@@ -2964,6 +2964,7 @@ static void find_deltas(struct object_entry **list, unsigned *list_size,
struct thread_params {
pthread_t thread;
struct object_entry **list;
+ struct packing_region *regions;
unsigned list_size;
unsigned remaining;
int window;
@@ -3278,6 +3279,164 @@ static void find_deltas_by_region(struct object_entry *list,
stop_progress(&progress_state);
}
+static void *threaded_find_deltas_by_path(void *arg)
+{
+ struct thread_params *me = arg;
+
+ progress_lock();
+ while (me->remaining) {
+ while (me->remaining) {
+ progress_unlock();
+ find_deltas_for_region(to_pack.objects,
+ me->regions,
+ me->processed);
+ progress_lock();
+ me->remaining--;
+ me->regions++;
+ }
+
+ me->working = 0;
+ pthread_cond_signal(&progress_cond);
+ progress_unlock();
+
+ /*
+ * We must not set ->data_ready before we wait on the
+ * condition because the main thread may have set it to 1
+ * before we get here. In order to be sure that new
+ * work is available if we see 1 in ->data_ready, it
+ * was initialized to 0 before this thread was spawned
+ * and we reset it to 0 right away.
+ */
+ pthread_mutex_lock(&me->mutex);
+ while (!me->data_ready)
+ pthread_cond_wait(&me->cond, &me->mutex);
+ me->data_ready = 0;
+ pthread_mutex_unlock(&me->mutex);
+
+ progress_lock();
+ }
+ progress_unlock();
+ /* leave ->working 1 so that this doesn't get more work assigned */
+ return NULL;
+}
+
+static void ll_find_deltas_by_region(struct object_entry *list,
+ struct packing_region *regions,
+ uint32_t start, uint32_t nr)
+{
+ struct thread_params *p;
+ int i, ret, active_threads = 0;
+ unsigned int processed = 0;
+ uint32_t progress_nr;
+ init_threaded_search();
+
+ if (!nr)
+ return;
+
+ progress_nr = regions[nr - 1].start + regions[nr - 1].nr;
+ if (delta_search_threads <= 1) {
+ find_deltas_by_region(list, regions, start, nr);
+ cleanup_threaded_search();
+ return;
+ }
+
+ if (progress > pack_to_stdout)
+ fprintf_ln(stderr, _("Path-based delta compression using up to %d threads"),
+ delta_search_threads);
+ CALLOC_ARRAY(p, delta_search_threads);
+
+ if (progress)
+ progress_state = start_progress(the_repository,
+ _("Compressing objects by path"),
+ progress_nr);
+ /* Partition the work amongst work threads. */
+ for (i = 0; i < delta_search_threads; i++) {
+ unsigned sub_size = nr / (delta_search_threads - i);
+
+ p[i].window = window;
+ p[i].depth = depth;
+ p[i].processed = &processed;
+ p[i].working = 1;
+ p[i].data_ready = 0;
+
+ p[i].regions = regions;
+ p[i].list_size = sub_size;
+ p[i].remaining = sub_size;
+
+ regions += sub_size;
+ nr -= sub_size;
+ }
+
+ /* Start work threads. */
+ for (i = 0; i < delta_search_threads; i++) {
+ if (!p[i].list_size)
+ continue;
+ pthread_mutex_init(&p[i].mutex, NULL);
+ pthread_cond_init(&p[i].cond, NULL);
+ ret = pthread_create(&p[i].thread, NULL,
+ threaded_find_deltas_by_path, &p[i]);
+ if (ret)
+ die(_("unable to create thread: %s"), strerror(ret));
+ active_threads++;
+ }
+
+ /*
+ * Now let's wait for work completion. Each time a thread is done
+ * with its work, we steal half of the remaining work from the
+ * thread with the largest number of unprocessed objects and give
+ * it to that newly idle thread. This ensure good load balancing
+ * until the remaining object list segments are simply too short
+ * to be worth splitting anymore.
+ */
+ while (active_threads) {
+ struct thread_params *target = NULL;
+ struct thread_params *victim = NULL;
+ unsigned sub_size = 0;
+
+ progress_lock();
+ for (;;) {
+ for (i = 0; !target && i < delta_search_threads; i++)
+ if (!p[i].working)
+ target = &p[i];
+ if (target)
+ break;
+ pthread_cond_wait(&progress_cond, &progress_mutex);
+ }
+
+ for (i = 0; i < delta_search_threads; i++)
+ if (p[i].remaining > 2*window &&
+ (!victim || victim->remaining < p[i].remaining))
+ victim = &p[i];
+ if (victim) {
+ sub_size = victim->remaining / 2;
+ target->regions = victim->regions + victim->remaining - sub_size;
+ victim->list_size -= sub_size;
+ victim->remaining -= sub_size;
+ }
+ target->list_size = sub_size;
+ target->remaining = sub_size;
+ target->working = 1;
+ progress_unlock();
+
+ pthread_mutex_lock(&target->mutex);
+ target->data_ready = 1;
+ pthread_cond_signal(&target->cond);
+ pthread_mutex_unlock(&target->mutex);
+
+ if (!sub_size) {
+ pthread_join(target->thread, NULL);
+ pthread_cond_destroy(&target->cond);
+ pthread_mutex_destroy(&target->mutex);
+ active_threads--;
+ }
+ }
+ cleanup_threaded_search();
+ free(p);
+
+ display_progress(progress_state, progress_nr);
+ stop_progress(&progress_state);
+}
+
static void prepare_pack(int window, int depth)
{
struct object_entry **delta_list;
@@ -3303,8 +3462,8 @@ static void prepare_pack(int window, int depth)
return;
if (path_walk)
- find_deltas_by_region(to_pack.objects, to_pack.regions,
- 0, to_pack.nr_regions);
+ ll_find_deltas_by_region(to_pack.objects, to_pack.regions,
+ 0, to_pack.nr_regions);
ALLOC_ARRAY(delta_list, to_pack.nr_objects);
nr_deltas = n = 0;