blob: 3a63810ad4fed132c9e7fe53109e34180ec83f98 [file] [log] [blame] [edit]
// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
//
// 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 "Resource.hpp"
#include "Memory.hpp"
#include "Debug.hpp"
namespace sw
{
Resource::Resource(size_t bytes) : size(bytes)
{
blocked = 0;
accessor = PUBLIC;
count = 0;
orphaned = false;
buffer = allocate(bytes);
}
Resource::~Resource()
{
deallocate(buffer);
}
void *Resource::lock(Accessor claimer)
{
criticalSection.lock();
while(count > 0 && accessor != claimer)
{
blocked++;
criticalSection.unlock();
unblock.wait();
criticalSection.lock();
blocked--;
}
accessor = claimer;
count++;
criticalSection.unlock();
return buffer;
}
void *Resource::lock(Accessor relinquisher, Accessor claimer)
{
criticalSection.lock();
// Release
while(count > 0 && accessor == relinquisher)
{
count--;
if(count == 0)
{
if(blocked)
{
unblock.signal();
}
else if(orphaned)
{
criticalSection.unlock();
delete this;
return 0;
}
}
}
// Acquire
while(count > 0 && accessor != claimer)
{
blocked++;
criticalSection.unlock();
unblock.wait();
criticalSection.lock();
blocked--;
}
accessor = claimer;
count++;
criticalSection.unlock();
return buffer;
}
void Resource::unlock()
{
criticalSection.lock();
ASSERT(count > 0);
count--;
if(count == 0)
{
if(blocked)
{
unblock.signal();
}
else if(orphaned)
{
criticalSection.unlock();
delete this;
return;
}
}
criticalSection.unlock();
}
void Resource::unlock(Accessor relinquisher)
{
criticalSection.lock();
ASSERT(count > 0);
while(count > 0 && accessor == relinquisher)
{
count--;
if(count == 0)
{
if(blocked)
{
unblock.signal();
}
else if(orphaned)
{
criticalSection.unlock();
delete this;
return;
}
}
}
criticalSection.unlock();
}
void Resource::destruct()
{
criticalSection.lock();
if(count == 0 && !blocked)
{
criticalSection.unlock();
delete this;
return;
}
orphaned = true;
criticalSection.unlock();
}
const void *Resource::data() const
{
return buffer;
}
}