Use mapped memory for uploading large textures.

gpu/command_buffer/client/mapped_memory.cc

 // Copyright (c) 2011 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 "gpu/command_buffer/client/mapped_memory.h"
 
 #include <algorithm>
 #include <functional>
 
 #include "base/logging.h"
@@ skipping 63 matching lines @@
           void* mem = chunk->Alloc(size);
           DCHECK(mem);
           *shm_id = chunk->shm_id();
           *shm_offset = chunk->GetOffset(mem);
           return mem;
         }
       }
     }
   }
 
+  if (max_free_bytes_ != kNoLimit &&
+      (allocated_memory_ + size) > max_free_bytes_) {

[jbauman, 2015/06/09 02:30:13]

This wasn't intended to be a hard limit, but rather to prevent it from using
memory unnecessarily (hence the name unused_memory_reclaim_limit for the
argument to the function). I think you should instead have a flag that treats it
as a hard limit, and only use that flag in the new cases.

[David Yen, 2015/06/09 17:07:08]

Ok, I've separated out this concept and added max_allocated_bytes_ that limits
the maximum number of bytes we allocate.

+    return NULL;
+  }
+
   // Make a new chunk to satisfy the request.
   CommandBuffer* cmd_buf = helper_->command_buffer();
   unsigned int chunk_size =
       ((size + chunk_size_multiple_ - 1) / chunk_size_multiple_) *
       chunk_size_multiple_;
   int32 id = -1;
   scoped_refptr<gpu::Buffer> shm =
       cmd_buf->CreateTransferBuffer(chunk_size, &id);
   if (id  < 0)
     return NULL;
@@ skipping 39 matching lines @@
     if (!chunk->InUse()) {
       cmd_buf->DestroyTransferBuffer(chunk->shm_id());
       allocated_memory_ -= chunk->GetSize();
       iter = chunks_.erase(iter);
     } else {
       ++iter;
     }
   }
 }
 
+void ScopedMappedMemoryPtr::Release() {
+  if (buffer_) {
+    mapped_memory_manager_->FreePendingToken(buffer_, helper_->InsertToken());
+    buffer_ = nullptr;
+    size_ = 0;
+    shm_id_ = 0;
+    shm_offset_ = 0;
+
+    if (flush_after_release_)
+      helper_->CommandBufferHelper::Flush();
+  }
+}
+
+void ScopedMappedMemoryPtr::Reset(uint32_t new_size) {
+  Release();
+
+  if (new_size) {
+    buffer_ = mapped_memory_manager_->Alloc(new_size, &shm_id_, &shm_offset_);
+    size_ = buffer_ ? new_size : 0;
+  }
+}
+
 }  // namespace gpu