minix/lib/libsockevent/sockevent_proc.c

   1 /* libsockevent - sockevent_proc.c - process suspension state management */
   2
   3 #include <minix/drivers.h>
   4 #include <minix/sockdriver.h>
   5
   6 #include "sockevent_proc.h"
   7
   8 static struct sockevent_proc sockevent_procs[NR_PROCS];
   9 static struct sockevent_proc *sockevent_freeprocs;
  10
  11 /*
  12  * Initialize the process suspension table.
  13  */
  14 void
  15 sockevent_proc_init(void)
  16 {
  17         unsigned int slot;
  18
  19         for (slot = 0; slot < __arraycount(sockevent_procs); slot++) {
  20                 sockevent_procs[slot].spr_next = sockevent_freeprocs;
  21                 sockevent_freeprocs = &sockevent_procs[slot];
  22         }
  23 }
  24
  25 /*
  26  * Allocate and return a new socket process suspension entry.  Return NULL if
  27  * no entries are available.
  28  */
  29 struct sockevent_proc *
  30 sockevent_proc_alloc(void)
  31 {
  32         struct sockevent_proc *spr;
  33
  34         if ((spr = sockevent_freeprocs) == NULL)
  35                 return NULL;
  36
  37         sockevent_freeprocs = spr->spr_next;
  38         spr->spr_next = NULL;
  39
  40         return spr;
  41 }
  42
  43 /*
  44  * Free up a previously allocated socket process suspension entry for reuse.
  45  */
  46 void
  47 sockevent_proc_free(struct sockevent_proc * spr)
  48 {
  49
  50         spr->spr_next = sockevent_freeprocs;
  51         sockevent_freeprocs = spr;
  52 }