Mutex: Cleanup and remove redundant code.

This commit is contained in:
bunnei 2015-01-20 18:33:23 -05:00
parent f09806aed2
commit 2f3020a102
3 changed files with 30 additions and 48 deletions

View file

@ -23,9 +23,8 @@ public:
bool initial_locked; ///< Initial lock state when mutex was created
bool locked; ///< Current locked state
Handle lock_thread; ///< Handle to thread that currently has mutex
std::string name; ///< Name of mutex (optional)
SharedPtr<Thread> current_thread; ///< Thread that has acquired the mutex
SharedPtr<Thread> holding_thread; ///< Thread that has acquired the mutex
bool ShouldWait() override;
void Acquire() override;
@ -33,18 +32,17 @@ public:
////////////////////////////////////////////////////////////////////////////////////////////////////
typedef std::multimap<Handle, Handle> MutexMap;
typedef std::multimap<SharedPtr<Thread>, SharedPtr<Mutex>> MutexMap;
static MutexMap g_mutex_held_locks;
/**
* Acquires the specified mutex for the specified thread
* @param mutex Mutex that is to be acquired
* @param thread Thread that will acquired
* @param thread Thread that will acquire the mutex
*/
void MutexAcquireLock(Mutex* mutex, Handle thread = GetCurrentThread()->GetHandle()) {
g_mutex_held_locks.insert(std::make_pair(thread, mutex->GetHandle()));
mutex->lock_thread = thread;
mutex->current_thread = Kernel::g_handle_table.Get<Thread>(thread);
void MutexAcquireLock(Mutex* mutex, Thread* thread) {
g_mutex_held_locks.insert(std::make_pair(thread, mutex));
mutex->holding_thread = thread;
}
/**
@ -55,51 +53,39 @@ void ResumeWaitingThread(Mutex* mutex) {
// Find the next waiting thread for the mutex...
auto next_thread = mutex->WakeupNextThread();
if (next_thread != nullptr) {
MutexAcquireLock(mutex, next_thread->GetHandle());
MutexAcquireLock(mutex, next_thread);
} else {
// Reset mutex lock thread handle, nothing is waiting
mutex->locked = false;
mutex->lock_thread = -1;
mutex->holding_thread = nullptr;
}
}
void MutexEraseLock(Mutex* mutex) {
Handle handle = mutex->GetHandle();
auto locked = g_mutex_held_locks.equal_range(mutex->lock_thread);
for (MutexMap::iterator iter = locked.first; iter != locked.second; ++iter) {
if (iter->second == handle) {
g_mutex_held_locks.erase(iter);
break;
}
}
mutex->lock_thread = -1;
}
void ReleaseThreadMutexes(Handle thread) {
void ReleaseThreadMutexes(Thread* thread) {
auto locked = g_mutex_held_locks.equal_range(thread);
// Release every mutex that the thread holds, and resume execution on the waiting threads
for (MutexMap::iterator iter = locked.first; iter != locked.second; ++iter) {
Mutex* mutex = g_handle_table.Get<Mutex>(iter->second).get();
ResumeWaitingThread(mutex);
for (auto iter = locked.first; iter != locked.second; ++iter) {
ResumeWaitingThread(iter->second.get());
}
// Erase all the locks that this thread holds
g_mutex_held_locks.erase(thread);
}
bool LockMutex(Mutex* mutex) {
// Mutex alread locked?
if (mutex->locked) {
return false;
}
MutexAcquireLock(mutex);
return true;
}
bool ReleaseMutex(Mutex* mutex) {
MutexEraseLock(mutex);
if (mutex->locked) {
auto locked = g_mutex_held_locks.equal_range(mutex->holding_thread);
for (MutexMap::iterator iter = locked.first; iter != locked.second; ++iter) {
if (iter->second == mutex) {
g_mutex_held_locks.erase(iter);
break;
}
}
ResumeWaitingThread(mutex);
}
return true;
}
@ -134,16 +120,12 @@ Mutex* CreateMutex(Handle& handle, bool initial_locked, const std::string& name)
mutex->locked = mutex->initial_locked = initial_locked;
mutex->name = name;
mutex->current_thread = nullptr;
mutex->holding_thread = nullptr;
// Acquire mutex with current thread if initialized as locked...
if (mutex->locked) {
MutexAcquireLock(mutex);
if (mutex->locked)
MutexAcquireLock(mutex, GetCurrentThread());
// Otherwise, reset lock thread handle
} else {
mutex->lock_thread = -1;
}
return mutex;
}
@ -160,13 +142,13 @@ Handle CreateMutex(bool initial_locked, const std::string& name) {
}
bool Mutex::ShouldWait() {
return locked && current_thread != GetCurrentThread();
return locked && holding_thread != GetCurrentThread();
}
void Mutex::Acquire() {
_assert_msg_(Kernel, !ShouldWait(), "object unavailable!");
locked = true;
MutexAcquireLock(this);
MutexAcquireLock(this, GetCurrentThread());
}
} // namespace

View file

@ -28,6 +28,6 @@ Handle CreateMutex(bool initial_locked, const std::string& name="Unknown");
* Releases all the mutexes held by the specified thread
* @param thread Thread that is holding the mutexes
*/
void ReleaseThreadMutexes(Handle thread);
void ReleaseThreadMutexes(Thread* thread);
} // namespace

View file

@ -100,7 +100,7 @@ static bool CheckWait_AddressArbiter(const Thread* thread, VAddr wait_address) {
/// Stops the current thread
void Thread::Stop(const char* reason) {
// Release all the mutexes that this thread holds
ReleaseThreadMutexes(GetHandle());
ReleaseThreadMutexes(this);
ChangeReadyState(this, false);
status = THREADSTATUS_DORMANT;