index-pack: protect deepest_delta in multithread code
deepest_delta is a global variable but is updated without protection in resolve_delta(), a multithreaded function. Add a new mutex for it, but only protect and update when it's actually used (i.e. show_stat is non-zero). Another variable that will not be updated is delta_depth in "struct object_entry" as it's only useful when show_stat is 1. Putting it in "if (show_stat)" makes it clearer. The local variable "stat" is renamed to "show_stat" after moving to global scope because the name "stat" conflicts with stat(2) syscall. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Nguyễn Thái Ngọc Duy committed
Mar 19, 2013 at 20:01 UTC
3aba2fddcbff6ba611c05eabeb4a8561c119275f
1 file changed
+23
-7
builtin/index-pack.c
+23
-7
@@ -78,6 +78,7 @@ static int nr_threads;
78
static int from_stdin;
79
static int strict;
80
static int verbose;
81
+static int show_stat;
82
83
static struct progress *progress;
84
@@ -108,6 +109,10 @@ static pthread_mutex_t work_mutex;
109
#define work_lock() lock_mutex(&work_mutex)
110
#define work_unlock() unlock_mutex(&work_mutex)
111
112
+static pthread_mutex_t deepest_delta_mutex;
113
+#define deepest_delta_lock() lock_mutex(&deepest_delta_mutex)
114
+#define deepest_delta_unlock() unlock_mutex(&deepest_delta_mutex)
115
+
116
static pthread_key_t key;
117
118
static inline void lock_mutex(pthread_mutex_t *mutex)
@@ -130,6 +135,8 @@ static void init_thread(void)
135
init_recursive_mutex(&read_mutex);
136
pthread_mutex_init(&counter_mutex, NULL);
137
pthread_mutex_init(&work_mutex, NULL);
138
+ if (show_stat)
139
+ pthread_mutex_init(&deepest_delta_mutex, NULL);
140
pthread_key_create(&key, NULL);
141
thread_data = xcalloc(nr_threads, sizeof(*thread_data));
142
threads_active = 1;
@@ -143,6 +150,8 @@ static void cleanup_thread(void)
150
pthread_mutex_destroy(&read_mutex);
151
pthread_mutex_destroy(&counter_mutex);
152
pthread_mutex_destroy(&work_mutex);
153
+ if (show_stat)
154
+ pthread_mutex_destroy(&deepest_delta_mutex);
155
pthread_key_delete(key);
156
free(thread_data);
157
}
@@ -158,6 +167,9 @@ static void cleanup_thread(void)
167
#define work_lock()
168
#define work_unlock()
169
170
+#define deepest_delta_lock()
171
+#define deepest_delta_unlock()
172
+
173
#endif
174
175
@@ -833,9 +845,13 @@ static void resolve_delta(struct object_entry *delta_obj,
845
void *base_data, *delta_data;
846
847
delta_obj->real_type = base->obj->real_type;
836
- delta_obj->delta_depth = base->obj->delta_depth + 1;
837
- if (deepest_delta < delta_obj->delta_depth)
838
- deepest_delta = delta_obj->delta_depth;
848
+ if (show_stat) {
849
+ delta_obj->delta_depth = base->obj->delta_depth + 1;
850
+ deepest_delta_lock();
851
+ if (deepest_delta < delta_obj->delta_depth)
852
+ deepest_delta = delta_obj->delta_depth;
853
+ deepest_delta_unlock();
854
+ }
855
delta_obj->base_object_no = base->obj - objects;
856
delta_data = get_data_from_pack(delta_obj);
857
base_data = get_base_data(base);
@@ -1461,7 +1477,7 @@ static void show_pack_info(int stat_only)
1477
1478
int cmd_index_pack(int argc, const char **argv, const char *prefix)
1479
{
1464
- int i, fix_thin_pack = 0, verify = 0, stat_only = 0, stat = 0;
1480
+ int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1481
const char *curr_pack, *curr_index;
1482
const char *index_name = NULL, *pack_name = NULL;
1483
const char *keep_name = NULL, *keep_msg = NULL;
@@ -1494,10 +1510,10 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
1510
verify = 1;
1511
} else if (!strcmp(arg, "--verify-stat")) {
1512
verify = 1;
1497
- stat = 1;
1513
+ show_stat = 1;
1514
} else if (!strcmp(arg, "--verify-stat-only")) {
1515
verify = 1;
1500
- stat = 1;
1516
+ show_stat = 1;
1517
stat_only = 1;
1518
} else if (!strcmp(arg, "--keep")) {
1519
keep_msg = "";
@@ -1605,7 +1621,7 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
1621
if (strict)
1622
check_objects();
1623
1608
- if (stat)
1624
+ if (show_stat)
1625
show_pack_info(stat_only);
1626
1627
idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));