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cli/vendor/aws-lc-sys/aws-lc/crypto/thread_pthread.c

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// Copyright (c) 2015, Google Inc.
// SPDX-License-Identifier: ISC
// Ensure we can't call OPENSSL_malloc circularly.
#define _BORINGSSL_PROHIBIT_OPENSSL_MALLOC
#include <errno.h>
#include "internal.h"
#if defined(OPENSSL_PTHREADS)
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/target.h>
#include <openssl/type_check.h>
OPENSSL_STATIC_ASSERT(sizeof(CRYPTO_MUTEX) >= sizeof(pthread_rwlock_t),
CRYPTO_MUTEX_is_too_small)
OPENSSL_STATIC_ASSERT(alignof(CRYPTO_MUTEX) >= alignof(pthread_rwlock_t),
CRYPTO_MUTEX_has_insufficient_alignment)
void CRYPTO_MUTEX_init(CRYPTO_MUTEX *lock) {
if (pthread_rwlock_init((pthread_rwlock_t *) lock, NULL) != 0) {
abort();
}
}
void CRYPTO_MUTEX_lock_read(CRYPTO_MUTEX *lock) {
if (pthread_rwlock_rdlock((pthread_rwlock_t *) lock) != 0) {
abort();
}
}
void CRYPTO_MUTEX_lock_write(CRYPTO_MUTEX *lock) {
if (pthread_rwlock_wrlock((pthread_rwlock_t *) lock) != 0) {
abort();
}
}
void CRYPTO_MUTEX_unlock_read(CRYPTO_MUTEX *lock) {
if (pthread_rwlock_unlock((pthread_rwlock_t *) lock) != 0) {
abort();
}
}
void CRYPTO_MUTEX_unlock_write(CRYPTO_MUTEX *lock) {
if (pthread_rwlock_unlock((pthread_rwlock_t *) lock) != 0) {
abort();
}
}
void CRYPTO_MUTEX_cleanup(CRYPTO_MUTEX *lock) {
pthread_rwlock_destroy((pthread_rwlock_t *) lock);
}
#ifdef __MINGW32__
#ifndef MIN
#define MINGW_AWSLC_MIN(X,Y) (((X) < (Y)) ? (X) : (Y))
#else
#define MINGW_AWSLC_MIN(X,Y) MIN(X,Y)
#endif
// MINGW implements nanosleep on X86_64 but not on other architectures.
// Prefer using nanosleep because of its higher resolution.
// https://gist.github.com/scivision/dbbbf33c2faf5a16f31fd6d144adc314 claims
// that MINGW only implements nanpsleep on X86, but not Arm64. The linked
// MINGW source code
// https://github.com/mingw-w64/mingw-w64/blob/master/mingw-w64-libraries/winpthreads/src/nanosleep.c
// does not seem to exclude any platforms though. But since this code is only
// really needed for X86 in the first place, avoid creating more availability
// risks.
#if defined(OPENSSL_X86_64)
#include <time.h>
// 100ms second in nanoseconds.
#define MINGW_MILLISECONDS_100 INT64_C(100000000)
#define MINGW_INITIAL_BACKOFF_DELAY 10
static void mingw_do_backoff(long *backoff) {
// Exponential backoff.
//
// iteration delay
// --------- ----------------
// 1 10 nsec
// 2 100 nsec
// 3 1,000 nsec
// 4 10,000 nsec
// 5 100,000 nsec
// 6 1,000,000 nsec
// 7 10,000,000 nsec
// 8 100,000,000 nsec
// 9 100,000,000 nsec
// ...
struct timespec sleep_time = {.tv_sec = 0, .tv_nsec = 0 };
// Cap backoff at 100,000,000 nsec (100ms).
*backoff = MINGW_AWSLC_MIN((*backoff) * 10, MINGW_MILLISECONDS_100);
// |nanosleep| can mutate |sleep_time|. Hence, we use |backoff| for state.
sleep_time.tv_nsec = *backoff;
nanosleep(&sleep_time, &sleep_time);
}
#else // defined(OPENSSL_X86_64)
#include <windows.h>
// 100 milliseconds.
#define MINGW_MILLISECONDS_100 INT64_C(100)
#define MINGW_INITIAL_BACKOFF_DELAY 1
static void mingw_do_backoff(long *backoff) {
// Additive backoff.
//
// iteration delay
// --------- -------
// 1 1 ms
// 2 10 ms
// 3 20 ms
// 4 30 ms
// 5 40 ms
// 6 50 ms
// 7 60 ms
// 8 70 ms
// 9 80 ms
// 10 90 ms
// 11 100 ms
// ...
// Cap backoff at 100ms.
*backoff = MINGW_AWSLC_MIN((*backoff) + 10, MINGW_MILLISECONDS_100);
Sleep((int)*backoff);
}
#endif // defined(OPENSSL_X86_64)
#endif // __MINGW32__
// Some MinGW pthreads implementations might fail on first use of
// locks initialized using PTHREAD_RWLOCK_INITIALIZER.
// See: https://sourceforge.net/p/mingw-w64/bugs/883/
typedef int (*pthread_rwlock_func_ptr)(pthread_rwlock_t *);
static int rwlock_EINVAL_fallback_retry(const pthread_rwlock_func_ptr func_ptr, pthread_rwlock_t* lock) {
int result = EINVAL;
#ifdef __MINGW32__
// This will be about 1 second of total backoff.
const int MAX_ATTEMPTS = 20;
int attempt_num = 0;
long backoff = MINGW_INITIAL_BACKOFF_DELAY;
do {
sched_yield();
attempt_num += 1;
result = func_ptr(lock);
mingw_do_backoff(&backoff);
} while(result == EINVAL && attempt_num < MAX_ATTEMPTS);
// To aid in debugging
if (result == EINVAL && attempt_num >= MAX_ATTEMPTS) {
fprintf(stderr, "ERROR: rwlock_EINVAL_fallback_retry() failed after %i attempts\n", MAX_ATTEMPTS);
}
#endif
return result;
}
void CRYPTO_STATIC_MUTEX_lock_read(struct CRYPTO_STATIC_MUTEX *lock) {
const int result = pthread_rwlock_rdlock(&lock->lock);
if (result != 0) {
if (result == EINVAL &&
0 == rwlock_EINVAL_fallback_retry(pthread_rwlock_rdlock, &lock->lock)) {
return;
}
abort();
}
}
void CRYPTO_STATIC_MUTEX_lock_write(struct CRYPTO_STATIC_MUTEX *lock) {
const int result = pthread_rwlock_wrlock(&lock->lock);
if (result != 0) {
if (result == EINVAL &&
0 == rwlock_EINVAL_fallback_retry(pthread_rwlock_wrlock, &lock->lock)) {
return;
}
abort();
}
}
void CRYPTO_STATIC_MUTEX_unlock_read(struct CRYPTO_STATIC_MUTEX *lock) {
if (pthread_rwlock_unlock(&lock->lock) != 0) {
abort();
}
}
void CRYPTO_STATIC_MUTEX_unlock_write(struct CRYPTO_STATIC_MUTEX *lock) {
if (pthread_rwlock_unlock(&lock->lock) != 0) {
abort();
}
}
#if !defined(NDEBUG)
int CRYPTO_STATIC_MUTEX_is_write_locked(struct CRYPTO_STATIC_MUTEX *lock) {
assert(lock != NULL);
int result = pthread_rwlock_tryrdlock(&lock->lock);
if (result == 0) {
// If we successfully acquired the lock, it wasn't locked
// Release it immediately and return false
pthread_rwlock_unlock(&lock->lock);
return 0;
}
// errno may be set to EDEADLK if the current thread is already has a write lock
if (result == EBUSY || result == EDEADLK) {
return 1;
}
return -1;
}
#endif
void CRYPTO_once(CRYPTO_once_t *once, void (*init)(void)) {
if (pthread_once(once, init) != 0) {
abort();
}
}
static pthread_mutex_t g_destructors_lock = PTHREAD_MUTEX_INITIALIZER;
static thread_local_destructor_t g_destructors[NUM_OPENSSL_THREAD_LOCALS];
// thread_local_destructor is called when a thread exits. It releases thread
// local data for that thread only.
static void thread_local_destructor(void *arg) {
if (arg == NULL) {
return;
}
thread_local_destructor_t destructors[NUM_OPENSSL_THREAD_LOCALS];
if (pthread_mutex_lock(&g_destructors_lock) != 0) {
return;
}
OPENSSL_memcpy(destructors, g_destructors, sizeof(destructors));
pthread_mutex_unlock(&g_destructors_lock);
unsigned i;
void **pointers = arg;
for (i = 0; i < NUM_OPENSSL_THREAD_LOCALS; i++) {
if (destructors[i] != NULL) {
destructors[i](pointers[i]);
}
}
free(pointers);
}
static pthread_once_t g_thread_local_init_once = PTHREAD_ONCE_INIT;
static pthread_key_t g_thread_local_key;
static int g_thread_local_key_created = 0;
static void thread_local_init(void) {
g_thread_local_key_created =
pthread_key_create(&g_thread_local_key, thread_local_destructor) == 0;
}
void *CRYPTO_get_thread_local(thread_local_data_t index) {
CRYPTO_once(&g_thread_local_init_once, thread_local_init);
if (!g_thread_local_key_created) {
return NULL;
}
void **pointers = pthread_getspecific(g_thread_local_key);
if (pointers == NULL) {
return NULL;
}
return pointers[index];
}
int CRYPTO_set_thread_local(thread_local_data_t index, void *value,
thread_local_destructor_t destructor) {
CRYPTO_once(&g_thread_local_init_once, thread_local_init);
if (!g_thread_local_key_created) {
destructor(value);
return 0;
}
void **pointers = pthread_getspecific(g_thread_local_key);
if (pointers == NULL) {
pointers = malloc(sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
if (pointers == NULL) {
destructor(value);
return 0;
}
OPENSSL_memset(pointers, 0, sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
if (pthread_setspecific(g_thread_local_key, pointers) != 0) {
free(pointers);
destructor(value);
return 0;
}
}
if (pthread_mutex_lock(&g_destructors_lock) != 0) {
destructor(value);
return 0;
}
g_destructors[index] = destructor;
pthread_mutex_unlock(&g_destructors_lock);
pointers[index] = value;
return 1;
}
int AWSLC_thread_local_clear(void) {
if (!g_thread_local_key_created) {
return 1;
}
void *pointers = pthread_getspecific(g_thread_local_key);
thread_local_destructor(pointers);
// By setting the value NULL, thread_local_destructor will not be called when
// this thread dies.
if (0 != pthread_setspecific(g_thread_local_key, NULL)) {
return 0;
}
return 1;
}
// This function is not thread-safe. It should only be called on a thread that
// is prepared to also call `dlclose` to unload our shared library.
int AWSLC_thread_local_shutdown(void) {
if (!g_thread_local_key_created) {
return 1;
}
// This deletes the thread local key
if (0 != pthread_key_delete(g_thread_local_key)) {
return 0;
}
g_thread_local_key_created = 0;
return 1;
}
#endif // OPENSSL_PTHREADS