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/*
* Copyright (C) 2013-2021 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#import "config.h"
#import "JSManagedValue.h"
#if JSC_OBJC_API_ENABLED
#import "APICast.h"
#import "Heap.h"
#import "JSContextInternal.h"
#import "JSValueInternal.h"
#import "JSWeakValue.h"
#import "WeakHandleOwner.h"
#import "ObjcRuntimeExtras.h"
#import "JSCInlines.h"
#import
#import
class JSManagedValueHandleOwner final : public JSC::WeakHandleOwner {
public:
void finalize(JSC::Handle, void* context) final;
bool isReachableFromOpaqueRoots(JSC::Handle, void* context, JSC::AbstractSlotVisitor&, ASCIILiteral*) final;
};
static JSManagedValueHandleOwner& managedValueHandleOwner()
{
static NeverDestroyed jsManagedValueHandleOwner;
return jsManagedValueHandleOwner;
}
@implementation JSManagedValue {
JSC::Weak m_globalObject;
RefPtr m_lock;
JSC::JSWeakValue m_weakValue;
RetainPtr m_owners;
}
+ (JSManagedValue *)managedValueWithValue:(JSValue *)value
{
return adoptNS([[self alloc] initWithValue:value]).autorelease();
}
+ (JSManagedValue *)managedValueWithValue:(JSValue *)value andOwner:(id)owner
{
auto managedValue = adoptNS([[self alloc] initWithValue:value]);
[value.context.virtualMachine addManagedReference:managedValue.get() withOwner:owner];
return managedValue.autorelease();
}
- (instancetype)init
{
return [self initWithValue:nil];
}
- (instancetype)initWithValue:(JSValue *)value
{
self = [super init];
if (!self)
return nil;
if (!value)
return self;
JSC::JSGlobalObject* globalObject = toJS([value.context JSGlobalContextRef]);
JSC::VM& vm = globalObject->vm();
JSC::JSLockHolder apiLocker(vm);
auto& owner = managedValueHandleOwner();
JSC::Weak weak(globalObject, &owner, (__bridge void*)self);
m_globalObject.swap(weak);
m_lock = vm.apiLock();
NSPointerFunctionsOptions weakIDOptions = NSPointerFunctionsWeakMemory | NSPointerFunctionsObjectPersonality;
NSPointerFunctionsOptions integerOptions = NSPointerFunctionsOpaqueMemory | NSPointerFunctionsIntegerPersonality;
m_owners = adoptNS([[NSMapTable alloc] initWithKeyOptions:weakIDOptions valueOptions:integerOptions capacity:1]);
JSC::JSValue jsValue = toJS(globalObject, [value JSValueRef]);
if (jsValue.isObject())
m_weakValue.setObject(uncheckedDowncast(jsValue.asCell()), owner, (__bridge void*)self);
else if (jsValue.isString())
m_weakValue.setString(uncheckedDowncast(jsValue.asCell()), owner, (__bridge void*)self);
else
m_weakValue.setPrimitive(jsValue);
return self;
}
- (void)dealloc
{
JSVirtualMachine *virtualMachine = [[[self value] context] virtualMachine];
if (virtualMachine) {
auto copy = adoptNS([m_owners copy]);
for (id owner in [copy keyEnumerator]) {
size_t count = reinterpret_cast(NSMapGet(m_owners.get(), (__bridge void*)owner));
while (count--)
[virtualMachine removeManagedReference:self withOwner:owner];
}
}
[self disconnectValue];
[super dealloc];
}
- (void)didAddOwner:(id)owner
{
size_t count = reinterpret_cast(NSMapGet(m_owners.get(), (__bridge void*)owner));
NSMapInsert(m_owners.get(), (__bridge void*)owner, reinterpret_cast(count + 1));
}
- (void)didRemoveOwner:(id)owner
{
size_t count = reinterpret_cast(NSMapGet(m_owners.get(), (__bridge void*)owner));
if (!count)
return;
if (count == 1) {
NSMapRemove(m_owners.get(), (__bridge void*)owner);
return;
}
NSMapInsert(m_owners.get(), (__bridge void*)owner, reinterpret_cast(count - 1));
}
- (JSValue *)value
{
if (!m_lock)
return nil;
WTF::Locker locker(m_lock.get());
RefPtr vm = m_lock->vm();
if (!vm)
return nil;
if (!m_globalObject)
return nil;
if (m_weakValue.isClear())
return nil;
JSC::JSGlobalObject* globalObject = m_globalObject.get();
JSContext *context = [JSContext contextWithJSGlobalContextRef:toGlobalRef(globalObject)];
JSC::JSValue value;
if (m_weakValue.isPrimitive())
value = m_weakValue.primitive();
else if (m_weakValue.isString())
value = m_weakValue.string();
else
value = m_weakValue.object();
return [JSValue valueWithJSValueRef:toRef(globalObject, value) inContext:context];
}
- (void)disconnectValue
{
m_globalObject.clear();
m_weakValue.clear();
}
@end
@interface JSManagedValue (PrivateMethods)
- (void)disconnectValue;
@end
bool JSManagedValueHandleOwner::isReachableFromOpaqueRoots(JSC::Handle, void* context, JSC::AbstractSlotVisitor& visitor, ASCIILiteral* reason)
{
if (reason) [[unlikely]]
*reason = "JSManagedValue is opaque root"_s;
JSManagedValue *managedValue = (__bridge JSManagedValue *)context;
return visitor.containsOpaqueRoot((__bridge void*)managedValue);
}
void JSManagedValueHandleOwner::finalize(JSC::Handle, void* context)
{
JSManagedValue *managedValue = (__bridge JSManagedValue *)context;
[managedValue disconnectValue];
}
#endif // JSC_OBJC_API_ENABLED