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-rw-r--r--libcutils/atomic-android-sh.c82
1 files changed, 36 insertions, 46 deletions
diff --git a/libcutils/atomic-android-sh.c b/libcutils/atomic-android-sh.c
index acbea97..abe7d25 100644
--- a/libcutils/atomic-android-sh.c
+++ b/libcutils/atomic-android-sh.c
@@ -35,6 +35,9 @@
* ARM implementation, in this file above.
* We follow the fact that the initializer for mutex is a simple zero
* value.
+ *
+ * (3) These operations are NOT safe for SMP, as there is no currently
+ * no definition for a memory barrier operation.
*/
#include <pthread.h>
@@ -46,18 +49,35 @@ static pthread_mutex_t _swap_locks[SWAP_LOCK_COUNT];
&_swap_locks[((unsigned)(void*)(addr) >> 3U) % SWAP_LOCK_COUNT]
-void android_atomic_write(int32_t value, volatile int32_t* addr) {
+int32_t android_atomic_acquire_load(volatile int32_t* addr)
+{
+ return *addr;
+}
+
+int32_t android_atomic_release_load(volatile int32_t* addr)
+{
+ return *addr;
+}
+
+void android_atomic_acquire_store(int32_t value, volatile int32_t* addr) {
int32_t oldValue;
do {
oldValue = *addr;
- } while (android_atomic_cmpxchg(oldValue, value, addr));
+ } while (android_atomic_release_cas(oldValue, value, addr));
+}
+
+void android_atomic_release_store(int32_t value, volatile int32_t* addr) {
+ int32_t oldValue;
+ do {
+ oldValue = *addr;
+ } while (android_atomic_release_cas(oldValue, value, addr));
}
int32_t android_atomic_inc(volatile int32_t* addr) {
int32_t oldValue;
do {
oldValue = *addr;
- } while (android_atomic_cmpxchg(oldValue, oldValue+1, addr));
+ } while (android_atomic_release_cas(oldValue, oldValue+1, addr));
return oldValue;
}
@@ -65,7 +85,7 @@ int32_t android_atomic_dec(volatile int32_t* addr) {
int32_t oldValue;
do {
oldValue = *addr;
- } while (android_atomic_cmpxchg(oldValue, oldValue-1, addr));
+ } while (android_atomic_release_cas(oldValue, oldValue-1, addr));
return oldValue;
}
@@ -73,7 +93,7 @@ int32_t android_atomic_add(int32_t value, volatile int32_t* addr) {
int32_t oldValue;
do {
oldValue = *addr;
- } while (android_atomic_cmpxchg(oldValue, oldValue+value, addr));
+ } while (android_atomic_release_cas(oldValue, oldValue+value, addr));
return oldValue;
}
@@ -81,7 +101,7 @@ int32_t android_atomic_and(int32_t value, volatile int32_t* addr) {
int32_t oldValue;
do {
oldValue = *addr;
- } while (android_atomic_cmpxchg(oldValue, oldValue&value, addr));
+ } while (android_atomic_release_cas(oldValue, oldValue&value, addr));
return oldValue;
}
@@ -89,11 +109,15 @@ int32_t android_atomic_or(int32_t value, volatile int32_t* addr) {
int32_t oldValue;
do {
oldValue = *addr;
- } while (android_atomic_cmpxchg(oldValue, oldValue|value, addr));
+ } while (android_atomic_release_cas(oldValue, oldValue|value, addr));
return oldValue;
}
-int32_t android_atomic_swap(int32_t value, volatile int32_t* addr) {
+int32_t android_atomic_acquire_swap(int32_t value, volatile int32_t* addr) {
+ return android_atomic_release_swap(value, addr);
+}
+
+int32_t android_atomic_release_swap(int32_t value, volatile int32_t* addr) {
int32_t oldValue;
do {
oldValue = *addr;
@@ -101,38 +125,13 @@ int32_t android_atomic_swap(int32_t value, volatile int32_t* addr) {
return oldValue;
}
-int android_atomic_cmpxchg(int32_t oldvalue, int32_t newvalue,
+int android_atomic_acquire_cmpxchg(int32_t oldvalue, int32_t newvalue,
volatile int32_t* addr) {
- int result;
- pthread_mutex_t* lock = SWAP_LOCK(addr);
-
- pthread_mutex_lock(lock);
-
- if (*addr == oldvalue) {
- *addr = newvalue;
- result = 0;
- } else {
- result = 1;
- }
- pthread_mutex_unlock(lock);
- return result;
+ return android_atomic_release_cmpxchg(oldValue, newValue, addr);
}
-int64_t android_quasiatomic_swap_64(int64_t value, volatile int64_t* addr) {
- int64_t oldValue;
- pthread_mutex_t* lock = SWAP_LOCK(addr);
-
- pthread_mutex_lock(lock);
-
- oldValue = *addr;
- *addr = value;
-
- pthread_mutex_unlock(lock);
- return oldValue;
-}
-
-int android_quasiatomic_cmpxchg_64(int64_t oldvalue, int64_t newvalue,
- volatile int64_t* addr) {
+int android_atomic_release_cmpxchg(int32_t oldvalue, int32_t newvalue,
+ volatile int32_t* addr) {
int result;
pthread_mutex_t* lock = SWAP_LOCK(addr);
@@ -148,12 +147,3 @@ int android_quasiatomic_cmpxchg_64(int64_t oldvalue, int64_t newvalue,
return result;
}
-int64_t android_quasiatomic_read_64(volatile int64_t* addr) {
- int64_t result;
- pthread_mutex_t* lock = SWAP_LOCK(addr);
-
- pthread_mutex_lock(lock);
- result = *addr;
- pthread_mutex_unlock(lock);
- return result;
-}