minix/kernel/system/do_getksig.c

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/* 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 */