xref: /minix3/minix/kernel/system/do_getksig.c (revision 433d6423c39e34ec4b79c950597bb2d236f886be)
1 /* The kernel call that is implemented in this file:
2  *	m_type: SYS_GETKSIG
3  *
4  * The parameters for this kernel call are:
5  *	m_sigcalls.endpt	# process with pending signals
6  *	m_sigcalls.map		# bit map with pending signals
7  */
8 
9 #include "kernel/system.h"
10 #include <signal.h>
11 #include <minix/endpoint.h>
12 
13 #if USE_GETKSIG
14 
15 /*===========================================================================*
16  *			      do_getksig				     *
17  *===========================================================================*/
do_getksig(struct proc * caller,message * m_ptr)18 int do_getksig(struct proc * caller, message * m_ptr)
19 {
20 /* The signal manager is ready to accept signals and repeatedly does a kernel
21  * call to get one. Find a process with pending signals. If no signals are
22  * available, return NONE in the process number field.
23  */
24   register struct proc *rp;
25 
26   /* Find the next process with pending signals. */
27   for (rp = BEG_USER_ADDR; rp < END_PROC_ADDR; rp++) {
28       if (RTS_ISSET(rp, RTS_SIGNALED)) {
29           if (caller->p_endpoint != priv(rp)->s_sig_mgr) continue;
30 	  /* store signaled process' endpoint */
31           m_ptr->m_sigcalls.endpt = rp->p_endpoint;
32           m_ptr->m_sigcalls.map = rp->p_pending;	/* pending signals map */
33           (void) sigemptyset(&rp->p_pending); 	/* clear map in the kernel */
34 	  RTS_UNSET(rp, RTS_SIGNALED);		/* blocked by SIG_PENDING */
35           return(OK);
36       }
37   }
38 
39   /* No process with pending signals was found. */
40   m_ptr->m_sigcalls.endpt = NONE;
41   return(OK);
42 }
43 #endif /* USE_GETKSIG */
44