imprecise mark and sweep native memory leak detector

libmemunreachable uses an imprecise mark and sweep pass over all memory
allocated by jemalloc in order to find unreachable allocations.

Change-Id: Ia70bbf31f5b40ff71dab28cfd6cd06c5ef01a2d4
diff --git a/libmemunreachable/ThreadCapture.h b/libmemunreachable/ThreadCapture.h
new file mode 100644
index 0000000..1022cad
--- /dev/null
+++ b/libmemunreachable/ThreadCapture.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef LIBMEMUNREACHABLE_THREAD_CAPTURE_H_
+#define LIBMEMUNREACHABLE_THREAD_CAPTURE_H_
+
+#include <utility>
+
+#include "Allocator.h"
+
+struct ThreadInfo {
+  pid_t tid;
+  allocator::vector<uintptr_t> regs;
+  std::pair<uintptr_t, uintptr_t> stack;
+};
+
+using TidList = allocator::vector<pid_t>;
+using ThreadInfoList = allocator::vector<ThreadInfo>;
+
+class ThreadCaptureImpl;
+
+class ThreadCapture {
+public:
+  ThreadCapture(pid_t pid, Allocator<ThreadCapture> allocator);
+  ~ThreadCapture();
+
+  bool ListThreads(TidList& tids);
+  bool CaptureThreads();
+  bool ReleaseThreads();
+  bool ReleaseThread(pid_t tid);
+  bool CapturedThreadInfo(ThreadInfoList& threads);
+  void InjectTestFunc(std::function<void(pid_t)>&& f);
+
+private:
+  ThreadCapture(const ThreadCapture&) = delete;
+  void operator=(const ThreadCapture&) = delete;
+
+  Allocator<ThreadCaptureImpl>::unique_ptr impl_;
+};
+
+#endif