gralloc1/mali_gralloc_reference.cpp

/*
 * Copyright (C) 2016 ARM Limited. All rights reserved.
 *
 * 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.
 */

#include "mali_gralloc_reference.h"

static pthread_mutex_t s_map_lock = PTHREAD_MUTEX_INITIALIZER;

int mali_gralloc_reference_retain(mali_gralloc_module const* module, buffer_handle_t handle)
{
	GRALLOC_UNUSED(module);

	if (private_handle_t::validate(handle) < 0)
	{
		AERR("Registering/Retaining invalid buffer %p, returning error", handle);
		return -EINVAL;
	}

	private_handle_t* hnd = (private_handle_t*)handle;
	pthread_mutex_lock(&s_map_lock);

	if (hnd->allocating_pid == getpid() || hnd->remote_pid == getpid())
	{
		hnd->ref_count++;
		pthread_mutex_unlock(&s_map_lock);
		return 0;
	}
	else
	{
		hnd->remote_pid = getpid();
		hnd->ref_count = 1;
	}

	int retval = -EINVAL;

	if (hnd->flags & private_handle_t::PRIV_FLAGS_FRAMEBUFFER)
	{
		AERR( "Can't register buffer %p as it is a framebuffer", handle );
	}
	else if (hnd->flags & (private_handle_t::PRIV_FLAGS_USES_ION))
	{
		retval = gralloc_register_buffer(module, hnd);
	}
	else
	{
		AERR("unkown buffer flags not supported. flags = %d", hnd->flags );
	}

	pthread_mutex_unlock(&s_map_lock);
	return retval;
}

int mali_gralloc_reference_release(mali_gralloc_module const* module, buffer_handle_t handle, bool canFree)
{

	if (private_handle_t::validate(handle) < 0)
	{
		AERR("unregistering/releasing invalid buffer %p, returning error", handle);
		return -EINVAL;
	}

	private_handle_t* hnd = (private_handle_t*)handle;
	pthread_mutex_lock(&s_map_lock);

	if (hnd->flags & private_handle_t::PRIV_FLAGS_FRAMEBUFFER)
	{
		AERR( "Can't unregister buffer %p as it is a framebuffer", handle );
		pthread_mutex_unlock(&s_map_lock);
		return 0;
	}

	if (hnd->ref_count == 0)
	{
		AERR( "Buffer %p should have already been released", handle);
		pthread_mutex_unlock(&s_map_lock);
		return -EINVAL;
	}

	if (hnd->allocating_pid == getpid())
	{
		hnd->ref_count--;

		if (hnd->ref_count == 0 && canFree)
		{
			mali_gralloc_buffer_free(module, handle);
			delete handle;
		}
	}
	else if (hnd->remote_pid == getpid()) // never unmap buffers that were not imported into this process
	{
		hnd->ref_count--;

		if (hnd->ref_count == 0)
		{

			if (hnd->flags & (private_handle_t::PRIV_FLAGS_USES_ION))
			{
				gralloc_unregister_buffer(module, hnd);
			}
			else
			{
				AERR("Unregistering/Releasing unknown buffer is not supported. Flags = %d", hnd->flags);
			}

			hnd->base = 0;
			hnd->writeOwner = 0;
		}
	}
	else
	{
		AERR( "Trying to unregister buffer %p from process %d that was not imported into current process: %d", hnd, hnd->remote_pid,getpid());
	}

	pthread_mutex_unlock(&s_map_lock);
	return 0;
}