diff options
Diffstat (limited to 'src/background_thread.c')
| -rw-r--r-- | src/background_thread.c | 62 |
1 files changed, 52 insertions, 10 deletions
diff --git a/src/background_thread.c b/src/background_thread.c index a7403b8..eb30eb5 100644 --- a/src/background_thread.c +++ b/src/background_thread.c @@ -20,6 +20,9 @@ size_t n_background_threads; /* Thread info per-index. */ background_thread_info_t *background_thread_info; +/* False if no necessary runtime support. */ +bool can_enable_background_thread; + /******************************************************************************/ #ifdef JEMALLOC_PTHREAD_CREATE_WRAPPER @@ -313,7 +316,7 @@ background_threads_disable_single(tsd_t *tsd, background_thread_info_t *info) { &background_thread_lock); } - pre_reentrancy(tsd); + pre_reentrancy(tsd, NULL); malloc_mutex_lock(tsd_tsdn(tsd), &info->mtx); bool has_thread; assert(info->state != background_thread_paused); @@ -344,6 +347,38 @@ background_threads_disable_single(tsd_t *tsd, background_thread_info_t *info) { static void *background_thread_entry(void *ind_arg); +static int +background_thread_create_signals_masked(pthread_t *thread, + const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg) { + /* + * Mask signals during thread creation so that the thread inherits + * an empty signal set. + */ + sigset_t set; + sigfillset(&set); + sigset_t oldset; + int mask_err = pthread_sigmask(SIG_SETMASK, &set, &oldset); + if (mask_err != 0) { + return mask_err; + } + int create_err = pthread_create_wrapper(thread, attr, start_routine, + arg); + /* + * Restore the signal mask. Failure to restore the signal mask here + * changes program behavior. + */ + int restore_err = pthread_sigmask(SIG_SETMASK, &oldset, NULL); + if (restore_err != 0) { + malloc_printf("<jemalloc>: background thread creation " + "failed (%d), and signal mask restoration failed " + "(%d)\n", create_err, restore_err); + if (opt_abort) { + abort(); + } + } + return create_err; +} + static void check_background_thread_creation(tsd_t *tsd, unsigned *n_created, bool *created_threads) { @@ -373,9 +408,9 @@ label_restart: */ malloc_mutex_unlock(tsd_tsdn(tsd), &background_thread_lock); - pre_reentrancy(tsd); - int err = pthread_create_wrapper(&info->thread, NULL, - background_thread_entry, (void *)(uintptr_t)i); + pre_reentrancy(tsd, NULL); + int err = background_thread_create_signals_masked(&info->thread, + NULL, background_thread_entry, (void *)(uintptr_t)i); post_reentrancy(tsd); if (err == 0) { @@ -464,7 +499,9 @@ static void * background_thread_entry(void *ind_arg) { unsigned thread_ind = (unsigned)(uintptr_t)ind_arg; assert(thread_ind < ncpus); - +#ifdef JEMALLOC_HAVE_PTHREAD_SETNAME_NP + pthread_setname_np(pthread_self(), "jemalloc_bg_thd"); +#endif if (opt_percpu_arena != percpu_arena_disabled) { set_current_thread_affinity((int)thread_ind); } @@ -520,12 +557,12 @@ background_thread_create(tsd_t *tsd, unsigned arena_ind) { return false; } - pre_reentrancy(tsd); + pre_reentrancy(tsd, NULL); /* * To avoid complications (besides reentrancy), create internal * background threads with the underlying pthread_create. */ - int err = pthread_create_wrapper(&info->thread, NULL, + int err = background_thread_create_signals_masked(&info->thread, NULL, background_thread_entry, (void *)thread_ind); post_reentrancy(tsd); @@ -785,9 +822,14 @@ background_thread_boot0(void) { #ifdef JEMALLOC_PTHREAD_CREATE_WRAPPER pthread_create_fptr = dlsym(RTLD_NEXT, "pthread_create"); if (pthread_create_fptr == NULL) { - malloc_write("<jemalloc>: Error in dlsym(RTLD_NEXT, " - "\"pthread_create\")\n"); - abort(); + can_enable_background_thread = false; + if (config_lazy_lock || opt_background_thread) { + malloc_write("<jemalloc>: Error in dlsym(RTLD_NEXT, " + "\"pthread_create\")\n"); + abort(); + } + } else { + can_enable_background_thread = true; } #endif return false; |