thread_timeout

thread_timeout is a Python (2) library. It provides a simple decorator @thread_timeout for executing of a potentially long-running operation and auto-terminating if operation hasn't finished in a fixed amount of time.

This allows a python program avoiding TASK_UNINTERRUPTIBLE state.

Example of the usage:

from thread_timeout import thread_timeout

@thread_timeout(10, kill=False)
def NFS_read(path):
    file(path, 'r').read()

try:
    print("Result: %s" % NFS_read('broken_nfs/file'))
except ExecTimeoutException:
    print ("NFS seems to be hung")

thread_timeout works by running specified function in separate thread while waiting for timeout (or finalization) of the thread. Decorated function returns value if the function completed before timeout seconds, otherwise it may try to terminate thread and then throws an exception according to kill value (see below) . Before trying to terminate thread decorator will wait kill_wait seconds.

thread_timeout(timeout, kill=True, kill_wait=0.1)

• timeout - seconds, floating, how long to wait thread.
• kill - if True (default) attempt to terminate thread with function.
• kill_wait - how long to wait after killing before reporting an unresponsive thread.

THREAD KILLING

Thread killing implemented on python level: it will terminate python code, but will not terminate any IO operations or subprocess calls.

Exceptions:

• ExecTimeoutException - function did not finish on time, timeout (base class for all following exceptions)
• KilledExecTimeoutException - there was a timeout and thread with function was killed successfully
• FailedKillExecTimeoutException - there was a timeout and kill attempt but the thread refuses to die
• NotKillExecTimeoutException - there was a timeout and there was no attempt to kill thread