kextd.tproj/PTLock.c

   1
   2 #include <PTLock.h>
   3 #include <stdlib.h>
   4 #include <mach/message.h>
   5
   6 #define mutex_t                pthread_mutex_t
   7 #define condition_t            pthread_cond_t
   8
   9 #define mutex_init(m)          pthread_mutex_init(m, NULL)
  10 #define mutex_free(m)          pthread_mutex_destroy(m)
  11 #define mutex_lock(m)          pthread_mutex_lock(m)
  12 #define mutex_unlock(m)        pthread_mutex_unlock(m)
  13
  14 #define condition_init(c)      pthread_cond_init(c, NULL)
  15 #define condition_free(c)      pthread_cond_destroy(c)
  16 #define condition_wait(c, m)   pthread_cond_wait(c, m)
  17 #define condition_signal(c)    pthread_cond_signal(c)
  18 #define condition_broadcast(c) pthread_cond_broadcast(c)
  19
  20
  21 typedef struct _PTLock {
  22     Boolean locked;
  23     pthread_mutex_t m;
  24     pthread_cond_t c;
  25 } PTLock;
  26
  27
  28 PTLockRef
  29 PTLockCreate(void)
  30 {
  31     PTLock * l;
  32
  33     l = (PTLock *)malloc(sizeof(PTLock));
  34     if ( !l )
  35         return NULL;
  36
  37     l->locked = false;
  38     mutex_init(&l->m);
  39     condition_init(&l->c);
  40
  41     return (PTLockRef)l;
  42 }
  43
  44 void
  45 PTLockFree(PTLockRef lock)
  46 {
  47     PTLock * l = (PTLock *)lock;
  48
  49     if ( !lock )
  50         return;
  51
  52     mutex_free(&l->m);
  53     condition_free(&l->c);
  54     free(lock);
  55 }
  56
  57 void
  58 PTLockTakeLock(PTLockRef lock)
  59 {
  60     PTLock * l = (PTLock *)lock;
  61
  62     mutex_lock(&l->m);
  63     while ( l->locked )
  64         condition_wait(&l->c, &l->m);
  65     l->locked = true;
  66     mutex_unlock(&l->m);
  67 }
  68
  69 void
  70 PTLockUnlock(PTLockRef lock)
  71 {
  72     PTLock * l = (PTLock *)lock;
  73
  74     mutex_lock(&l->m);
  75     l->locked = false;
  76     condition_signal(&l->c);
  77     mutex_unlock(&l->m);
  78 }
  79
  80 Boolean
  81 PTLockTryLock(PTLockRef lock)
  82 {
  83     PTLock * l = (PTLock *)lock;
  84
  85     Boolean ret;
  86
  87     mutex_lock(&l->m);
  88     ret = !l->locked;
  89     if ( ret )
  90         l->locked = true;
  91     mutex_unlock(&l->m);
  92
  93     return ret;
  94 }
  95