Multiprocess test client: Android child process launcher rework.

base/test/multiprocess_test_android.cc

Index: base/test/multiprocess_test_android.cc
diff --git a/base/test/multiprocess_test_android.cc b/base/test/multiprocess_test_android.cc
index f58b452d1cb316184884c6e7e19a196ed6a90c8c..c74f013da1cacc0ca292de356c5ad746c08c5b31 100644
--- a/base/test/multiprocess_test_android.cc
+++ b/base/test/multiprocess_test_android.cc
@@ -4,451 +4,87 @@
 
 #include "base/test/multiprocess_test.h"
 
-#include <errno.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <unistd.h>
-
-#include <memory>
-#include <utility>
 #include <vector>
 
+#include "base/android/context_utils.h"
+#include "base/android/jni_android.h"
+#include "base/android/jni_array.h"
+#include "base/android/scoped_java_ref.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
-#include "base/containers/hash_tables.h"
-#include "base/lazy_instance.h"
 #include "base/logging.h"
-#include "base/macros.h"
-#include "base/pickle.h"
-#include "base/posix/global_descriptors.h"
-#include "base/posix/unix_domain_socket_linux.h"
-#include "testing/multiprocess_func_list.h"
+#include "jni/MainReturnCodeResult_jni.h"
+#include "jni/MultiprocessTestClientLauncher_jni.h"
 
 namespace base {
 
-namespace {
-
-const int kMaxMessageSize = 1024 * 1024;
-const int kFragmentSize = 4096;
-
-// Message sent between parent process and helper child process.
-enum class MessageType : uint32_t {
-  START_REQUEST,
-  START_RESPONSE,
-  WAIT_REQUEST,
-  WAIT_RESPONSE,
-};
-
-struct MessageHeader {
-  uint32_t size;
-  MessageType type;
-};
-
-struct StartProcessRequest {
-  MessageHeader header =
-      {sizeof(StartProcessRequest), MessageType::START_REQUEST};
-
-  uint32_t num_args = 0;
-  uint32_t num_fds = 0;
-};
-
-struct StartProcessResponse {
-  MessageHeader header =
-      {sizeof(StartProcessResponse), MessageType::START_RESPONSE};
-
-  pid_t child_pid;
-};
-
-struct WaitProcessRequest {
-  MessageHeader header =
-      {sizeof(WaitProcessRequest), MessageType::WAIT_REQUEST};
-
-  pid_t pid;
-  uint64_t timeout_ms;
-};
-
-struct WaitProcessResponse {
-  MessageHeader header =
-      {sizeof(WaitProcessResponse), MessageType::WAIT_RESPONSE};
-
-  bool success = false;
-  int32_t exit_code = 0;
-};
-
-// Helper class that implements an alternate test child launcher for
-// multi-process tests. The default implementation doesn't work if the child is
-// launched after starting threads. However, for some tests (i.e. Mojo), this
-// is necessary. This implementation works around that issue by forking a helper
-// process very early in main(), before any real work is done. Then, when a
-// child needs to be spawned, a message is sent to that helper process, which
-// then forks and returns the result to the parent. The forked child then calls
-// main() and things look as though a brand new process has been fork/exec'd.
-class LaunchHelper {
- public:
-  using MainFunction = int (*)(int, char**);
-
-  LaunchHelper() {}
-
-  // Initialise the alternate test child implementation.
-  void Init(MainFunction main);
-
-  // Starts a child test helper process.
-  Process StartChildTestHelper(const std::string& procname,
-                               const CommandLine& base_command_line,
-                               const LaunchOptions& options);
-
-  // Waits for a child test helper process.
-  bool WaitForChildExitWithTimeout(const Process& process, TimeDelta timeout,
-                                   int* exit_code);
-
-  bool IsReady() const { return child_fd_ != -1; }
-  bool IsChild() const { return is_child_; }
-
- private:
-  // Wrappers around sendmsg/recvmsg that supports message fragmentation.
-  void Send(int fd, const MessageHeader* msg, const std::vector<int>& fds);
-  ssize_t Recv(int fd, void* buf, std::vector<ScopedFD>* fds);
-
-  // Parent process implementation.
-  void DoParent(int fd);
-  // Helper process implementation.
-  void DoHelper(int fd);
-
-  void StartProcessInHelper(const StartProcessRequest* request,
-                           std::vector<ScopedFD> fds);
-  void WaitForChildInHelper(const WaitProcessRequest* request);
-
-  bool is_child_ = false;
-
-  // Parent vars.
-  int child_fd_ = -1;
-
-  // Helper vars.
-  int parent_fd_ = -1;
-  MainFunction main_ = nullptr;
-
-  DISALLOW_COPY_AND_ASSIGN(LaunchHelper);
-};
-
-void LaunchHelper::Init(MainFunction main) {
-  main_ = main;
-
-  // Create a communication channel between the parent and child launch helper.
-  // fd[0] belongs to the parent, fd[1] belongs to the child.
-  int fds[2] = {-1, -1};
-  int rv = socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds);
-  PCHECK(rv == 0);
-  CHECK_NE(-1, fds[0]);
-  CHECK_NE(-1, fds[1]);
-
-  pid_t pid = fork();
-  PCHECK(pid >= 0) << "Fork failed";
-  if (pid) {
-    // Parent.
-    rv = close(fds[1]);
-    PCHECK(rv == 0);
-    DoParent(fds[0]);
-  } else {
-    // Helper.
-    rv = close(fds[0]);
-    PCHECK(rv == 0);
-    DoHelper(fds[1]);
-    NOTREACHED();
-    _exit(0);
-  }
-}
-
-void LaunchHelper::Send(
-    int fd, const MessageHeader* msg, const std::vector<int>& fds) {
-  uint32_t bytes_remaining = msg->size;
-  const char* buf = reinterpret_cast<const char*>(msg);
-  while (bytes_remaining) {
-    size_t send_size =
-        (bytes_remaining > kFragmentSize) ? kFragmentSize : bytes_remaining;
-    bool success = UnixDomainSocket::SendMsg(
-        fd, buf, send_size,
-        (bytes_remaining == msg->size) ? fds : std::vector<int>());
-    CHECK(success);
-    bytes_remaining -= send_size;
-    buf += send_size;
-  }
-}
-
-ssize_t LaunchHelper::Recv(int fd, void* buf, std::vector<ScopedFD>* fds) {
-  ssize_t size = UnixDomainSocket::RecvMsg(fd, buf, kFragmentSize, fds);
-  if (size <= 0)
-    return size;
-
-  const MessageHeader* header = reinterpret_cast<const MessageHeader*>(buf);
-  CHECK(header->size < kMaxMessageSize);
-  uint32_t bytes_remaining = header->size - size;
-  char* buffer = reinterpret_cast<char*>(buf);
-  buffer += size;
-  while (bytes_remaining) {
-    std::vector<ScopedFD> dummy_fds;
-    size = UnixDomainSocket::RecvMsg(fd, buffer, kFragmentSize, &dummy_fds);
-    if (size <= 0)
-      return size;
-
-    CHECK(dummy_fds.empty());
-    CHECK(size == kFragmentSize ||
-          static_cast<size_t>(size) == bytes_remaining);
-    bytes_remaining -= size;
-    buffer += size;
-  }
-  return header->size;
-}
-
-void LaunchHelper::DoParent(int fd) {
-  child_fd_ = fd;
-}
-
-void LaunchHelper::DoHelper(int fd) {
-  parent_fd_ = fd;
-  is_child_ = true;
-  std::unique_ptr<char[]> buf(new char[kMaxMessageSize]);
-  while (true) {
-    // Wait for a message from the parent.
-    std::vector<ScopedFD> fds;
-    ssize_t size = Recv(parent_fd_, buf.get(), &fds);
-    if (size == 0 || (size < 0 && errno == ECONNRESET)) {
-      _exit(0);
-    }
-    PCHECK(size > 0);
-
-    const MessageHeader* header =
-        reinterpret_cast<const MessageHeader*>(buf.get());
-    CHECK_EQ(static_cast<ssize_t>(header->size), size);
-    switch (header->type) {
-      case MessageType::START_REQUEST:
-        StartProcessInHelper(
-            reinterpret_cast<const StartProcessRequest*>(buf.get()),
-            std::move(fds));
-        break;
-      case MessageType::WAIT_REQUEST:
-        WaitForChildInHelper(
-            reinterpret_cast<const WaitProcessRequest*>(buf.get()));
-        break;
-      default:
-        LOG(FATAL) << "Unsupported message type: "
-                   << static_cast<uint32_t>(header->type);
-    }
-  }
-}
-
-void LaunchHelper::StartProcessInHelper(const StartProcessRequest* request,
-                                        std::vector<ScopedFD> fds) {
-  pid_t pid = fork();
-  PCHECK(pid >= 0) << "Fork failed";
-  if (pid) {
-    // Helper.
-    StartProcessResponse resp;
-    resp.child_pid = pid;
-    Send(parent_fd_, reinterpret_cast<const MessageHeader*>(&resp),
-         std::vector<int>());
-  } else {
-    // Child.
-    PCHECK(close(parent_fd_) == 0);
-    parent_fd_ = -1;
-    CommandLine::Reset();
-
-    Pickle serialised_extra(reinterpret_cast<const char*>(request + 1),
-                            request->header.size - sizeof(StartProcessRequest));
-    PickleIterator iter(serialised_extra);
-    std::vector<std::string> args;
-    for (size_t i = 0; i < request->num_args; i++) {
-      std::string arg;
-      CHECK(iter.ReadString(&arg));
-      args.push_back(std::move(arg));
-    }
-
-    CHECK_EQ(request->num_fds, fds.size());
-    for (size_t i = 0; i < request->num_fds; i++) {
-      int new_fd;
-      CHECK(iter.ReadInt(&new_fd));
-      int old_fd = fds[i].release();
-      if (new_fd != old_fd) {
-        if (dup2(old_fd, new_fd) < 0) {
-          PLOG(FATAL) << "dup2";
-        }
-        PCHECK(close(old_fd) == 0);
-      }
-    }
+// A very basic implementation for Android. On Android tests can run in an APK
+// and we don't have an executable to exec*. This implementation does the bare
+// minimum to execute the method specified by procname (in the child process).
+//  - All options except |fds_to_remap| are ignored.
+//
+// NOTE: This MUST NOT run on the main thread of the NativeTest application.
+Process SpawnMultiProcessTestChild(const std::string& procname,
+                                   const CommandLine& base_command_line,
+                                   const LaunchOptions& options) {
+  JNIEnv* env = android::AttachCurrentThread();
+  DCHECK(env);
 
-    // argv has argc+1 elements, where the last element is NULL.
-    std::unique_ptr<char*[]> argv(new char*[args.size() + 1]);
-    for (size_t i = 0; i < args.size(); i++) {
-      argv[i] = const_cast<char*>(args[i].c_str());
+  std::vector<int> fd_keys;
+  std::vector<int> fd_fds;
+  if (options.fds_to_remap) {
+    for (auto& iter : *options.fds_to_remap) {
+      fd_keys.push_back(iter.second);
+      fd_fds.push_back(iter.first);
     }
-    argv[args.size()] = nullptr;
-    _exit(main_(args.size(), argv.get()));
-    NOTREACHED();
   }
-}
-
-void LaunchHelper::WaitForChildInHelper(const WaitProcessRequest* request) {
-  Process process(request->pid);
-  TimeDelta timeout = TimeDelta::FromMilliseconds(request->timeout_ms);
-  int exit_code = -1;
-  bool success = process.WaitForExitWithTimeout(timeout, &exit_code);
-
-  WaitProcessResponse resp;
-  resp.exit_code = exit_code;
-  resp.success = success;
-  Send(parent_fd_, reinterpret_cast<const MessageHeader*>(&resp),
-       std::vector<int>());
-}
 
-Process LaunchHelper::StartChildTestHelper(const std::string& procname,
-                                           const CommandLine& base_command_line,
-                                           const LaunchOptions& options) {
+  android::ScopedJavaLocalRef<jobjectArray> fds =
+      android::Java_MultiprocessTestClientLauncher_makeFdInfoArray(
+          env, base::android::ToJavaIntArray(env, fd_keys),
+          base::android::ToJavaIntArray(env, fd_fds));
 
   CommandLine command_line(base_command_line);
-  if (!command_line.HasSwitch(switches::kTestChildProcess))
+  if (!command_line.HasSwitch(switches::kTestChildProcess)) {
     command_line.AppendSwitchASCII(switches::kTestChildProcess, procname);
-
-  StartProcessRequest request;
-  Pickle serialised_extra;
-  const CommandLine::StringVector& argv = command_line.argv();
-  for (const auto& arg : argv)
-    CHECK(serialised_extra.WriteString(arg));
-  request.num_args = argv.size();
-
-  std::vector<int> fds_to_send;
-  if (options.fds_to_remap) {
-    for (auto p : *options.fds_to_remap) {
-      CHECK(serialised_extra.WriteInt(p.second));
-      fds_to_send.push_back(p.first);
-    }
-    request.num_fds = options.fds_to_remap->size();
   }
 
-  size_t buf_size = sizeof(StartProcessRequest) + serialised_extra.size();
-  request.header.size = buf_size;
-  std::unique_ptr<char[]> buffer(new char[buf_size]);
-  memcpy(buffer.get(), &request, sizeof(StartProcessRequest));
-  memcpy(buffer.get() + sizeof(StartProcessRequest), serialised_extra.data(),
-         serialised_extra.size());
-
-  // Send start message.
-  Send(child_fd_, reinterpret_cast<const MessageHeader*>(buffer.get()),
-       fds_to_send);
-
-  // Synchronously get response.
-  StartProcessResponse response;
-  std::vector<ScopedFD> recv_fds;
-  ssize_t resp_size = Recv(child_fd_, &response, &recv_fds);
-  PCHECK(resp_size == sizeof(StartProcessResponse));
-
-  return Process(response.child_pid);
+  android::ScopedJavaLocalRef<jobjectArray> j_argv =
+      android::ToJavaArrayOfStrings(env, command_line.argv());
+  jint pid = android::Java_MultiprocessTestClientLauncher_launchClient(
+      env, android::GetApplicationContext(), j_argv, fds);
+  return Process(pid);
 }
 
-bool LaunchHelper::WaitForChildExitWithTimeout(
-    const Process& process, TimeDelta timeout, int* exit_code) {
-
-  WaitProcessRequest request;
-  request.pid = process.Handle();
-  request.timeout_ms = timeout.InMilliseconds();
-
-  Send(child_fd_, reinterpret_cast<const MessageHeader*>(&request),
-       std::vector<int>());
-
-  WaitProcessResponse response;
-  std::vector<ScopedFD> recv_fds;
-  ssize_t resp_size = Recv(child_fd_, &response, &recv_fds);
-  PCHECK(resp_size == sizeof(WaitProcessResponse));
-
-  if (!response.success)
+bool WaitForMultiprocessTestChildExit(const Process& process,
+                                      TimeDelta timeout,
+                                      int* exit_code) {
+  JNIEnv* env = android::AttachCurrentThread();
+  DCHECK(env);
+
+  base::android::ScopedJavaLocalRef<jobject> result_code =
+      android::Java_MultiprocessTestClientLauncher_waitForMainToReturn(
+          env, android::GetApplicationContext(), process.Pid(),
+          static_cast<int32_t>(timeout.InMilliseconds()));
+  if (result_code.is_null() ||
+      Java_MainReturnCodeResult_hasTimedOut(env, result_code)) {
     return false;
-
-  *exit_code = response.exit_code;
+  }
+  if (exit_code) {
+    *exit_code = Java_MainReturnCodeResult_getReturnCode(env, result_code);
+  }
   return true;
 }
 
-LazyInstance<LaunchHelper>::Leaky g_launch_helper;
-
-}  // namespace
-
-void InitAndroidMultiProcessTestHelper(int (*main)(int, char**)) {
-  DCHECK(main);
-  // Don't allow child processes to themselves create new child processes.
-  if (g_launch_helper.Get().IsChild())
-    return;
-  g_launch_helper.Get().Init(main);
-}
-
-bool AndroidIsChildProcess() {
-  return g_launch_helper.Get().IsChild();
-}
-
-bool AndroidWaitForChildExitWithTimeout(
-    const Process& process, TimeDelta timeout, int* exit_code) {
-  CHECK(g_launch_helper.Get().IsReady());
-  return g_launch_helper.Get().WaitForChildExitWithTimeout(
-      process, timeout, exit_code);
-}
-
-// A very basic implementation for Android. On Android tests can run in an APK
-// and we don't have an executable to exec*. This implementation does the bare
-// minimum to execute the method specified by procname (in the child process).
-//  - All options except |fds_to_remap| are ignored.
-Process SpawnMultiProcessTestChild(const std::string& procname,
-                                   const CommandLine& base_command_line,
-                                   const LaunchOptions& options) {
-  if (g_launch_helper.Get().IsReady()) {
-    return g_launch_helper.Get().StartChildTestHelper(
-        procname, base_command_line, options);
-  }
-
-  // TODO(viettrungluu): The FD-remapping done below is wrong in the presence of
-  // cycles (e.g., fd1 -> fd2, fd2 -> fd1). crbug.com/326576
-  FileHandleMappingVector empty;
-  const FileHandleMappingVector* fds_to_remap =
-      options.fds_to_remap ? options.fds_to_remap : &empty;
-
-  pid_t pid = fork();
-
-  if (pid < 0) {
-    PLOG(ERROR) << "fork";
-    return Process();
-  }
-  if (pid > 0) {
-    // Parent process.
-    return Process(pid);
-  }
-  // Child process.
-  base::hash_set<int> fds_to_keep_open;
-  for (FileHandleMappingVector::const_iterator it = fds_to_remap->begin();
-       it != fds_to_remap->end(); ++it) {
-    fds_to_keep_open.insert(it->first);
-  }
-  // Keep standard FDs (stdin, stdout, stderr, etc.) open since this
-  // is not meant to spawn a daemon.
-  int base = GlobalDescriptors::kBaseDescriptor;
-  for (int fd = base; fd < sysconf(_SC_OPEN_MAX); ++fd) {
-    if (fds_to_keep_open.find(fd) == fds_to_keep_open.end()) {
-      close(fd);
-    }
-  }
-  for (FileHandleMappingVector::const_iterator it = fds_to_remap->begin();
-       it != fds_to_remap->end(); ++it) {
-    int old_fd = it->first;
-    int new_fd = it->second;
-    if (dup2(old_fd, new_fd) < 0) {
-      PLOG(FATAL) << "dup2";
-    }
-    close(old_fd);
-  }
-  CommandLine::Reset();
-  CommandLine::Init(0, nullptr);
-  CommandLine* command_line = CommandLine::ForCurrentProcess();
-  command_line->InitFromArgv(base_command_line.argv());
-  if (!command_line->HasSwitch(switches::kTestChildProcess))
-    command_line->AppendSwitchASCII(switches::kTestChildProcess, procname);
+bool TerminateMultiProcessTestChild(const Process& process,
+                                    int exit_code,
+                                    bool wait) {
+  JNIEnv* env = android::AttachCurrentThread();
+  DCHECK(env);
 
-  _exit(multi_process_function_list::InvokeChildProcessTest(procname));
-  return Process();
+  return android::Java_MultiprocessTestClientLauncher_terminate(
+      env, android::GetApplicationContext(), process.Pid(), exit_code, wait);
 }
 
 }  // namespace base