aboutsummaryrefslogtreecommitdiffstats
path: root/python/urllib3/util/wait.py
diff options
context:
space:
mode:
authorJames Taylor <user234683@users.noreply.github.com>2019-09-06 16:31:13 -0700
committerJames Taylor <user234683@users.noreply.github.com>2019-09-06 16:31:13 -0700
commit3d57e14df7ba5f14a634295caf3b2e60da50bfe2 (patch)
tree4903bcb79a49ad714a1a9129765b9545405c9978 /python/urllib3/util/wait.py
parentac32b24b2a011292b704a3f27e8fd08a7ae9424b (diff)
downloadyt-local-3d57e14df7ba5f14a634295caf3b2e60da50bfe2.tar.lz
yt-local-3d57e14df7ba5f14a634295caf3b2e60da50bfe2.tar.xz
yt-local-3d57e14df7ba5f14a634295caf3b2e60da50bfe2.zip
Remove windows python distribution from repo and add requirements.txt
Diffstat (limited to 'python/urllib3/util/wait.py')
-rw-r--r--python/urllib3/util/wait.py150
1 files changed, 0 insertions, 150 deletions
diff --git a/python/urllib3/util/wait.py b/python/urllib3/util/wait.py
deleted file mode 100644
index 4db71ba..0000000
--- a/python/urllib3/util/wait.py
+++ /dev/null
@@ -1,150 +0,0 @@
-import errno
-from functools import partial
-import select
-import sys
-try:
- from time import monotonic
-except ImportError:
- from time import time as monotonic
-
-__all__ = ["NoWayToWaitForSocketError", "wait_for_read", "wait_for_write"]
-
-
-class NoWayToWaitForSocketError(Exception):
- pass
-
-
-# How should we wait on sockets?
-#
-# There are two types of APIs you can use for waiting on sockets: the fancy
-# modern stateful APIs like epoll/kqueue, and the older stateless APIs like
-# select/poll. The stateful APIs are more efficient when you have a lots of
-# sockets to keep track of, because you can set them up once and then use them
-# lots of times. But we only ever want to wait on a single socket at a time
-# and don't want to keep track of state, so the stateless APIs are actually
-# more efficient. So we want to use select() or poll().
-#
-# Now, how do we choose between select() and poll()? On traditional Unixes,
-# select() has a strange calling convention that makes it slow, or fail
-# altogether, for high-numbered file descriptors. The point of poll() is to fix
-# that, so on Unixes, we prefer poll().
-#
-# On Windows, there is no poll() (or at least Python doesn't provide a wrapper
-# for it), but that's OK, because on Windows, select() doesn't have this
-# strange calling convention; plain select() works fine.
-#
-# So: on Windows we use select(), and everywhere else we use poll(). We also
-# fall back to select() in case poll() is somehow broken or missing.
-
-if sys.version_info >= (3, 5):
- # Modern Python, that retries syscalls by default
- def _retry_on_intr(fn, timeout):
- return fn(timeout)
-else:
- # Old and broken Pythons.
- def _retry_on_intr(fn, timeout):
- if timeout is None:
- deadline = float("inf")
- else:
- deadline = monotonic() + timeout
-
- while True:
- try:
- return fn(timeout)
- # OSError for 3 <= pyver < 3.5, select.error for pyver <= 2.7
- except (OSError, select.error) as e:
- # 'e.args[0]' incantation works for both OSError and select.error
- if e.args[0] != errno.EINTR:
- raise
- else:
- timeout = deadline - monotonic()
- if timeout < 0:
- timeout = 0
- if timeout == float("inf"):
- timeout = None
- continue
-
-
-def select_wait_for_socket(sock, read=False, write=False, timeout=None):
- if not read and not write:
- raise RuntimeError("must specify at least one of read=True, write=True")
- rcheck = []
- wcheck = []
- if read:
- rcheck.append(sock)
- if write:
- wcheck.append(sock)
- # When doing a non-blocking connect, most systems signal success by
- # marking the socket writable. Windows, though, signals success by marked
- # it as "exceptional". We paper over the difference by checking the write
- # sockets for both conditions. (The stdlib selectors module does the same
- # thing.)
- fn = partial(select.select, rcheck, wcheck, wcheck)
- rready, wready, xready = _retry_on_intr(fn, timeout)
- return bool(rready or wready or xready)
-
-
-def poll_wait_for_socket(sock, read=False, write=False, timeout=None):
- if not read and not write:
- raise RuntimeError("must specify at least one of read=True, write=True")
- mask = 0
- if read:
- mask |= select.POLLIN
- if write:
- mask |= select.POLLOUT
- poll_obj = select.poll()
- poll_obj.register(sock, mask)
-
- # For some reason, poll() takes timeout in milliseconds
- def do_poll(t):
- if t is not None:
- t *= 1000
- return poll_obj.poll(t)
-
- return bool(_retry_on_intr(do_poll, timeout))
-
-
-def null_wait_for_socket(*args, **kwargs):
- raise NoWayToWaitForSocketError("no select-equivalent available")
-
-
-def _have_working_poll():
- # Apparently some systems have a select.poll that fails as soon as you try
- # to use it, either due to strange configuration or broken monkeypatching
- # from libraries like eventlet/greenlet.
- try:
- poll_obj = select.poll()
- _retry_on_intr(poll_obj.poll, 0)
- except (AttributeError, OSError):
- return False
- else:
- return True
-
-
-def wait_for_socket(*args, **kwargs):
- # We delay choosing which implementation to use until the first time we're
- # called. We could do it at import time, but then we might make the wrong
- # decision if someone goes wild with monkeypatching select.poll after
- # we're imported.
- global wait_for_socket
- if _have_working_poll():
- wait_for_socket = poll_wait_for_socket
- elif hasattr(select, "select"):
- wait_for_socket = select_wait_for_socket
- else: # Platform-specific: Appengine.
- wait_for_socket = null_wait_for_socket
- return wait_for_socket(*args, **kwargs)
-
-
-def wait_for_read(sock, timeout=None):
- """ Waits for reading to be available on a given socket.
- Returns True if the socket is readable, or False if the timeout expired.
- """
- return wait_for_socket(sock, read=True, timeout=timeout)
-
-
-def wait_for_write(sock, timeout=None):
- """ Waits for writing to be available on a given socket.
- Returns True if the socket is readable, or False if the timeout expired.
- """
- return wait_for_socket(sock, write=True, timeout=timeout)