Make tcp_client_socket_unittest pass on Linux....

net/base/tcp_client_socket_libevent.cc

Index: net/base/tcp_client_socket_libevent.cc
===================================================================
--- net/base/tcp_client_socket_libevent.cc	(revision 0)
+++ net/base/tcp_client_socket_libevent.cc	(revision 0)
@@ -0,0 +1,275 @@
+// Copyright (c) 2006-2008 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 "net/base/tcp_client_socket.h"
+#include "net/base/net_errors.h"
+#include "third_party/libevent/event.h"
+#include "base/message_loop.h"
+
+#include <sys/socket.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+
+namespace net {
+
+#ifndef INVALID_SOCKET
+#define INVALID_SOCKET (unsigned)(-1)
+#endif
+
+static int MapPosixError(int err) {
+  // There are numerous posix error codes, but these are the ones we thus far
+  // find interesting.
+  switch (err) {
+    default:
+      return ERR_FAILED;
+  }
+}
+
+//-----------------------------------------------------------------------------
+
+TCPClientSocket::TCPClientSocket(const AddressList& addresses)
+    : socket_(INVALID_SOCKET),
+      addresses_(addresses),
+      current_ai_(addresses_.head()),
+      wait_state_(NOT_WAITING) {
+  event_ = new struct event;
+}
+
+TCPClientSocket::~TCPClientSocket() {
+  Disconnect();
+  delete event_;
+}
+
+int TCPClientSocket::Connect(CompletionCallback* callback) {
+  // If already connected, then just return OK.
+  if (socket_ != INVALID_SOCKET)
+    return OK;
+
+  const struct addrinfo* ai = current_ai_;
+  DCHECK(ai);
+
+  int rv = CreateSocket(ai);
+  if (rv != OK)
+    return rv;
+
+  if (!connect(socket_, ai->ai_addr, static_cast<int>(ai->ai_addrlen))) {
+    // Connected without waiting!
+    return OK;
+  }
+
+  if (errno != EINPROGRESS && errno != EWOULDBLOCK) {
+    LOG(ERROR) << "connect failed: " << errno;
+    return MapPosixError(errno);
+  }
+
+  // Initialize event_ and link it to our MessagePump.
+  // POLLOUT is set if the connection is established. POLLIN is set if the connection fails,
+  // so select for both read and write.
+  ::event_set(event_, socket_, EV_READ|EV_WRITE|EV_PERSIST, TCPClientSocket_libevent_cb, this);
+  ::event_base_set(MessageLoop::current()->pump_libevent()->getEventbase(), event_);
+  if (::event_add(event_, NULL))
+    return ERR_FAILED;
+
+  wait_state_ = WAITING_CONNECT;
+  callback_ = callback;
+  return ERR_IO_PENDING;
+}
+
+int TCPClientSocket::ReconnectIgnoringLastError(CompletionCallback* callback) {
+  // No ignorable errors!
+  return ERR_FAILED;
+}
+
+void TCPClientSocket::Disconnect() {
+  if (socket_ == INVALID_SOCKET)
+    return;
+
+  ::event_del(event_);
+  close(socket_);
+  socket_ = INVALID_SOCKET;
+
+  // Reset for next time.
+  current_ai_ = addresses_.head();
+}
+
+bool TCPClientSocket::IsConnected() const {
+  if (socket_ == INVALID_SOCKET || wait_state_ == WAITING_CONNECT)
+    return false;
+
+  // Check if connection is alive.
+  char c;
+  int rv = recv(socket_, &c, 1, MSG_PEEK);
+  if (rv == 0)
+    return false;
+
+  return true;
+}
+
+int TCPClientSocket::Read(char* buf,
+                          int buf_len,
+                          CompletionCallback* callback) {
+  DCHECK(socket_ != INVALID_SOCKET);
+  DCHECK(wait_state_ == NOT_WAITING);
+  DCHECK(!callback_);
+  DCHECK(callback); // null callback not allowed?
+  DCHECK(buf_len > 0);
+
+  int nread = read(socket_, buf, buf_len);
+  if (nread > 0) {
+    return nread;
+  }
+  if (nread == -1 && errno != EWOULDBLOCK)
+    return MapPosixError(errno);
+
+  ::event_set(event_, socket_, EV_READ|EV_PERSIST, TCPClientSocket_libevent_cb, this);
+  ::event_base_set(MessageLoop::current()->pump_libevent()->getEventbase(), event_);
+  if (::event_add(event_, NULL))
+    return ERR_FAILED;
+  buf_ = buf;
+  buf_len_ = buf_len;
+  wait_state_ = WAITING_READ;
+  callback_ = callback;
+  return ERR_IO_PENDING;
+}
+
+int TCPClientSocket::Write(const char* buf,
+                           int buf_len,
+                           CompletionCallback* callback) {
+  DCHECK(socket_ != INVALID_SOCKET);
+  DCHECK(wait_state_ == NOT_WAITING);
+  DCHECK(!callback_);
+  DCHECK(buf_len > 0);
+
+  int nwrite = write(socket_, buf, buf_len);
+  if (nwrite > 0) {
+    return nwrite;
+  }
+  if (nwrite == -1 && errno != EWOULDBLOCK)
+    return MapPosixError(errno);
+
+  ::event_set(event_, socket_, EV_WRITE|EV_PERSIST, TCPClientSocket_libevent_cb, this);
+  ::event_base_set(MessageLoop::current()->pump_libevent()->getEventbase(), event_);
+  if (::event_add(event_, NULL))
+    return ERR_FAILED;
+  buf_ = const_cast<char *>(buf);
+  buf_len_ = buf_len;
+  wait_state_ = WAITING_WRITE;
+  callback_ = callback;
+  return ERR_IO_PENDING;
+}
+
+int TCPClientSocket::CreateSocket(const struct addrinfo* ai) {
+  socket_ = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+  if (socket_ == INVALID_SOCKET)
+    return MapPosixError(errno);
+
+  // All our socket I/O is nonblocking
+  int flags = fcntl(socket_, F_GETFL, 0);
+  if (-1 == flags)
+    flags = 0;
+  if (fcntl(socket_, F_SETFL, flags | O_NONBLOCK))
+    return MapPosixError(errno);
+  
+  return OK;
+}
+
+void TCPClientSocket::DoCallback(int rv) {
+  DCHECK(rv != ERR_IO_PENDING);
+  DCHECK(callback_);
+
+  // since Run may result in Read being called, clear callback_ up front.
+  CompletionCallback* c = callback_;
+  callback_ = NULL;
+  c->Run(rv);
+}
+
+void TCPClientSocket::DidCompleteConnect() {
+  int result = ERR_UNEXPECTED;
+
+  wait_state_ = NOT_WAITING;
+
+  /* check to see if connect succeeded */
+  int error_code = -1;
+  socklen_t len = sizeof(error_code);
+  if (getsockopt(socket_, SOL_SOCKET, SO_ERROR, (char *)&error_code, &len) < 0) {
+    result = MapPosixError(errno);
+  } else if (error_code == EINPROGRESS) {
+    result = ERR_IO_PENDING;
+  } else if (current_ai_->ai_next && (
+        error_code == EADDRNOTAVAIL ||
+        error_code == EAFNOSUPPORT ||
+        error_code == ECONNREFUSED ||
+        error_code == ENETUNREACH ||
+        error_code == EHOSTUNREACH ||
+        error_code == ETIMEDOUT)) {
+      const struct addrinfo* next = current_ai_->ai_next;
+      Disconnect();
+      current_ai_ = next;
+      result = Connect(callback_);
+  } else if (error_code) {
+      result = MapPosixError(error_code);
+  } else {
+      result = 0;
+      ::event_del(event_);
+  }
+
+  if (result != ERR_IO_PENDING)
+    DoCallback(result);
+}
+
+void TCPClientSocket::DidCompleteIO() {
+  int result;
+  int n;
+
+  switch (wait_state_) {
+  case WAITING_READ:
+    n = read(socket_, buf_, buf_len_);
+    break;
+  case WAITING_WRITE:
+    n = write(socket_, buf_, buf_len_);
+    break;
+  }
+
+  if (n > 0)
+    result = n;
+  else if (n == 0) {
+    // TODO: can we tell why it was closed, and return a more informative message?
+    // And why does the unit test want to see zero?
+    //result = ERR_CONNECTION_CLOSED;
+    result = 0;
+  } else
+    result = MapPosixError(errno);
+
+  if (result != ERR_IO_PENDING) {
+    wait_state_ = NOT_WAITING;
+    ::event_del(event_);
+    DoCallback(result);
+  }
+}
+
+void TCPClientSocket::OnLibeventNotification(short flags) {
+
+  switch (wait_state_) {
+    case WAITING_CONNECT:
+      DidCompleteConnect();
+      break;
+    case WAITING_READ:
+    case WAITING_WRITE:
+      DidCompleteIO();
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
+extern "C" void TCPClientSocket_libevent_cb(int socket, short flags, void *context) {
+  TCPClientSocket* that = static_cast<TCPClientSocket*>(context);
+  DCHECK(that->socket_ == socket);
+  that->OnLibeventNotification(flags);
+}
+
+}  // namespace net
+