diff options
| -rw-r--r-- | builtin/index-pack.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/builtin/index-pack.c b/builtin/index-pack.c index 9e9eb4b74e..885fa93fd3 100644 --- a/builtin/index-pack.c +++ b/builtin/index-pack.c @@ -115,6 +115,10 @@ static pthread_mutex_t deepest_delta_mutex; #define deepest_delta_lock() lock_mutex(&deepest_delta_mutex) #define deepest_delta_unlock() unlock_mutex(&deepest_delta_mutex) +static pthread_mutex_t type_cas_mutex; +#define type_cas_lock() lock_mutex(&type_cas_mutex) +#define type_cas_unlock() unlock_mutex(&type_cas_mutex) + static pthread_key_t key; static inline void lock_mutex(pthread_mutex_t *mutex) @@ -137,6 +141,7 @@ static void init_thread(void) init_recursive_mutex(&read_mutex); pthread_mutex_init(&counter_mutex, NULL); pthread_mutex_init(&work_mutex, NULL); + pthread_mutex_init(&type_cas_mutex, NULL); if (show_stat) pthread_mutex_init(&deepest_delta_mutex, NULL); pthread_key_create(&key, NULL); @@ -152,6 +157,7 @@ static void cleanup_thread(void) pthread_mutex_destroy(&read_mutex); pthread_mutex_destroy(&counter_mutex); pthread_mutex_destroy(&work_mutex); + pthread_mutex_destroy(&type_cas_mutex); if (show_stat) pthread_mutex_destroy(&deepest_delta_mutex); pthread_key_delete(key); @@ -850,7 +856,6 @@ static void resolve_delta(struct object_entry *delta_obj, { void *base_data, *delta_data; - delta_obj->real_type = base->obj->real_type; if (show_stat) { delta_obj->delta_depth = base->obj->delta_depth + 1; deepest_delta_lock(); @@ -876,6 +881,26 @@ static void resolve_delta(struct object_entry *delta_obj, counter_unlock(); } +/* + * Standard boolean compare-and-swap: atomically check whether "*type" is + * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched + * and return false. + */ +static int compare_and_swap_type(enum object_type *type, + enum object_type want, + enum object_type set) +{ + enum object_type old; + + type_cas_lock(); + old = *type; + if (old == want) + *type = set; + type_cas_unlock(); + + return old == want; +} + static struct base_data *find_unresolved_deltas_1(struct base_data *base, struct base_data *prev_base) { @@ -903,7 +928,10 @@ static struct base_data *find_unresolved_deltas_1(struct base_data *base, struct object_entry *child = objects + deltas[base->ref_first].obj_no; struct base_data *result = alloc_base_data(); - assert(child->real_type == OBJ_REF_DELTA); + if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA, + base->obj->real_type)) + die("BUG: child->real_type != OBJ_REF_DELTA"); + resolve_delta(child, base, result); if (base->ref_first == base->ref_last && base->ofs_last == -1) free_base_data(base); @@ -917,6 +945,7 @@ static struct base_data *find_unresolved_deltas_1(struct base_data *base, struct base_data *result = alloc_base_data(); assert(child->real_type == OBJ_OFS_DELTA); + child->real_type = base->obj->real_type; resolve_delta(child, base, result); if (base->ofs_first == base->ofs_last) free_base_data(base); |