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 #include "base/posix/global_descriptors.h"
6 #include "base/test/multiprocess_test.h"
7
8 #include <unistd.h>
9
10 #include "base/containers/hash_tables.h"
11 #include "base/logging.h"
12 #include "testing/multiprocess_func_list.h"
13
14 namespace base {
15
16 // A very basic implementation for Android. On Android tests can run in an APK
17 // and we don't have an executable to exec*. This implementation does the bare
18 // minimum to execute the method specified by procname (in the child process).
19 // - |base_command_line| is ignored.
20 // - All options except |fds_to_remap| are ignored.
SpawnMultiProcessTestChild(const std::string & procname,const CommandLine & base_command_line,const LaunchOptions & options)21 ProcessHandle SpawnMultiProcessTestChild(const std::string& procname,
22 const CommandLine& base_command_line,
23 const LaunchOptions& options) {
24 // TODO(viettrungluu): The FD-remapping done below is wrong in the presence of
25 // cycles (e.g., fd1 -> fd2, fd2 -> fd1). crbug.com/326576
26 FileHandleMappingVector empty;
27 const FileHandleMappingVector* fds_to_remap =
28 options.fds_to_remap ? options.fds_to_remap : ∅
29
30 pid_t pid = fork();
31
32 if (pid < 0) {
33 PLOG(ERROR) << "fork";
34 return kNullProcessHandle;
35 }
36 if (pid > 0) {
37 // Parent process.
38 return pid;
39 }
40 // Child process.
41 std::hash_set<int> fds_to_keep_open;
42 for (FileHandleMappingVector::const_iterator it = fds_to_remap->begin();
43 it != fds_to_remap->end(); ++it) {
44 fds_to_keep_open.insert(it->first);
45 }
46 // Keep standard FDs (stdin, stdout, stderr, etc.) open since this
47 // is not meant to spawn a daemon.
48 int base = GlobalDescriptors::kBaseDescriptor;
49 for (int fd = base; fd < sysconf(_SC_OPEN_MAX); ++fd) {
50 if (fds_to_keep_open.find(fd) == fds_to_keep_open.end()) {
51 close(fd);
52 }
53 }
54 for (FileHandleMappingVector::const_iterator it = fds_to_remap->begin();
55 it != fds_to_remap->end(); ++it) {
56 int old_fd = it->first;
57 int new_fd = it->second;
58 if (dup2(old_fd, new_fd) < 0) {
59 PLOG(FATAL) << "dup2";
60 }
61 close(old_fd);
62 }
63 _exit(multi_process_function_list::InvokeChildProcessTest(procname));
64 return 0;
65 }
66
67 } // namespace base
68