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 #include "qemu/thread.h"
  10
  11 #include "vcard.h"
  12 #include "vreader.h"
  13 #include "vevent.h"
  14
  15 VEvent *
  16 vevent_new(VEventType type, VReader *reader, VCard *card)
  17 {
  18     VEvent *new_vevent;
  19
  20     new_vevent = (VEvent *)g_malloc(sizeof(VEvent));
  21     new_vevent->next = NULL;
  22     new_vevent->type = type;
  23     new_vevent->reader = vreader_reference(reader);
  24     new_vevent->card = vcard_reference(card);
  25
  26     return new_vevent;
  27 }
  28
  29 void
  30 vevent_delete(VEvent *vevent)
  31 {
  32     if (vevent == NULL) {
  33         return;
  34     }
  35     vreader_free(vevent->reader);
  36     vcard_free(vevent->card);
  37     g_free(vevent);
  38 }
  39
  40 /*
  41  * VEvent queue management
  42  */
  43
  44 static VEvent *vevent_queue_head;
  45 static VEvent *vevent_queue_tail;
  46 static QemuMutex vevent_queue_lock;
  47 static QemuCond vevent_queue_condition;
  48
  49 void vevent_queue_init(void)
  50 {
  51     qemu_mutex_init(&vevent_queue_lock);
  52     qemu_cond_init(&vevent_queue_condition);
  53     vevent_queue_head = vevent_queue_tail = NULL;
  54 }
  55
  56 void
  57 vevent_queue_vevent(VEvent *vevent)
  58 {
  59     vevent->next = NULL;
  60     qemu_mutex_lock(&vevent_queue_lock);
  61     if (vevent_queue_head) {
  62         assert(vevent_queue_tail);
  63         vevent_queue_tail->next = vevent;
  64     } else {
  65         vevent_queue_head = vevent;
  66     }
  67     vevent_queue_tail = vevent;
  68     qemu_cond_signal(&vevent_queue_condition);
  69     qemu_mutex_unlock(&vevent_queue_lock);
  70 }
  71
  72 /* must have lock */
  73 static VEvent *
  74 vevent_dequeue_vevent(void)
  75 {
  76     VEvent *vevent = NULL;
  77     if (vevent_queue_head) {
  78         vevent = vevent_queue_head;
  79         vevent_queue_head = vevent->next;
  80         vevent->next = NULL;
  81     }
  82     return vevent;
  83 }
  84
  85 VEvent *vevent_wait_next_vevent(void)
  86 {
  87     VEvent *vevent;
  88
  89     qemu_mutex_lock(&vevent_queue_lock);
  90     while ((vevent = vevent_dequeue_vevent()) == NULL) {
  91         qemu_cond_wait(&vevent_queue_condition, &vevent_queue_lock);
  92     }
  93     qemu_mutex_unlock(&vevent_queue_lock);
  94     return vevent;
  95 }
  96
  97 VEvent *vevent_get_next_vevent(void)
  98 {
  99     VEvent *vevent;
 100
 101     qemu_mutex_lock(&vevent_queue_lock);
 102     vevent = vevent_dequeue_vevent();
 103     qemu_mutex_unlock(&vevent_queue_lock);
 104     return vevent;
 105 }
 106