Make SharedMemoryHandle a class on Mac.

content/browser/renderer_host/media/video_capture_buffer_pool.cc

 // Copyright (c) 2013 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 "content/browser/renderer_host/media/video_capture_buffer_pool.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
 #include "content/browser/gpu/browser_gpu_memory_buffer_manager.h"
@@ skipping 54 matching lines @@
       : data_(data), size_(size), handle_(handle) {}
   ~SimpleBufferHandle() override {}
 
   size_t size() const override { return size_; }
   void* data() override { return data_; }
   gfx::GpuMemoryBufferType GetType() override {
     return gfx::SHARED_MEMORY_BUFFER;
   }
   ClientBuffer AsClientBuffer() override { return nullptr; }
   base::PlatformFile AsPlatformFile() override {
-#if defined(OS_POSIX)
+#if defined(OS_MACOSX)

[mcasas, 2015/06/17 21:33:11]

OS_MACOSX implies OS_POSIX, right? [1]

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/build/build_config...

[erikchen, 2015/06/18 17:58:33]

I don't understand your question. Yes, OS_MACOSX implies OS_POSIX, but it's also
possible to have OS_POSIX without OS_MACOSX (android, linux, chromeos, etc.)

+    return handle_.GetFileDescriptor()->fd;
+#elif defined(OS_POSIX)
     return handle_.fd;
 #elif defined(OS_WIN)
     return handle_;
 #endif

[Nico, 2015/06/17 04:03:21]

maybe there could be some function for this direction too, given that it's
needed in a few places?

[erikchen, 2015/06/17 17:38:55]

This change showed up in a recent rebase against top of tree, and I just wanted
to get it compiling again so I could merge the change (and not have to deal with
future merge problems). As far as I can tell, this function is only ever called
on Linux. I was planning on chatting with the OWNER about this later in the
development cycle of Mach shared memory. (This is temporary blocked on my
Windows attachment broker IPC work).

   }
 
  private:
   void* const data_;
   const size_t size_;
   const base::SharedMemoryHandle handle_;
 };
 
 // A holder of a GpuMemoryBuffer-backed buffer, Map()ed on ctor and Unmap()ed on
 // dtor. Holds a weak reference to its GpuMemoryBuffer.
 // TODO(mcasas) Map()ed on ctor, or on first use?
 class GpuMemoryBufferBufferHandle
     final : public VideoCaptureBufferPool::BufferHandle {
  public:
   GpuMemoryBufferBufferHandle(gfx::GpuMemoryBuffer* gmb, size_t size)
       : gmb_(gmb),
         data_(new void* [GpuMemoryBufferImpl::
                              NumberOfPlanesForGpuMemoryBufferFormat(
                                  gmb_->GetFormat())]),
         size_(size) {
     DCHECK(gmb && !gmb_->IsMapped());
     gmb_->Map(data_.get());
   }
   ~GpuMemoryBufferBufferHandle() override { gmb_->Unmap(); }
 
   size_t size() const override { return size_; }
   void* data() override { return data_[0]; }
   gfx::GpuMemoryBufferType GetType() override {
     return gmb_->GetHandle().type;

[reveman, 2015/06/17 19:24:10]

Unrelated to this patch but the use of GetHandle() here and below is a layering
violation. Users of GpuMemoryBuffers should not be calling GetHandle and be
poking around in that struct. We might make this opaque and private to the IPC
code in content/ that it's intended for and this code will then break.

[mcasas, 2015/06/17 21:33:11]

Currently this is just used for a DCHECK and some
double-checking that we're in a platform where
|gmb_| is a DmaBuf, and the latter can be done
via #if defined(USE_OZONE).

   }
   ClientBuffer AsClientBuffer() override { return gmb_->AsClientBuffer(); }
   base::PlatformFile AsPlatformFile() override {
     DCHECK_EQ(gmb_->GetHandle().type, gfx::SHARED_MEMORY_BUFFER);
-#if defined(OS_POSIX)
+#if defined(OS_MACOSX)
+    return gmb_->GetHandle().handle.GetFileDescriptor()->fd;
+#elif defined(OS_POSIX)
     return gmb_->GetHandle().handle.fd;
 #elif defined(OS_WIN)
     return gmb_->GetHandle().handle;
 #endif
   }
 
  private:
   gfx::GpuMemoryBuffer* const gmb_;
   scoped_ptr<void*[]> data_;
   const size_t size_;
@@ skipping 284 matching lines @@
   return buffer_id;
 }
 
 VideoCaptureBufferPool::Tracker* VideoCaptureBufferPool::GetTracker(
     int buffer_id) {
   TrackerMap::const_iterator it = trackers_.find(buffer_id);
   return (it == trackers_.end()) ? NULL : it->second;
 }
 
 }  // namespace content