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.

diff --git a/Makefile b/Makefile
index 2c6dad8a7513be819cdf5b4fe411533ea63aa8da..97e8385b6643b963c54affb3ae621fc93fad28b5 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -141,10 +141,6 @@ include shared.mak
 #
 # Define NO_PTHREADS if you do not have or do not want to use Pthreads.
 #
-# Define THREAD_BARRIER_PTHREAD if your system has pthread_barrier_t. Barrier
-# support is optional and is only helpful when building with SANITIZE=leak, as
-# it is used to eliminate some races in the leak-checker.
-#
 # Define NO_PREAD if you have a problem with pread() system call (e.g.
 # cygwin1.dll before v1.5.22).
 #
@@ -2083,9 +2079,6 @@ ifdef NO_PTHREADS
 else
        BASIC_CFLAGS += $(PTHREAD_CFLAGS)
        EXTLIBS += $(PTHREAD_LIBS)
-       ifdef THREAD_BARRIER_PTHREAD
-               BASIC_CFLAGS += -DTHREAD_BARRIER_PTHREAD
-       endif
 endif
 
 ifdef HAVE_PATHS_H

diff --git a/builtin/grep.c b/builtin/grep.c
index 61b2c27490980b1df556dde49926faba556ee64b..d00ee76f24cfdea8ac15e08f812aa5868906940c 100644 (file)
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -101,9 +101,6 @@ static pthread_cond_t cond_write;
 /* Signalled when we are finished with everything. */
 static pthread_cond_t cond_result;
 
-/* Synchronize the start of all threads */
-static maybe_thread_barrier_t start_barrier;
-
 static int skip_first_line;
 
 static void add_work(struct grep_opt *opt, struct grep_source *gs)
@@ -201,8 +198,6 @@ static void *run(void *arg)
        int hit = 0;
        struct grep_opt *opt = arg;
 
-       maybe_thread_barrier_wait(&start_barrier);
-
        while (1) {
                struct work_item *w = get_work();
                if (!w)
@@ -234,7 +229,6 @@ static void start_threads(struct grep_opt *opt)
        pthread_cond_init(&cond_add, NULL);
        pthread_cond_init(&cond_write, NULL);
        pthread_cond_init(&cond_result, NULL);
-       maybe_thread_barrier_init(&start_barrier, NULL, num_threads + 1);
        grep_use_locks = 1;
        enable_obj_read_lock();
 
@@ -254,7 +248,6 @@ static void start_threads(struct grep_opt *opt)
                        die(_("grep: failed to create thread: %s"),
                            strerror(err));
        }
-       maybe_thread_barrier_wait(&start_barrier);
 }
 
 static int wait_all(void)
@@ -291,7 +284,6 @@ static int wait_all(void)
        pthread_cond_destroy(&cond_add);
        pthread_cond_destroy(&cond_write);
        pthread_cond_destroy(&cond_result);
-       maybe_thread_barrier_destroy(&start_barrier);
        grep_use_locks = 0;
        disable_obj_read_lock();
 

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 27b120f26c7a689dc5e5f5deecfd79a52e54fcc0..0b62b2589f10f97aacab4614db158666850b78f6 100644 (file)
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -185,8 +185,6 @@ static pthread_mutex_t deepest_delta_mutex;
 
 static pthread_key_t key;
 
-static maybe_thread_barrier_t start_barrier;
-
 static inline void lock_mutex(pthread_mutex_t *mutex)
 {
        if (threads_active)
@@ -211,7 +209,6 @@ static void init_thread(void)
        if (show_stat)
                pthread_mutex_init(&deepest_delta_mutex, NULL);
        pthread_key_create(&key, NULL);
-       maybe_thread_barrier_init(&start_barrier, NULL, nr_threads);
        CALLOC_ARRAY(thread_data, nr_threads);
        for (i = 0; i < nr_threads; i++) {
                thread_data[i].pack_fd = xopen(curr_pack, O_RDONLY);
@@ -234,7 +231,6 @@ static void cleanup_thread(void)
        for (i = 0; i < nr_threads; i++)
                close(thread_data[i].pack_fd);
        pthread_key_delete(key);
-       maybe_thread_barrier_destroy(&start_barrier);
        free(thread_data);
 }
 
@@ -1104,8 +1100,6 @@ static int compare_ref_delta_entry(const void *a, const void *b)
 
 static void *threaded_second_pass(void *data)
 {
-       if (threads_active)
-               maybe_thread_barrier_wait(&start_barrier);
        if (data)
                set_thread_data(data);
        for (;;) {

diff --git a/ci/lib.sh b/ci/lib.sh
index 6a1267fbcb3c8bc180a363ef3b1618e6dbfccca5..8885ee3c3f86c62e8783d27756b8779bd491e7e6 100755 (executable)
--- a/ci/lib.sh
+++ b/ci/lib.sh
@@ -385,7 +385,6 @@ linux-musl)
        ;;
 linux-leaks|linux-reftable-leaks)
        export SANITIZE=leak
-       export THREAD_BARRIER_PTHREAD=1
        ;;
 linux-asan-ubsan)
        export SANITIZE=address,undefined

diff --git a/thread-utils.h b/thread-utils.h
index 3df5be9916de376cda4ee837393de4e663649db4..4961487ed914f4fea817df26904109bb05f2a2c5 100644 (file)
--- a/thread-utils.h
+++ b/thread-utils.h
@@ -53,22 +53,5 @@ int dummy_pthread_init(void *);
 int online_cpus(void);
 int init_recursive_mutex(pthread_mutex_t*);
 
-#ifdef THREAD_BARRIER_PTHREAD
-#define maybe_thread_barrier_t pthread_barrier_t
-#define maybe_thread_barrier_init pthread_barrier_init
-#define maybe_thread_barrier_wait pthread_barrier_wait
-#define maybe_thread_barrier_destroy pthread_barrier_destroy
-#else
-#define maybe_thread_barrier_t int
-static inline int maybe_thread_barrier_init(maybe_thread_barrier_t *b UNUSED,
-                                           void *attr UNUSED,
-                                           unsigned nr UNUSED)
-{
-       errno = ENOSYS;
-       return -1;
-}
-#define maybe_thread_barrier_wait(barrier)
-#define maybe_thread_barrier_destroy(barrier)
-#endif
 
 #endif /* THREAD_COMPAT_H */