lib: Refactor gathering CPU core count

[sliver-openvswitch.git] / lib / ovs-thread.c

diff --git a/lib/ovs-thread.c b/lib/ovs-thread.c
index c8b2c15..02436e5 100644 (file)
--- a/lib/ovs-thread.c
+++ b/lib/ovs-thread.c
@@ -47,6 +47,7 @@ static bool multithreaded;
     void \
     ovs_##TYPE##_##FUN##_at(const struct ovs_##TYPE *l_, \
                             const char *where) \
+        OVS_NO_THREAD_SAFETY_ANALYSIS \
     { \
         struct ovs_##TYPE *l = CONST_CAST(struct ovs_##TYPE *, l_); \
         int error = pthread_##TYPE##_##FUN(&l->lock); \
@@ -63,6 +64,7 @@ LOCK_FUNCTION(rwlock, wrlock);
     int \
     ovs_##TYPE##_##FUN##_at(const struct ovs_##TYPE *l_, \
                             const char *where) \
+        OVS_NO_THREAD_SAFETY_ANALYSIS \
     { \
         struct ovs_##TYPE *l = CONST_CAST(struct ovs_##TYPE *, l_); \
         int error = pthread_##TYPE##_##FUN(&l->lock); \
@@ -81,6 +83,7 @@ TRY_LOCK_FUNCTION(rwlock, trywrlock);
 #define UNLOCK_FUNCTION(TYPE, FUN) \
     void \
     ovs_##TYPE##_##FUN(const struct ovs_##TYPE *l_) \
+        OVS_NO_THREAD_SAFETY_ANALYSIS \
     { \
         struct ovs_##TYPE *l = CONST_CAST(struct ovs_##TYPE *, l_); \
         int error; \
@@ -114,6 +117,8 @@ UNLOCK_FUNCTION(rwlock, destroy);
         }                                               \
     }
 
+XPTHREAD_FUNC1(pthread_mutex_lock, pthread_mutex_t *);
+XPTHREAD_FUNC1(pthread_mutex_unlock, pthread_mutex_t *);
 XPTHREAD_FUNC1(pthread_mutexattr_init, pthread_mutexattr_t *);
 XPTHREAD_FUNC1(pthread_mutexattr_destroy, pthread_mutexattr_t *);
 XPTHREAD_FUNC2(pthread_mutexattr_settype, pthread_mutexattr_t *, int);
@@ -124,11 +129,14 @@ XPTHREAD_FUNC1(pthread_cond_destroy, pthread_cond_t *);
 XPTHREAD_FUNC1(pthread_cond_signal, pthread_cond_t *);
 XPTHREAD_FUNC1(pthread_cond_broadcast, pthread_cond_t *);
 
+XPTHREAD_FUNC2(pthread_join, pthread_t, void **);
+
 typedef void destructor_func(void *);
 XPTHREAD_FUNC2(pthread_key_create, pthread_key_t *, destructor_func *);
+XPTHREAD_FUNC2(pthread_setspecific, pthread_key_t, const void *);
 
-void
-ovs_mutex_init(const struct ovs_mutex *l_, int type)
+static void
+ovs_mutex_init__(const struct ovs_mutex *l_, int type)
 {
     struct ovs_mutex *l = CONST_CAST(struct ovs_mutex *, l_);
     pthread_mutexattr_t attr;
@@ -144,6 +152,20 @@ ovs_mutex_init(const struct ovs_mutex *l_, int type)
     xpthread_mutexattr_destroy(&attr);
 }
 
+/* Initializes 'mutex' as a normal (non-recursive) mutex. */
+void
+ovs_mutex_init(const struct ovs_mutex *mutex)
+{
+    ovs_mutex_init__(mutex, PTHREAD_MUTEX_ERRORCHECK);
+}
+
+/* Initializes 'mutex' as a recursive mutex. */
+void
+ovs_mutex_init_recursive(const struct ovs_mutex *mutex)
+{
+    ovs_mutex_init__(mutex, PTHREAD_MUTEX_RECURSIVE);
+}
+
 void
 ovs_rwlock_init(const struct ovs_rwlock *l_)
 {
@@ -166,18 +188,49 @@ ovs_mutex_cond_wait(pthread_cond_t *cond, const struct ovs_mutex *mutex_)
         ovs_abort(error, "pthread_cond_wait failed");
     }
 }
+\f
+DEFINE_EXTERN_PER_THREAD_DATA(ovsthread_id, 0);
+
+struct ovsthread_aux {
+    void *(*start)(void *);
+    void *arg;
+};
+
+static void *
+ovsthread_wrapper(void *aux_)
+{
+    static atomic_uint next_id = ATOMIC_VAR_INIT(1);
+
+    struct ovsthread_aux *auxp = aux_;
+    struct ovsthread_aux aux;
+    unsigned int id;
+
+    atomic_add(&next_id, 1, &id);
+    *ovsthread_id_get() = id;
+
+    aux = *auxp;
+    free(auxp);
+
+    return aux.start(aux.arg);
+}
 
 void
 xpthread_create(pthread_t *threadp, pthread_attr_t *attr,
                 void *(*start)(void *), void *arg)
 {
+    struct ovsthread_aux *aux;
     pthread_t thread;
     int error;
 
     forbid_forking("multiple threads exist");
     multithreaded = true;
 
-    error = pthread_create(threadp ? threadp : &thread, attr, start, arg);
+    aux = xmalloc(sizeof *aux);
+    aux->start = start;
+    aux->arg = arg;
+
+    error = pthread_create(threadp ? threadp : &thread, attr,
+                           ovsthread_wrapper, aux);
     if (error) {
         ovs_abort(error, "pthread_create failed");
     }
@@ -256,4 +309,14 @@ may_fork(void)
 {
     return !must_not_fork;
 }
+\f
+/* Returns the total number of cores on this system, or 0 if the number cannot
+ * be determined. */
+unsigned int
+count_cpu_cores(void)
+{
+    long int n_cores = sysconf(_SC_NPROCESSORS_ONLN);
+
+    return n_cores > 0 ? n_cores : 0;
+}
 #endif