create an stl-compatible wrapper around aos_sync mutexes and use it
Change-Id: I1f7ec0c5366b0ef985563225365db18dec8b70bd
diff --git a/aos/common/stl_mutex.h b/aos/common/stl_mutex.h
new file mode 100644
index 0000000..9242312
--- /dev/null
+++ b/aos/common/stl_mutex.h
@@ -0,0 +1,144 @@
+#ifndef AOS_COMMON_STL_MUTEX_H_
+#define AOS_COMMON_STL_MUTEX_H_
+
+#include <mutex>
+
+#include "aos/linux_code/ipc_lib/aos_sync.h"
+#include "aos/common/logging/logging.h"
+#include "aos/common/type_traits.h"
+#include "aos/common/macros.h"
+
+namespace aos {
+
+// A mutex with the same API and semantics as ::std::mutex, with the addition of
+// methods for checking if the previous owner died and a constexpr default
+// constructor.
+// Definitely safe to put in SHM.
+// This uses the pthread_mutex semantics for owner-died: once somebody dies with
+// the lock held, anybody else who takes it will see true for owner_died() until
+// one of them calls consistent(). It is an error to call unlock() when
+// owner_died() returns true.
+class stl_mutex {
+ public:
+ constexpr stl_mutex() : native_handle_() {}
+
+ void lock() {
+ const int ret = mutex_grab(&native_handle_);
+ switch (ret) {
+ case 0:
+ break;
+ case 1:
+ owner_died_ = true;
+ break;
+ default:
+ LOG(FATAL, "mutex_grab(%p) failed with %d\n", &native_handle_, ret);
+ }
+ }
+
+ bool try_lock() {
+ const int ret = mutex_trylock(&native_handle_);
+ switch (ret) {
+ case 0:
+ return true;
+ case 1:
+ owner_died_ = true;
+ return true;
+ case 4:
+ return false;
+ default:
+ LOG(FATAL, "mutex_trylock(%p) failed with %d\n", &native_handle_, ret);
+ }
+ }
+
+ void unlock() {
+ CHECK(!owner_died_);
+ mutex_unlock(&native_handle_);
+ }
+
+ typedef aos_mutex *native_handle_type;
+ native_handle_type native_handle() { return &native_handle_; }
+
+ bool owner_died() const { return owner_died_; }
+ void consistent() { owner_died_ = false; }
+
+ private:
+ aos_mutex native_handle_;
+
+ bool owner_died_ = false;
+
+ DISALLOW_COPY_AND_ASSIGN(stl_mutex);
+};
+
+// A mutex with the same API and semantics as ::std::recursive_mutex, with the
+// addition of methods for checking if the previous owner died and a constexpr
+// default constructor.
+// Definitely safe to put in SHM.
+// This uses the pthread_mutex semantics for owner-died: once somebody dies with
+// the lock held, anybody else who takes it will see true for owner_died() until
+// one of them calls consistent(). It is an error to call unlock() or lock()
+// again when owner_died() returns true.
+class stl_recursive_mutex {
+ public:
+ constexpr stl_recursive_mutex() {}
+
+ void lock() {
+ if (mutex_islocked(mutex_.native_handle())) {
+ CHECK(!owner_died());
+ ++recursive_locks_;
+ } else {
+ mutex_.lock();
+ if (mutex_.owner_died()) {
+ recursive_locks_ = 0;
+ } else {
+ CHECK_EQ(0, recursive_locks_);
+ }
+ }
+ }
+ bool try_lock() {
+ if (mutex_islocked(mutex_.native_handle())) {
+ CHECK(!owner_died());
+ ++recursive_locks_;
+ return true;
+ } else {
+ if (mutex_.try_lock()) {
+ if (mutex_.owner_died()) {
+ recursive_locks_ = 0;
+ } else {
+ CHECK_EQ(0, recursive_locks_);
+ }
+ return true;
+ } else {
+ return false;
+ }
+ }
+ }
+ void unlock() {
+ if (recursive_locks_ == 0) {
+ mutex_.unlock();
+ } else {
+ --recursive_locks_;
+ }
+ }
+
+ typedef stl_mutex::native_handle_type native_handle_type;
+ native_handle_type native_handle() { return mutex_.native_handle(); }
+
+ bool owner_died() const { return mutex_.owner_died(); }
+ void consistent() { mutex_.consistent(); }
+
+ private:
+ stl_mutex mutex_;
+ int recursive_locks_ = 0;
+
+ DISALLOW_COPY_AND_ASSIGN(stl_recursive_mutex);
+};
+
+// Convenient typedefs for various types of locking objects.
+typedef ::std::lock_guard<stl_mutex> mutex_lock_guard;
+typedef ::std::lock_guard<stl_recursive_mutex> recursive_lock_guard;
+typedef ::std::unique_lock<stl_mutex> mutex_unique_lock;
+typedef ::std::unique_lock<stl_recursive_mutex> recursive_unique_lock;
+
+} // namespace aos
+
+#endif // AOS_COMMON_STL_MUTEX_H_