Refactor lock related code

core/lock.cpp

@@ -96,8 +96,7 @@ size_t GetLocksCount() { return LocksCount.load(); }
 
 void LockClass::Yield()
 {
-	if (CPU::Interrupts(CPU::Check) &&
-		TaskManager &&
+	if (CPU::Interrupts(CPU::Check) && TaskManager &&
 		!TaskManager->IsPanic())
 	{
 		TaskManager->Yield();
@@ -123,10 +122,8 @@ void LockClass::DeadLock(SpinLockData &Lock)
 		CCore = CoreData->ID;
 
 	warn("Potential deadlock in lock '%s' held by '%s'! %ld %s in queue. Interrupts are %s. Core %ld held by %ld. (%ld times happened)",
-		 Lock.AttemptingToGet, Lock.CurrentHolder,
-		 Lock.Count, Lock.Count > 1 ? "locks" : "lock",
-		 CPU::Interrupts(CPU::Check) ? "enabled" : "disabled",
-		 CCore, Lock.Core, this->DeadLocks);
+		 Lock.AttemptingToGet, Lock.CurrentHolder, Lock.Count, Lock.Count > 1 ? "locks" : "lock",
+		 CPU::Interrupts(CPU::Check) ? "enabled" : "disabled", CCore, Lock.Core, this->DeadLocks);
 
 #ifdef PRINT_BACKTRACE
 	PrintStacktrace(&Lock);
@@ -201,10 +198,8 @@ void LockClass::TimeoutDeadLock(SpinLockData &Lock, uint64_t Timeout)
 	uint64_t Counter = TimeManager->GetCounter();
 
 	warn("Potential deadlock in lock '%s' held by '%s'! %ld %s in queue. Interrupts are %s. Core %ld held by %ld. Timeout in %ld (%ld ticks remaining).",
-		 Lock.AttemptingToGet, Lock.CurrentHolder,
-		 Lock.Count, Lock.Count > 1 ? "locks" : "lock",
-		 CPU::Interrupts(CPU::Check) ? "enabled" : "disabled",
-		 CCore, Lock.Core, Timeout, Timeout - Counter);
+		 Lock.AttemptingToGet, Lock.CurrentHolder, Lock.Count, Lock.Count > 1 ? "locks" : "lock",
+		 CPU::Interrupts(CPU::Check) ? "enabled" : "disabled", CCore, Lock.Core, Timeout, Timeout - Counter);
 
 #ifdef PRINT_BACKTRACE
 	PrintStacktrace(&Lock);

include/lock.hpp

@@ -68,6 +68,32 @@ public:
 	int TimeoutLock(const char *FunctionName, uint64_t Timeout);
 };
 
+class spin_lock
+{
+private:
+	LockClass lc;
+
+public:
+	bool locked()
+	{
+		return this->lc.Locked();
+	}
+
+	bool lock(const char *FunctionName)
+	{
+		return this->lc.Lock(FunctionName) == 0;
+	}
+
+	bool unlock()
+	{
+		return this->lc.Unlock() == 0;
+	}
+
+	spin_lock() = default;
+	spin_lock(const spin_lock &) = delete;
+	~spin_lock() = default;
+};
+
 /** @brief Please use this macro to create a new smart lock. */
 class SmartLockClass
 {
@@ -106,6 +132,7 @@ public:
 		this->LockPointer = &Lock;
 		this->LockPointer->TimeoutLock(FunctionName, Timeout);
 	}
+
 	~SmartTimeoutLockClass()
 	{
 		this->LockPointer->Unlock();
@@ -128,6 +155,7 @@ public:
 		this->LockPointer = &Lock;
 		this->LockPointer->Lock(FunctionName);
 	}
+
 	~SmartLockCriticalSectionClass()
 	{
 		this->LockPointer->Unlock();
@@ -153,6 +181,7 @@ public:
 			InterruptsEnabled = true;
 		CPU::Interrupts(CPU::Disable);
 	}
+
 	~SmartCriticalSectionClass()
 	{
 		if (InterruptsEnabled)

include_std/mutex

@@ -25,6 +25,21 @@
 
 namespace std
 {
+
+	struct defer_lock_t
+	{
+		explicit defer_lock_t() = default;
+	};
+
+	struct try_to_lock_t
+	{
+		explicit try_to_lock_t() = default;
+	};
+	struct adopt_lock_t
+	{
+		explicit adopt_lock_t() = default;
+	};
+
 	/**
 	 * A mutex implementation.
 	 *
@@ -35,7 +50,7 @@ namespace std
 	{
 	private:
 		atomic_bool Locked = false;
-		vector<Tasking::TCB *> Waiting;
+		list<Tasking::TCB *> Waiting;
 		Tasking::TCB *Holder = nullptr;
 
 	public:
@@ -43,24 +58,37 @@ namespace std
 		bool try_lock();
 		void unlock();
 
-		mutex() = default;
+		mutex();
 		mutex(const mutex &) = delete;
-		~mutex() = default;
+		~mutex();
 	};
 
 	template <class Mutex>
 	class lock_guard
 	{
 	private:
-		Mutex &m;
+		Mutex &mutexRef;
 
 	public:
-		explicit lock_guard(Mutex &mutex)
-			: m(mutex) { m.lock(); }
+		explicit lock_guard(Mutex &m)
+			: mutexRef(m)
+		{
+			mutexRef.lock();
+		}
 
-		~lock_guard() { m.unlock(); }
+		lock_guard(Mutex &m, adopt_lock_t t)
+			: mutexRef(m)
+		{
+			/* Do nothing */
+		}
 
 		lock_guard(const lock_guard &) = delete;
+
+		~lock_guard()
+		{
+			mutexRef.unlock();
+		}
+
 		lock_guard &operator=(const lock_guard &) = delete;
 	};
 }

library/std/mutex.cpp

@@ -29,53 +29,80 @@ namespace std
 {
 	void mutex::lock()
 	{
+	RetryLock:
 		bool Result = this->Locked.exchange(true, std::memory_order_acquire);
-		__sync;
 
-		if (Result)
+		TCB *tcb = thisThread;
+		if (Result == true)
 		{
-			this->Waiting.push_back(thisThread);
-			thisThread->Block();
+			debug("%#lx: Mutex is locked, blocking task %d (\"%s\" : %d)", this,
+				  tcb->ID, tcb->Parent->Name, tcb->Parent->ID);
+
+			this->Waiting.push_back(tcb);
+			tcb->Block();
 			TaskManager->Yield();
-			return;
+			goto RetryLock;
 		}
 
-		this->Holder = thisThread;
-		this->Waiting.erase(std::find(this->Waiting.begin(),
-									  this->Waiting.end(),
-									  thisThread));
+		this->Holder = tcb;
+		this->Waiting.remove(tcb);
+
+		debug("%#lx: Mutex locked by task %d (\"%s\" : %d)", this,
+			  tcb->ID, tcb->Parent->Name, tcb->Parent->ID);
 	}
 
 	bool mutex::try_lock()
 	{
 		bool Result = this->Locked.exchange(true, std::memory_order_acquire);
-		__sync;
 
-		if (!Result)
+		TCB *tcb = thisThread;
+		if (Result == true)
 		{
-			this->Holder = thisThread;
-			this->Waiting.erase(std::find(this->Waiting.begin(),
-										  this->Waiting.end(),
-										  thisThread));
+			debug("%#lx: Mutex is locked, task %d (\"%s\" : %d) failed to lock", this,
+				  tcb->ID, tcb->Parent->Name, tcb->Parent->ID);
+			return false;
 		}
-		return !Result;
+
+		this->Holder = tcb;
+		this->Waiting.remove(tcb);
+
+		debug("%#lx: Mutex locked by task %d (\"%s\" : %d)", this,
+			  tcb->ID, tcb->Parent->Name, tcb->Parent->ID);
+		return true;
 	}
 
 	void mutex::unlock()
 	{
-		__sync;
+		TCB *tcb = thisThread;
+		assert(this->Holder == tcb);
+
+		this->Holder = nullptr;
 		this->Locked.store(false, std::memory_order_release);
 
-		if (!this->Waiting.empty())
+		if (this->Waiting.empty())
 		{
-			this->Holder = this->Waiting[0];
-
-			this->Holder = this->Waiting.front();
-			this->Waiting.erase(this->Waiting.begin());
-			this->Holder->Unblock();
-			TaskManager->Yield();
+			debug("%#lx: Mutex unlocked, no tasks to unblock", this);
+			return;
 		}
-		else
-			this->Holder = nullptr;
+
+		TCB *Next = this->Waiting.front();
+		this->Waiting.pop_front();
+
+		debug("%#lx: Mutex unlocked, task %d (\"%s\" : %d) unblocked", this,
+			  Next->ID, Next->Parent->Name, Next->Parent->ID);
+
+		Next->Unblock();
+	}
+
+	mutex::mutex()
+	{
+		debug("%#lx: Creating mutex", this);
+	}
+
+	mutex::~mutex()
+	{
+		debug("%#lx: Destroying mutex", this);
+		assert(this->Holder == nullptr);
+		assert(this->Waiting.empty());
 	}
 }