#!python
# -*- mode: python; Encoding: utf-8; coding: utf-8 -*-
# Last updated: <2022/08/13 20:15:55 +0900>
"""
Python mutex sample. Windows only.

Windows10 x64 21H2 + Python 3.9.13 64bit
"""

import win32event
import win32api
import winerror
import win32security
import time
import sys

MUTEXNAME = "python_mutex_sample_01"


def main():
    sa = win32security.SECURITY_ATTRIBUTES()
    sa.SECURITY_DESCRIPTOR.SetSecurityDescriptorDacl(True, None, False)

    mtx = win32event.CreateMutex(sa, False, MUTEXNAME)
    err = win32api.GetLastError()
    if not mtx or err == winerror.ERROR_ALREADY_EXISTS:
        # Process exists
        print("%s already exists" % MUTEXNAME)
        sys.exit(0)
    else:
        # New process
        print("New process.")
        for i in range(10):
            print(i)
            time.sleep(1)

    if mtx:
        # win32event.ReleaseMutex(mtx)
        # win32api.CloseHandle(mtx)
        mtx.Close()


if __name__ == '__main__':
    main()