan_mutexset.cc
new file mode 100644
index 0000000000000..21587770f687b
--- /dev/null
+++ b/lib/tsan/rtl/tsan_mutexset.cc
@@ -0,0 +1,89 @@
+//===-- tsan_mutexset.cc --------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer (TSan), a race detector.
+//
+//===----------------------------------------------------------------------===//
+#include "tsan_mutexset.h"
+#include "tsan_rtl.h"
+
+namespace __tsan {
+
+const uptr MutexSet::kMaxSize;
+
+MutexSet::MutexSet() {
+  size_ = 0;
+  internal_memset(&descs_, 0, sizeof(descs_));
+}
+
+void MutexSet::Add(u64 id, bool write, u64 epoch) {
+  // Look up existing mutex with the same id.
+  for (uptr i = 0; i < size_; i++) {
+    if (descs_[i].id == id) {
+      descs_[i].count++;
+      descs_[i].epoch = epoch;
+      return;
+    }
+  }
+  // On overflow, find the oldest mutex and drop it.
+  if (size_ == kMaxSize) {
+    u64 minepoch = (u64)-1;
+    u64 mini = (u64)-1;
+    for (uptr i = 0; i < size_; i++) {
+      if (descs_[i].epoch < minepoch) {
+        minepoch = descs_[i].epoch;
+        mini = i;
+      }
+    }
+    RemovePos(mini);
+    CHECK_EQ(size_, kMaxSize - 1);
+  }
+  // Add new mutex descriptor.
+  descs_[size_].id = id;
+  descs_[size_].write = write;
+  descs_[size_].epoch = epoch;
+  descs_[size_].count = 1;
+  size_++;
+}
+
+void MutexSet::Del(u64 id, bool write) {
+  for (uptr i = 0; i < size_; i++) {
+    if (descs_[i].id == id) {
+      if (--descs_[i].count == 0)
+        RemovePos(i);
+      return;
+    }
+  }
+}
+
+void MutexSet::Remove(u64 id) {
+  for (uptr i = 0; i < size_; i++) {
+    if (descs_[i].id == id) {
+      RemovePos(i);
+      return;
+    }
+  }
+}
+
+void MutexSet::RemovePos(uptr i) {
+  CHECK_LT(i, size_);
+  descs_[i] = descs_[size_ - 1];
+  size_--;
+}
+
+uptr MutexSet::Size() const {
+  return size_;
+}
+
+MutexSet::Desc MutexSet::Get(uptr i) const {
+  CHECK_LT(i, size_);
+  return descs_[i];
+}
+
+}  // namespace __tsan