| /* Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "apr.h" |
| #include "apr_atomic.h" |
| #include "apr_thread_mutex.h" |
| |
| #include "apr_private.h" |
| |
| #include <stdlib.h> |
| |
| #if defined(__GNUC__) && defined(__STRICT_ANSI__) && !defined(USE_GENERIC_ATOMICS) |
| /* force use of generic atomics if building e.g. with -std=c89, which |
| * doesn't allow inline asm */ |
| #define USE_GENERIC_ATOMICS |
| #endif |
| |
| #if (defined(__i386__) || defined(__x86_64__)) \ |
| && defined(__GNUC__) && !defined(USE_GENERIC_ATOMICS) |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, |
| apr_uint32_t with, |
| apr_uint32_t cmp) |
| { |
| apr_uint32_t prev; |
| |
| asm volatile ("lock; cmpxchgl %1, %2" |
| : "=a" (prev) |
| : "r" (with), "m" (*(mem)), "0"(cmp) |
| : "memory", "cc"); |
| return prev; |
| } |
| #define APR_OVERRIDE_ATOMIC_CAS32 |
| |
| static apr_uint32_t inline intel_atomic_add32(volatile apr_uint32_t *mem, |
| apr_uint32_t val) |
| { |
| asm volatile ("lock; xaddl %0,%1" |
| : "=r"(val), "=m"(*mem) /* outputs */ |
| : "0"(val), "m"(*mem) /* inputs */ |
| : "memory", "cc"); |
| return val; |
| } |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, |
| apr_uint32_t val) |
| { |
| return intel_atomic_add32(mem, val); |
| } |
| #define APR_OVERRIDE_ATOMIC_ADD32 |
| |
| APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| asm volatile ("lock; subl %1, %0" |
| : |
| : "m" (*(mem)), "r" (val) |
| : "memory", "cc"); |
| } |
| #define APR_OVERRIDE_ATOMIC_SUB32 |
| |
| APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem) |
| { |
| unsigned char prev; |
| |
| asm volatile ("lock; decl %1;\n\t" |
| "setnz %%al" |
| : "=a" (prev) |
| : "m" (*(mem)) |
| : "memory", "cc"); |
| return prev; |
| } |
| #define APR_OVERRIDE_ATOMIC_DEC32 |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem) |
| { |
| return intel_atomic_add32(mem, 1); |
| } |
| #define APR_OVERRIDE_ATOMIC_INC32 |
| |
| APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| *mem = val; |
| } |
| #define APR_OVERRIDE_ATOMIC_SET32 |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t prev = val; |
| |
| asm volatile ("lock; xchgl %0, %1" |
| : "=r" (prev) |
| : "m" (*(mem)), "0"(prev) |
| : "memory"); |
| return prev; |
| } |
| #define APR_OVERRIDE_ATOMIC_XCHG32 |
| |
| /*#define apr_atomic_init(pool) APR_SUCCESS*/ |
| |
| #endif /* (__linux__ || __EMX__ || __FreeBSD__) && __i386__ */ |
| |
| #if (defined(__PPC__) || defined(__ppc__)) && defined(__GNUC__) \ |
| && !defined(USE_GENERIC_ATOMICS) |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, |
| apr_uint32_t swap, |
| apr_uint32_t cmp) |
| { |
| apr_uint32_t prev; |
| |
| asm volatile ("0:\n\t" /* retry local label */ |
| "lwarx %0,0,%1\n\t" /* load prev and reserve */ |
| "cmpw %0,%3\n\t" /* does it match cmp? */ |
| "bne- 1f\n\t" /* ...no, bail out */ |
| "stwcx. %2,0,%1\n\t" /* ...yes, conditionally |
| store swap */ |
| "bne- 0b\n\t" /* start over if we lost |
| the reservation */ |
| "1:" /* exit local label */ |
| |
| : "=&r"(prev) /* output */ |
| : "b" (mem), "r" (swap), "r"(cmp) /* inputs */ |
| : "memory", "cc"); /* clobbered */ |
| return prev; |
| } |
| #define APR_OVERRIDE_ATOMIC_CAS32 |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, |
| apr_uint32_t delta) |
| { |
| apr_uint32_t prev, temp; |
| |
| asm volatile ("0:\n\t" /* retry local label */ |
| "lwarx %0,0,%2\n\t" /* load prev and reserve */ |
| "add %1,%0,%3\n\t" /* temp = prev + delta */ |
| "stwcx. %1,0,%2\n\t" /* conditionally store */ |
| "bne- 0b" /* start over if we lost |
| the reservation */ |
| |
| /*XXX find a cleaner way to define the temp |
| * it's not an output |
| */ |
| : "=&r" (prev), "=&r" (temp) /* output, temp */ |
| : "b" (mem), "r" (delta) /* inputs */ |
| : "memory", "cc"); /* clobbered */ |
| return prev; |
| } |
| #define APR_OVERRIDE_ATOMIC_ADD32 |
| |
| #endif /* __PPC__ && __GNUC__ */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_INIT) |
| |
| #if APR_HAS_THREADS |
| #define NUM_ATOMIC_HASH 7 |
| /* shift by 2 to get rid of alignment issues */ |
| #define ATOMIC_HASH(x) (unsigned int)(((unsigned long)(x)>>2)%(unsigned int)NUM_ATOMIC_HASH) |
| static apr_thread_mutex_t **hash_mutex; |
| #endif /* APR_HAS_THREADS */ |
| |
| #if APR_HAS_THREADS |
| static apr_status_t atomic_cleanup(void *data) |
| { |
| if (hash_mutex == data) |
| hash_mutex = NULL; |
| |
| return APR_SUCCESS; |
| } |
| #endif |
| |
| apr_status_t apr_atomic_init(apr_pool_t *p) |
| { |
| #if APR_HAS_THREADS |
| int i; |
| apr_status_t rv; |
| |
| if (hash_mutex != NULL) |
| return APR_SUCCESS; |
| |
| hash_mutex = apr_palloc(p, sizeof(apr_thread_mutex_t*) * NUM_ATOMIC_HASH); |
| apr_pool_cleanup_register(p, hash_mutex, atomic_cleanup, |
| apr_pool_cleanup_null); |
| |
| for (i = 0; i < NUM_ATOMIC_HASH; i++) { |
| rv = apr_thread_mutex_create(&(hash_mutex[i]), |
| APR_THREAD_MUTEX_DEFAULT, p); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| } |
| #endif /* APR_HAS_THREADS */ |
| return APR_SUCCESS; |
| } |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_INIT) */ |
| |
| /* abort() if 'x' does not evaluate to APR_SUCCESS. */ |
| #define CHECK(x) do { if ((x) != APR_SUCCESS) abort(); } while (0) |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_ADD32) |
| #if defined(APR_OVERRIDE_ATOMIC_CAS32) |
| apr_uint32_t apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t old_value, new_value; |
| |
| do { |
| old_value = *mem; |
| new_value = old_value + val; |
| } while (apr_atomic_cas32(mem, new_value, old_value) != old_value); |
| return old_value; |
| } |
| #else |
| apr_uint32_t apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t old_value; |
| |
| #if APR_HAS_THREADS |
| apr_thread_mutex_t *lock = hash_mutex[ATOMIC_HASH(mem)]; |
| |
| CHECK(apr_thread_mutex_lock(lock)); |
| old_value = *mem; |
| *mem += val; |
| CHECK(apr_thread_mutex_unlock(lock)); |
| #else |
| old_value = *mem; |
| *mem += val; |
| #endif /* APR_HAS_THREADS */ |
| return old_value; |
| } |
| #endif /* defined(APR_OVERRIDE_ATOMIC_CAS32) */ |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_ADD32) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_SUB32) |
| #if defined(APR_OVERRIDE_ATOMIC_CAS32) |
| void apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t old_value, new_value; |
| |
| do { |
| old_value = *mem; |
| new_value = old_value - val; |
| } while (apr_atomic_cas32(mem, new_value, old_value) != old_value); |
| } |
| #else |
| void apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| #if APR_HAS_THREADS |
| apr_thread_mutex_t *lock = hash_mutex[ATOMIC_HASH(mem)]; |
| |
| CHECK(apr_thread_mutex_lock(lock)); |
| *mem -= val; |
| CHECK(apr_thread_mutex_unlock(lock)); |
| #else |
| *mem -= val; |
| #endif /* APR_HAS_THREADS */ |
| } |
| #endif /* defined(APR_OVERRIDE_ATOMIC_CAS32) */ |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_SUB32) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_SET32) |
| void apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| #if APR_HAS_THREADS |
| apr_thread_mutex_t *lock = hash_mutex[ATOMIC_HASH(mem)]; |
| |
| CHECK(apr_thread_mutex_lock(lock)); |
| *mem = val; |
| CHECK(apr_thread_mutex_unlock(lock)); |
| #else |
| *mem = val; |
| #endif /* APR_HAS_THREADS */ |
| } |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_SET32) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_INC32) |
| apr_uint32_t apr_atomic_inc32(volatile apr_uint32_t *mem) |
| { |
| return apr_atomic_add32(mem, 1); |
| } |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_INC32) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_DEC32) |
| #if defined(APR_OVERRIDE_ATOMIC_CAS32) |
| int apr_atomic_dec32(volatile apr_uint32_t *mem) |
| { |
| apr_uint32_t old_value, new_value; |
| |
| do { |
| old_value = *mem; |
| new_value = old_value - 1; |
| } while (apr_atomic_cas32(mem, new_value, old_value) != old_value); |
| return old_value != 1; |
| } |
| #else |
| int apr_atomic_dec32(volatile apr_uint32_t *mem) |
| { |
| #if APR_HAS_THREADS |
| apr_thread_mutex_t *lock = hash_mutex[ATOMIC_HASH(mem)]; |
| apr_uint32_t new; |
| |
| CHECK(apr_thread_mutex_lock(lock)); |
| (*mem)--; |
| new = *mem; |
| CHECK(apr_thread_mutex_unlock(lock)); |
| return new; |
| #else |
| (*mem)--; |
| return *mem; |
| #endif /* APR_HAS_THREADS */ |
| } |
| #endif /* defined(APR_OVERRIDE_ATOMIC_CAS32) */ |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_DEC32) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_CAS32) |
| apr_uint32_t apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with, |
| apr_uint32_t cmp) |
| { |
| apr_uint32_t prev; |
| #if APR_HAS_THREADS |
| apr_thread_mutex_t *lock = hash_mutex[ATOMIC_HASH(mem)]; |
| |
| CHECK(apr_thread_mutex_lock(lock)); |
| prev = *mem; |
| if (prev == cmp) { |
| *mem = with; |
| } |
| CHECK(apr_thread_mutex_unlock(lock)); |
| #else |
| prev = *mem; |
| if (prev == cmp) { |
| *mem = with; |
| } |
| #endif /* APR_HAS_THREADS */ |
| return prev; |
| } |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_CAS32) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_XCHG32) |
| #if defined(APR_OVERRIDE_ATOMIC_CAS32) |
| apr_uint32_t apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t prev; |
| do { |
| prev = *mem; |
| } while (apr_atomic_cas32(mem, val, prev) != prev); |
| return prev; |
| } |
| #else |
| apr_uint32_t apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t prev; |
| #if APR_HAS_THREADS |
| apr_thread_mutex_t *lock = hash_mutex[ATOMIC_HASH(mem)]; |
| |
| CHECK(apr_thread_mutex_lock(lock)); |
| prev = *mem; |
| *mem = val; |
| CHECK(apr_thread_mutex_unlock(lock)); |
| #else |
| prev = *mem; |
| *mem = val; |
| #endif /* APR_HAS_THREADS */ |
| return prev; |
| } |
| #endif /* defined(APR_OVERRIDE_ATOMIC_CAS32) */ |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_XCHG32) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_CASPTR) |
| void *apr_atomic_casptr(volatile void **mem, void *with, const void *cmp) |
| { |
| void *prev; |
| #if APR_HAS_THREADS |
| apr_thread_mutex_t *lock = hash_mutex[ATOMIC_HASH(mem)]; |
| |
| CHECK(apr_thread_mutex_lock(lock)); |
| prev = *(void **)mem; |
| if (prev == cmp) { |
| *mem = with; |
| } |
| CHECK(apr_thread_mutex_unlock(lock)); |
| #else |
| prev = *(void **)mem; |
| if (prev == cmp) { |
| *mem = with; |
| } |
| #endif /* APR_HAS_THREADS */ |
| return prev; |
| } |
| #endif /* !defined(APR_OVERRIDE_ATOMIC_CASPTR) */ |
| |
| #if !defined(APR_OVERRIDE_ATOMIC_READ32) |
| APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem) |
| { |
| return *mem; |
| } |
| #endif |
| |
