cow.h File Reference

Copy-on-write helper macro for IR ffi::ObjectRef types. More...

#include <tvm/ffi/object.h>
#include <utility>

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Namespaces
	tvm
	An object that builds and maintains block scope and StmtSref mapping for Dependence analysis.

Macros
#define	TVM_DEFINE_OBJECT_REF_COW_METHOD(ObjectName)
	Define CopyOnWrite function in an ffi::ObjectRef. More...

Detailed Description

Copy-on-write helper macro for IR ffi::ObjectRef types.

Macro Definition Documentation

TVM_DEFINE_OBJECT_REF_COW_METHOD

#define TVM_DEFINE_OBJECT_REF_COW_METHOD

(

ObjectName

)

Value:

  static_assert(ObjectName::_type_final,                                   \
                "TVM's CopyOnWrite may only be used for "                  \
                "Object types that are declared as final, "                \
                "using the TVM_FFI_DECLARE_OBJECT_INFO_FINAL macro.");     \
  ObjectName* CopyOnWrite() {                                              \
    TVM_FFI_ICHECK(data_ != nullptr);                                      \
    if (!data_.unique()) {                                                 \
      auto n = ::tvm::ffi::make_object<ObjectName>(*(operator->()));       \
      ::tvm::ffi::ObjectPtr<::tvm::ffi::Object>(std::move(n)).swap(data_); \
    }                                                                      \
    return static_cast<ObjectName*>(data_.get());                          \
  }

Define CopyOnWrite function in an ffi::ObjectRef.

Parameters

ObjectName

The Type of the Node.

CopyOnWrite will generate a unique copy of the internal node. The node will be copied if it is referenced by multiple places. The function returns the raw pointer to the node to allow modification of the content.

MyCOWObjectRef ref, ref2;
ref2 = ref;
ref.CopyOnWrite()->value = new_value;
assert(ref2->value == old_value);
assert(ref->value == new_value);