projects / apple / javascriptcore.git / blame
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|---|---|---|
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1 | /* |
| 2 | * Copyright (C) 2013 Apple Inc. All rights reserved. | |
| 3 | * | |
| 4 | * Redistribution and use in source and binary forms, with or without | |
| 5 | * modification, are permitted provided that the following conditions | |
| 6 | * are met: | |
| 7 | * 1. Redistributions of source code must retain the above copyright | |
| 8 | * notice, this list of conditions and the following disclaimer. | |
| 9 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 10 | * notice, this list of conditions and the following disclaimer in the | |
| 11 | * documentation and/or other materials provided with the distribution. | |
| 12 | * | |
| 13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' | |
| 14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, | |
| 15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| 16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS | |
| 17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| 18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| 19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
| 20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
| 21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF | |
| 23 | * THE POSSIBILITY OF SUCH DAMAGE. | |
| 24 | */ | |
| 25 | ||
| 26 | #ifndef JSManagedValue_h | |
| 27 | #define JSManagedValue_h | |
| 28 | ||
| 29 | #import <JavaScriptCore/JSBase.h> | |
| 30 | ||
| 31 | #if JSC_OBJC_API_ENABLED | |
| 32 | ||
| 33 | @class JSValue; | |
| 34 | @class JSContext; | |
| 35 | ||
| 36 | // JSManagedValue represents a "conditionally retained" JSValue. | |
| 37 | // "Conditionally retained" means that as long as either the JSManagedValue | |
| 38 | // JavaScript value is reachable through the JavaScript object graph | |
| 39 | // or the JSManagedValue object is reachable through the external Objective-C | |
| 40 | // object graph as reported to the JSVirtualMachine using | |
| 41 | // addManagedReference:withOwner:, the corresponding JavaScript value will | |
| 42 | // be retained. However, if neither of these conditions are true, the | |
| 43 | // corresponding JSValue will be released and set to nil. | |
| 44 | // | |
| 45 | // The primary use case for JSManagedValue is for safely referencing JSValues | |
| 46 | // from the Objective-C heap. It is incorrect to store a JSValue into an | |
| 47 | // Objective-C heap object, as this can very easily create a reference cycle, | |
| 48 | // keeping the entire JSContext alive. | |
| 49 | NS_CLASS_AVAILABLE(10_9, 7_0) | |
| 50 | @interface JSManagedValue : NSObject | |
| 51 | ||
| 52 | // Convenience method for creating JSManagedValues from JSValues. | |
| 53 | + (JSManagedValue *)managedValueWithValue:(JSValue *)value; | |
| 54 | ||
| 55 | // Create a JSManagedValue. | |
| 56 | - (id)initWithValue:(JSValue *)value; | |
| 57 | ||
| 58 | // Get the JSValue to which this JSManagedValue refers. If the JavaScript value has been collected, | |
| 59 | // this method returns nil. | |
| 60 | - (JSValue *)value; | |
| 61 | ||
| 62 | @end | |
| 63 | ||
| 64 | #endif // JSC_OBJC_API_ENABLED | |
| 65 | ||
| 66 | #endif // JSManagedValue_h |