signals

问题 i want to to update field whenever an instance been created i tried signals but it seems complicate to ManyToManyField class MobileCustomer(models.Model): customer = models.CharField(max_length=30) phone = models.CharField(max_length=13) mobile = models.ManyToManyField(MobileStorage,through='SelectMobile') class SelectMobile(models.Model): mobile = models.ForeignKey(MobileStorage,on_delete=models.CASCADE) item = models.ForeignKey(MobileCustomer,on_delete=models.CASCADE) quantity = models

问题 i want to to update field whenever an instance been created i tried signals but it seems complicate to ManyToManyField class MobileCustomer(models.Model): customer = models.CharField(max_length=30) phone = models.CharField(max_length=13) mobile = models.ManyToManyField(MobileStorage,through='SelectMobile') class SelectMobile(models.Model): mobile = models.ForeignKey(MobileStorage,on_delete=models.CASCADE) item = models.ForeignKey(MobileCustomer,on_delete=models.CASCADE) quantity = models

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 20 hours ago . Improve this question I want to float a window by signal with param in pyqt5. I used already QDockWidget but i can launch only one float window. I need multiple floating window by some pramas. is there any easy way to do this? from PyQt5.QtWidgets import QMainWindow, QApplication, QPushButton,

问题 I want to count the (more or less) exact amount of instructions for some piece of code. Additionally, I want to receive a Signal after a specific amount of instructions passed. For this purpose, I use the overflow signal behaviour provided by perf_event_open. I'm using the second way the manpage proposes to achieve overflow signals: Signal overflow Events can be set to deliver a signal when a threshold is crossed. The signal handler is set up using the poll(2), select(2), epoll(2) and fcntl(2

问题 It seem that the only implementation that provide Safe Cross-Thread Signals for both the Signal class and what's being called in the slot is QT. (Maybe I'm wrong?). But I cannot use QT in the project I'm doing. So how could I provide safe Slots call from a different thread (Using Boost::signals2 for example)? Are mutex inside the slot the only way? I think signals2 protect themself but not what's being done inside the slot. Thanks 回答1: You can combine boost::bind and boost ASIO to create

问题 I have the following code in my perl script which somehow doesn't seem to work: my $thr; sub start__server_thread() { $thr = threads->create(\&iperf_start_server, $_[0], $_[1], $_[2]); print("Value of thread is $thr\n"); &START_SERVER_RESPONSE($controller_ip, $controller_port, "success", 2345, $_[1]); } sub iperf_start_server() { # Do some stuff here and then handle the signal $SIG{'SIGSTOP'} = sub { print("Stop signal received\n"); $thr->exit(); $flag = 1; }; } sub stop_server() { my ($dat,

问题 I have the following code in my perl script which somehow doesn't seem to work: my $thr; sub start__server_thread() { $thr = threads->create(\&iperf_start_server, $_[0], $_[1], $_[2]); print("Value of thread is $thr\n"); &START_SERVER_RESPONSE($controller_ip, $controller_port, "success", 2345, $_[1]); } sub iperf_start_server() { # Do some stuff here and then handle the signal $SIG{'SIGSTOP'} = sub { print("Stop signal received\n"); $thr->exit(); $flag = 1; }; } sub stop_server() { my ($dat,

问题 It is possible to do IPC (inter process communication) using signal catch and signal raise? I made two programs. In the first program I did handling of signals, and in the other program I just raised signal which I want to handle in another program. I'ts working fine for me but I want to do communication between these two programs using signals and also want to send some bytes of data with this raise signal. How can I do this? I want to pass messages with this signal also. Can i do it? It is

问题 I have the following script: tail -f nohup.out echo 5 When I press Ctrl + C on tail -f , the script stops running: the 5 is not printed. How can I run the command echo 5 after I stop the tail command? 回答1: Ctrl + C sends the SIGINT signal to all the processes in the foreground process group. While tail is running, the process group consists of the tail process and the shell running the script. Use the trap builtin to override the default behavior of the signal. trap " " INT tail -f nohup.out

问题 I have the following script: tail -f nohup.out echo 5 When I press Ctrl + C on tail -f , the script stops running: the 5 is not printed. How can I run the command echo 5 after I stop the tail command? 回答1: Ctrl + C sends the SIGINT signal to all the processes in the foreground process group. While tail is running, the process group consists of the tail process and the shell running the script. Use the trap builtin to override the default behavior of the signal. trap " " INT tail -f nohup.out