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/*
* Copyright (C) 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.
*/
#pragma once
#include "ProcessIdentifier.h"
#include <wtf/Hasher.h>
#include <wtf/Markable.h>
#include <wtf/text/MakeString.h>
#include <wtf/text/TextStream.h>
namespace WebCore {
template <typename T>
class ProcessQualified {
public:
// This class is used when a single process retains objects representing things in multiple other processes.
// (E.g. resources in the GPU process.)
// Generally, objects are identified uniquely per process, but if multiple processes share them to a single
// process, the single process should distinguish between them by augmenting the objects with the
// ProcessIdentifier of the process which created them.
ProcessQualified(T&& object, ProcessIdentifier processIdentifier)
: m_object(WTFMove(object))
, m_processIdentifier(processIdentifier)
{
}
ProcessQualified(const T& object, ProcessIdentifier processIdentifier)
: m_object(object)
, m_processIdentifier(processIdentifier)
{
}
ProcessQualified(WTF::HashTableDeletedValueType)
: m_object(WTF::HashTableDeletedValue)
, m_processIdentifier(WTF::HashTableDeletedValue)
{
}
operator bool() const
{
return static_cast<bool>(m_object);
}
const T& object() const
{
return m_object;
}
ProcessIdentifier processIdentifier() const
{
return m_processIdentifier;
}
bool isHashTableDeletedValue() const
{
return m_processIdentifier.isHashTableDeletedValue();
}
friend bool operator==(const ProcessQualified&, const ProcessQualified&) = default;
static ProcessQualified generate() { return { T::generate(), Process::identifier() }; }
// MonotonicObjectIdentifier support
static ProcessQualified generateMonotonic() { return { T(), Process::identifier() }; }
ProcessQualified next() const { return { m_object.next(), m_processIdentifier }; }
ProcessQualified& increment() { m_object.increment(); return *this; }
String toString() const { return makeString(m_processIdentifier.toUInt64(), '-', m_object.toUInt64()); }
String loggingString() const { return toString(); }
// Comparison operators for callers that have already verified that
// the objects originate from the same process.
bool lessThanSameProcess(const ProcessQualified& other)
{
ASSERT(processIdentifier() == other.processIdentifier());
return object() < other.object();
}
bool lessThanOrEqualSameProcess(const ProcessQualified& other)
{
ASSERT(processIdentifier() == other.processIdentifier());
return object() <= other.object();
}
bool greaterThanSameProcess(const ProcessQualified& other)
{
ASSERT(processIdentifier() == other.processIdentifier());
return object() > other.object();
}
bool greaterThanOrEqualSameProcess(const ProcessQualified& other)
{
ASSERT(processIdentifier() == other.processIdentifier());
return object() >= other.object();
}
struct MarkableTraits {
static bool isEmptyValue(const ProcessQualified& identifier) { return T::MarkableTraits::isEmptyValue(identifier.object()); }
static constexpr ProcessQualified emptyValue() { return { T::MarkableTraits::emptyValue(), ProcessIdentifier::MarkableTraits::emptyValue() }; }
};
private:
T m_object;
ProcessIdentifier m_processIdentifier;
};
template<typename T>
bool operator>(const ProcessQualified<T>&, const ProcessQualified<T>&) = delete;
template<typename T>
bool operator>=(const ProcessQualified<T>&, const ProcessQualified<T>&) = delete;
template<typename T>
bool operator<(const ProcessQualified<T>&, const ProcessQualified<T>&) = delete;
template<typename T>
bool operator<=(const ProcessQualified<T>&, const ProcessQualified<T>&) = delete;
template <typename T>
inline TextStream& operator<<(TextStream& ts, const ProcessQualified<T>& processQualified)
{
ts << "ProcessQualified(" << processQualified.object() << ", " << processQualified.processIdentifier() << ')';
return ts;
}
template <typename T>
inline void add(Hasher& hasher, const ProcessQualified<T>& processQualified)
{
add(hasher, processQualified.object());
add(hasher, processQualified.processIdentifier());
}
} // namespace WebCore
namespace WTF {
template<typename T> struct DefaultHash;
template<typename T> struct DefaultHash<WebCore::ProcessQualified<T>> {
static unsigned hash(const WebCore::ProcessQualified<T>& processQualified)
{
return computeHash(processQualified);
}
static bool equal(const WebCore::ProcessQualified<T>& a, const WebCore::ProcessQualified<T>& b)
{
return a == b;
}
static const bool safeToCompareToEmptyOrDeleted = DefaultHash<T>::safeToCompareToEmptyOrDeleted;
};
template<typename T> struct HashTraits<WebCore::ProcessQualified<T>> : SimpleClassHashTraits<WebCore::ProcessQualified<T>> {
static constexpr bool emptyValueIsZero = HashTraits<T>::emptyValueIsZero;
static WebCore::ProcessQualified<T> emptyValue() { return { HashTraits<T>::emptyValue(), HashTraits<WebCore::ProcessIdentifier>::emptyValue() }; }
static bool isEmptyValue(const WebCore::ProcessQualified<T>& value) { return value.object().isHashTableEmptyValue(); }
};
class ProcessQualifiedStringTypeAdapter {
public:
unsigned length() const { return lengthOfIntegerAsString(m_processIdentifier) + lengthOfIntegerAsString(m_objectIdentifier) + 1; }
bool is8Bit() const { return true; }
template<typename CharacterType> void writeTo(std::span<CharacterType> destination) const
{
auto processIdentifierLength = lengthOfIntegerAsString(m_processIdentifier);
writeIntegerToBuffer(m_processIdentifier, destination);
destination[processIdentifierLength] = '-';
writeIntegerToBuffer(m_objectIdentifier, destination.subspan(processIdentifierLength + 1));
}
protected:
explicit ProcessQualifiedStringTypeAdapter(uint64_t processIdentifier, uint64_t objectIdentifier)
: m_processIdentifier(processIdentifier)
, m_objectIdentifier(objectIdentifier)
{ }
private:
uint64_t m_processIdentifier;
uint64_t m_objectIdentifier;
};
template<typename T>
class StringTypeAdapter<WebCore::ProcessQualified<T>, void> : public ProcessQualifiedStringTypeAdapter {
public:
explicit StringTypeAdapter(const WebCore::ProcessQualified<T>& processQualified)
: ProcessQualifiedStringTypeAdapter(processQualified.processIdentifier().toUInt64(), processQualified.object().toUInt64()) { }
};
} // namespace WTF
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