Implement IPC::ChannelFactory, a class that accept()s on a UNIX socket.

ipc/unix_domain_socket_util_unittest.cc

+// Copyright 2013 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 <sys/socket.h>
+
+#include "base/bind.h"
+#include "base/file_util.h"
+#include "base/files/file_path.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/threading/thread.h"
+#include "base/threading/thread_restrictions.h"
+#include "ipc/unix_domain_socket_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class SocketAcceptor : public MessageLoopForIO::Watcher {
+ public:
+  SocketAcceptor(int fd, base::MessageLoopProxy* target_thread)
+      : server_fd_(-1),
+        started_watching_event_(false, false),
+        accepted_event_(false, false) {
+    target_thread->PostTask(FROM_HERE,
+        base::Bind(&SocketAcceptor::StartWatching, base::Unretained(this), fd));
+  }
+
+  virtual ~SocketAcceptor() {
+    watcher_.StopWatchingFileDescriptor();
+  }
+
+  int server_fd() { return server_fd_; }

[Mark Mentovai, 2013/03/05 20:08:03]

This method can be const, just for kicks.

[jeremya, 2013/03/06 05:03:18]

Done.

+
+  void WaitUntilReady() {
+    started_watching_event_.Wait();
+  }
+  void WaitForAccept() {
+    accepted_event_.Wait();
+  }
+
+ private:
+  void StartWatching(int fd) {
+    MessageLoopForIO::current()->WatchFileDescriptor(
+        fd,
+        true,
+        MessageLoopForIO::WATCH_READ,
+        &watcher_,
+        this);
+    started_watching_event_.Signal();
+  }
+  virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE {
+    ASSERT_EQ(-1, server_fd_);
+    IPC::ServerAcceptConnection(fd, &server_fd_);
+    watcher_.StopWatchingFileDescriptor();
+    accepted_event_.Signal();
+  }
+  virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE {}
+
+  int server_fd_;
+  MessageLoopForIO::FileDescriptorWatcher watcher_;
+  base::WaitableEvent started_watching_event_;
+  base::WaitableEvent accepted_event_;
+
+  DISALLOW_COPY_AND_ASSIGN(SocketAcceptor);
+};
+
+base::FilePath GetChannelDir() {
+  return base::FilePath("/var/tmp");
+}
+
+class TestUnixSocketConnection {
+ public:
+  TestUnixSocketConnection()
+      : worker_("WorkerThread"),
+        server_listen_fd_(-1),
+        server_fd_(-1),
+        client_fd_(-1),
+        acceptor_(NULL) {
+    socket_name_ = GetChannelDir().Append("TestSocket");
+    base::Thread::Options options;
+    options.message_loop_type = MessageLoop::TYPE_IO;
+    worker_.StartWithOptions(options);
+  }
+
+  bool CreateServerSocket() {
+    IPC::CreateServerUnixDomainSocket(socket_name_, &server_listen_fd_);
+    if (server_listen_fd_ < 0)
+      return false;
+    // TODO stat socket_name and check that there's a socket present

[Mark Mentovai, 2013/03/05 20:08:03]

OK, so do this.

[jeremya, 2013/03/06 05:03:18]

Done.

+    acceptor_ = new SocketAcceptor(server_listen_fd_,
+                                   worker_.message_loop_proxy());
+    acceptor_->WaitUntilReady();
+    return true;
+  }
+
+  bool CreateClientSocket() {
+    DCHECK(server_listen_fd_ >= 0);
+    IPC::CreateClientUnixDomainSocket(socket_name_, &client_fd_);
+    if (client_fd_ < 0)
+      return false;
+    acceptor_->WaitForAccept();
+    server_fd_ = acceptor_->server_fd();
+    return server_fd_ >= 0;
+  }
+
+  virtual ~TestUnixSocketConnection() {
+    if (acceptor_)
+      delete acceptor_;
+    if (client_fd_)
+      close(client_fd_);
+    if (server_fd_)
+      close(server_fd_);
+    if (server_listen_fd_) {
+      close(server_listen_fd_);
+      unlink(socket_name_.value().c_str());
+    }
+  }
+
+  int client_fd() { return client_fd_; }
+  int server_fd() { return server_fd_; }
+
+ private:
+  base::Thread worker_;
+  base::FilePath socket_name_;
+  int server_listen_fd_;
+  int server_fd_;
+  int client_fd_;
+  SocketAcceptor* acceptor_;
+};
+
+// Ensure that IPC::CreateServerUnixDomainSocket creates a socket that
+// IPC::CreateClientUnixDomainSocket can successfully connect to.
+TEST(UnixDomainSocketUtil, Connect) {
+  TestUnixSocketConnection connection;
+  ASSERT_TRUE(connection.CreateServerSocket());
+  ASSERT_TRUE(connection.CreateClientSocket());
+}
+
+// Ensure that messages can be sent across the resulting socket.
+TEST(UnixDomainSocketUtil, SendReceive) {
+  TestUnixSocketConnection connection;
+  ASSERT_TRUE(connection.CreateServerSocket());
+  ASSERT_TRUE(connection.CreateClientSocket());
+
+  const char buffer[] = "Hello, server!";
+  size_t buf_len = strlen(buffer) + 1;

[Mark Mentovai, 2013/03/05 20:08:03]

You could just use sizeof(buffer).

[jeremya, 2013/03/06 05:03:18]

Done.

+  size_t sent_bytes = send(connection.client_fd(), buffer, buf_len, 0);

[Mark Mentovai, 2013/03/05 20:08:03]

HANDLE_EINTR here and on line 151.

[jeremya, 2013/03/06 05:03:18]

Done.

+  ASSERT_EQ(buf_len, sent_bytes);
+  scoped_array<char> recv_buf(new char[buf_len]);

[Mark Mentovai, 2013/03/05 20:08:03]

You could just have a char recv_buf[sizeof(buffer)] instead of having to deal
with new and a scoper.

[jeremya, 2013/03/06 05:03:18]

Done.

+  size_t received_bytes =
+      recv(connection.server_fd(), recv_buf.get(), buf_len, 0);
+  ASSERT_EQ(buf_len, received_bytes);
+  ASSERT_EQ(0, strncmp(recv_buf.get(), buffer, buf_len));

[Mark Mentovai, 2013/03/05 20:08:03]

Use memcmp. You have sizes in hand and you want to treat embedded NULs
transparently.

[jeremya, 2013/03/06 05:03:18]

Done.

+}
+
+}

[Mark Mentovai, 2013/03/05 20:08:03]

}  // namespace

[jeremya, 2013/03/06 05:03:18]

Done.