Skip to content

add cow_ptr_t.h #758

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
lambda7xx wants to merge 2 commits into from
Closed

add cow_ptr_t.h #758

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
2878139
add cow_ptr_t.h
lambda7xx Jun 8, 2023
4572966
remove the nullptr for cow_ptr_t
lambda7xx Jun 8, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
68 changes: 47 additions & 21 deletions lib/utils/include/utils/graph/cow_ptr_t.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,11 +8,20 @@

namespace FlexFlow {

template <typename T> struct cow_ptr_t {
cow_ptr_t() { this->set_unique(nullptr); }
cow_ptr_t(std::shared_ptr<T> ptr) { this->set_shared(std::move(ptr)); }
cow_ptr_t(std::unique_ptr<T> ptr) { this->set_unique(std::move(ptr)); }
cow_ptr_t(T const &val) { this->set_unique(make_unique<T>(val)); }
template <typename T>
struct cow_ptr_t {
cow_ptr_t() {
this->set_unique(nullptr);
}
cow_ptr_t(std::shared_ptr<T> ptr) {
this->set_shared(std::move(ptr));
}
cow_ptr_t(std::unique_ptr<T> ptr) {
this->set_unique(std::move(ptr));
}
cow_ptr_t(T const &val) {
this->set_unique(make_unique<T>(val));
}
cow_ptr_t(cow_ptr_t const &other) {
this->set_shared(other.get_shared_ptr());
}
Expand All @@ -24,7 +33,9 @@ template <typename T> struct cow_ptr_t {
using shared_t = std::shared_ptr<T const>;
using unique_t = std::unique_ptr<T>;

T const *get() const { return &this->ref(); }
T const *get() const {
return &this->ref();
}

T const &ref() const {
if (this->has_unique_access()) {
Expand All @@ -34,26 +45,35 @@ template <typename T> struct cow_ptr_t {
}
}

T const &operator*() const { return this->get(); }
T const &operator*() const {
return this->get();
}

T const *operator->() const { return &this->get(); }
T const *operator->() const {
return this->get();
}

std::shared_ptr<T const> get_shared_ptr() const {
if (this->has_unique_access()) {
this->set_shared(shared_ptr(this->get_unique()));
this->set_shared(shared_t(this->get_unique()));
}
return this->get_shared();
}

T *mutable_ptr() const {
if (this->has_unique_access()) {
return *this->get_unique();
return this->get_unique().get();
} else {
this->set_unique(unique_t(this->get_shared()->clone()));
}
auto shared = this->get_shared();
this->set_unique(unique_t(shared->clone()));
auto ptr = mpark::get_if<unique_t>(&this->ptr);
return ptr->get();
}
}

T &mutable_ref() const { return *this->mutable_ptr(); }
T &mutable_ref() const {
return *this->mutable_ptr();
}

bool has_unique_access() const {
return holds_alternative<unique_t>(this->ptr);
Expand All @@ -74,23 +94,29 @@ template <typename T> struct cow_ptr_t {
}

private:
void set_shared(shared_t ptr) {
this->ptr = variant<shared_t>(std::move(ptr));
void set_shared(shared_t ptr) const {
this->ptr =
variant<std::unique_ptr<T>, std::shared_ptr<T const>>(std::move(ptr));
}

void set_unique(unique_t ptr) {
this->ptr = variant<unique_t>(std::move(ptr));
void set_unique(std::unique_ptr<T> ptr) const {
this->ptr =
variant<std::unique_ptr<T>, std::shared_ptr<T const>>(std::move(ptr));
}

std::unique_ptr<T> &get_unique() const { return get<unique_t>(this->ptr); }
std::unique_ptr<T> get_unique() const {
auto ptr = mpark::get_if<unique_t>(&this->ptr);
return std::move(*ptr);
}

std::shared_ptr<T const> &get_shared() const {
return get<shared_t>(this->ptr);
std::shared_ptr<T const> get_shared() const {
auto ptr = mpark::get_if<shared_t>(&this->ptr);
return *ptr;
}

mutable variant<std::unique_ptr<T>, std::shared_ptr<T const>> ptr;
};

} // namespace FlexFlow

#endif
#endif