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#include "signal_handler.h"
#include <errno.h>
namespace ov4
{
/*
* sigchld_handler - The kernel sends a SIGCHLD to the shell whenever
* a child job terminates (becomes a zombie), or stops because it
* received a SIGSTOP or SIGTSTP signal. The handler reaps all
* available zombie children, but doesn't wait for any other
* currently running children to terminate.
*/
void sigchld_handler([[maybe_unused]] int sig)
{
int errno_backup = errno;
sigset_t prev;
block_handler(&prev);
int status, pid;
safe_debug("SIGCHLD\n");
while ((pid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0)
{
// signal'd or stopped or normally quit
// print terminated/stopped message
if (WIFSIGNALED(status) || WIFSTOPPED(status))
{
int jid = pid2jid(pid);
safe_output("Job [", jid, "] (", pid, ") ");
if (!WIFSTOPPED(status) && WTERMSIG(status) == SIGINT)
safe_print("terminated");
else if (WIFSTOPPED(status))
safe_print("stopped");
else
safe_print("idk");
safe_print(" by signal ");
if (WIFSTOPPED(status))
safe_print(WSTOPSIG(status));
else
safe_print(WTERMSIG(status));
safe_print("\n");
}
// handle job table
// and save exit/signal code
// stopped
if (WIFSTOPPED(status))
{
safe_output("Process suspended PID: ", pid, "\n");
sigset_t prev_inner;
block_all(&prev_inner);
job_suspend(pid);
sigprocmask(SIG_SETMASK, &prev_inner, nullptr);
}
// other type of signal'd
// or normally quit
else {
safe_output("Process terminated PID: ", pid, "\n");
sigset_t prev_inner;
block_all(&prev_inner);
deletejob(pid);
sigprocmask(SIG_SETMASK, &prev_inner, nullptr);
// terminated normally
// so that exit code should be available
if (WIFEXITED(status))
{
safe_output("Exit code: ", WEXITSTATUS(status), "\n");
if (pid == exit_required_pid)
{
exit_code = WEXITSTATUS(status);
safe_logger("sigchld_handler: required PID detected: ", pid, "\n");
}
}
// if signal'd
else if (WIFSIGNALED(status))
{
safe_output("Signal code: ", WTERMSIG(status), "\n");
if (pid == exit_required_pid)
{
exit_code = SIGNAL_EXIT_CODE_BASE + WTERMSIG(status);
safe_logger("sigchld_handler: required PID detected: ", pid, "\n");
}
}
}
}
sigprocmask(SIG_SETMASK, &prev, nullptr);
errno = errno_backup;
return;
}
}
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