#pragma once
#include <atomic>
#include <wtf/NeverDestroyed.h>
namespace WTF {
template <typename IdentifierType, typename ClassType>
class IdentifiedBase {
public:
IdentifierType identifier() const
{
return m_identifier;
}
protected:
IdentifiedBase(const IdentifiedBase& other)
: m_identifier(other.m_identifier)
{
}
explicit IdentifiedBase(IdentifierType identifier)
: m_identifier(identifier)
{
}
private:
IdentifierType m_identifier;
};
template <typename T>
class Identified : public IdentifiedBase<uint64_t, T> {
protected:
Identified()
: IdentifiedBase<uint64_t, T>(generateIdentifier())
{
}
Identified(const Identified&) = default;
explicit Identified(uint64_t identifier)
: IdentifiedBase<uint64_t, T>(identifier)
{
}
private:
static uint64_t generateIdentifier()
{
static uint64_t currentIdentifier;
return ++currentIdentifier;
}
};
template <typename T>
class ThreadSafeIdentified : public IdentifiedBase<uint64_t, T> {
protected:
ThreadSafeIdentified()
: IdentifiedBase<uint64_t, T>(generateIdentifier())
{
}
ThreadSafeIdentified(const ThreadSafeIdentified&) = default;
explicit ThreadSafeIdentified(uint64_t identifier)
: IdentifiedBase<uint64_t, T>(identifier)
{
}
private:
static uint64_t generateIdentifier()
{
static LazyNeverDestroyed<std::atomic<uint64_t>> currentIdentifier;
static std::once_flag initializeCurrentIdentifier;
std::call_once(initializeCurrentIdentifier, [] {
currentIdentifier.construct(0);
});
return ++currentIdentifier.get();
}
};
}
using WTF::Identified;
using WTF::ThreadSafeIdentified;