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1# Copyright (C) 2011 Google Inc. All rights reserved.
2#
3# Redistribution and use in source and binary forms, with or without
4# modification, are permitted provided that the following conditions are
5# met:
6#
7#     * Redistributions of source code must retain the above copyright
8# notice, this list of conditions and the following disclaimer.
9#     * Redistributions in binary form must reproduce the above
10# copyright notice, this list of conditions and the following disclaimer
11# in the documentation and/or other materials provided with the
12# distribution.
13#     * Neither the name of Google Inc. nor the names of its
14# contributors may be used to endorse or promote products derived from
15# this software without specific prior written permission.
16#
17# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29"""Base class with common routines between the Apache, Lighttpd, and websocket servers."""
30
31import errno
32import logging
33import socket
34import sys
35import tempfile
36import time
37
38
39_log = logging.getLogger(__name__)
40
41
42class ServerError(Exception):
43    pass
44
45
46class HttpServerBase(object):
47    """A skeleton class for starting and stopping servers used by the layout tests."""
48
49    def __init__(self, port_obj, number_of_servers=None):
50        self._executive = port_obj._executive
51        self._filesystem = port_obj._filesystem
52        self._name = '<virtual>'
53        self._mappings = {}
54        self._pid = None
55        self._pid_file = None
56        self._port_obj = port_obj
57        self._number_of_servers = number_of_servers
58
59        # We need a non-checkout-dependent place to put lock files, etc. We
60        # don't use the Python default on the Mac because it defaults to a
61        # randomly-generated directory under /var/folders and no one would ever
62        # look there.
63        tmpdir = tempfile.gettempdir()
64        if port_obj.host.platform.is_mac():
65            tmpdir = '/tmp'
66
67        self._runtime_path = self._filesystem.join(tmpdir, "WebKit")
68        self._filesystem.maybe_make_directory(self._runtime_path)
69
70    def start(self):
71        """Starts the server. It is an error to start an already started server.
72
73        This method also stops any stale servers started by a previous instance."""
74        assert not self._pid, '%s server is already running' % self._name
75
76        # Stop any stale servers left over from previous instances.
77        if self._filesystem.exists(self._pid_file):
78            try:
79                self._pid = int(self._filesystem.read_text_file(self._pid_file))
80                self._stop_running_server()
81            except (ValueError, UnicodeDecodeError):
82                # These could be raised if the pid file is corrupt.
83                self._remove_pid_file()
84            self._pid = None
85
86        self._remove_stale_logs()
87        self._prepare_config()
88        self._check_that_all_ports_are_available()
89
90        self._pid = self._spawn_process()
91
92        if self._wait_for_action(self._is_server_running_on_all_ports):
93            _log.debug("%s successfully started (pid = %d)" % (self._name, self._pid))
94        else:
95            self._stop_running_server()
96            raise ServerError('Failed to start %s server' % self._name)
97
98    def stop(self):
99        """Stops the server. Stopping a server that isn't started is harmless."""
100        actual_pid = None
101        try:
102            if self._filesystem.exists(self._pid_file):
103                try:
104                    actual_pid = int(self._filesystem.read_text_file(self._pid_file))
105                except (ValueError, UnicodeDecodeError):
106                    # These could be raised if the pid file is corrupt.
107                    pass
108                if not self._pid:
109                    self._pid = actual_pid
110
111            if not self._pid:
112                return
113
114            if not actual_pid:
115                _log.warning('Failed to stop %s: pid file is missing' % self._name)
116                return
117            if self._pid != actual_pid:
118                _log.warning('Failed to stop %s: pid file contains %d, not %d' %
119                            (self._name, actual_pid, self._pid))
120                # Try to kill the existing pid, anyway, in case it got orphaned.
121                self._executive.kill_process(self._pid)
122                self._pid = None
123                return
124
125            _log.debug("Attempting to shut down %s server at pid %d" % (self._name, self._pid))
126            self._stop_running_server()
127            _log.debug("%s server at pid %d stopped" % (self._name, self._pid))
128            self._pid = None
129        finally:
130            # Make sure we delete the pid file no matter what happens.
131            self._remove_pid_file()
132
133    def _prepare_config(self):
134        """This routine can be overridden by subclasses to do any sort
135        of initialization required prior to starting the server that may fail."""
136        pass
137
138    def _remove_stale_logs(self):
139        """This routine can be overridden by subclasses to try and remove logs
140        left over from a prior run. This routine should log warnings if the
141        files cannot be deleted, but should not fail unless failure to
142        delete the logs will actually cause start() to fail."""
143        pass
144
145    def _spawn_process(self):
146        """This routine must be implemented by subclasses to actually start the server.
147
148        This routine returns the pid of the started process, and also ensures that that
149        pid has been written to self._pid_file."""
150        raise NotImplementedError()
151
152    def _stop_running_server(self):
153        """This routine must be implemented by subclasses to actually stop the running server listed in self._pid_file."""
154        raise NotImplementedError()
155
156    # Utility routines.
157
158    def _remove_pid_file(self):
159        if self._filesystem.exists(self._pid_file):
160            self._filesystem.remove(self._pid_file)
161
162    def _remove_log_files(self, folder, starts_with):
163        files = self._filesystem.listdir(folder)
164        for file in files:
165            if file.startswith(starts_with):
166                full_path = self._filesystem.join(folder, file)
167                self._filesystem.remove(full_path)
168
169    def _wait_for_action(self, action, wait_secs=20.0, sleep_secs=1.0):
170        """Repeat the action for wait_sec or until it succeeds, sleeping for sleep_secs
171        in between each attempt. Returns whether it succeeded."""
172        start_time = time.time()
173        while time.time() - start_time < wait_secs:
174            if action():
175                return True
176            _log.debug("Waiting for action: %s" % action)
177            time.sleep(sleep_secs)
178
179        return False
180
181    def _is_server_running_on_all_ports(self):
182        """Returns whether the server is running on all the desired ports."""
183        if not self._executive.check_running_pid(self._pid):
184            _log.debug("Server isn't running at all")
185            raise ServerError("Server exited")
186
187        for mapping in self._mappings:
188            s = socket.socket()
189            port = mapping['port']
190            try:
191                s.connect(('localhost', port))
192                _log.debug("Server running on %d" % port)
193            except IOError, e:
194                if e.errno not in (errno.ECONNREFUSED, errno.ECONNRESET):
195                    raise
196                _log.debug("Server NOT running on %d: %s" % (port, e))
197                return False
198            finally:
199                s.close()
200        return True
201
202    def _check_that_all_ports_are_available(self):
203        for mapping in self._mappings:
204            s = socket.socket()
205            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
206            port = mapping['port']
207            try:
208                s.bind(('localhost', port))
209            except IOError, e:
210                if e.errno in (errno.EALREADY, errno.EADDRINUSE):
211                    raise ServerError('Port %d is already in use.' % port)
212                elif sys.platform == 'win32' and e.errno in (errno.WSAEACCES,):  # pylint: disable=E1101
213                    raise ServerError('Port %d is already in use.' % port)
214                else:
215                    raise
216            finally:
217                s.close()
218