Use socket.sendfile() instead of os.sendfile().

Fixes #2223.

Unfortunately, eventlet doesn't implement GreenSocket.sendfile, so we have to do it for it.

Add gevent and eventlet to tox.ini and add tests to make sure we can at least import the workers. Some tests that this actually functions would be nice...

Update the gevent and eventlet setup extras to require the versions that are enforced in their worker modules.

.travis.yml

@@ -1,33 +1,31 @@
-sudo: false
 language: python
 matrix:
   include:
     - python: 3.8
       env: TOXENV=lint
-      dist: xenial
-      sudo: true
     - python: 3.5
       env: TOXENV=py35
     - python: 3.6
       env: TOXENV=py36
     - python: 3.7
       env: TOXENV=py37
-      dist: xenial
-      sudo: true
     - python: pypy3
-      env: TOXENV=pypy3
+      env:
+        - TOXENV=pypy3
+        # Embedded c-ares takes a long time to build and
+        # as-of 2020-01-04 there are no PyPy3 manylinux
+        # wheels for gevent on PyPI.
+        - GEVENTSETUP_EMBED_CARES=no
       dist: xenial
     - python: 3.8
       env: TOXENV=py38
-      dist: xenial
-      sudo: true
     - python: 3.8
       env: TOXENV=docs-lint
-      dist: xenial
-      sudo: true
-install: pip install tox
+install: pip install -U tox coverage
 # TODO: https://github.com/tox-dev/tox/issues/149
 script: tox --recreate
+after_success:
+    - if [ -f .coverage ]; then coverage report ; fi
 cache:
   directories:
     - .tox

gunicorn/http/wsgi.py

@@ -360,12 +360,6 @@ class Response(object):
             offset = os.lseek(fileno, 0, os.SEEK_CUR)
             if self.response_length is None:
                 filesize = os.fstat(fileno).st_size
-
-                # The file may be special and sendfile will fail.
-                # It may also be zero-length, but that is okay.
-                if filesize == 0:
-                    return False
-
                 nbytes = filesize - offset
             else:
                 nbytes = self.response_length
@@ -378,12 +372,7 @@ class Response(object):
             chunk_size = "%X\r\n" % nbytes
             self.sock.sendall(chunk_size.encode('utf-8'))
 
-        sockno = self.sock.fileno()
-        sent = 0
-
-        while sent != nbytes:
-            count = min(nbytes - sent, BLKSIZE)
-            sent += os.sendfile(sockno, fileno, offset + sent, count)
+        self.sock.sendfile(respiter.filelike, count=nbytes)
 
         if self.is_chunked():
             self.sock.sendall(b"\r\n")

gunicorn/workers/geventlet.py

@@ -4,8 +4,6 @@
 # See the NOTICE for more information.
 
 from functools import partial
-import errno
-import os
 import sys
 
 try:
@@ -19,22 +17,49 @@ else:
 
 from eventlet import hubs, greenthread
 from eventlet.greenio import GreenSocket
-from eventlet.hubs import trampoline
 from eventlet.wsgi import ALREADY_HANDLED as EVENTLET_ALREADY_HANDLED
 import greenlet
 
 from gunicorn.workers.base_async import AsyncWorker
 
 
-def _eventlet_sendfile(fdout, fdin, offset, nbytes, _os_sendfile=os.sendfile):
-    while True:
-        try:
-            return _os_sendfile(fdout, fdin, offset, nbytes)
-        except OSError as e:
-            if e.args[0] == errno.EAGAIN:
-                trampoline(fdout, write=True)
-            else:
-                raise
+def _eventlet_socket_sendfile(self, file, offset=0, count=None):
+    # Based on the implementation in gevent which in turn is slightly
+    # modified from the standard library implementation.
+    if self.gettimeout() == 0:
+        raise ValueError("non-blocking sockets are not supported")
+    if offset:
+        file.seek(offset)
+    blocksize = min(count, 8192) if count else 8192
+    total_sent = 0
+    # localize variable access to minimize overhead
+    file_read = file.read
+    sock_send = self.send
+    try:
+        while True:
+            if count:
+                blocksize = min(count - total_sent, blocksize)
+                if blocksize <= 0:
+                    break
+            data = memoryview(file_read(blocksize))
+            if not data:
+                break  # EOF
+            while True:
+                try:
+                    sent = sock_send(data)
+                except BlockingIOError:
+                    continue
+                else:
+                    total_sent += sent
+                    if sent < len(data):
+                        data = data[sent:]
+                    else:
+                        break
+        return total_sent
+    finally:
+        if total_sent > 0 and hasattr(file, 'seek'):
+            file.seek(offset + total_sent)
+
 
 
 def _eventlet_serve(sock, handle, concurrency):
@@ -79,7 +104,17 @@ def _eventlet_stop(client, server, conn):
 
 
 def patch_sendfile():
-    setattr(os, "sendfile", _eventlet_sendfile)
+    # As of eventlet 0.25.1, GreenSocket.sendfile doesn't exist,
+    # meaning the native implementations of socket.sendfile will be used.
+    # If os.sendfile exists, it will attempt to use that, failing explicitly
+    # if the socket is in non-blocking mode, which the underlying
+    # socket object /is/. Even the regular _sendfile_use_send will
+    # fail in that way; plus, it would use the underlying socket.send which isn't
+    # properly cooperative. So we have to monkey-patch a working socket.sendfile()
+    # into GreenSocket; in this method, `self.send` will be the GreenSocket's
+    # send method which is properly cooperative.
+    if not hasattr(GreenSocket, 'sendfile'):
+        GreenSocket.sendfile = _eventlet_socket_sendfile
 
 
 class EventletWorker(AsyncWorker):

gunicorn/workers/ggevent.py

@@ -3,7 +3,6 @@
 # This file is part of gunicorn released under the MIT license.
 # See the NOTICE for more information.
 
-import errno
 import os
 import sys
 from datetime import datetime
@@ -30,21 +29,6 @@ from gunicorn.workers.base_async import AsyncWorker
 VERSION = "gevent/%s gunicorn/%s" % (gevent.__version__, gunicorn.__version__)
 
 
-def _gevent_sendfile(fdout, fdin, offset, nbytes, _os_sendfile=os.sendfile):
-    while True:
-        try:
-            return _os_sendfile(fdout, fdin, offset, nbytes)
-        except OSError as e:
-            if e.args[0] == errno.EAGAIN:
-                socket.wait_write(fdout)
-            else:
-                raise
-
-
-def patch_sendfile():
-    setattr(os, "sendfile", _gevent_sendfile)
-
-
 class GeventWorker(AsyncWorker):
 
     server_class = None
@@ -53,9 +37,6 @@ class GeventWorker(AsyncWorker):
     def patch(self):
         monkey.patch_all()
 
-        # monkey patch sendfile to make it none blocking
-        patch_sendfile()
-
         # patch sockets
         sockets = []
         for s in self.sockets:

requirements_test.txt

@@ -1,4 +1,6 @@
 aiohttp
+gevent
+eventlet
 coverage
 pytest
 pytest-cov

setup.py

@@ -76,8 +76,8 @@ install_requires = [
 ]
 
 extras_require = {
-    'gevent':  ['gevent>=0.13'],
-    'eventlet': ['eventlet>=0.9.7'],
+    'gevent':  ['gevent>=1.4.0'],
+    'eventlet': ['eventlet>=0.24.1'],
     'tornado': ['tornado>=0.2'],
     'gthread': [],
     'setproctitle': ['setproctitle'],

tests/workers/test_geventlet.py

@@ -0,0 +1,7 @@
+# -*- coding: utf-8 -
+#
+# This file is part of gunicorn released under the MIT license.
+# See the NOTICE for more information.
+
+def test_import():
+    __import__('gunicorn.workers.geventlet')

tests/workers/test_ggevent.py

@@ -0,0 +1,7 @@
+# -*- coding: utf-8 -
+#
+# This file is part of gunicorn released under the MIT license.
+# See the NOTICE for more information.
+
+def test_import():
+    __import__('gunicorn.workers.ggevent')

tox.ini

@@ -4,7 +4,7 @@ skipsdist = True
 
 [testenv]
 usedevelop = True
-commands = py.test {posargs}
+commands = py.test --cov=gunicorn {posargs}
 deps =
   -rrequirements_test.txt