最佳答案
您可能喜欢将任务分解为基本步骤:
- 编写一个函数来创建一个子进程来执行您提供的函数。
- 重复使用该函数来创建所需的流程树。
例子:
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
int level = 1;
char const offsets[] = "\t\t\t\t\t\t\t\t";
pid_t create_child_process(int(*child_fn)()) {
// Flush the output buffers to avoid duplicate output from the child process.
fflush(stdout);
fflush(stderr);
pid_t child_pid = fork();
switch(child_pid) {
case 0: // Child process.
++level;
exit(child_fn());
case -1: // fork() failed.
abort();
default: // Parent process.
printf("%.*s %u spawned %u\n", level, offsets, (unsigned)getpid(), (unsigned)child_pid);
return child_pid;
}
}
void wait_for_any_child() {
int wstatus;
pid_t child_pid = wait(&wstatus);
if(child_pid == -1)
abort();
printf("%.*s %u terminated\n", level, offsets, (unsigned)child_pid);
}
int p2() { return 0; }
int p5() { return 0; }
int p6() { return 0; }
int p7() { return 0; }
int p4() {
create_child_process(p5);
create_child_process(p6);
create_child_process(p7);
wait_for_any_child();
wait_for_any_child();
wait_for_any_child();
return 0;
}
int p3() {
create_child_process(p4);
wait_for_any_child();
return 0;
}
int p1() {
printf("%u started\n", (unsigned)getpid());
create_child_process(p2);
create_child_process(p3);
wait_for_any_child();
wait_for_any_child();
printf("%u terminated\n", (unsigned)getpid());
return 0;
}
int main() {
return p1();
}
输出:
5962 started
5962 spawned 5963
5962 spawned 5964
5963 terminated
5964 spawned 5965
5965 spawned 5966
5965 spawned 5967
5965 spawned 5968
5966 terminated
5967 terminated
5968 terminated
5965 terminated
5964 terminated
5962 terminated
关于c - 使用 fork() 的 Linux 进程树,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55971838/