aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/python/grpcio/grpc/framework/core/_expiration.py
blob: d94bdf2d2b71d5a73f0ce1403404a53f1101b084 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
# Copyright 2015, Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""State and behavior for operation expiration."""

import time

from grpc.framework.core import _interfaces
from grpc.framework.foundation import later
from grpc.framework.interfaces.base import base


class _ExpirationManager(_interfaces.ExpirationManager):
  """An implementation of _interfaces.ExpirationManager."""

  def __init__(
      self, commencement, timeout, maximum_timeout, lock, termination_manager,
      transmission_manager):
    """Constructor.

    Args:
      commencement: The time in seconds since the epoch at which the operation
        began.
      timeout: A length of time in seconds to allow for the operation to run.
      maximum_timeout: The maximum length of time in seconds to allow for the
        operation to run despite what is requested via this object's
        change_timout method.
      lock: The operation-wide lock.
      termination_manager: The _interfaces.TerminationManager for the operation.
      transmission_manager: The _interfaces.TransmissionManager for the
        operation.
    """
    self._lock = lock
    self._termination_manager = termination_manager
    self._transmission_manager = transmission_manager
    self._commencement = commencement
    self._maximum_timeout = maximum_timeout

    self._timeout = timeout
    self._deadline = commencement + timeout
    self._index = None
    self._future = None

  def _expire(self, index):
    def expire():
      with self._lock:
        if self._future is not None and index == self._index:
          self._future = None
          self._termination_manager.expire()
          self._transmission_manager.abort(base.Outcome.EXPIRED)
    return expire

  def start(self):
    self._index = 0
    self._future = later.later(self._timeout, self._expire(0))

  def change_timeout(self, timeout):
    if self._future is not None and timeout != self._timeout:
      self._future.cancel()
      new_timeout = min(timeout, self._maximum_timeout)
      new_index = self._index + 1
      self._timeout = new_timeout
      self._deadline = self._commencement + new_timeout
      self._index = new_index
      delay = self._deadline - time.time()
      self._future = later.later(delay, self._expire(new_index))
      if new_timeout != timeout:
        self._transmission_manager.timeout(new_timeout)

  def deadline(self):
    return self._deadline

  def terminate(self):
    if self._future:
      self._future.cancel()
      self._future = None
    self._deadline_index = None


def invocation_expiration_manager(
    timeout, lock, termination_manager, transmission_manager):
  """Creates an _interfaces.ExpirationManager appropriate for front-side use.

  Args:
    timeout: A length of time in seconds to allow for the operation to run.
    lock: The operation-wide lock.
    termination_manager: The _interfaces.TerminationManager for the operation.
    transmission_manager: The _interfaces.TransmissionManager for the
      operation.

  Returns:
    An _interfaces.ExpirationManager appropriate for invocation-side use.
  """
  expiration_manager = _ExpirationManager(
      time.time(), timeout, timeout, lock, termination_manager,
      transmission_manager)
  expiration_manager.start()
  return expiration_manager


def service_expiration_manager(
    timeout, default_timeout, maximum_timeout, lock, termination_manager,
    transmission_manager):
  """Creates an _interfaces.ExpirationManager appropriate for back-side use.

  Args:
    timeout: A length of time in seconds to allow for the operation to run. May
      be None in which case default_timeout will be used.
    default_timeout: The default length of time in seconds to allow for the
      operation to run if the front-side customer has not specified such a value
      (or if the value they specified is not yet known).
    maximum_timeout: The maximum length of time in seconds to allow for the
      operation to run.
    lock: The operation-wide lock.
    termination_manager: The _interfaces.TerminationManager for the operation.
    transmission_manager: The _interfaces.TransmissionManager for the
      operation.

  Returns:
    An _interfaces.ExpirationManager appropriate for service-side use.
  """
  expiration_manager = _ExpirationManager(
      time.time(), default_timeout if timeout is None else timeout,
      maximum_timeout, lock, termination_manager, transmission_manager)
  expiration_manager.start()
  return expiration_manager