Caffe2 - C++ API
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Public Member Functions
c10::DataPtr Class Reference

Public Member Functions

 DataPtr (void *data, Device device)
 DataPtr (void *data, void *ctx, DeleterFnPtr ctx_deleter, Device device)
void * operator-> () const
void clear ()
void * get () const
void * get_context () const
void * release_context ()
std::unique_ptr< void, DeleterFnPtr > && move_context ()
 operator bool () const
template<typename T >
Tcast_context (DeleterFnPtr expected_deleter) const
DeleterFnPtr get_deleter () const
C10_NODISCARD bool compare_exchange_deleter (DeleterFnPtr expected_deleter, DeleterFnPtr new_deleter)
 Compare the deleter in a DataPtr to expected_deleter. More...
Device device () const
void unsafe_set_device (Device device)

Detailed Description

Definition at line 19 of file Allocator.h.

Member Function Documentation

C10_NODISCARD bool c10::DataPtr::compare_exchange_deleter ( DeleterFnPtr  expected_deleter,
DeleterFnPtr  new_deleter 

Compare the deleter in a DataPtr to expected_deleter.

If it matches, replace the deleter with new_deleter and return true; otherwise, does nothing and returns false.

In general, it is not safe to unconditionally set the deleter on a DataPtr, because you don't know what the deleter is, and thus will have a hard time properly disposing of the deleter without storing the original deleter (this is difficult to do, because DeleterFnPtr is not a closure, and because the context on DataPtr is only a single word, you generally don't have enough space to store both the original deleter and its context). However, in some cases, you know /exactly/ what the deleter is, and you have a new deleter that manually wraps the old one. In this case, you can safely swap the deleter after asserting that the deleters line up.

What are the requirements on new_deleter? It must still properly dispose of the void* pointer passed in as its argument, where void* is whatever the context of the original deleter is. So in general, you expect the new deleter to look something like this:

 [](void* ptr) {

Note that it won't work to close over the original allocator; you don't have enough space to do that! Also, it's unsafe to assume that the passed in pointer in question is the memory pointer in question; it might not be; be sure to read the source code of the Allocator in question to confirm this.

Definition at line 96 of file Allocator.h.

The documentation for this class was generated from the following file: