PPAPI: Implement PPB_FileMapping on POSIX

ppapi/proxy/file_mapping_resource.h

+// Copyright (c) 2014 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.
+
+#ifndef PPAPI_PROXY_FILE_MAPPING_RESOURCE_H_
+#define PPAPI_PROXY_FILE_MAPPING_RESOURCE_H_
+
+#include "ppapi/proxy/file_io_resource.h"
+#include "ppapi/proxy/plugin_resource.h"
+#include "ppapi/proxy/ppapi_proxy_export.h"
+#include "ppapi/thunk/ppb_file_mapping_api.h"
+
+namespace ppapi {
+namespace proxy {
+
+// The proxy-side resource for PPB_FileMapping.
+class PPAPI_PROXY_EXPORT FileMappingResource
+      : public PluginResource,
+        public thunk::PPB_FileMapping_API {
+ public:
+  FileMappingResource(Connection connection, PP_Instance instance);
+
+ private:
+  virtual ~FileMappingResource();
+
+  // Resource implementation.
+  virtual thunk::PPB_FileMapping_API* AsPPB_FileMapping_API() OVERRIDE;
+
+  // PPB_FileMapping_API implementation.
+  virtual int32_t Map(PP_Instance instance,
+                      PP_Resource file_io,
+                      int64_t length,
+                      uint32_t map_protection,
+                      uint32_t map_flags,
+                      int64_t offset,
+                      void** address,
+                      scoped_refptr<TrackedCallback> callback) OVERRIDE;
+  virtual int32_t Unmap(PP_Instance instance,
+                        const void* address,
+                        int64_t length,
+                        scoped_refptr<TrackedCallback> callback) OVERRIDE;
+  virtual int64_t GetMapPageSize(PP_Instance instance) OVERRIDE;
+
+  struct MapResult {
+    MapResult() : result(PP_ERROR_FAILED), address(NULL) {
+    }
+    int32_t result;
+    void* address;
+  };
+  void OnMapCompleted(void** mapped_address_out_param,
+                      int64_t length,
+                      scoped_refptr<TrackedCallback> callback,
+                      const MapResult& map_result);
+
+  // These perform the actual operations in platform-dependent ways,
+  // synchronously on the thread on which their invoked, and do not require the
+  // the proxy lock to be acquired. Map, Unmap, and GetMapPageSize forward
+  // calls to these. See file_mapping_resource_posix.cc and
+  // file_mapping_resource_win.cc for the implementations of the Do* functions.

[bbudge, 2014/01/25 01:04:55]

Rework. How about this?

  // These functions perform potentially blocking operations so they should not
  // be called on the main thread or while we hold the proxy lock. Their
  // implementation is platform specific. See file_mapping_resource_posix.cc and
  // file_mapping_resource_win.cc.

Hmm, you might also append _Blocking to the function names.

[dmichael (off chromium), 2014/01/27 18:29:53]

Thanks, that's much better. Only downside is I don't do anything special for
GetMapPageSize, so I added a little extra comment before it and didn't append
"Blocking" there. Let me know what you think.

+  static MapResult DoMap(scoped_refptr<FileIOResource::FileHandleHolder> handle,
+                         void* address_hint,
+                         int64_t length,
+                         uint32_t map_protection,
+                         uint32_t map_flags,
+                         int64_t offset);
+  static int32_t DoUnmap(const void* address,
+                         int64_t length);
+  static int64_t DoGetMapPageSize();
+
+  DISALLOW_COPY_AND_ASSIGN(FileMappingResource);
+};
+
+}  // namespace proxy
+}  // namespace ppapi
+
+#endif  // PPAPI_PROXY_FILE_MAPPING_RESOURCE_H_