Revert "Revert "Revert "Revert "Remove incorrect android_atomic_...64 use.""""

After fixing b/16874785.

This reverts commit f010a05c7e.

Original comment, which actually describes the effect of this:

Change the mExtras field in Binder.h to be a stdatomic.h atomic
value, and replace references to it with proper stdatomic.h calls.
This removes one of a small number of remaining 64 bit
android_atomic references.  It also replaces the erroneously
non-atomic read accesses to mExtras.

It would be better if this used the C++11 <atomic> facility,
but we don't quite have that yet.

Fixes

Bug:16513433

Change-Id: I1645ca5d6f60595bf5d388913665ce4b8780b26d
(cherry picked from commit 3effababf2)
This commit is contained in:
Hans Boehm 2014-08-12 22:56:00 +00:00
parent bcbf97ef8f
commit 08ff802151
2 changed files with 21 additions and 15 deletions

View File

@ -17,6 +17,8 @@
#ifndef ANDROID_BINDER_H
#define ANDROID_BINDER_H
#include <stdatomic.h>
#include <stdint.h>
#include <binder/IBinder.h>
// ---------------------------------------------------------------------------
@ -69,7 +71,7 @@ private:
class Extras;
Extras* mExtras;
atomic_uintptr_t mExtras; // should be atomic<Extras *>
void* mReserved0;
};

View File

@ -16,7 +16,7 @@
#include <binder/Binder.h>
#include <utils/Atomic.h>
#include <stdatomic.h>
#include <utils/misc.h>
#include <binder/BpBinder.h>
#include <binder/IInterface.h>
@ -71,8 +71,8 @@ public:
// ---------------------------------------------------------------------------
BBinder::BBinder()
: mExtras(NULL)
{
atomic_init(&mExtras, 0);
}
bool BBinder::isBinderAlive() const
@ -139,19 +139,19 @@ void BBinder::attachObject(
const void* objectID, void* object, void* cleanupCookie,
object_cleanup_func func)
{
Extras* e = mExtras;
Extras* e = reinterpret_cast<Extras*>(
atomic_load_explicit(&mExtras, memory_order_acquire));
if (!e) {
e = new Extras;
#ifdef __LP64__
if (android_atomic_release_cas64(0, reinterpret_cast<int64_t>(e),
reinterpret_cast<volatile int64_t*>(&mExtras)) != 0) {
#else
if (android_atomic_cmpxchg(0, reinterpret_cast<int32_t>(e),
reinterpret_cast<volatile int32_t*>(&mExtras)) != 0) {
#endif
uintptr_t* expected = 0;
if (!atomic_compare_exchange_strong_explicit(
&mExtras, &expected,
reinterpret_cast<uintptr_t>(e),
memory_order_release,
memory_order_acquire)) {
delete e;
e = mExtras;
e = reinterpret_cast<Extras*>(expected); // Filled in by CAS
}
if (e == 0) return; // out of memory
}
@ -162,7 +162,8 @@ void BBinder::attachObject(
void* BBinder::findObject(const void* objectID) const
{
Extras* e = mExtras;
Extras* e = reinterpret_cast<Extras*>(
atomic_load_explicit(&mExtras, memory_order_acquire));
if (!e) return NULL;
AutoMutex _l(e->mLock);
@ -171,7 +172,8 @@ void* BBinder::findObject(const void* objectID) const
void BBinder::detachObject(const void* objectID)
{
Extras* e = mExtras;
Extras* e = reinterpret_cast<Extras*>(
atomic_load_explicit(&mExtras, memory_order_acquire));
if (!e) return;
AutoMutex _l(e->mLock);
@ -185,7 +187,9 @@ BBinder* BBinder::localBinder()
BBinder::~BBinder()
{
if (mExtras) delete mExtras;
Extras* e = reinterpret_cast<Extras*>(
atomic_load_explicit(&mExtras, memory_order_relaxed));
if (e) delete e;
}