Add a "native_support" service.

services/native_support/process_controller_impl.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 "services/native_support/process_controller_impl.h"
+
+#include <errno.h>
+#include <signal.h>
+#include <sys/types.h>
+
+#include <utility>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "base/task_runner.h"
+#include "base/threading/simple_thread.h"
+#include "mojo/services/files/public/interfaces/types.mojom.h"
+#include "services/native_support/process_io_redirection.h"
+
+namespace native_support {
+
+namespace {
+
+void WaitForProcess(
+    base::Process process,
+    scoped_refptr<base::TaskRunner> done_runner,
+    const base::Callback<void(mojo::files::Error, int32_t)>& done_callback) {
+  int exit_status = 0;
+  mojo::files::Error result = process.WaitForExit(&exit_status)
+                                  ? mojo::files::ERROR_OK
+                                  : mojo::files::ERROR_UNKNOWN;
+  done_runner->PostTask(
+      FROM_HERE,
+      base::Bind(done_callback, result, static_cast<int32_t>(exit_status)));
+}
+
+void TerminateProcess(base::Process process) {
+  if (!process.Terminate(-1, true))
+    LOG(ERROR) << "Failed to kill PID " << process.Pid();
+}
+
+}  // namespace
+
+ProcessControllerImpl::ProcessControllerImpl(
+    scoped_refptr<base::TaskRunner> worker_runner,
+    mojo::InterfaceRequest<ProcessController> request,
+    base::Process process,
+    std::unique_ptr<ProcessIORedirection> process_io_redirection)
+    : worker_runner_(worker_runner.Pass()),
+      binding_(this, request.Pass()),
+      process_(process.Pass()),
+      process_io_redirection_(std::move(process_io_redirection)),
+      weak_factory_(this) {
+  DCHECK(process_.IsValid());
+}
+
+ProcessControllerImpl::~ProcessControllerImpl() {
+  if (process_.IsValid()) {
+    worker_runner_->PostTask(
+        FROM_HERE, base::Bind(&TerminateProcess, base::Passed(&process_)));
+  }
+}
+
+void ProcessControllerImpl::Wait(const WaitCallback& callback) {
+  if (!process_.IsValid()) {
+    // TODO(vtl): This isn't quite right.
+    callback.Run(mojo::files::ERROR_UNAVAILABLE, 0);
+    return;
+  }
+
+  worker_runner_->PostTask(
+      FROM_HERE, base::Bind(&WaitForProcess, base::Passed(&process_),
+                            base::MessageLoop::current()->task_runner(),
+                            base::Bind(&ProcessControllerImpl::OnWaitComplete,
+                                       weak_factory_.GetWeakPtr(), callback)));
+}
+
+void ProcessControllerImpl::Kill(int32_t signal, const KillCallback& callback) {
+  callback.Run(KillHelper(signal));
+}
+
+void ProcessControllerImpl::OnWaitComplete(const WaitCallback& callback,
+                                           mojo::files::Error result,
+                                           int32_t exit_status) {
+  callback.Run(result, exit_status);
+}
+
+mojo::files::Error ProcessControllerImpl::KillHelper(int32_t signal) {
+  if (signal < 0)
+    return mojo::files::ERROR_INVALID_ARGUMENT;
+
+  if (!process_.IsValid()) {
+    LOG(ERROR) << "Kill() called after Wait()";
+    // TODO(vtl): This error code isn't quite right, but "unavailable" (which
+    // would also be wrong) is used for a more appropriate purpose below.
+    return mojo::files::ERROR_INVALID_ARGUMENT;
+  }
+
+  // |base::HandleType| is just a typedef for |pid_t|.
+  pid_t pid = process_.Handle();
+
+  // Note: |kill()| is not interruptible.
+  if (kill(pid, static_cast<int>(signal)) == 0)
+    return mojo::files::ERROR_OK;
+
+  switch (errno) {
+    case EINVAL:
+      return mojo::files::ERROR_INVALID_ARGUMENT;
+    case EPERM:
+      return mojo::files::ERROR_PERMISSION_DENIED;
+    case ESRCH:
+      return mojo::files::ERROR_UNAVAILABLE;
+    default:
+      break;
+  }
+  return mojo::files::ERROR_UNKNOWN;
+}
+
+}  // namespace native_support