In Python multithreading, How to end the sub-thread which in blocking state when main thread received SIGINT signal?
In Python multithreading, only the main thread can receive signals, and join() method will block the main thread and then can not receive signals
So after th main thread received the signal, how to end(/kill) the child thread which in the blocking state ?
The following code sub-thread receive_task1 is blocking in the os. read()(receiving serial data, and no data recieved yet) function.
Is there any way to let os. read () function exit?
Normally, If os. read() is used in the main thread and Ctrl + C can be used by default to interrupt, but how can this be best done now?
import os
import signal
import threading
import time
def test(signum, frame):
print("nreceived sig %d" % (signum))
print("how to make os.read(...) in rcv_task1 thread stop? ")
print("except use sys.exit(1)")
def receive_task1():
fd = os.open("/dev/ttyUSB1", os.O_RDWR)
os.read(fd, 10)
print("receive thread end")
signal.signal(signal.SIGINT, test)
rcv_task1 = threading.Thread(target=receive_task1)
rcv_task1.setDaemon(True)
rcv_task1.start()
while(1):
time.sleep(1)
python multithreading signals copy-paste interrupt
asked Nov 14 '18 at 7:14
neucrackneucrack
11
add a comment |
In Python multithreading, only the main thread can receive signals, and join() method will block the main thread and then can not receive signals
So after th main thread received the signal, how to end(/kill) the child thread which in the blocking state ?
The following code sub-thread receive_task1 is blocking in the os. read()(receiving serial data, and no data recieved yet) function.
Is there any way to let os. read () function exit?
Normally, If os. read() is used in the main thread and Ctrl + C can be used by default to interrupt, but how can this be best done now?
import os
import signal
import threading
import time
def test(signum, frame):
print("nreceived sig %d" % (signum))
print("how to make os.read(...) in rcv_task1 thread stop? ")
print("except use sys.exit(1)")
def receive_task1():
fd = os.open("/dev/ttyUSB1", os.O_RDWR)
os.read(fd, 10)
print("receive thread end")
signal.signal(signal.SIGINT, test)
rcv_task1 = threading.Thread(target=receive_task1)
rcv_task1.setDaemon(True)
rcv_task1.start()
while(1):
time.sleep(1)
python multithreading signals copy-paste interrupt
asked Nov 14 '18 at 7:14
neucrackneucrack
11
Because the thread is in a blocking system call, the only way out is something that unblocks it: either the system call completes OK, or it fails. The easiest way to make it fail is to send a signal to the thread. The details vary from one OS to another.
– torek
Nov 14 '18 at 7:20
add a comment |
In Python multithreading, only the main thread can receive signals, and join() method will block the main thread and then can not receive signals
So after th main thread received the signal, how to end(/kill) the child thread which in the blocking state ?
The following code sub-thread receive_task1 is blocking in the os. read()(receiving serial data, and no data recieved yet) function.
Is there any way to let os. read () function exit?
Normally, If os. read() is used in the main thread and Ctrl + C can be used by default to interrupt, but how can this be best done now?
import os
import signal
import threading
import time
def test(signum, frame):
print("nreceived sig %d" % (signum))
print("how to make os.read(...) in rcv_task1 thread stop? ")
print("except use sys.exit(1)")
def receive_task1():
fd = os.open("/dev/ttyUSB1", os.O_RDWR)
os.read(fd, 10)
print("receive thread end")
signal.signal(signal.SIGINT, test)
rcv_task1 = threading.Thread(target=receive_task1)
rcv_task1.setDaemon(True)
rcv_task1.start()
while(1):
time.sleep(1)
python multithreading signals copy-paste interrupt
asked Nov 14 '18 at 7:14
neucrackneucrack
11
In Python multithreading, only the main thread can receive signals, and join() method will block the main thread and then can not receive signals
So after th main thread received the signal, how to end(/kill) the child thread which in the blocking state ?
The following code sub-thread receive_task1 is blocking in the os. read()(receiving serial data, and no data recieved yet) function.
Is there any way to let os. read () function exit?
Normally, If os. read() is used in the main thread and Ctrl + C can be used by default to interrupt, but how can this be best done now?
import os
import signal
import threading
import time
def test(signum, frame):
print("nreceived sig %d" % (signum))
print("how to make os.read(...) in rcv_task1 thread stop? ")
print("except use sys.exit(1)")
def receive_task1():
fd = os.open("/dev/ttyUSB1", os.O_RDWR)
os.read(fd, 10)
print("receive thread end")
signal.signal(signal.SIGINT, test)
rcv_task1 = threading.Thread(target=receive_task1)
rcv_task1.setDaemon(True)
rcv_task1.start()
while(1):
time.sleep(1)
python multithreading signals copy-paste interrupt
python multithreading signals copy-paste interrupt
asked Nov 14 '18 at 7:14
neucrackneucrack
11
asked Nov 14 '18 at 7:14
neucrackneucrack
11
asked Nov 14 '18 at 7:14
neucrackneucrack
11
asked Nov 14 '18 at 7:14
neucrackneucrack
11
asked Nov 14 '18 at 7:14
neucrackneucrack
11
11
Because the thread is in a blocking system call, the only way out is something that unblocks it: either the system call completes OK, or it fails. The easiest way to make it fail is to send a signal to the thread. The details vary from one OS to another.
– torek
Nov 14 '18 at 7:20
add a comment |
Because the thread is in a blocking system call, the only way out is something that unblocks it: either the system call completes OK, or it fails. The easiest way to make it fail is to send a signal to the thread. The details vary from one OS to another.
– torek
Nov 14 '18 at 7:20
Because the thread is in a blocking system call, the only way out is something that unblocks it: either the system call completes OK, or it fails. The easiest way to make it fail is to send a signal to the thread. The details vary from one OS to another.
– torek
Nov 14 '18 at 7:20
Because the thread is in a blocking system call, the only way out is something that unblocks it: either the system call completes OK, or it fails. The easiest way to make it fail is to send a signal to the thread. The details vary from one OS to another.
– torek
Nov 14 '18 at 7:20
add a comment |
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Because the thread is in a blocking system call, the only way out is something that unblocks it: either the system call completes OK, or it fails. The easiest way to make it fail is to send a signal to the thread. The details vary from one OS to another.
– torek
Nov 14 '18 at 7:20