/*
- * Copyright (c) 2013 Nicira, Inc.
+ * Copyright (c) 2013, 2014 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <unistd.h>
#include "compiler.h"
#include "hash.h"
+#include "ovs-rcu.h"
#include "poll-loop.h"
#include "socket-util.h"
#include "util.h"
ovs_abort(error, "%s failed", #FUNCTION); \
} \
}
+#define XPTHREAD_FUNC3(FUNCTION, PARAM1, PARAM2, PARAM3)\
+ void \
+ x##FUNCTION(PARAM1 arg1, PARAM2 arg2, PARAM3 arg3) \
+ { \
+ int error = FUNCTION(arg1, arg2, arg3); \
+ if (OVS_UNLIKELY(error)) { \
+ ovs_abort(error, "%s failed", #FUNCTION); \
+ } \
+ }
XPTHREAD_FUNC1(pthread_mutex_lock, pthread_mutex_t *);
XPTHREAD_FUNC1(pthread_mutex_unlock, pthread_mutex_t *);
XPTHREAD_FUNC2(pthread_mutexattr_settype, pthread_mutexattr_t *, int);
XPTHREAD_FUNC2(pthread_mutexattr_gettype, pthread_mutexattr_t *, int *);
+XPTHREAD_FUNC1(pthread_rwlockattr_init, pthread_rwlockattr_t *);
+XPTHREAD_FUNC1(pthread_rwlockattr_destroy, pthread_rwlockattr_t *);
+#ifdef PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
+XPTHREAD_FUNC2(pthread_rwlockattr_setkind_np, pthread_rwlockattr_t *, int);
+#endif
+
XPTHREAD_FUNC2(pthread_cond_init, pthread_cond_t *, pthread_condattr_t *);
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_FUNC3(pthread_barrier_init, pthread_barrier_t *,
+ pthread_barrierattr_t *, unsigned int);
+XPTHREAD_FUNC1(pthread_barrier_destroy, pthread_barrier_t *);
+
XPTHREAD_FUNC2(pthread_join, pthread_t, void **);
typedef void destructor_func(void *);
XPTHREAD_FUNC2(pthread_key_create, pthread_key_t *, destructor_func *);
+XPTHREAD_FUNC1(pthread_key_delete, pthread_key_t);
XPTHREAD_FUNC2(pthread_setspecific, pthread_key_t, const void *);
static void
ovs_mutex_init__(mutex, PTHREAD_MUTEX_RECURSIVE);
}
+/* Initializes 'mutex' as a recursive mutex. */
+void
+ovs_mutex_init_adaptive(const struct ovs_mutex *mutex)
+{
+#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
+ ovs_mutex_init__(mutex, PTHREAD_MUTEX_ADAPTIVE_NP);
+#else
+ ovs_mutex_init(mutex);
+#endif
+}
+
void
ovs_rwlock_init(const struct ovs_rwlock *l_)
{
struct ovs_rwlock *l = CONST_CAST(struct ovs_rwlock *, l_);
+ pthread_rwlockattr_t attr;
int error;
l->where = NULL;
+
+ xpthread_rwlockattr_init(&attr);
+#ifdef PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
+ xpthread_rwlockattr_setkind_np(
+ &attr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
+#endif
error = pthread_rwlock_init(&l->lock, NULL);
if (OVS_UNLIKELY(error)) {
ovs_abort(error, "pthread_rwlock_init failed");
}
+ xpthread_rwlockattr_destroy(&attr);
}
void
ovs_mutex_cond_wait(pthread_cond_t *cond, const struct ovs_mutex *mutex_)
{
struct ovs_mutex *mutex = CONST_CAST(struct ovs_mutex *, mutex_);
- int error = pthread_cond_wait(cond, &mutex->lock);
+ int error;
+
+ ovsrcu_quiesce_start();
+ error = pthread_cond_wait(cond, &mutex->lock);
+ ovsrcu_quiesce_end();
+
if (OVS_UNLIKELY(error)) {
ovs_abort(error, "pthread_cond_wait failed");
}
}
+
+int
+xpthread_barrier_wait(pthread_barrier_t *barrier)
+{
+ int error;
+
+ error = pthread_barrier_wait(barrier);
+ if (error && OVS_UNLIKELY(error != PTHREAD_BARRIER_SERIAL_THREAD)) {
+ ovs_abort(error, "pthread_barrier_wait failed");
+ }
+
+ return error;
+}
\f
DEFINE_EXTERN_PER_THREAD_DATA(ovsthread_id, 0);
aux = *auxp;
free(auxp);
+ ovsrcu_quiesce_end();
return aux.start(aux.arg);
}
forbid_forking("multiple threads exist");
multithreaded = true;
+ ovsrcu_quiesce_end();
aux = xmalloc(sizeof *aux);
aux->start = start;
ovs_mutex_unlock(&once->mutex);
}
\f
+bool
+single_threaded(void)
+{
+ return !multithreaded;
+}
+
/* Asserts that the process has not yet created any threads (beyond the initial
* thread).
*
}
}
+#ifndef _WIN32
/* Forks the current process (checking that this is allowed). Aborts with
* VLOG_FATAL if fork() returns an error, and otherwise returns the value
* returned by fork().
}
return pid;
}
+#endif
/* Notes that the process must not call fork() from now on, for the specified
* 'reason'. (The process may still fork() if it execs itself immediately
return !must_not_fork;
}
\f
-/* ovsthread_counter.
- *
- * We implement the counter as an array of N_COUNTERS individual counters, each
- * with its own lock. Each thread uses one of the counters chosen based on a
- * hash of the thread's ID, the idea being that, statistically, different
- * threads will tend to use different counters and therefore avoid
- * interfering with each other.
- *
- * Undoubtedly, better implementations are possible. */
-
-/* Basic counter structure. */
-struct ovsthread_counter__ {
- struct ovs_mutex mutex;
- unsigned long long int value;
-};
-
-/* Pad the basic counter structure to 64 bytes to avoid cache line
- * interference. */
-struct ovsthread_counter {
- struct ovsthread_counter__ c;
- char pad[ROUND_UP(sizeof(struct ovsthread_counter__), 64)
- - sizeof(struct ovsthread_counter__)];
-};
+/* ovsthread_stats. */
-#define N_COUNTERS 16
-
-struct ovsthread_counter *
-ovsthread_counter_create(void)
+void
+ovsthread_stats_init(struct ovsthread_stats *stats)
{
- struct ovsthread_counter *c;
int i;
- c = xmalloc(N_COUNTERS * sizeof *c);
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_init(&c[i].c.mutex);
- c[i].c.value = 0;
+ ovs_mutex_init(&stats->mutex);
+ for (i = 0; i < ARRAY_SIZE(stats->buckets); i++) {
+ stats->buckets[i] = NULL;
}
- return c;
}
void
-ovsthread_counter_destroy(struct ovsthread_counter *c)
+ovsthread_stats_destroy(struct ovsthread_stats *stats)
{
- if (c) {
- int i;
-
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_destroy(&c[i].c.mutex);
- }
- free(c);
- }
+ ovs_mutex_destroy(&stats->mutex);
}
-void
-ovsthread_counter_inc(struct ovsthread_counter *c, unsigned long long int n)
+void *
+ovsthread_stats_bucket_get(struct ovsthread_stats *stats,
+ void *(*new_bucket)(void))
{
- c = &c[hash_int(ovsthread_id_self(), 0) % N_COUNTERS];
-
- ovs_mutex_lock(&c->c.mutex);
- c->c.value += n;
- ovs_mutex_unlock(&c->c.mutex);
+ unsigned int idx = ovsthread_id_self() & (ARRAY_SIZE(stats->buckets) - 1);
+ void *bucket = stats->buckets[idx];
+ if (!bucket) {
+ ovs_mutex_lock(&stats->mutex);
+ bucket = stats->buckets[idx];
+ if (!bucket) {
+ bucket = stats->buckets[idx] = new_bucket();
+ }
+ ovs_mutex_unlock(&stats->mutex);
+ }
+ return bucket;
}
-unsigned long long int
-ovsthread_counter_read(const struct ovsthread_counter *c)
+size_t
+ovs_thread_stats_next_bucket(const struct ovsthread_stats *stats, size_t i)
{
- unsigned long long int sum;
- int i;
-
- sum = 0;
- for (i = 0; i < N_COUNTERS; i++) {
- ovs_mutex_lock(&c[i].c.mutex);
- sum += c[i].c.value;
- ovs_mutex_unlock(&c[i].c.mutex);
+ for (; i < ARRAY_SIZE(stats->buckets); i++) {
+ if (stats->buckets[i]) {
+ break;
+ }
}
- return sum;
+ return i;
}
+
\f
/* Parses /proc/cpuinfo for the total number of physical cores on this system
* across all CPU packages, not counting hyper-threads.
static long int n_cores;
if (ovsthread_once_start(&once)) {
+#ifndef _WIN32
parse_cpuinfo(&n_cores);
if (!n_cores) {
n_cores = sysconf(_SC_NPROCESSORS_ONLN);
}
+#else
+ SYSTEM_INFO sysinfo;
+ GetSystemInfo(&sysinfo);
+ n_cores = sysinfo.dwNumberOfProcessors;
+#endif
ovsthread_once_done(&once);
}
return n_cores > 0 ? n_cores : 0;
}
+\f
+/* ovsthread_key. */
+
+#define L1_SIZE 1024
+#define L2_SIZE 1024
+#define MAX_KEYS (L1_SIZE * L2_SIZE)
+
+/* A piece of thread-specific data. */
+struct ovsthread_key {
+ struct list list_node; /* In 'inuse_keys' or 'free_keys'. */
+ void (*destructor)(void *); /* Called at thread exit. */
+
+ /* Indexes into the per-thread array in struct ovsthread_key_slots.
+ * This key's data is stored in p1[index / L2_SIZE][index % L2_SIZE]. */
+ unsigned int index;
+};
+
+/* Per-thread data structure. */
+struct ovsthread_key_slots {
+ struct list list_node; /* In 'slots_list'. */
+ void **p1[L1_SIZE];
+};
+
+/* Contains "struct ovsthread_key_slots *". */
+static pthread_key_t tsd_key;
+
+/* Guards data structures below. */
+static struct ovs_mutex key_mutex = OVS_MUTEX_INITIALIZER;
+
+/* 'inuse_keys' holds "struct ovsthread_key"s that have been created and not
+ * yet destroyed.
+ *
+ * 'free_keys' holds "struct ovsthread_key"s that have been deleted and are
+ * ready for reuse. (We keep them around only to be able to easily locate
+ * free indexes.)
+ *
+ * Together, 'inuse_keys' and 'free_keys' hold an ovsthread_key for every index
+ * from 0 to n_keys - 1, inclusive. */
+static struct list inuse_keys OVS_GUARDED_BY(key_mutex)
+ = LIST_INITIALIZER(&inuse_keys);
+static struct list free_keys OVS_GUARDED_BY(key_mutex)
+ = LIST_INITIALIZER(&free_keys);
+static unsigned int n_keys OVS_GUARDED_BY(key_mutex);
+
+/* All existing struct ovsthread_key_slots. */
+static struct list slots_list OVS_GUARDED_BY(key_mutex)
+ = LIST_INITIALIZER(&slots_list);
+
+static void *
+clear_slot(struct ovsthread_key_slots *slots, unsigned int index)
+{
+ void **p2 = slots->p1[index / L2_SIZE];
+ if (p2) {
+ void **valuep = &p2[index % L2_SIZE];
+ void *value = *valuep;
+ *valuep = NULL;
+ return value;
+ } else {
+ return NULL;
+ }
+}
+
+static void
+ovsthread_key_destruct__(void *slots_)
+{
+ struct ovsthread_key_slots *slots = slots_;
+ struct ovsthread_key *key;
+ unsigned int n;
+ int i;
+
+ ovs_mutex_lock(&key_mutex);
+ list_remove(&slots->list_node);
+ LIST_FOR_EACH (key, list_node, &inuse_keys) {
+ void *value = clear_slot(slots, key->index);
+ if (value && key->destructor) {
+ key->destructor(value);
+ }
+ }
+ n = n_keys;
+ ovs_mutex_unlock(&key_mutex);
+
+ for (i = 0; i < n / L2_SIZE; i++) {
+ free(slots->p1[i]);
+ }
+ free(slots);
+}
+
+/* Initializes '*keyp' as a thread-specific data key. The data items are
+ * initially null in all threads.
+ *
+ * If a thread exits with non-null data, then 'destructor', if nonnull, will be
+ * called passing the final data value as its argument. 'destructor' must not
+ * call any thread-specific data functions in this API.
+ *
+ * This function is similar to xpthread_key_create(). */
+void
+ovsthread_key_create(ovsthread_key_t *keyp, void (*destructor)(void *))
+{
+ static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
+ struct ovsthread_key *key;
+
+ if (ovsthread_once_start(&once)) {
+ xpthread_key_create(&tsd_key, ovsthread_key_destruct__);
+ ovsthread_once_done(&once);
+ }
+
+ ovs_mutex_lock(&key_mutex);
+ if (list_is_empty(&free_keys)) {
+ key = xmalloc(sizeof *key);
+ key->index = n_keys++;
+ if (key->index >= MAX_KEYS) {
+ abort();
+ }
+ } else {
+ key = CONTAINER_OF(list_pop_back(&free_keys),
+ struct ovsthread_key, list_node);
+ }
+ list_push_back(&inuse_keys, &key->list_node);
+ key->destructor = destructor;
+ ovs_mutex_unlock(&key_mutex);
+
+ *keyp = key;
+}
+
+/* Frees 'key'. The destructor supplied to ovsthread_key_create(), if any, is
+ * not called.
+ *
+ * This function is similar to xpthread_key_delete(). */
+void
+ovsthread_key_delete(ovsthread_key_t key)
+{
+ struct ovsthread_key_slots *slots;
+
+ ovs_mutex_lock(&key_mutex);
+
+ /* Move 'key' from 'inuse_keys' to 'free_keys'. */
+ list_remove(&key->list_node);
+ list_push_back(&free_keys, &key->list_node);
+
+ /* Clear this slot in all threads. */
+ LIST_FOR_EACH (slots, list_node, &slots_list) {
+ clear_slot(slots, key->index);
+ }
+
+ ovs_mutex_unlock(&key_mutex);
+}
+
+static void **
+ovsthread_key_lookup__(const struct ovsthread_key *key)
+{
+ struct ovsthread_key_slots *slots;
+ void **p2;
+
+ slots = pthread_getspecific(tsd_key);
+ if (!slots) {
+ slots = xzalloc(sizeof *slots);
+
+ ovs_mutex_lock(&key_mutex);
+ pthread_setspecific(tsd_key, slots);
+ list_push_back(&slots_list, &slots->list_node);
+ ovs_mutex_unlock(&key_mutex);
+ }
+
+ p2 = slots->p1[key->index / L2_SIZE];
+ if (!p2) {
+ p2 = xzalloc(L2_SIZE * sizeof *p2);
+ slots->p1[key->index / L2_SIZE] = p2;
+ }
+
+ return &p2[key->index % L2_SIZE];
+}
+
+/* Sets the value of thread-specific data item 'key', in the current thread, to
+ * 'value'.
+ *
+ * This function is similar to pthread_setspecific(). */
+void
+ovsthread_setspecific(ovsthread_key_t key, const void *value)
+{
+ *ovsthread_key_lookup__(key) = CONST_CAST(void *, value);
+}
+
+/* Returns the value of thread-specific data item 'key' in the current thread.
+ *
+ * This function is similar to pthread_getspecific(). */
+void *
+ovsthread_getspecific(ovsthread_key_t key)
+{
+ return *ovsthread_key_lookup__(key);
+}
#endif