#include "shared_mutex.h"
#include "core/error/error_macros.h"

void SharedMutex::lock_shared() {
	this->lock.lock();
	this->shared_count++;
	this->lock.unlock();
}

void SharedMutex::unlock_shared() {
	this->lock.lock();
	this->shared_count--;
	ERR_FAIL_COND_EDMSG(this->shared_count < 0, "SharedMutex::unlock_shared, shared_count < 0");
	this->lock.unlock();
}

void SharedMutex::lock_exclusive() {
	while (true) {
		this->lock.lock();
		if (this->shared_count == 0) {
			return;
		}
		this->lock.unlock();
	}
}

void SharedMutex::unlock_exclusive() {
	this->lock.unlock();
}

bool SharedMutex::is_locked() {
	if (this->lock.try_lock()) {
		bool locked{ this->shared_count != 0 };
		this->lock.unlock();
		return locked;
	} else {
		return false;
	}
}

SharedMutex::LockExclusive::LockExclusive(SharedMutex &mutex) : mtx{ mutex } {
	this->mtx.lock_exclusive();
}

SharedMutex::LockExclusive::~LockExclusive() {
	this->mtx.unlock_exclusive();
}

SharedMutex::LockShared::LockShared(SharedMutex &mutex) : mtx{ mutex } {
	this->mtx.lock_shared();
}

SharedMutex::LockShared::~LockShared() {
	this->mtx.unlock_shared();
}