Revert barrier-based LSan threading race workaround
The extra "barrier" approach was too much code whose sole purpose was to work around a race that is not even ours (i.e. in LSan's teardown code). In preparation for queuing a solution taking a much-less-invasive approach, let's revert them.
Junio C Hamano committed
Jan 1, 2025 at 14:13 UTC
fc89d14c639faec779956b4e3cd873c07bd4327b
5 files changed
-39
Makefile
-7
@@ -141,10 +141,6 @@ include shared.mak
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#
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# Define NO_PTHREADS if you do not have or do not want to use Pthreads.
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#
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-# Define THREAD_BARRIER_PTHREAD if your system has pthread_barrier_t. Barrier
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-# support is optional and is only helpful when building with SANITIZE=leak, as
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-# it is used to eliminate some races in the leak-checker.
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-#
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# Define NO_PREAD if you have a problem with pread() system call (e.g.
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# cygwin1.dll before v1.5.22).
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#
@@ -2083,9 +2079,6 @@ ifdef NO_PTHREADS
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else
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BASIC_CFLAGS += $(PTHREAD_CFLAGS)
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EXTLIBS += $(PTHREAD_LIBS)
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- ifdef THREAD_BARRIER_PTHREAD
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- BASIC_CFLAGS += -DTHREAD_BARRIER_PTHREAD
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- endif
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endif
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ifdef HAVE_PATHS_H
builtin/grep.c
-8
@@ -101,9 +101,6 @@ static pthread_cond_t cond_write;
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/* Signalled when we are finished with everything. */
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static pthread_cond_t cond_result;
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-/* Synchronize the start of all threads */
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-static maybe_thread_barrier_t start_barrier;
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-
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static int skip_first_line;
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static void add_work(struct grep_opt *opt, struct grep_source *gs)
@@ -201,8 +198,6 @@ static void *run(void *arg)
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int hit = 0;
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struct grep_opt *opt = arg;
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- maybe_thread_barrier_wait(&start_barrier);
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-
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while (1) {
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struct work_item *w = get_work();
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if (!w)
@@ -234,7 +229,6 @@ static void start_threads(struct grep_opt *opt)
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pthread_cond_init(&cond_add, NULL);
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pthread_cond_init(&cond_write, NULL);
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pthread_cond_init(&cond_result, NULL);
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- maybe_thread_barrier_init(&start_barrier, NULL, num_threads + 1);
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grep_use_locks = 1;
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enable_obj_read_lock();
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@@ -254,7 +248,6 @@ static void start_threads(struct grep_opt *opt)
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die(_("grep: failed to create thread: %s"),
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strerror(err));
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}
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- maybe_thread_barrier_wait(&start_barrier);
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}
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static int wait_all(void)
@@ -291,7 +284,6 @@ static int wait_all(void)
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pthread_cond_destroy(&cond_add);
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pthread_cond_destroy(&cond_write);
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pthread_cond_destroy(&cond_result);
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- maybe_thread_barrier_destroy(&start_barrier);
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grep_use_locks = 0;
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disable_obj_read_lock();
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builtin/index-pack.c
-6
@@ -185,8 +185,6 @@ static pthread_mutex_t deepest_delta_mutex;
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static pthread_key_t key;
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-static maybe_thread_barrier_t start_barrier;
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-
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static inline void lock_mutex(pthread_mutex_t *mutex)
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{
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if (threads_active)
@@ -211,7 +209,6 @@ static void init_thread(void)
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if (show_stat)
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pthread_mutex_init(&deepest_delta_mutex, NULL);
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pthread_key_create(&key, NULL);
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- maybe_thread_barrier_init(&start_barrier, NULL, nr_threads);
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CALLOC_ARRAY(thread_data, nr_threads);
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for (i = 0; i < nr_threads; i++) {
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thread_data[i].pack_fd = xopen(curr_pack, O_RDONLY);
@@ -234,7 +231,6 @@ static void cleanup_thread(void)
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for (i = 0; i < nr_threads; i++)
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close(thread_data[i].pack_fd);
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pthread_key_delete(key);
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- maybe_thread_barrier_destroy(&start_barrier);
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free(thread_data);
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}
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@@ -1104,8 +1100,6 @@ static int compare_ref_delta_entry(const void *a, const void *b)
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static void *threaded_second_pass(void *data)
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{
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- if (threads_active)
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- maybe_thread_barrier_wait(&start_barrier);
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if (data)
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set_thread_data(data);
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for (;;) {
ci/lib.sh
-1
@@ -385,7 +385,6 @@ linux-musl)
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;;
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linux-leaks|linux-reftable-leaks)
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export SANITIZE=leak
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- export THREAD_BARRIER_PTHREAD=1
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;;
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linux-asan-ubsan)
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export SANITIZE=address,undefined
thread-utils.h
-17
@@ -53,22 +53,5 @@ int dummy_pthread_init(void *);
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int online_cpus(void);
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int init_recursive_mutex(pthread_mutex_t*);
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-#ifdef THREAD_BARRIER_PTHREAD
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-#define maybe_thread_barrier_t pthread_barrier_t
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-#define maybe_thread_barrier_init pthread_barrier_init
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-#define maybe_thread_barrier_wait pthread_barrier_wait
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-#define maybe_thread_barrier_destroy pthread_barrier_destroy
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-#else
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-#define maybe_thread_barrier_t int
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-static inline int maybe_thread_barrier_init(maybe_thread_barrier_t *b UNUSED,
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- void *attr UNUSED,
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- unsigned nr UNUSED)
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-{
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- errno = ENOSYS;
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- return -1;
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-}
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-#define maybe_thread_barrier_wait(barrier)
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-#define maybe_thread_barrier_destroy(barrier)
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-#endif
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#endif /* THREAD_COMPAT_H */