Revert "Delete CC."

cc/resources/resource_pool.cc

+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cc/resources/resource_pool.h"
+
+#include "cc/resources/resource_provider.h"
+#include "cc/resources/scoped_resource.h"
+
+namespace cc {
+
+ResourcePool::ResourcePool(ResourceProvider* resource_provider, GLenum target)
+    : resource_provider_(resource_provider),
+      target_(target),
+      max_memory_usage_bytes_(0),
+      max_unused_memory_usage_bytes_(0),
+      max_resource_count_(0),
+      memory_usage_bytes_(0),
+      unused_memory_usage_bytes_(0),
+      resource_count_(0) {}
+
+ResourcePool::~ResourcePool() {
+  while (!busy_resources_.empty()) {
+    DidFinishUsingResource(busy_resources_.front());
+    busy_resources_.pop_front();
+  }
+
+  SetResourceUsageLimits(0, 0, 0);
+  DCHECK_EQ(0u, unused_resources_.size());
+  DCHECK_EQ(0u, memory_usage_bytes_);
+  DCHECK_EQ(0u, unused_memory_usage_bytes_);
+  DCHECK_EQ(0u, resource_count_);
+}
+
+scoped_ptr<ScopedResource> ResourcePool::AcquireResource(
+    const gfx::Size& size, ResourceFormat format) {
+  for (ResourceList::iterator it = unused_resources_.begin();
+       it != unused_resources_.end();
+       ++it) {
+    ScopedResource* resource = *it;
+    DCHECK(resource_provider_->CanLockForWrite(resource->id()));
+
+    if (resource->format() != format)
+      continue;
+    if (resource->size() != size)
+      continue;
+
+    unused_resources_.erase(it);
+    unused_memory_usage_bytes_ -= resource->bytes();
+    return make_scoped_ptr(resource);
+  }
+
+  scoped_ptr<ScopedResource> resource =
+      ScopedResource::Create(resource_provider_);
+  resource->AllocateManaged(size, target_, format);
+
+  memory_usage_bytes_ += resource->bytes();
+  ++resource_count_;
+  return resource.Pass();
+}
+
+void ResourcePool::ReleaseResource(scoped_ptr<ScopedResource> resource) {
+  busy_resources_.push_back(resource.release());
+}
+
+void ResourcePool::SetResourceUsageLimits(size_t max_memory_usage_bytes,
+                                          size_t max_unused_memory_usage_bytes,
+                                          size_t max_resource_count) {
+  max_memory_usage_bytes_ = max_memory_usage_bytes;
+  max_unused_memory_usage_bytes_ = max_unused_memory_usage_bytes;
+  max_resource_count_ = max_resource_count;
+
+  ReduceResourceUsage();
+}
+
+void ResourcePool::ReduceResourceUsage() {
+  while (!unused_resources_.empty()) {
+    if (!ResourceUsageTooHigh())
+      break;
+
+    // LRU eviction pattern. Most recently used might be blocked by
+    // a read lock fence but it's still better to evict the least
+    // recently used as it prevents a resource that is hard to reuse
+    // because of unique size from being kept around. Resources that
+    // can't be locked for write might also not be truly free-able.
+    // We can free the resource here but it doesn't mean that the
+    // memory is necessarily returned to the OS.
+    ScopedResource* resource = unused_resources_.front();
+    unused_resources_.pop_front();
+    memory_usage_bytes_ -= resource->bytes();
+    unused_memory_usage_bytes_ -= resource->bytes();
+    --resource_count_;
+    delete resource;
+  }
+}
+
+bool ResourcePool::ResourceUsageTooHigh() {
+  if (resource_count_ > max_resource_count_)
+    return true;
+  if (memory_usage_bytes_ > max_memory_usage_bytes_)
+    return true;
+  if (unused_memory_usage_bytes_ > max_unused_memory_usage_bytes_)
+    return true;
+  return false;
+}
+
+void ResourcePool::CheckBusyResources(bool wait_if_needed) {
+  ResourceList::iterator it = busy_resources_.begin();
+
+  while (it != busy_resources_.end()) {
+    ScopedResource* resource = *it;
+
+    if (wait_if_needed)
+      resource_provider_->WaitReadLockIfNeeded(resource->id());
+
+    if (resource_provider_->CanLockForWrite(resource->id())) {
+      DidFinishUsingResource(resource);
+      it = busy_resources_.erase(it);
+    } else {
+      ++it;
+    }
+  }
+}
+
+void ResourcePool::DidFinishUsingResource(ScopedResource* resource) {
+  unused_memory_usage_bytes_ += resource->bytes();
+  unused_resources_.push_back(resource);
+}
+
+}  // namespace cc