libcacard/event.c

   1 /*
   2  * event queue implementation.
   3  *
   4  * This code is licensed under the GNU LGPL, version 2.1 or later.
   5  * See the COPYING.LIB file in the top-level directory.
   6  */
   7
   8 #include "qemu-common.h"
   9
  10 #include "vcard.h"
  11 #include "vreader.h"
  12 #include "vevent.h"
  13
  14 VEvent *
  15 vevent_new(VEventType type, VReader *reader, VCard *card)
  16 {
  17     VEvent *new_vevent;
  18
  19     new_vevent = g_new(VEvent, 1);
  20     new_vevent->next = NULL;
  21     new_vevent->type = type;
  22     new_vevent->reader = vreader_reference(reader);
  23     new_vevent->card = vcard_reference(card);
  24
  25     return new_vevent;
  26 }
  27
  28 void
  29 vevent_delete(VEvent *vevent)
  30 {
  31     if (vevent == NULL) {
  32         return;
  33     }
  34     vreader_free(vevent->reader);
  35     vcard_free(vevent->card);
  36     g_free(vevent);
  37 }
  38
  39 /*
  40  * VEvent queue management
  41  */
  42
  43 static VEvent *vevent_queue_head;
  44 static VEvent *vevent_queue_tail;
  45 static CompatGMutex vevent_queue_lock;
  46 static CompatGCond vevent_queue_condition;
  47
  48 void vevent_queue_init(void)
  49 {
  50     vevent_queue_head = vevent_queue_tail = NULL;
  51 }
  52
  53 void
  54 vevent_queue_vevent(VEvent *vevent)
  55 {
  56     vevent->next = NULL;
  57     g_mutex_lock(&vevent_queue_lock);
  58     if (vevent_queue_head) {
  59         assert(vevent_queue_tail);
  60         vevent_queue_tail->next = vevent;
  61     } else {
  62         vevent_queue_head = vevent;
  63     }
  64     vevent_queue_tail = vevent;
  65     g_cond_signal(&vevent_queue_condition);
  66     g_mutex_unlock(&vevent_queue_lock);
  67 }
  68
  69 /* must have lock */
  70 static VEvent *
  71 vevent_dequeue_vevent(void)
  72 {
  73     VEvent *vevent = NULL;
  74     if (vevent_queue_head) {
  75         vevent = vevent_queue_head;
  76         vevent_queue_head = vevent->next;
  77         vevent->next = NULL;
  78     }
  79     return vevent;
  80 }
  81
  82 VEvent *vevent_wait_next_vevent(void)
  83 {
  84     VEvent *vevent;
  85
  86     g_mutex_lock(&vevent_queue_lock);
  87     while ((vevent = vevent_dequeue_vevent()) == NULL) {
  88         g_cond_wait(&vevent_queue_condition, &vevent_queue_lock);
  89     }
  90     g_mutex_unlock(&vevent_queue_lock);
  91     return vevent;
  92 }
  93
  94 VEvent *vevent_get_next_vevent(void)
  95 {
  96     VEvent *vevent;
  97
  98     g_mutex_lock(&vevent_queue_lock);
  99     vevent = vevent_dequeue_vevent();
 100     g_mutex_unlock(&vevent_queue_lock);
 101     return vevent;
 102 }
 103