diff options
| -rw-r--r-- | lib/ovs-thread.c | 61 | ||||
| -rw-r--r-- | lib/ovs-thread.h | 6 |
2 files changed, 53 insertions, 14 deletions
diff --git a/lib/ovs-thread.c b/lib/ovs-thread.c index b686e4548..805cba622 100644 --- a/lib/ovs-thread.c +++ b/lib/ovs-thread.c @@ -299,21 +299,53 @@ ovs_spin_init(const struct ovs_spin *spin) } #endif +struct ovs_barrier_impl { + uint32_t size; /* Number of threads to wait. */ + atomic_count count; /* Number of threads already hit the barrier. */ + struct seq *seq; + struct ovs_refcount refcnt; +}; + +static void +ovs_barrier_impl_ref(struct ovs_barrier_impl *impl) +{ + ovs_refcount_ref(&impl->refcnt); +} + +static void +ovs_barrier_impl_unref(struct ovs_barrier_impl *impl) +{ + if (ovs_refcount_unref(&impl->refcnt) == 1) { + seq_destroy(impl->seq); + free(impl); + } +} + /* Initializes the 'barrier'. 'size' is the number of threads * expected to hit the barrier. */ void ovs_barrier_init(struct ovs_barrier *barrier, uint32_t size) { - barrier->size = size; - atomic_count_init(&barrier->count, 0); - barrier->seq = seq_create(); + struct ovs_barrier_impl *impl; + + impl = xmalloc(sizeof *impl); + impl->size = size; + atomic_count_init(&impl->count, 0); + impl->seq = seq_create(); + ovs_refcount_init(&impl->refcnt); + + ovsrcu_set(&barrier->impl, impl); } /* Destroys the 'barrier'. */ void ovs_barrier_destroy(struct ovs_barrier *barrier) { - seq_destroy(barrier->seq); + struct ovs_barrier_impl *impl; + + impl = ovsrcu_get(struct ovs_barrier_impl *, &barrier->impl); + ovsrcu_set(&barrier->impl, NULL); + ovs_barrier_impl_unref(impl); } /* Makes the calling thread block on the 'barrier' until all @@ -325,23 +357,30 @@ ovs_barrier_destroy(struct ovs_barrier *barrier) void ovs_barrier_block(struct ovs_barrier *barrier) { - uint64_t seq = seq_read(barrier->seq); + struct ovs_barrier_impl *impl; uint32_t orig; + uint64_t seq; - orig = atomic_count_inc(&barrier->count); - if (orig + 1 == barrier->size) { - atomic_count_set(&barrier->count, 0); + impl = ovsrcu_get(struct ovs_barrier_impl *, &barrier->impl); + ovs_barrier_impl_ref(impl); + + seq = seq_read(impl->seq); + orig = atomic_count_inc(&impl->count); + if (orig + 1 == impl->size) { + atomic_count_set(&impl->count, 0); /* seq_change() serves as a release barrier against the other threads, * so the zeroed count is visible to them as they continue. */ - seq_change(barrier->seq); + seq_change(impl->seq); } else { /* To prevent thread from waking up by other event, * keeps waiting for the change of 'barrier->seq'. */ - while (seq == seq_read(barrier->seq)) { - seq_wait(barrier->seq, seq); + while (seq == seq_read(impl->seq)) { + seq_wait(impl->seq, seq); poll_block(); } } + + ovs_barrier_impl_unref(impl); } DEFINE_EXTERN_PER_THREAD_DATA(ovsthread_id, OVSTHREAD_ID_UNSET); diff --git a/lib/ovs-thread.h b/lib/ovs-thread.h index 7ee98bd4e..3b444ccdc 100644 --- a/lib/ovs-thread.h +++ b/lib/ovs-thread.h @@ -21,16 +21,16 @@ #include <stddef.h> #include <sys/types.h> #include "ovs-atomic.h" +#include "ovs-rcu.h" #include "openvswitch/thread.h" #include "util.h" struct seq; /* Poll-block()-able barrier similar to pthread_barrier_t. */ +struct ovs_barrier_impl; struct ovs_barrier { - uint32_t size; /* Number of threads to wait. */ - atomic_count count; /* Number of threads already hit the barrier. */ - struct seq *seq; + OVSRCU_TYPE(struct ovs_barrier_impl *) impl; }; /* Wrappers for pthread_mutexattr_*() that abort the process on any error. */ |