minix/kernel/system/do_getksig.c

   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  *===========================================================================*/
  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 */