Kannel: Open Source WAP and SMS gateway  $Revision: 5037 $
semaphore.c
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56 
57 /*
58  * semaphore.c - implementation of semaphores
59  *
60  * Lars Wirzenius
61  * Alexander Malysh <a.malysh@centrium.de>, 2004
62  */
63 
64 
65 #include "gwlib/gwlib.h"
66 
67 #ifdef HAVE_SEMAPHORE
68 #include <semaphore.h>
69 #include <errno.h>
70 #endif
71 
72 struct Semaphore {
73 #ifdef HAVE_SEMAPHORE
74  sem_t sem;
75 #else
77 #endif
78 };
79 
80 
82 {
83  Semaphore *semaphore;
84 #ifndef HAVE_SEMAPHORE
85  static char item;
86 #endif
87 
88  semaphore = gw_malloc(sizeof(*semaphore));
89 
90 #ifdef HAVE_SEMAPHORE
91  if (sem_init(&semaphore->sem, 0, (unsigned int) n) != 0)
92  panic(errno, "Could not initialize semaphore.");
93 #else
94  semaphore->list = gwlist_create();
95  gwlist_add_producer(semaphore->list);
96  while (n-- > 0)
97  gwlist_produce(semaphore->list, &item);
98 #endif
99 
100  return semaphore;
101 }
102 
103 
104 void semaphore_destroy(Semaphore *semaphore)
105 {
106  if (semaphore != NULL) {
107 #ifdef HAVE_SEMAPHORE
108  if (sem_destroy(&semaphore->sem) != 0)
109  panic(errno, "Destroying semaphore while some threads are waiting.");
110 #else
111  gwlist_destroy(semaphore->list, NULL);
112 #endif
113  gw_free(semaphore);
114  }
115 }
116 
117 
118 void semaphore_up(Semaphore *semaphore)
119 {
120 #ifndef HAVE_SEMAPHORE
121  static char item;
122  gw_assert(semaphore != NULL);
123  gwlist_produce(semaphore->list, &item);
124 #else
125  gw_assert(semaphore != NULL);
126  if (sem_post(&semaphore->sem) != 0)
127  error(errno, "Value for semaphore is out of range.");
128 #endif
129 }
130 
131 
132 void semaphore_down(Semaphore *semaphore)
133 {
134  gw_assert(semaphore != NULL);
135 #ifdef HAVE_SEMAPHORE
136  sem_wait(&semaphore->sem);
137 #else
138  gwlist_consume(semaphore->list);
139 #endif
140 }
141 
142 
144 {
145  gw_assert(semaphore != NULL);
146 #ifdef HAVE_SEMAPHORE
147  {
148  int val;
149  if (sem_getvalue(&semaphore->sem, &val) != 0)
150  panic(errno, "Could not get semaphore value.");
151  return val;
152  }
153 #else
154  return gwlist_len(semaphore->list);
155 #endif
156 }
157 
void error(int err, const char *fmt,...)
Definition: log.c:612
void semaphore_up(Semaphore *semaphore)
Definition: semaphore.c:118
Semaphore * semaphore_create(long n)
Definition: semaphore.c:81
void gwlist_produce(List *list, void *item)
Definition: list.c:411
long gwlist_len(List *list)
Definition: list.c:166
void semaphore_down(Semaphore *semaphore)
Definition: semaphore.c:132
long semaphore_getvalue(Semaphore *semaphore)
Definition: semaphore.c:143
void semaphore_destroy(Semaphore *semaphore)
Definition: semaphore.c:104
List * list
Definition: semaphore.c:76
gw_assert(wtls_machine->packet_to_send!=NULL)
void * gwlist_consume(List *list)
Definition: list.c:427
#define panic
Definition: log.h:87
#define gwlist_create()
Definition: list.h:136
void gwlist_add_producer(List *list)
Definition: list.c:383
Definition: list.c:102
void gwlist_destroy(List *list, gwlist_item_destructor_t *destructor)
Definition: list.c:145
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