arg_t _waitpid(void)
{
ptptr p;
int retval;
if (statloc && !valaddr((char *) statloc, sizeof(int))) {
udata.u_error = EFAULT;
return (-1);
}
/* FIXME: move this scan into the main loop and also error
on a complete loop finding no matchi for pid */
/* See if we have any children. */
for (p = ptab; p < ptab_end; ++p) {
if (p->p_status && p->p_pptr == udata.u_ptab
&& p != udata.u_ptab)
goto ok;
}
udata.u_error = ECHILD;
return (-1);
ok:
if (pid == 0)
pid = -udata.u_ptab->p_pgrp;
/* Search for an exited child; */
for (;;) {
chksigs();
if (udata.u_cursig) {
udata.u_error = EINTR;
return -1;
}
for (p = ptab; p < ptab_end; ++p) {
if (p->p_status == P_ZOMBIE
&& p->p_pptr == udata.u_ptab) {
if (pid == -1 || p->p_pid == pid
|| p->p_pgrp == -pid) {
if (statloc)
uputw(p->p_exitval,
statloc);
retval = p->p_pid;
p->p_status = P_EMPTY;
/* Add in child's time info. It was stored on top */
/* of p_priority in the childs process table entry. */
udata.u_cutime += ((clock_t *)p->p_priority)[0];
udata.u_cstime += ((clock_t *)p->p_priority)[1];
return retval;
}
}
}
/* Nothing yet, so wait */
if (options & WNOHANG)
break;
psleep(udata.u_ptab);
}
udata.u_error = EINTR;
return -1;
}
static int iopoll(int sofar)
{
/* Ought to be a core helper for this lot ? */
if (need_reschedule())
_sched_yield();
if (chksigs()) {
if (sofar)
return sofar;
udata.u_error = EINTR;
return -1;
}
return 0;
}
int psleep_flags(void *p, unsigned char flags)
{
if (flags & O_NDELAY) {
udata.u_error = EAGAIN;
return -1;
}
psleep(p);
if (chksigs()) {
udata.u_error = EINTR;
return -1;
}
return 0;
}
static uint8_t iopoll(void)
{
/* Ought to be a core helper for this lot ? */
if (need_reschedule())
_sched_yield();
if (chksigs()) {
if (!udata.u_done) {
udata.u_error = EINTR;
udata.u_done = (usize_t)-1;
}
return 1;
}
return 0;
}
int psleep_flags_io(void *p, unsigned char flags)
{
if (flags & O_NDELAY) {
if (!udata.u_done) {
udata.u_done = (usize_t)-1;
udata.u_error = EAGAIN;
}
return -1;
}
psleep(p);
if (chksigs()) {
if (!udata.u_done) {
udata.u_done = (usize_t)-1;
udata.u_error = EINTR;
}
return -1;
}
return 0;
}
// Fuzix system call handler
// we arrive here from syscall.s with the kernel paged in, using the kernel stack, interrupts enabled.
void unix_syscall(void)
{
// NO LOCAL VARIABLES PLEASE
udata.u_error = 0;
/* Fuzix saves the Stack Pointer and arguments in the
* Assembly Language Function handler in lowlevel.s
*/
if (udata.u_callno >= FUZIX_SYSCALL_COUNT) {
udata.u_error = EINVAL;
} else {
#ifdef DEBUG
kprintf("\t\tpid %d: syscall %d\t%s(%x, %x, %x)\n",
udata.u_ptab->p_pid, udata.u_callno,
syscall_name[udata.u_callno], udata.u_argn,
udata.u_argn1, udata.u_argn2);
#endif
// dispatch system call
udata.u_retval = (*syscall_dispatch[udata.u_callno]) ();
#ifdef DEBUG
kprintf("\t\t\tpid %d: ret syscall %d, ret %x err %d\n",
udata.u_ptab->p_pid, udata.u_callno,
udata.u_retval, udata.u_error);
#endif
}
udata.u_ptab->p_timeout = 0;
chksigs();
di();
if (runticks >= udata.u_ptab->p_priority && nready > 1) {
/* Time to switch out? - we may have overstayed our welcome inside
a syscall so switch straight afterwards */
udata.u_ptab->p_status = P_READY;
switchout();
}
ei();
}
