fork

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . main(){ int i; for(i=0;i<4;i++) fork(); while(1); } Is the above graph, the output of the code? 回答1: No, that's not quite correct though it's close. Think about the properties of all those processes down the left hand side. p0 creates four children, p1 creates three, and so on. Since this is undoubtedly

问题 fork() calls outside a loop are easy to figure out, but when they are inside a loop I find it difficult. Can anyone figuratively explain how the processes branch out with an example like this one? #include <stdio.h> int main(){ int i; for(i=0;i<2;i++) { fork(); printf("hi"); fork(); } exit(0); } 回答1: Ideally, this would be the case: There is one "hi" printed with each process (abbreviated as proc) Each fork doubles the number of process (each process spawns one child) The calculation could be

问题 I have simple C program which executes an application using fork() and execl(). If execl() fails to run the application, then I have to call a function in the parent process and exit from the child process. If execl() successfully runs the application, then I have show a success log from the parent process. So, parent process should wait for the child's execl() call (just the call, not till the end of execution of the application), get some information about it status, and then make decisions

问题 I have a Flask app running in a forked Gunicorn environment, but the stacktraces are getting interleaved in the logfile. Can each fork have its own logfile? or can each logger have exclusive access while writing to the log? 回答1: Can each fork have its own logfile? Yes, although you probably don't need, or want, that. The easiest way to do this is to just stick os.getpid() somewhere in the filename. or can each logger have exclusive access while writing to the log? There are a few ways to do

问题 I'm trying to clone a running JVM with POSIX fork. The way I get access to fork is through JNI (i.e. https://github.com/kohsuke/akuma/blob/master/src/main/java/com/sun/akuma/CLibrary.java). After the fork, I'd like both the parent and the child to do some computation and then exit. The following is the test code. After the fork, I can see two lines of "After the fork.", meaning that both the parent and the child reach this point. But then, the parent process exits normally while the child

问题 I want to make a simple program, that fork, and the child writes into the named pipe and the parent reads and displays from the named pipe. The problem is that it enters the parent, does the first printf and then it gets weird, it doesn't do anything else, does not get to the second printf, it just ways for input in the console. #include <string.h> #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> void main() { char t

问题 I have a question regarding on how to design the following system: My system is built of several clients listening to an environment. When a audio threshold is breached they send their information to a server, that has children listening on each connection. The server needs information from all the clients to make the necessary calculations. Currently the server is working in UNIX and has forked out connections. They are working independently. What I want to do is to tell the parent (in the

问题 I have have a main process that forks a number of subprocesses. I want to be able to kill these child processes off when my main process gets the kill signal. Ideally I would want to do something along the lines of: def handler(signum, frame, pid_list): log('Killing Process') for pid in pid_list: os.kill(pid, signal.SIGTERM) os.waitpid(pid, 0) # need sys.exit() if __name__ == "__main__": <code that creates child processes, pids> signal.signal(signal.SIGTERM, handler(pid_list)) But of course,

问题 I'm doing some parallel programming (multiprocessing) and I need the parent to: 1) Fork several children 2) AFTER all the children have been created, simply WAIT for all of them to terminate 3) After all the children are terminated, do some other work. This is what I tried: int main(int argc, char **argv[]) { int j, i; pid_t children[3]; int pid; // Fork the processes for(j = 0; j < 3; j++){ if((children[j] = fork()) == 0){ // Child process for(i = 0; i < 2; i++){ printf("child %d printing:

问题 I have managed to fork and exec a different program from within my app. I'm currently working on how to wait until the process called from exec returns a result through a pipe or stdout. However, can I have a group of processes using a single fork, or do I have to fork many times and call the same program again? Can I get a PID for each different process ? I want my app to call the same program I'm currently calling many times but with different parameters: I want a group of 8 processes of