| | 1 | // © 2016 and later: Unicode, Inc. and others. |
| | 2 | // License & terms of use: http://www.unicode.org/copyright.html |
| | 3 | /* |
| | 4 | ****************************************************************************** |
| | 5 | * Copyright (C) 2015, International Business Machines |
| | 6 | * Corporation and others. All Rights Reserved. |
| | 7 | ****************************************************************************** |
| | 8 | * sharedobject.cpp |
| | 9 | */ |
| | 10 | #include "sharedobject.h" |
| | 11 | #include "uassert.h" |
| | 12 | |
| | 13 | U_NAMESPACE_BEGIN |
| | 14 | |
| | 15 | SharedObject::~SharedObject() {} |
| | 16 | |
| | 17 | UnifiedCacheBase::~UnifiedCacheBase() {} |
| | 18 | |
| | 19 | void |
| | 20 | SharedObject::addRef(UBool fromWithinCache) const { |
| | 21 | umtx_atomic_inc(&totalRefCount); |
| | 22 | |
| | 23 | // Although items in use may not be correct immediately, it |
| | 24 | // will be correct eventually. |
| | 25 | if (umtx_atomic_inc(&hardRefCount) == 1 && cachePtr != NULL) { |
| | 26 | // If this object is cached, and the hardRefCount goes from 0 to 1, |
| | 27 | // then the increment must happen from within the cache while the |
| | 28 | // cache global mutex is locked. In this way, we can be rest assured |
| | 29 | // that data races can't happen if the cache performs some task if |
| | 30 | // the hardRefCount is zero while the global cache mutex is locked. |
| | 31 | (void)fromWithinCache; // Suppress unused variable warning in non-debug builds. |
| | 32 | U_ASSERT(fromWithinCache); |
| | 33 | cachePtr->incrementItemsInUse(); |
| | 34 | } |
| | 35 | } |
| | 36 | |
| | 37 | void |
| | 38 | SharedObject::removeRef(UBool fromWithinCache) const { |
| | 39 | UBool decrementItemsInUse = (umtx_atomic_dec(&hardRefCount) == 0); |
| | 40 | UBool allReferencesGone = (umtx_atomic_dec(&totalRefCount) == 0); |
| | 41 | |
| | 42 | // Although items in use may not be correct immediately, it |
| | 43 | // will be correct eventually. |
| | 44 | if (decrementItemsInUse && cachePtr != NULL) { |
| | 45 | if (fromWithinCache) { |
| | 46 | cachePtr->decrementItemsInUse(); |
| | 47 | } else { |
| | 48 | cachePtr->decrementItemsInUseWithLockingAndEviction(); |
| | 49 | } |
| | 50 | } |
| | 51 | if (allReferencesGone) { |
| | 52 | delete this; |
| | 53 | } |
| | 54 | } |
| | 55 | |
| | 56 | void |
| | 57 | SharedObject::addSoftRef() const { |
| | 58 | umtx_atomic_inc(&totalRefCount); |
| | 59 | ++softRefCount; |
| | 60 | } |
| | 61 | |
| | 62 | void |
| | 63 | SharedObject::removeSoftRef() const { |
| | 64 | --softRefCount; |
| | 65 | if (umtx_atomic_dec(&totalRefCount) == 0) { |
| | 66 | delete this; |
| | 67 | } |
| | 68 | } |
| | 69 | |
| | 70 | int32_t |
| | 71 | SharedObject::getRefCount() const { |
| | 72 | return umtx_loadAcquire(totalRefCount); |
| | 73 | } |
| | 74 | |
| | 75 | int32_t |
| | 76 | SharedObject::getHardRefCount() const { |
| | 77 | return umtx_loadAcquire(hardRefCount); |
| | 78 | } |
| | 79 | |
| | 80 | void |
| | 81 | SharedObject::deleteIfZeroRefCount() const { |
| | 82 | if(getRefCount() == 0) { |
| | 83 | delete this; |
| | 84 | } |
| | 85 | } |
| | 86 | |
| | 87 | U_NAMESPACE_END |
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