1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef TESTING_MULTIPROCESS_FUNC_LIST_H_
6#define TESTING_MULTIPROCESS_FUNC_LIST_H_
7
8#include <string>
9
10// This file provides the plumbing to register functions to be executed
11// as the main function of a child process in a multi-process test.
12// This complements the MultiProcessTest class which provides facilities
13// for launching such tests.
14//
15// The MULTIPROCESS_TEST_MAIN() macro registers a string -> func_ptr mapping
16// by creating a new global instance of the AppendMultiProcessTest() class
17// this means that by the time that we reach our main() function the mapping
18// is already in place.
19//
20// Example usage:
21//  MULTIPROCESS_TEST_MAIN(a_test_func) {
22//    // Code here runs in a child process.
23//    return 0;
24//  }
25//
26// The prototype of a_test_func is implicitly
27//   int test_main_func_name();
28
29namespace multi_process_function_list {
30
31// Type for child process main functions.
32typedef int (*TestMainFunctionPtr)();
33
34// Type for child setup functions.
35typedef void (*SetupFunctionPtr)();
36
37// Helper class to append a test function to the global mapping.
38// Used by the MULTIPROCESS_TEST_MAIN macro.
39class AppendMultiProcessTest {
40 public:
41  // |main_func_ptr| is the main function that is run in the child process.
42  // |setup_func_ptr| is a function run when the global mapping is added.
43  AppendMultiProcessTest(std::string test_name,
44                         TestMainFunctionPtr main_func_ptr,
45                         SetupFunctionPtr setup_func_ptr);
46};
47
48// Invoke the main function of a test previously registered with
49// MULTIPROCESS_TEST_MAIN()
50int InvokeChildProcessTest(std::string test_name);
51
52// This macro creates a global MultiProcessTest::AppendMultiProcessTest object
53// whose constructor does the work of adding the global mapping.
54#define MULTIPROCESS_TEST_MAIN(test_main) \
55  MULTIPROCESS_TEST_MAIN_WITH_SETUP(test_main, NULL)
56
57// Same as above but lets callers specify a setup method that is run in the
58// child process, just before the main function is run.  This facilitates
59// adding a generic one-time setup function for multiple tests.
60#define MULTIPROCESS_TEST_MAIN_WITH_SETUP(test_main, test_setup) \
61  int test_main(); \
62  namespace { \
63    multi_process_function_list::AppendMultiProcessTest \
64    AddMultiProcessTest##_##test_main(#test_main, (test_main), (test_setup)); \
65  } \
66  int test_main()
67
68}  // namespace multi_process_function_list
69
70#endif  // TESTING_MULTIPROCESS_FUNC_LIST_H_
71