minix/kernel/system/do_getksig.c
Jorrit Herder 198c976f7e System processes can be signaled; signals are transformed in SYS_EVENT message
that passes signal map along. This mechanisms is also used for nonuser signals
like SIGKMESS, SIGKSTOP, SIGKSIG.

Revised comments of many system call handlers. Renamed setpriority to nice.
2005-07-19 12:21:36 +00:00

47 lines
1.5 KiB
C

/* The system call that is implemented in this file:
* m_type: SYS_GETKSIG
*
* The parameters for this system call are:
* m2_i1: SIG_PROC # process with pending signals
* m2_l1: SIG_MAP # bit map with pending signals
*
*/
#include "../system.h"
#include <signal.h>
#include <sys/sigcontext.h>
#if USE_GETKSIG
/*===========================================================================*
* do_getksig *
*===========================================================================*/
PUBLIC int do_getksig(m_ptr)
message *m_ptr; /* pointer to request message */
{
/* PM is ready to accept signals and repeatedly does a system call to get
* one. Find a process with pending signals. If no signals are available,
* return NONE in the process number field.
* It is not sufficient to ready the process when PM is informed, because
* PM can block waiting for FS to do a core dump.
*/
register struct proc *rp;
/* Find the next process with pending signals. */
for (rp = BEG_USER_ADDR; rp < END_PROC_ADDR; rp++) {
if (rp->p_rts_flags & SIGNALED) {
m_ptr->SIG_PROC = rp->p_nr; /* store signaled process */
m_ptr->SIG_MAP = rp->p_pending; /* pending signals map */
sigemptyset(&rp->p_pending); /* ball is in PM's court */
rp->p_rts_flags &= ~SIGNALED; /* blocked by SIG_PENDING */
return(OK);
}
}
/* No process with pending signals was found. */
m_ptr->SIG_PROC = NONE;
return(OK);
}
#endif /* USE_GETKSIG */