CODEWITHSUNDEEP
pythonmultithreading
Razer
Razer

Reputation: 8201

Determine if thread has been started

How to determine if a python thread has been started? There is a method is_alive() but this is true before and while a thread is running.

Upvotes: 6

Views: 7131

Answers (3)

ndpu
ndpu

Reputation: 22561

Use isAlive (or is_alive) Thread class method.

Python 2.7 http://hg.python.org/cpython/file/2.7/Lib/threading.py#l995

def isAlive(self):
    """Return whether the thread is alive.

    This method returns True just before the run() method starts until just
    after the run() method terminates. The module function enumerate()
    returns a list of all alive threads.

    """
    assert self.__initialized, "Thread.__init__() not called"
    return self.__started.is_set() and not self.__stopped

Python 3 https://github.com/python/cpython/blob/master/Lib/threading.py

def is_alive(self):
    """Return whether the thread is alive.
    This method returns True just before the run() method starts until just
    after the run() method terminates. The module function enumerate()
    returns a list of all alive threads.
    """
    assert self._initialized, "Thread.__init__() not called"
    if self._is_stopped or not self._started.is_set():
        return False
    self._wait_for_tstate_lock(False)
    return not self._is_stopped

Upvotes: 2

gslavin
gslavin

Reputation: 711

You can look at the ident field of the Thread instance. The Python 2.7 documentation for Threading describes ident as

The ‘thread identifier’ of this thread or None if the thread has not been started.

Upvotes: 9

NPE
NPE

Reputation: 500167

You could have the thread function set a boolean flag on startup, and then check that flag.

Upvotes: 1

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