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-rw-r--r--runtime/monitor.h106
1 files changed, 56 insertions, 50 deletions
diff --git a/runtime/monitor.h b/runtime/monitor.h
index 71fe716..044f76e 100644
--- a/runtime/monitor.h
+++ b/runtime/monitor.h
@@ -30,47 +30,28 @@
namespace art {
-/*
- * Monitor shape field. Used to distinguish thin locks from fat locks.
- */
-#define LW_SHAPE_THIN 0
-#define LW_SHAPE_FAT 1
-
-/*
- * Hash state field. Used to signify that an object has had its
- * identity hash code exposed or relocated.
- */
-#define LW_HASH_STATE_UNHASHED 0
-#define LW_HASH_STATE_HASHED 1
-#define LW_HASH_STATE_HASHED_AND_MOVED 3
-#define LW_HASH_STATE_MASK 0x3
-#define LW_HASH_STATE_SHIFT 1
-#define LW_HASH_STATE(x) (((x) >> LW_HASH_STATE_SHIFT) & LW_HASH_STATE_MASK)
-
-/*
- * Lock owner field. Contains the thread id of the thread currently
- * holding the lock.
- */
-#define LW_LOCK_OWNER_MASK 0xffff
-#define LW_LOCK_OWNER_SHIFT 3
-#define LW_LOCK_OWNER(x) (((x) >> LW_LOCK_OWNER_SHIFT) & LW_LOCK_OWNER_MASK)
-
namespace mirror {
class ArtMethod;
class Object;
} // namespace mirror
+class LockWord;
class Thread;
class StackVisitor;
class Monitor {
public:
+ // The default number of spins that are done before thread suspension is used to forcibly inflate
+ // a lock word. See Runtime::max_spins_before_thin_lock_inflation_.
+ constexpr static size_t kDefaultMaxSpinsBeforeThinLockInflation = 50;
+
~Monitor();
static bool IsSensitiveThread();
static void Init(uint32_t lock_profiling_threshold, bool (*is_sensitive_thread_hook)());
- static uint32_t GetThinLockId(uint32_t raw_lock_word)
- NO_THREAD_SAFETY_ANALYSIS; // Reading lock owner without holding lock is racy.
+ // Return the thread id of the lock owner or 0 when there is no owner.
+ static uint32_t GetLockOwnerThreadId(mirror::Object* obj)
+ NO_THREAD_SAFETY_ANALYSIS; // TODO: Reading lock owner without holding lock is racy.
static void MonitorEnter(Thread* thread, mirror::Object* obj)
EXCLUSIVE_LOCK_FUNCTION(monitor_lock_)
@@ -80,9 +61,13 @@ class Monitor {
UNLOCK_FUNCTION(monitor_lock_);
static void Notify(Thread* self, mirror::Object* obj)
- SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+ InflateAndNotify(self, obj, false);
+ }
static void NotifyAll(Thread* self, mirror::Object* obj)
- SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+ InflateAndNotify(self, obj, true);
+ }
static void Wait(Thread* self, mirror::Object* obj, int64_t ms, int32_t ns,
bool interruptShouldThrow, ThreadState why)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
@@ -92,7 +77,8 @@ class Monitor {
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Used to implement JDWP's ThreadReference.CurrentContendedMonitor.
- static mirror::Object* GetContendedMonitor(Thread* thread);
+ static mirror::Object* GetContendedMonitor(Thread* thread)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Calls 'callback' once for each lock held in the single stack frame represented by
// the current state of 'stack_visitor'.
@@ -100,19 +86,33 @@ class Monitor {
void* callback_context)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
- static bool IsValidLockWord(int32_t lock_word);
+ static bool IsValidLockWord(LockWord lock_word);
+
+ // TODO: SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
+ mirror::Object* GetObject() const {
+ return obj_;
+ }
- mirror::Object* GetObject();
void SetObject(mirror::Object* object);
+ Thread* GetOwner() const NO_THREAD_SAFETY_ANALYSIS {
+ return owner_;
+ }
+
private:
explicit Monitor(Thread* owner, mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+ // Install the monitor into its object, may fail if another thread installs a different monitor
+ // first.
+ bool Install(Thread* self)
+ LOCKS_EXCLUDED(monitor_lock_)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
void AppendToWaitSet(Thread* thread) EXCLUSIVE_LOCKS_REQUIRED(monitor_lock_);
void RemoveFromWaitSet(Thread* thread) EXCLUSIVE_LOCKS_REQUIRED(monitor_lock_);
- static void Inflate(Thread* self, mirror::Object* obj)
+ static void Inflate(Thread* self, Thread* owner, mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void LogContentionEvent(Thread* self, uint32_t wait_ms, uint32_t sample_percent,
@@ -123,43 +123,49 @@ class Monitor {
LOCKS_EXCLUDED(Locks::thread_list_lock_)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
- void Lock(Thread* self) EXCLUSIVE_LOCK_FUNCTION(monitor_lock_);
- bool Unlock(Thread* thread, bool for_wait) UNLOCK_FUNCTION(monitor_lock_);
+ void Lock(Thread* self)
+ LOCKS_EXCLUDED(monitor_lock_)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+ bool Unlock(Thread* thread)
+ LOCKS_EXCLUDED(monitor_lock_)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
- void Notify(Thread* self) NO_THREAD_SAFETY_ANALYSIS;
- void NotifyWithLock(Thread* self)
- EXCLUSIVE_LOCKS_REQUIRED(monitor_lock_)
+ static void InflateAndNotify(Thread* self, mirror::Object* obj, bool notify_all)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
- void NotifyAll(Thread* self) NO_THREAD_SAFETY_ANALYSIS;
- void NotifyAllWithLock()
- EXCLUSIVE_LOCKS_REQUIRED(monitor_lock_)
+ void Notify(Thread* self)
+ LOCKS_EXCLUDED(monitor_lock_)
+ SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ void NotifyAll(Thread* self)
+ LOCKS_EXCLUDED(monitor_lock_)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void Wait(Thread* self, int64_t msec, int32_t nsec, bool interruptShouldThrow, ThreadState why)
- NO_THREAD_SAFETY_ANALYSIS;
- void WaitWithLock(Thread* self, int64_t ms, int32_t ns, bool interruptShouldThrow, ThreadState why)
- EXCLUSIVE_LOCKS_REQUIRED(monitor_lock_)
+ LOCKS_EXCLUDED(monitor_lock_)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Translates the provided method and pc into its declaring class' source file and line number.
void TranslateLocation(const mirror::ArtMethod* method, uint32_t pc,
- const char*& source_file, uint32_t& line_number) const
+ const char** source_file, uint32_t* line_number) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+ uint32_t GetOwnerThreadId();
+
static bool (*is_sensitive_thread_hook_)();
static uint32_t lock_profiling_threshold_;
Mutex monitor_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
+ ConditionVariable monitor_contenders_ GUARDED_BY(monitor_lock_);
// Which thread currently owns the lock?
- Thread* volatile owner_;
+ Thread* volatile owner_ GUARDED_BY(monitor_lock_);
// Owner's recursive lock depth.
int lock_count_ GUARDED_BY(monitor_lock_);
- // What object are we part of (for debugging).
+ // What object are we part of.
mirror::Object* obj_;
// Threads currently waiting on this monitor.
@@ -205,9 +211,9 @@ class MonitorInfo {
public:
explicit MonitorInfo(mirror::Object* o) EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_);
- Thread* owner;
- size_t entry_count;
- std::vector<Thread*> waiters;
+ Thread* owner_;
+ size_t entry_count_;
+ std::vector<Thread*> waiters_;
private:
DISALLOW_COPY_AND_ASSIGN(MonitorInfo);
generated by cgit v1.1 at 2024-09-15 12:04:47 +0000