Create a broker interface for the new Mojo EDK so that the browser can create and duplicate messa...

mojo/edk/system/simple_token_serializer_win.cc

+// Copyright 2015 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 "mojo/edk/system/simple_token_serializer_win.h"
+
+#include <windows.h>
+
+#include "base/process/process.h"
+#include "mojo/edk/embedder/platform_channel_pair.h"
+
+namespace mojo {
+namespace edk {
+
+SimpleTokenSerializer::SimpleTokenSerializer() {
+}
+
+SimpleTokenSerializer::~SimpleTokenSerializer() {
+}
+
+void SimpleTokenSerializer::CreatePlatformChannelPair(
+    ScopedPlatformHandle* server, ScopedPlatformHandle* client) {
+  PlatformChannelPair channel_pair;
+  *server = channel_pair.PassServerHandle();
+  *client = channel_pair.PassClientHandle();
+}
+
+void SimpleTokenSerializer::HandleToToken(
+    const PlatformHandle* platform_handles,
+    size_t count,
+    uint64_t* tokens) {
+  // Since we're not sure which process might ultimately deserialize the message
+  // we can't duplicate the handle now. Instead, write the process ID and handle
+  // now and let the receiver duplicate it.
+  uint32_t current_process_id = base::GetCurrentProcId();
+  for (size_t i = 0; i < count; ++i) {
+    tokens[i] = current_process_id;
+    tokens[i] = tokens[i] << 32;
+    // Windows HANDLES are always 32 bit per
+    // https://msdn.microsoft.com/en-us/library/windows/desktop/aa384203(v=vs.85).aspx
+#if defined(_WIN64)
+    tokens[i] |= static_cast<int32_t>(
+        reinterpret_cast<int64_t>(platform_handles[i].handle));
+#else
+    tokens[i] |= reinterpret_cast<int32_t>(platform_handles[i].handle);
+#endif
+  }
+}
+
+void SimpleTokenSerializer::TokenToHandle(const uint64_t* tokens,
+                                          size_t count,
+                                          PlatformHandle* handles) {
+  for (size_t i = 0; i < count; ++i) {
+    DWORD pid = tokens[i] >> 32;
+#if defined(_WIN64)
+    // Sign-extend to preserve INVALID_HANDLE_VALUE.
+    HANDLE source_handle = reinterpret_cast<HANDLE>(
+        static_cast<int64_t>(static_cast<int32_t>(tokens[i] & 0xFFFFFFFF)));
+#else
+    HANDLE source_handle = reinterpret_cast<HANDLE>(tokens[i] & 0xFFFFFFFF);
+#endif
+    base::Process sender =
+        base::Process::OpenWithAccess(pid, PROCESS_DUP_HANDLE);
+    handles[i] = PlatformHandle();
+    if (!sender.IsValid()) {
+      // Sender died.
+    } else {
+      BOOL dup_result = DuplicateHandle(
+          sender.Handle(), source_handle,
+          base::GetCurrentProcessHandle(), &handles[i].handle, 0,
+          FALSE, DUPLICATE_SAME_ACCESS | DUPLICATE_CLOSE_SOURCE);
+      DCHECK(dup_result);
+    }
+  }
+}
+
+}  // namespace edk
+}  // namespace mojo