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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <assert.h>
#include <errno.h>
#include <sys/wait.h>
#include <syscall.h>
#include <unistd.h>
extern "C" {
pid_t wait(int* wstatus)
{
return waitpid(-1, wstatus, 0);
}
pid_t waitpid(pid_t waitee, int* wstatus, int options)
{
siginfo_t siginfo;
idtype_t idtype;
id_t id;
if (waitee < -1) {
idtype = P_PGID;
id = -waitee;
} else if (waitee == -1) {
idtype = P_ALL;
id = 0;
} else if (waitee == 0) {
idtype = P_PGID;
id = getgid();
} else {
idtype = P_PID;
id = waitee;
}
// To be able to detect if a child was found when WNOHANG is set,
// we need to clear si_pid, which will only be set if it was found.
siginfo.si_pid = 0;
int rc = waitid(idtype, id, &siginfo, options | WEXITED);
if (rc < 0)
return rc;
if (wstatus) {
if ((options & WNOHANG) && siginfo.si_pid == 0) {
// No child in a waitable state was found. All other fields
// in siginfo are undefined
*wstatus = 0;
return 0;
}
switch (siginfo.si_code) {
case CLD_EXITED:
*wstatus = siginfo.si_status << 8;
break;
case CLD_KILLED:
*wstatus = siginfo.si_status;
break;
case CLD_STOPPED:
*wstatus = siginfo.si_status << 8 | 0x7f;
break;
case CLD_CONTINUED:
*wstatus = 0;
return 0; // return 0 if running
default:
VERIFY_NOT_REACHED();
}
}
return siginfo.si_pid;
}
int waitid(idtype_t idtype, id_t id, siginfo_t* infop, int options)
{
Syscall::SC_waitid_params params { idtype, id, infop, options };
int rc = syscall(SC_waitid, ¶ms);
__RETURN_WITH_ERRNO(rc, rc, -1);
}
}
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