dcelasun commented on a change in pull request #2200:
URL: https://github.com/apache/thrift/pull/2200#discussion_r464505274
##########
File path: lib/py/src/transport/TSocket.py
##########
@@ -74,7 +74,30 @@ def setHandle(self, h):
self.handle = h
def isOpen(self):
- return self.handle is not None
+ if self.handle is None:
+ return False
+
+ # this lets us cheaply see if the other end of the socket is still
+ # connected. if disconnected, we'll get EOF back (expressed as zero
+ # bytes of data) otherwise we'll get one byte or an error indicating
+ # we'd have to block for data.
+ #
+ # note that we're not doing this with socket.MSG_DONTWAIT because 1)
+ # it's linux-specific and 2) gevent-patched sockets hide EAGAIN from us
+ # when timeout is non-zero.
+ original_timeout = self.handle.gettimeout()
+ try:
+ self.handle.settimeout(0)
+ try:
+ peeked_bytes = self.handle.recv(1, socket.MSG_PEEK)
+ except (socket.error, OSError) as exc: # on modern python this is
just BlockingIOError
+ if exc.errno == errno.EWOULDBLOCK:
Review comment:
Yeah, seems like it:
```
If no messages are available at the socket [...] the value -1 is
returned and the external variable errno is set to EAGAIN or EWOULDBLOCK
```
Though I don't know what the behaviour is on Windows.
For EOF, returning is better since `isOpen` didn't throw before and it would
be a breaking change.
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