Merge branch 'mainstream'

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

diff --git a/lib/ovs-thread.c b/lib/ovs-thread.c
index 4d64b92..aa3ad15 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; \
@@ -126,11 +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;
@@ -146,6 +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_)
 {
@@ -168,18 +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");
     }
@@ -258,4 +309,82 @@ may_fork(void)
 {
     return !must_not_fork;
 }
+\f
+/* Parses /proc/cpuinfo for the total number of physical cores on this system
+ * across all CPU packages, not counting hyper-threads.
+ *
+ * Sets *n_cores to the total number of cores on this system, or 0 if the
+ * number cannot be determined. */
+static void
+parse_cpuinfo(long int *n_cores)
+{
+    static const char file_name[] = "/proc/cpuinfo";
+    char line[128];
+    uint64_t cpu = 0; /* Support up to 64 CPU packages on a single system. */
+    long int cores = 0;
+    FILE *stream;
+
+    stream = fopen(file_name, "r");
+    if (!stream) {
+        VLOG_DBG("%s: open failed (%s)", file_name, ovs_strerror(errno));
+        return;
+    }
+
+    while (fgets(line, sizeof line, stream)) {
+        unsigned int id;
+
+        /* Find the next CPU package. */
+        if (ovs_scan(line, "physical id%*[^:]: %u", &id)) {
+            if (id > 63) {
+                VLOG_WARN("Counted over 64 CPU packages on this system. "
+                          "Parsing %s for core count may be inaccurate.",
+                          file_name);
+                cores = 0;
+                break;
+            }
+
+            if (cpu & (1 << id)) {
+                /* We've already counted this package's cores. */
+                continue;
+            }
+            cpu |= 1 << id;
+
+            /* Find the number of cores for this package. */
+            while (fgets(line, sizeof line, stream)) {
+                int count;
+
+                if (ovs_scan(line, "cpu cores%*[^:]: %u", &count)) {
+                    cores += count;
+                    break;
+                }
+            }
+        }
+    }
+    fclose(stream);
+
+    *n_cores = cores;
+}
+
+/* Returns the total number of cores on this system, or 0 if the number cannot
+ * be determined.
+ *
+ * Tries not to count hyper-threads, but may be inaccurate - particularly on
+ * platforms that do not provide /proc/cpuinfo, but also if /proc/cpuinfo is
+ * formatted different to the layout that parse_cpuinfo() expects. */
+int
+count_cpu_cores(void)
+{
+    static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
+    static long int n_cores;
+
+    if (ovsthread_once_start(&once)) {
+        parse_cpuinfo(&n_cores);
+        if (!n_cores) {
+            n_cores = sysconf(_SC_NPROCESSORS_ONLN);
+        }
+        ovsthread_once_done(&once);
+    }
+
+    return n_cores > 0 ? n_cores : 0;
+}
 #endif