diff options
Diffstat (limited to 'src/python/grpcio/tests/_runner.py')
| -rw-r--r-- | src/python/grpcio/tests/_runner.py | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/python/grpcio/tests/_runner.py b/src/python/grpcio/tests/_runner.py index b0dbd92a49..32a31ce00e 100644 --- a/src/python/grpcio/tests/_runner.py +++ b/src/python/grpcio/tests/_runner.py @@ -43,6 +43,13 @@ import uuid from tests import _loader from tests import _result +# This number needs to be large enough to outpace output on stdout and stderr +# from the gRPC core, otherwise we could end up in a potential deadlock. This +# stems from the OS waiting on someone to clear a filled pipe buffer while the +# GIL is held from a write to stderr from gRPC core, but said someone is in +# Python code thus necessitating GIL acquisition. +_READ_BYTES = 2**20 + class CapturePipe(object): """A context-manager pipe to redirect output to a byte array. @@ -76,6 +83,10 @@ class CapturePipe(object): flags = fcntl.fcntl(self._read_fd, fcntl.F_GETFL) fcntl.fcntl(self._read_fd, fcntl.F_SETFL, flags | os.O_NONBLOCK) self._read_thread = threading.Thread(target=self._read) + # If the user wants to exit from the Python program and hits ctrl-C and the + # read thread is somehow deadlocked with something else, the Python code may + # refuse to exit. This prevents that by making the read thread second-class. + self._read_thread.daemon = True self._read_thread.start() def stop(self): @@ -93,7 +104,7 @@ class CapturePipe(object): self.output = bytearray() while True: select.select([self._read_fd], [], []) - read_bytes = os.read(self._read_fd, 1024) + read_bytes = os.read(self._read_fd, _READ_BYTES) if read_bytes: self.output.extend(read_bytes) else: |