watchos2/watchos2/Kernel.cpp

#include "watchos.h"
#include "IRunnable.h"

struct KernelHandle
{
	kernel_handle_t handle;
	kernel_handle_destructor_t destructor;
	void* object;
	uint references;
	uint32_t well_known = 0;
};

struct KernelTask
{
	kernel_handle_t handle;
	Task* task;
};

void destruct_task(kernel_handle_t handle, void* object)
{
	delete object;
}

Kernel::Kernel()
{
	for (int i = 0; i < KERNEL_MAX_HANDLES; i++)
	{
		m_handle[i] = nullptr;
	}

	for (int i = 0; i < KERNEL_MAX_TASKS; i++)
	{
		m_task[i] = nullptr;
	}
}

kernel_handle_t Kernel::allocHandle(byte type, void* object, kernel_handle_destructor_t destructor, uint32_t well_known)
{
	for (int i = 0; i < KERNEL_MAX_HANDLES; i++)
	{
		if (m_handle[i] == nullptr)
		{
			m_handle[i] = new KernelHandle();
			m_handle[i]->handle = type | m_next_handle++;
			m_handle[i]->destructor = destructor;
			m_handle[i]->object = object;
			m_handle[i]->references = 1;
			m_handle[i]->well_known = well_known;
			return m_handle[i]->handle;
		}
	}
	watchos::panic("Exceeded KERNEL_MAX_HANDLES");
}

void Kernel::freeHandle(kernel_handle_t handle)
{
	for (int i = 0; i < KERNEL_MAX_HANDLES; i++)
	{
		if (m_handle[i] != nullptr && m_handle[i]->handle == handle)
		{
			if (m_handle[i]->destructor != nullptr)
			{
				(m_handle[i]->destructor)(handle, m_handle[i]->object);
			}
			delete m_handle[i];
			m_handle[i] = nullptr;
		}
	}
}

void* Kernel::getHandle(kernel_handle_t handle)
{
	for (int i = 0; i < KERNEL_MAX_HANDLES; i++)
	{
		if (m_handle[i] != nullptr && m_handle[i]->handle == handle)
		{
			m_handle[i]->references++;
			return m_handle[i]->object;
		}
	}
	watchos::panic("Attempt to access invalid Kernel handle");
}

void* Kernel::getHandle(uint32_t well_known)
{
	for (int i = 0; i < KERNEL_MAX_HANDLES; i++)
	{
		if (m_handle[i] != nullptr && m_handle[i]->well_known == well_known)
		{
			m_handle[i]->references++;
			return m_handle[i]->object;
		}
	}
	watchos::panic("Attempt to access invalid Kernel handle by well-known id: %#10x", well_known);
}

void Kernel::releaseHandle(kernel_handle_t handle)
{
	for (int i = 0; i < KERNEL_MAX_HANDLES; i++)
	{
		if (m_handle[i] != nullptr && m_handle[i]->handle == handle)
		{
			m_handle[i]->references--;

			if (m_handle[i]->references == 0)
			{
				freeHandle(handle);
			}

			return;
		}
	}

	watchos::panic("Attempt to release invalid Kernel handle");
}

kernel_handle_t Kernel::registerTask(Task* task)
{
	for (int i = 0; i < KERNEL_MAX_TASKS; i++)
	{
		if (m_task[i] == nullptr)
		{
			m_task[i] = new KernelTask();
			m_task[i]->handle = allocHandle(WATCHOS_HANDLE_TYPE_TASK, (void*)destruct_task);
			m_task[i]->task = task;
			return m_task[i]->handle;
		}
	}

	watchos::panic("Exceeded KERNEL_MAX_TASKS");
}

void Kernel::unregisterTask(Task* task)
{
	for (int i = 0; i < KERNEL_MAX_TASKS; i++)
	{
		if (m_task[i] != nullptr && m_task[i]->task == task)
		{
			releaseHandle(m_task[i]->handle);
			delete m_task[i];
			m_task[i] = nullptr;
			return;
		}
	}
}

void Kernel::tick()
{
	for (int i = 0; i < KERNEL_MAX_TASKS; i++)
	{
		if (m_task[i] != nullptr)
		{
			IRunnable* runnable = dynamic_cast<IRunnable*>(m_task[i]->task);
			if (runnable != nullptr)
			{
				runnable->tick();
			}
		}
	}
}