auto import from //depot/cupcake/@135843
diff --git a/libs/utils/RefBase.cpp b/libs/utils/RefBase.cpp
new file mode 100644
index 0000000..0bd1af4
--- /dev/null
+++ b/libs/utils/RefBase.cpp
@@ -0,0 +1,534 @@
+/*
+ * Copyright (C) 2005 The Android Open Source Project
+ *
+ * Licensed 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.
+ */
+
+#define LOG_TAG "RefBase"
+
+#include <utils/RefBase.h>
+
+#include <utils/Atomic.h>
+#include <utils/CallStack.h>
+#include <utils/KeyedVector.h>
+#include <utils/Log.h>
+#include <utils/threads.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <typeinfo>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+// compile with refcounting debugging enabled
+#define DEBUG_REFS 0
+#define DEBUG_REFS_ENABLED_BY_DEFAULT 1
+#define DEBUG_REFS_CALLSTACK_ENABLED 1
+
+// log all reference counting operations
+#define PRINT_REFS 0
+
+// ---------------------------------------------------------------------------
+
+namespace android {
+
+#define INITIAL_STRONG_VALUE (1<<28)
+
+// ---------------------------------------------------------------------------
+
+class RefBase::weakref_impl : public RefBase::weakref_type
+{
+public:
+ volatile int32_t mStrong;
+ volatile int32_t mWeak;
+ RefBase* const mBase;
+ volatile int32_t mFlags;
+
+
+#if !DEBUG_REFS
+
+ weakref_impl(RefBase* base)
+ : mStrong(INITIAL_STRONG_VALUE)
+ , mWeak(0)
+ , mBase(base)
+ , mFlags(0)
+ {
+ }
+
+ void addStrongRef(const void* /*id*/) { }
+ void removeStrongRef(const void* /*id*/) { }
+ void addWeakRef(const void* /*id*/) { }
+ void removeWeakRef(const void* /*id*/) { }
+ void printRefs() const { }
+ void trackMe(bool, bool) { }
+
+#else
+
+ weakref_impl(RefBase* base)
+ : mStrong(INITIAL_STRONG_VALUE)
+ , mWeak(0)
+ , mBase(base)
+ , mFlags(0)
+ , mStrongRefs(NULL)
+ , mWeakRefs(NULL)
+ , mTrackEnabled(!!DEBUG_REFS_ENABLED_BY_DEFAULT)
+ , mRetain(false)
+ {
+ //LOGI("NEW weakref_impl %p for RefBase %p", this, base);
+ }
+
+ ~weakref_impl()
+ {
+ LOG_ALWAYS_FATAL_IF(!mRetain && mStrongRefs != NULL, "Strong references remain!");
+ LOG_ALWAYS_FATAL_IF(!mRetain && mWeakRefs != NULL, "Weak references remain!");
+ }
+
+ void addStrongRef(const void* id)
+ {
+ addRef(&mStrongRefs, id, mStrong);
+ }
+
+ void removeStrongRef(const void* id)
+ {
+ if (!mRetain)
+ removeRef(&mStrongRefs, id);
+ else
+ addRef(&mStrongRefs, id, -mStrong);
+ }
+
+ void addWeakRef(const void* id)
+ {
+ addRef(&mWeakRefs, id, mWeak);
+ }
+
+ void removeWeakRef(const void* id)
+ {
+ if (!mRetain)
+ removeRef(&mWeakRefs, id);
+ else
+ addRef(&mWeakRefs, id, -mWeak);
+ }
+
+ void trackMe(bool track, bool retain)
+ {
+ mTrackEnabled = track;
+ mRetain = retain;
+ }
+
+ void printRefs() const
+ {
+ String8 text;
+
+ {
+ AutoMutex _l(const_cast<weakref_impl*>(this)->mMutex);
+
+ char buf[128];
+ sprintf(buf, "Strong references on RefBase %p (weakref_type %p):\n", mBase, this);
+ text.append(buf);
+ printRefsLocked(&text, mStrongRefs);
+ sprintf(buf, "Weak references on RefBase %p (weakref_type %p):\n", mBase, this);
+ text.append(buf);
+ printRefsLocked(&text, mWeakRefs);
+ }
+
+ {
+ char name[100];
+ snprintf(name, 100, "/data/%p.stack", this);
+ int rc = open(name, O_RDWR | O_CREAT | O_APPEND);
+ if (rc >= 0) {
+ write(rc, text.string(), text.length());
+ close(rc);
+ LOGD("STACK TRACE for %p saved in %s", this, name);
+ }
+ else LOGE("FAILED TO PRINT STACK TRACE for %p in %s: %s", this,
+ name, strerror(errno));
+ }
+ }
+
+private:
+ struct ref_entry
+ {
+ ref_entry* next;
+ const void* id;
+#if DEBUG_REFS_CALLSTACK_ENABLED
+ CallStack stack;
+#endif
+ int32_t ref;
+ };
+
+ void addRef(ref_entry** refs, const void* id, int32_t mRef)
+ {
+ if (mTrackEnabled) {
+ AutoMutex _l(mMutex);
+ ref_entry* ref = new ref_entry;
+ // Reference count at the time of the snapshot, but before the
+ // update. Positive value means we increment, negative--we
+ // decrement the reference count.
+ ref->ref = mRef;
+ ref->id = id;
+#if DEBUG_REFS_CALLSTACK_ENABLED
+ ref->stack.update(2);
+#endif
+
+ ref->next = *refs;
+ *refs = ref;
+ }
+ }
+
+ void removeRef(ref_entry** refs, const void* id)
+ {
+ if (mTrackEnabled) {
+ AutoMutex _l(mMutex);
+
+ ref_entry* ref = *refs;
+ while (ref != NULL) {
+ if (ref->id == id) {
+ *refs = ref->next;
+ delete ref;
+ return;
+ }
+
+ refs = &ref->next;
+ ref = *refs;
+ }
+
+ LOG_ALWAYS_FATAL("RefBase: removing id %p on RefBase %p (weakref_type %p) that doesn't exist!",
+ id, mBase, this);
+ }
+ }
+
+ void printRefsLocked(String8* out, const ref_entry* refs) const
+ {
+ char buf[128];
+ while (refs) {
+ char inc = refs->ref >= 0 ? '+' : '-';
+ sprintf(buf, "\t%c ID %p (ref %d):\n",
+ inc, refs->id, refs->ref);
+ out->append(buf);
+#if DEBUG_REFS_CALLSTACK_ENABLED
+ out->append(refs->stack.toString("\t\t"));
+#else
+ out->append("\t\t(call stacks disabled)");
+#endif
+ refs = refs->next;
+ }
+ }
+
+ Mutex mMutex;
+ ref_entry* mStrongRefs;
+ ref_entry* mWeakRefs;
+
+ bool mTrackEnabled;
+ // Collect stack traces on addref and removeref, instead of deleting the stack references
+ // on removeref that match the address ones.
+ bool mRetain;
+
+#if 0
+ void addRef(KeyedVector<const void*, int32_t>* refs, const void* id)
+ {
+ AutoMutex _l(mMutex);
+ ssize_t i = refs->indexOfKey(id);
+ if (i >= 0) {
+ ++(refs->editValueAt(i));
+ } else {
+ i = refs->add(id, 1);
+ }
+ }
+
+ void removeRef(KeyedVector<const void*, int32_t>* refs, const void* id)
+ {
+ AutoMutex _l(mMutex);
+ ssize_t i = refs->indexOfKey(id);
+ LOG_ALWAYS_FATAL_IF(i < 0, "RefBase: removing id %p that doesn't exist!", id);
+ if (i >= 0) {
+ int32_t val = --(refs->editValueAt(i));
+ if (val == 0) {
+ refs->removeItemsAt(i);
+ }
+ }
+ }
+
+ void printRefs(const KeyedVector<const void*, int32_t>& refs)
+ {
+ const size_t N=refs.size();
+ for (size_t i=0; i<N; i++) {
+ printf("\tID %p: %d remain\n", refs.keyAt(i), refs.valueAt(i));
+ }
+ }
+
+ mutable Mutex mMutex;
+ KeyedVector<const void*, int32_t> mStrongRefs;
+ KeyedVector<const void*, int32_t> mWeakRefs;
+#endif
+
+#endif
+};
+
+// ---------------------------------------------------------------------------
+
+void RefBase::incStrong(const void* id) const
+{
+ weakref_impl* const refs = mRefs;
+ refs->addWeakRef(id);
+ refs->incWeak(id);
+
+ refs->addStrongRef(id);
+ const int32_t c = android_atomic_inc(&refs->mStrong);
+ LOG_ASSERT(c > 0, "incStrong() called on %p after last strong ref", refs);
+#if PRINT_REFS
+ LOGD("incStrong of %p from %p: cnt=%d\n", this, id, c);
+#endif
+ if (c != INITIAL_STRONG_VALUE) {
+ return;
+ }
+
+ android_atomic_add(-INITIAL_STRONG_VALUE, &refs->mStrong);
+ const_cast<RefBase*>(this)->onFirstRef();
+}
+
+void RefBase::decStrong(const void* id) const
+{
+ weakref_impl* const refs = mRefs;
+ refs->removeStrongRef(id);
+ const int32_t c = android_atomic_dec(&refs->mStrong);
+#if PRINT_REFS
+ LOGD("decStrong of %p from %p: cnt=%d\n", this, id, c);
+#endif
+ LOG_ASSERT(c >= 1, "decStrong() called on %p too many times", refs);
+ if (c == 1) {
+ const_cast<RefBase*>(this)->onLastStrongRef(id);
+ if ((refs->mFlags&OBJECT_LIFETIME_WEAK) != OBJECT_LIFETIME_WEAK) {
+ delete this;
+ }
+ }
+ refs->removeWeakRef(id);
+ refs->decWeak(id);
+}
+
+void RefBase::forceIncStrong(const void* id) const
+{
+ weakref_impl* const refs = mRefs;
+ refs->addWeakRef(id);
+ refs->incWeak(id);
+
+ refs->addStrongRef(id);
+ const int32_t c = android_atomic_inc(&refs->mStrong);
+ LOG_ASSERT(c >= 0, "forceIncStrong called on %p after ref count underflow",
+ refs);
+#if PRINT_REFS
+ LOGD("forceIncStrong of %p from %p: cnt=%d\n", this, id, c);
+#endif
+
+ switch (c) {
+ case INITIAL_STRONG_VALUE:
+ android_atomic_add(-INITIAL_STRONG_VALUE, &refs->mStrong);
+ // fall through...
+ case 0:
+ const_cast<RefBase*>(this)->onFirstRef();
+ }
+}
+
+int32_t RefBase::getStrongCount() const
+{
+ return mRefs->mStrong;
+}
+
+
+
+RefBase* RefBase::weakref_type::refBase() const
+{
+ return static_cast<const weakref_impl*>(this)->mBase;
+}
+
+void RefBase::weakref_type::incWeak(const void* id)
+{
+ weakref_impl* const impl = static_cast<weakref_impl*>(this);
+ impl->addWeakRef(id);
+ const int32_t c = android_atomic_inc(&impl->mWeak);
+ LOG_ASSERT(c >= 0, "incWeak called on %p after last weak ref", this);
+}
+
+void RefBase::weakref_type::decWeak(const void* id)
+{
+ weakref_impl* const impl = static_cast<weakref_impl*>(this);
+ impl->removeWeakRef(id);
+ const int32_t c = android_atomic_dec(&impl->mWeak);
+ LOG_ASSERT(c >= 1, "decWeak called on %p too many times", this);
+ if (c != 1) return;
+
+ if ((impl->mFlags&OBJECT_LIFETIME_WEAK) != OBJECT_LIFETIME_WEAK) {
+ if (impl->mStrong == INITIAL_STRONG_VALUE)
+ delete impl->mBase;
+ else {
+// LOGV("Freeing refs %p of old RefBase %p\n", this, impl->mBase);
+ delete impl;
+ }
+ } else {
+ impl->mBase->onLastWeakRef(id);
+ if ((impl->mFlags&OBJECT_LIFETIME_FOREVER) != OBJECT_LIFETIME_FOREVER) {
+ delete impl->mBase;
+ }
+ }
+}
+
+bool RefBase::weakref_type::attemptIncStrong(const void* id)
+{
+ incWeak(id);
+
+ weakref_impl* const impl = static_cast<weakref_impl*>(this);
+
+ int32_t curCount = impl->mStrong;
+ LOG_ASSERT(curCount >= 0, "attemptIncStrong called on %p after underflow",
+ this);
+ while (curCount > 0 && curCount != INITIAL_STRONG_VALUE) {
+ if (android_atomic_cmpxchg(curCount, curCount+1, &impl->mStrong) == 0) {
+ break;
+ }
+ curCount = impl->mStrong;
+ }
+
+ if (curCount <= 0 || curCount == INITIAL_STRONG_VALUE) {
+ bool allow;
+ if (curCount == INITIAL_STRONG_VALUE) {
+ // Attempting to acquire first strong reference... this is allowed
+ // if the object does NOT have a longer lifetime (meaning the
+ // implementation doesn't need to see this), or if the implementation
+ // allows it to happen.
+ allow = (impl->mFlags&OBJECT_LIFETIME_WEAK) != OBJECT_LIFETIME_WEAK
+ || impl->mBase->onIncStrongAttempted(FIRST_INC_STRONG, id);
+ } else {
+ // Attempting to revive the object... this is allowed
+ // if the object DOES have a longer lifetime (so we can safely
+ // call the object with only a weak ref) and the implementation
+ // allows it to happen.
+ allow = (impl->mFlags&OBJECT_LIFETIME_WEAK) == OBJECT_LIFETIME_WEAK
+ && impl->mBase->onIncStrongAttempted(FIRST_INC_STRONG, id);
+ }
+ if (!allow) {
+ decWeak(id);
+ return false;
+ }
+ curCount = android_atomic_inc(&impl->mStrong);
+
+ // If the strong reference count has already been incremented by
+ // someone else, the implementor of onIncStrongAttempted() is holding
+ // an unneeded reference. So call onLastStrongRef() here to remove it.
+ // (No, this is not pretty.) Note that we MUST NOT do this if we
+ // are in fact acquiring the first reference.
+ if (curCount > 0 && curCount < INITIAL_STRONG_VALUE) {
+ impl->mBase->onLastStrongRef(id);
+ }
+ }
+
+ impl->addWeakRef(id);
+ impl->addStrongRef(id);
+
+#if PRINT_REFS
+ LOGD("attemptIncStrong of %p from %p: cnt=%d\n", this, id, curCount);
+#endif
+
+ if (curCount == INITIAL_STRONG_VALUE) {
+ android_atomic_add(-INITIAL_STRONG_VALUE, &impl->mStrong);
+ impl->mBase->onFirstRef();
+ }
+
+ return true;
+}
+
+bool RefBase::weakref_type::attemptIncWeak(const void* id)
+{
+ weakref_impl* const impl = static_cast<weakref_impl*>(this);
+
+ int32_t curCount = impl->mWeak;
+ LOG_ASSERT(curCount >= 0, "attemptIncWeak called on %p after underflow",
+ this);
+ while (curCount > 0) {
+ if (android_atomic_cmpxchg(curCount, curCount+1, &impl->mWeak) == 0) {
+ break;
+ }
+ curCount = impl->mWeak;
+ }
+
+ if (curCount > 0) {
+ impl->addWeakRef(id);
+ }
+
+ return curCount > 0;
+}
+
+int32_t RefBase::weakref_type::getWeakCount() const
+{
+ return static_cast<const weakref_impl*>(this)->mWeak;
+}
+
+void RefBase::weakref_type::printRefs() const
+{
+ static_cast<const weakref_impl*>(this)->printRefs();
+}
+
+void RefBase::weakref_type::trackMe(bool enable, bool retain)
+{
+ static_cast<const weakref_impl*>(this)->trackMe(enable, retain);
+}
+
+RefBase::weakref_type* RefBase::createWeak(const void* id) const
+{
+ mRefs->incWeak(id);
+ return mRefs;
+}
+
+RefBase::weakref_type* RefBase::getWeakRefs() const
+{
+ return mRefs;
+}
+
+RefBase::RefBase()
+ : mRefs(new weakref_impl(this))
+{
+// LOGV("Creating refs %p with RefBase %p\n", mRefs, this);
+}
+
+RefBase::~RefBase()
+{
+// LOGV("Destroying RefBase %p (refs %p)\n", this, mRefs);
+ if (mRefs->mWeak == 0) {
+// LOGV("Freeing refs %p of old RefBase %p\n", mRefs, this);
+ delete mRefs;
+ }
+}
+
+void RefBase::extendObjectLifetime(int32_t mode)
+{
+ android_atomic_or(mode, &mRefs->mFlags);
+}
+
+void RefBase::onFirstRef()
+{
+}
+
+void RefBase::onLastStrongRef(const void* /*id*/)
+{
+}
+
+bool RefBase::onIncStrongAttempted(uint32_t flags, const void* id)
+{
+ return (flags&FIRST_INC_STRONG) ? true : false;
+}
+
+void RefBase::onLastWeakRef(const void* /*id*/)
+{
+}
+
+}; // namespace android