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| //===------------------SharedCluster.h --------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef utility_SharedCluster_h_
#define utility_SharedCluster_h_
#include "lldb/Utility/LLDBAssert.h"
#include "lldb/Utility/SharingPtr.h"
#include "llvm/ADT/SmallPtrSet.h"
#include <mutex>
namespace lldb_private {
namespace imp {
template <typename T>
class shared_ptr_refcount : public lldb_private::imp::shared_count {
public:
template <class Y>
shared_ptr_refcount(Y *in) : shared_count(0), manager(in) {}
shared_ptr_refcount() : shared_count(0) {}
~shared_ptr_refcount() override {}
void on_zero_shared() override { manager->DecrementRefCount(); }
private:
T *manager;
};
} // namespace imp
template <class T> class ClusterManager {
public:
ClusterManager() : m_objects(), m_external_ref(0), m_mutex() {}
~ClusterManager() {
for (typename llvm::SmallPtrSet<T *, 16>::iterator pos = m_objects.begin(),
end = m_objects.end();
pos != end; ++pos) {
T *object = *pos;
delete object;
}
// Decrement refcount should have been called on this ClusterManager, and
// it should have locked the mutex, now we will unlock it before we destroy
// it...
m_mutex.unlock();
}
void ManageObject(T *new_object) {
std::lock_guard<std::mutex> guard(m_mutex);
m_objects.insert(new_object);
}
typename lldb_private::SharingPtr<T> GetSharedPointer(T *desired_object) {
{
std::lock_guard<std::mutex> guard(m_mutex);
m_external_ref++;
if (0 == m_objects.count(desired_object)) {
lldbassert(false && "object not found in shared cluster when expected");
desired_object = nullptr;
}
}
return typename lldb_private::SharingPtr<T>(
desired_object, new imp::shared_ptr_refcount<ClusterManager>(this));
}
private:
void DecrementRefCount() {
m_mutex.lock();
m_external_ref--;
if (m_external_ref == 0)
delete this;
else
m_mutex.unlock();
}
friend class imp::shared_ptr_refcount<ClusterManager>;
llvm::SmallPtrSet<T *, 16> m_objects;
int m_external_ref;
std::mutex m_mutex;
};
} // namespace lldb_private
#endif // utility_SharedCluster_h_
|