python庫之_thread

　　官方參考文檔：https://docs.python.org/3.7/library/_thread.html

_thread庫方法

（1） _thread.error

（2）_thread.LockTyoe

（3）_thread.start_new_thread

（4）_thread.interrupt_main

　　Raise a KeyboardInterrupt exception in the main thread. A subthread can use this function to interrupt the main thread.

（5）_thread.exit

（6）_thread.allocate_lock

import _thread

a_lock = _thread.allocate_lock()

with a_lock:
    print("a_lock is locked while this executes")

（7）_thread.get_ident

（8）_thread.stack_size

（9）_thread.TIMEOUT_MAX

（10）lock.acquire(waitflag=1,timeout=-1)

　　Without any optional argument, this method acquires the lock unconditionally, if necessary waiting until it is released by another thread (only one thread at a time can acquire a lock — that’s their reason for existence).

　　If the integer waitflag argument is present, the action depends on its value: if it is zero, the lock is only acquired if it can be acquired immediately without waiting, while if it is nonzero, the lock is acquired unconditionally as above.

　　If the floating-point timeout argument is present and positive, it specifies the maximum wait time in seconds before returning. A negative timeout argument specifies an unbounded wait. You cannot specify a timeout if waitflag is zero.

　　The return value is True if the lock is acquired successfully, False if not.

（11）lock.release()

（12）lock.locked()