[PATCH v3 1/2] pack-objects: move read mutex to packing_data struct
- From
Patrick Hogg <phogg@novamoon.net>
- Date
- Jan 24, 2019, 01:05 UTC
- Message-ID
- <20190124010521.28452-1-phogg@novamoon.net>
ac77d0c37 ("pack-objects: shrink size field in struct object_entry", 2018-04-14) added an extra usage of read_lock/read_unlock in the newly introduced oe_get_size_slow for thread safety in parallel calls to try_delta(). Unfortunately oe_get_size_slow is also used in serial code, some of which is called before the first invocation of ll_find_deltas. As such the read mutex is not guaranteed to be initialized.
Resolve this by moving the read mutex to packing_data and initializing it in prepare_packing_data which is initialized in cmd_pack_objects.
Signed-off-by: Patrick Hogg <phogg@novamoon.net> --- builtin/pack-objects.c | 7 ++----- pack-objects.c | 1 + pack-objects.h | 10 ++++++++++ 3 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index 411aefd68..506061b4c 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -1954,9 +1954,8 @@ static int delta_cacheable(unsigned long src_size, unsigned long trg_size, } /* Protect access to object database */ -static pthread_mutex_t read_mutex; -#define read_lock() pthread_mutex_lock(&read_mutex) -#define read_unlock() pthread_mutex_unlock(&read_mutex) +#define read_lock() packing_data_read_lock(&to_pack) +#define read_unlock() packing_data_read_unlock(&to_pack) /* Protect delta_cache_size */ static pthread_mutex_t cache_mutex; @@ -2381,7 +2380,6 @@ static pthread_cond_t progress_cond; */ static void init_threaded_search(void) { - init_recursive_mutex(&read_mutex); pthread_mutex_init(&cache_mutex, NULL); pthread_mutex_init(&progress_mutex, NULL); pthread_cond_init(&progress_cond, NULL); @@ -2392,7 +2390,6 @@ static void cleanup_threaded_search(void) { set_try_to_free_routine(old_try_to_free_routine); pthread_cond_destroy(&progress_cond); - pthread_mutex_destroy(&read_mutex); pthread_mutex_destroy(&cache_mutex); pthread_mutex_destroy(&progress_mutex); } diff --git a/pack-objects.c b/pack-objects.c index b6cdbb016..3554c43ac 100644 --- a/pack-objects.c +++ b/pack-objects.c @@ -150,6 +150,7 @@ void prepare_packing_data(struct packing_data *pdata) 1UL << OE_DELTA_SIZE_BITS); #ifndef NO_PTHREADS pthread_mutex_init(&pdata->lock, NULL); + init_recursive_mutex(&pdata->read_lock); #endif } diff --git a/pack-objects.h b/pack-objects.h index dc869f26c..0a038e3bc 100644 --- a/pack-objects.h +++ b/pack-objects.h @@ -146,6 +146,7 @@ struct packing_data { struct packed_git **in_pack; pthread_mutex_t lock; + pthread_mutex_t read_lock; /* * This list contains entries for bases which we know the other side @@ -174,6 +175,15 @@ static inline void packing_data_unlock(struct packing_data *pdata) pthread_mutex_unlock(&pdata->lock); } +static inline void packing_data_read_lock(struct packing_data *pdata) +{ + pthread_mutex_lock(&pdata->read_lock); +} +static inline void packing_data_read_unlock(struct packing_data *pdata) +{ + pthread_mutex_unlock(&pdata->read_lock); +} + struct object_entry *packlist_alloc(struct packing_data *pdata, const unsigned char *sha1, uint32_t index_pos);
-- 2.20.1.windows.1