Refactor multiprocess test code to allow multiple child processes to be launched.

test/win/win_child_process_test.cc

+// Copyright 2015 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "test/win/win_child_process.h"
+
+#include <windows.h>
+
+#include "base/basictypes.h"
+#include "gtest/gtest.h"
+
+namespace crashpad {
+namespace test {
+namespace {
+
+int ReadInt(HANDLE handle) {
+  int value = 0;
+  DWORD bytes_read = 0;
+  EXPECT_TRUE(::ReadFile(handle, &value, sizeof(value), &bytes_read, nullptr));
+  EXPECT_EQ(sizeof(value), bytes_read);
+  return value;
+}
+
+void WriteInt(HANDLE handle, int value) {
+  DWORD bytes_written = 0;
+  EXPECT_TRUE(
+      ::WriteFile(handle, &value, sizeof(value), &bytes_written, nullptr));
+  EXPECT_EQ(sizeof(value), bytes_written);
+}
+
+class TestWinChildProcess final : public WinChildProcess {
+ public:
+  TestWinChildProcess() : WinChildProcess() {}
+
+  ~TestWinChildProcess() {}
+
+ private:
+  // WinChildProcess will have already exercised the pipes.
+  void Run() override {
+    int value = ReadInt(ReadPipeHandle());
+    WriteInt(WritePipeHandle(), value);
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(TestWinChildProcess);
+};
+
+TEST(WinChildProcessTest, WinChildProcess) {
+  WinChildProcess::EntryPoint<TestWinChildProcess>();
+
+  WinChildProcess::Launch();
+}
+
+TEST(WinChildProcessTest, MultipleChildren) {
+  WinChildProcess::EntryPoint<TestWinChildProcess>();
+
+  scoped_ptr<WinChildProcess::Handles> handles_1 = WinChildProcess::Launch();
+  scoped_ptr<WinChildProcess::Handles> handles_2 = WinChildProcess::Launch();
+  scoped_ptr<WinChildProcess::Handles> handles_3 = WinChildProcess::Launch();
+
+  WriteInt(handles_1->write.get(), 1);
+  WriteInt(handles_2->write.get(), 2);
+  WriteInt(handles_3->write.get(), 3);
+  ASSERT_EQ(3, ReadInt(handles_3->read.get()));
+  ASSERT_EQ(2, ReadInt(handles_2->read.get()));
+  ASSERT_EQ(1, ReadInt(handles_1->read.get()));
+}
+
+}  // namespace
+}  // namespace test
+}  // namespace crashpad