Created
June 14, 2017 18:08
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| // | |
| // main.c | |
| // processes | |
| // | |
| // Created by AlexDenisov on 14.06.17. | |
| // Copyright © 2017 Low Level Bits. All rights reserved. | |
| // | |
| #include <assert.h> | |
| #include <signal.h> | |
| #include <unistd.h> | |
| #include <iostream> | |
| #include <chrono> | |
| #include <thread> | |
| using namespace std; | |
| pid_t mullFork(const char *processName) { | |
| static int childrenCount = 0; | |
| childrenCount++; | |
| const pid_t pid = fork(); | |
| if (pid == -1) { | |
| cout << "Failed to create " << processName | |
| << " after creating " << childrenCount | |
| << " child processes\n"; | |
| cout << "Shutting down\n"; | |
| exit(1); | |
| } | |
| return pid; | |
| } | |
| void do_fork() { | |
| const pid_t watchdogPID = mullFork("watchdog"); | |
| if (watchdogPID == 0) { | |
| const pid_t timerPID = mullFork("timer"); | |
| if (timerPID == 0) { | |
| std::this_thread::sleep_for(std::chrono::seconds(5)); | |
| exit(0); | |
| } | |
| const pid_t workerPID = mullFork("worker"); | |
| if (workerPID == 0) { | |
| std::this_thread::sleep_for(std::chrono::milliseconds(100)); | |
| exit(42); | |
| } | |
| int status = 0; | |
| const pid_t exitedPID = waitpid(WAIT_ANY, &status, 0); | |
| if (exitedPID == timerPID) { | |
| /// Timer Process finished first, meaning that the worker timed out | |
| kill(workerPID, SIGKILL); | |
| cout << "Timed out\n"; | |
| } else if (exitedPID == workerPID) { | |
| kill(timerPID, SIGKILL); | |
| /// Worker Process finished first | |
| /// Need to check whether it has signaled (crashed) or finished normally | |
| if (WIFSIGNALED(status)) { | |
| cout << "Crashed\n"; | |
| } | |
| else if (WIFEXITED(status) && WEXITSTATUS(status) != 42) { | |
| cout << "Abnormal Exit\n"; | |
| } else { | |
| cout << "All good\n"; | |
| } | |
| } else { | |
| assert(0 && "Should not reach!"); | |
| } | |
| wait(nullptr); | |
| exit(0); | |
| } else { | |
| pid_t pid = 0; | |
| while ( (pid = waitpid(watchdogPID, 0, 0)) == -1 ) {} | |
| } | |
| wait(0); | |
| } | |
| int main(int argc, const char * argv[]) { | |
| for (int i = 0; i < 10000; i++) { | |
| cout << i << " "; | |
| do_fork(); | |
| } | |
| return 0; | |
| } |
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