#define JEMALLOC_MUTEX_C_ #include "jemalloc/internal/jemalloc_preamble.h" #include "jemalloc/internal/jemalloc_internal_includes.h" #include "jemalloc/internal/assert.h" #include "jemalloc/internal/malloc_io.h" #include "jemalloc/internal/spin.h" #ifndef _CRT_SPINCOUNT #define _CRT_SPINCOUNT 4000 #endif /******************************************************************************/ /* Data. */ #ifdef JEMALLOC_LAZY_LOCK bool isthreaded = false; #endif #ifdef JEMALLOC_MUTEX_INIT_CB static bool postpone_init = true; static malloc_mutex_t *postponed_mutexes = NULL; #endif /******************************************************************************/ /* * We intercept pthread_create() calls in order to toggle isthreaded if the * process goes multi-threaded. */ #if defined(JEMALLOC_LAZY_LOCK) && !defined(_WIN32) JEMALLOC_EXPORT int pthread_create(pthread_t *__restrict thread, const pthread_attr_t *__restrict attr, void *(*start_routine)(void *), void *__restrict arg) { return pthread_create_wrapper(thread, attr, start_routine, arg); } #endif /******************************************************************************/ #ifdef JEMALLOC_MUTEX_INIT_CB JEMALLOC_EXPORT int _pthread_mutex_init_calloc_cb(pthread_mutex_t *mutex, void *(calloc_cb)(size_t, size_t)); #endif void malloc_mutex_lock_slow(malloc_mutex_t *mutex) { mutex_prof_data_t *data = &mutex->prof_data; nstime_t before = NSTIME_ZERO_INITIALIZER; if (ncpus == 1) { goto label_spin_done; } int cnt = 0, max_cnt = MALLOC_MUTEX_MAX_SPIN; do { spin_cpu_spinwait(); if (!malloc_mutex_trylock_final(mutex)) { data->n_spin_acquired++; return; } } while (cnt++ < max_cnt); if (!config_stats) { /* Only spin is useful when stats is off. */ malloc_mutex_lock_final(mutex); return; } label_spin_done: nstime_update(&before); /* Copy before to after to avoid clock skews. */ nstime_t after; nstime_copy(&after, &before); uint32_t n_thds = atomic_fetch_add_u32(&data->n_waiting_thds, 1, ATOMIC_RELAXED) + 1; /* One last try as above two calls may take quite some cycles. */ if (!malloc_mutex_trylock_final(mutex)) { atomic_fetch_sub_u32(&data->n_waiting_thds, 1, ATOMIC_RELAXED); data->n_spin_acquired++; return; } /* True slow path. */ malloc_mutex_lock_final(mutex); /* Update more slow-path only counters. */ atomic_fetch_sub_u32(&data->n_waiting_thds, 1, ATOMIC_RELAXED); nstime_update(&after); nstime_t delta; nstime_copy(&delta, &after); nstime_subtract(&delta, &before); data->n_wait_times++; nstime_add(&data->tot_wait_time, &delta); if (nstime_compare(&data->max_wait_time, &delta) < 0) { nstime_copy(&data->max_wait_time, &delta); } if (n_thds > data->max_n_thds) { data->max_n_thds = n_thds; } } static void mutex_prof_data_init(mutex_prof_data_t *data) { memset(data, 0, sizeof(mutex_prof_data_t)); nstime_init(&data->max_wait_time, 0); nstime_init(&data->tot_wait_time, 0); data->prev_owner = NULL; } void malloc_mutex_prof_data_reset(tsdn_t *tsdn, malloc_mutex_t *mutex) { malloc_mutex_assert_owner(tsdn, mutex); mutex_prof_data_init(&mutex->prof_data); } static int mutex_addr_comp(const witness_t *witness1, void *mutex1, const witness_t *witness2, void *mutex2) { assert(mutex1 != NULL); assert(mutex2 != NULL); uintptr_t mu1int = (uintptr_t)mutex1; uintptr_t mu2int = (uintptr_t)mutex2; if (mu1int < mu2int) { return -1; } else if (mu1int == mu2int) { return 0; } else { return 1; } } bool malloc_mutex_init(malloc_mutex_t *mutex, const char *name, witness_rank_t rank, malloc_mutex_lock_order_t lock_order) { mutex_prof_data_init(&mutex->prof_data); #ifdef _WIN32 # if _WIN32_WINNT >= 0x0600 InitializeSRWLock(&mutex->lock); # else if (!InitializeCriticalSectionAndSpinCount(&mutex->lock, _CRT_SPINCOUNT)) { return true; } # endif #elif (defined(JEMALLOC_OS_UNFAIR_LOCK)) mutex->lock = OS_UNFAIR_LOCK_INIT; #elif (defined(JEMALLOC_OSSPIN)) mutex->lock = 0; #elif (defined(JEMALLOC_MUTEX_INIT_CB)) if (postpone_init) { mutex->postponed_next = postponed_mutexes; postponed_mutexes = mutex; } else { if (_pthread_mutex_init_calloc_cb(&mutex->lock, bootstrap_calloc) != 0) { return true; } } #else pthread_mutexattr_t attr; if (pthread_mutexattr_init(&attr) != 0) { return true; } pthread_mutexattr_settype(&attr, MALLOC_MUTEX_TYPE); if (pthread_mutex_init(&mutex->lock, &attr) != 0) { pthread_mutexattr_destroy(&attr); return true; } pthread_mutexattr_destroy(&attr); #endif if (config_debug) { mutex->lock_order = lock_order; if (lock_order == malloc_mutex_address_ordered) { witness_init(&mutex->witness, name, rank, mutex_addr_comp, mutex); } else { witness_init(&mutex->witness, name, rank, NULL, NULL); } } return false; } void malloc_mutex_prefork(tsdn_t *tsdn, malloc_mutex_t *mutex) { malloc_mutex_lock(tsdn, mutex); } void malloc_mutex_postfork_parent(tsdn_t *tsdn, malloc_mutex_t *mutex) { malloc_mutex_unlock(tsdn, mutex); } void malloc_mutex_postfork_child(tsdn_t *tsdn, malloc_mutex_t *mutex) { #ifdef JEMALLOC_MUTEX_INIT_CB malloc_mutex_unlock(tsdn, mutex); #else if (malloc_mutex_init(mutex, mutex->witness.name, mutex->witness.rank, mutex->lock_order)) { malloc_printf(": Error re-initializing mutex in " "child\n"); if (opt_abort) { abort(); } } #endif } bool malloc_mutex_boot(void) { #ifdef JEMALLOC_MUTEX_INIT_CB postpone_init = false; while (postponed_mutexes != NULL) { if (_pthread_mutex_init_calloc_cb(&postponed_mutexes->lock, bootstrap_calloc) != 0) { return true; } postponed_mutexes = postponed_mutexes->postponed_next; } #endif return false; }