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/*
* Copyright (C) 2008 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 ART_RUNTIME_MONITOR_H_
#define ART_RUNTIME_MONITOR_H_
#include <pthread.h>
#include <stdint.h>
#include <iosfwd>
#include <list>
#include <vector>
#include "base/mutex.h"
#include "root_visitor.h"
#include "thread_state.h"
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 Thread;
class StackVisitor;
class Monitor {
public:
~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.
static void MonitorEnter(Thread* thread, mirror::Object* obj)
EXCLUSIVE_LOCK_FUNCTION(monitor_lock_)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static bool MonitorExit(Thread* thread, mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
UNLOCK_FUNCTION(monitor_lock_);
static void Notify(Thread* self, mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static void NotifyAll(Thread* self, mirror::Object* obj)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static void Wait(Thread* self, mirror::Object* obj, int64_t ms, int32_t ns,
bool interruptShouldThrow, ThreadState why)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static void DescribeWait(std::ostream& os, const Thread* thread)
LOCKS_EXCLUDED(Locks::thread_suspend_count_lock_)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Used to implement JDWP's ThreadReference.CurrentContendedMonitor.
static mirror::Object* GetContendedMonitor(Thread* thread);
// Calls 'callback' once for each lock held in the single stack frame represented by
// the current state of 'stack_visitor'.
static void VisitLocks(StackVisitor* stack_visitor, void (*callback)(mirror::Object*, void*),
void* callback_context)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static bool IsValidLockWord(int32_t lock_word);
mirror::Object* GetObject();
private:
explicit Monitor(Thread* owner, mirror::Object* obj)
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)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void LogContentionEvent(Thread* self, uint32_t wait_ms, uint32_t sample_percent,
const char* owner_filename, uint32_t owner_line_number)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static void FailedUnlock(mirror::Object* obj, Thread* expected_owner, Thread* found_owner, Monitor* mon)
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 Notify(Thread* self) NO_THREAD_SAFETY_ANALYSIS;
void NotifyWithLock(Thread* self)
EXCLUSIVE_LOCKS_REQUIRED(monitor_lock_)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void NotifyAll(Thread* self) NO_THREAD_SAFETY_ANALYSIS;
void NotifyAllWithLock()
EXCLUSIVE_LOCKS_REQUIRED(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_)
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
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
static bool (*is_sensitive_thread_hook_)();
static uint32_t lock_profiling_threshold_;
Mutex monitor_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
// Which thread currently owns the lock?
Thread* volatile owner_;
// Owner's recursive lock depth.
int lock_count_ GUARDED_BY(monitor_lock_);
// What object are we part of (for debugging).
mirror::Object* const obj_;
// Threads currently waiting on this monitor.
Thread* wait_set_ GUARDED_BY(monitor_lock_);
// Method and dex pc where the lock owner acquired the lock, used when lock
// sampling is enabled. locking_method_ may be null if the lock is currently
// unlocked, or if the lock is acquired by the system when the stack is empty.
const mirror::ArtMethod* locking_method_ GUARDED_BY(monitor_lock_);
uint32_t locking_dex_pc_ GUARDED_BY(monitor_lock_);
friend class MonitorInfo;
friend class MonitorList;
friend class mirror::Object;
DISALLOW_COPY_AND_ASSIGN(Monitor);
};
class MonitorList {
public:
MonitorList();
~MonitorList();
void Add(Monitor* m);
void SweepMonitorList(IsMarkedTester is_marked, void* arg)
SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_);
void DisallowNewMonitors();
void AllowNewMonitors();
private:
bool allow_new_monitors_ GUARDED_BY(monitor_list_lock_);
Mutex monitor_list_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
ConditionVariable monitor_add_condition_ GUARDED_BY(monitor_list_lock_);
std::list<Monitor*> list_ GUARDED_BY(monitor_list_lock_);
friend class Monitor;
DISALLOW_COPY_AND_ASSIGN(MonitorList);
};
// Collects information about the current state of an object's monitor.
// This is very unsafe, and must only be called when all threads are suspended.
// For use only by the JDWP implementation.
class MonitorInfo {
public:
explicit MonitorInfo(mirror::Object* o) EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_);
Thread* owner;
size_t entry_count;
std::vector<Thread*> waiters;
private:
DISALLOW_COPY_AND_ASSIGN(MonitorInfo);
};
} // namespace art
#endif // ART_RUNTIME_MONITOR_H_
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