minix3/kernel/system/do_getksig.c

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2020-02-21 00:59:27 +05:30
/* The kernel call that is implemented in this file:
* m_type: SYS_GETKSIG
*
* The parameters for this kernel call are:
* m_sigcalls.endpt # process with pending signals
* m_sigcalls.map # bit map with pending signals
*/
#include "kernel/system.h"
#include <signal.h>
#include <minix/endpoint.h>
#if USE_GETKSIG
/*===========================================================================*
* do_getksig *
*===========================================================================*/
int do_getksig(struct proc * caller, message * m_ptr)
{
/* The signal manager is ready to accept signals and repeatedly does a kernel
* call to get one. Find a process with pending signals. If no signals are
* available, return NONE in the process number field.
*/
register struct proc *rp;
/* Find the next process with pending signals. */
for (rp = BEG_USER_ADDR; rp < END_PROC_ADDR; rp++) {
if (RTS_ISSET(rp, RTS_SIGNALED)) {
if (caller->p_endpoint != priv(rp)->s_sig_mgr) continue;
/* store signaled process' endpoint */
m_ptr->m_sigcalls.endpt = rp->p_endpoint;
m_ptr->m_sigcalls.map = rp->p_pending; /* pending signals map */
(void) sigemptyset(&rp->p_pending); /* clear map in the kernel */
RTS_UNSET(rp, RTS_SIGNALED); /* blocked by SIG_PENDING */
return(OK);
}
}
/* No process with pending signals was found. */
m_ptr->m_sigcalls.endpt = NONE;
return(OK);
}
#endif /* USE_GETKSIG */