minix/lib/libddekit/src/condvar.c

   1 #include "common.h"
   2
   3 #include <ddekit/condvar.h>
   4 #include <ddekit/lock.h>
   5 #include <ddekit/memory.h>
   6
   7 #ifdef DDEBUG_LEVEL_CONDVAR
   8 #undef DDEBUG
   9 #define DDEBUG DDEBUG_LEVEL_CONDVAR
  10 #endif
  11
  12 #include "debug.h"
  13 #include "util.h"
  14 #include "thread.h"
  15
  16 struct ddekit_condvar {
  17         ddekit_thread_t * wait_queue;
  18 };
  19
  20 /*****************************************************************************/
  21 /*      ddekit_condvar_init                                                  */
  22 /*****************************************************************************/
  23 ddekit_condvar_t * ddekit_condvar_init(void) {
  24         ddekit_condvar_t *cv;
  25         cv = (ddekit_condvar_t *) ddekit_simple_malloc(sizeof(ddekit_condvar_t));
  26         DDEBUG_MSG_VERBOSE("cv: %p", cv);
  27         return cv;
  28 }
  29
  30 /*****************************************************************************/
  31 /*      ddekit_condvar_deinit                                                */
  32 /*****************************************************************************/
  33 void ddekit_condvar_deinit(ddekit_condvar_t *cvp) {
  34         DDEBUG_MSG_VERBOSE("cv: %p", cvp);
  35         ddekit_simple_free(cvp);
  36 }
  37
  38 /*****************************************************************************/
  39 /*      ddekit_condvar_wait                                                  */
  40 /*****************************************************************************/
  41 void ddekit_condvar_wait(ddekit_condvar_t *cv, ddekit_lock_t *mp) {
  42
  43         DDEBUG_MSG_VERBOSE("wait cv: %p, thread id: %d, name: %s",
  44                 cv, ddekit_thread_myself()->id,  ddekit_thread_myself()->name);
  45
  46         ddekit_lock_unlock(mp);
  47
  48         if(cv->wait_queue == NULL) {
  49                         cv->wait_queue = ddekit_thread_myself();
  50         } else {
  51                 ddekit_thread_t *pos = cv->wait_queue;
  52                 while(pos->next != NULL) {
  53                         pos = pos->next;
  54                 }
  55                 pos->next = ddekit_thread_myself();
  56         }
  57
  58         _ddekit_thread_schedule();
  59
  60         DDEBUG_MSG_VERBOSE("wakeup cv: %p, thread id: %d, name: %s",
  61                 cv, ddekit_thread_myself()->id,  ddekit_thread_myself()->name);
  62
  63         ddekit_lock_lock(mp);
  64 }
  65 /*****************************************************************************/
  66 /*      ddekit_condvar_wait_timed                                            */
  67 /*****************************************************************************/
  68 int ddekit_condvar_wait_timed
  69 (ddekit_condvar_t *cvp, ddekit_lock_t *mp, int timo)
  70 {
  71         /*
  72          * Only used by ddefbsd, so not implemented
  73          */
  74         WARN_UNIMPL;
  75         return 0;
  76 }
  77
  78
  79 /*****************************************************************************/
  80 /*      ddekit_condvar_signal                                                */
  81 /*****************************************************************************/
  82 void ddekit_condvar_signal(ddekit_condvar_t *cv)
  83 {
  84
  85         DDEBUG_MSG_VERBOSE("cv: %p", cv);
  86
  87         if(cv->wait_queue) {
  88                 ddekit_thread_t *th = cv->wait_queue;
  89                 cv->wait_queue = th->next;
  90                 th->next = NULL;
  91                 _ddekit_thread_enqueue(th);
  92
  93                 DDEBUG_MSG_VERBOSE("waking up cv: %p, thread id: %d, name: %s",
  94                         cv, th->id, th->name);
  95         }
  96         ddekit_thread_schedule();
  97 }
  98
  99
 100 /*****************************************************************************/
 101 /*      ddekit_condvar_broadcast                                             */
 102 /*****************************************************************************/
 103 void ddekit_condvar_broadcast(ddekit_condvar_t *cv) {
 104
 105         DDEBUG_MSG_VERBOSE("cv: %p", cv);
 106
 107         while (cv->wait_queue) {
 108                 ddekit_thread_t *th = cv->wait_queue;
 109                 cv->wait_queue = th->next;
 110                 th->next = NULL;
 111                 _ddekit_thread_enqueue(th);
 112
 113                 DDEBUG_MSG_VERBOSE("waking up cv: %p, thread id: %d, name: %s",
 114                         cv, th->id, th->name);
 115
 116         }
 117         ddekit_thread_schedule();
 118 }
 119