public:

DebuggerState(const DebugOptions& debug_options);

virtual ~DebuggerState();

// Returns a summary string for RepeatedPtrFields of DebugTensorWatches.

const string SummarizeDebugTensorWatches() override;

// Insert special-purpose debug nodes to graph. See the documentation of

// DebugNodeInserter::InsertNodes() for details.

Status DecorateGraphForDebug(Graph* graph, Device* device) override;

const protobuf::RepeatedPtrField<DebugTensorWatch>& watches;

private:

std::unordered_set<string> debug_urls_;

public:

// EXPERIMENTAL: Insert special debug ops (e.g., DebugIdentity) to graph for

// debugging. Currently, such ops need to take exactly one input and has the

// string attribute "tensor_name" to indicate what tensor it watches.

// For example, before the node insertion, the graph may look like:

//

// A:0 -----------1----------> B

// |

// ---------2-----------> C

//

// wherein the output slot 0 of node A feeds as the input to nodes B through

// edge 1 and to node C through edge 2.

// After the node insertion, assuming both B and C have non-Ref input, the

// graph becomes:

// A:0 ---3---> Copy -----------4----------> B

// |

// ---------5--------> C

// |

// ---------6--------> X

//

// If a node (e.g., B) has Ref input, the graph becomes:

//

// --------------------------------> B

// |

// A:0 ---3-----> Copy -----------4----------> C

// |

// -----------5--------> X

//

// In other words, we do not feed Refs to deep-copies to downstream nodes.

//

// Copy is the inserted deep-copy node that copies the input tensor on-device

// (e.g., CPU-to-CPU or GPU-to-GPU deep copy) that reduces the likelihood of

// racy updates during the debug watches. X is the newly created debug node

// that transforms the input (copy of the watched tensor) into a debug signal.

//

// DebugIdentity is the simplest debugging paradigm, in which the debug signal

// (i.e., X:0) equals the tensor itself. More sophisticated debug ops can be

// used to transform the tensor into other debug signals. An example is the

// DebugNanCounter op.

//

// If the nodes (A, B and C) are located on GPU and the edges from A to B or C

// is HOST_MEMORY, then the CopyHost op will be used instead of the Copy op.

static Status InsertNodes(

const protobuf::RepeatedPtrField<DebugTensorWatch>& watches, Graph* graph,

Device* device);

// Get canonical name of a copy node.

static const string GetCopyNodeName(const string& node_name,

const int output_slot);

// Get canonical name of a debug node.

static const string GetDebugNodeName(const string& tensor_name,

const int debug_op_num,

const string& debug_op_name);

private:

static Status CreateCopyNode(Graph* graph, const DeviceType device_type,

const bool is_host_memory,

const string& src_node_name,

const int src_output, const DataType src_dt,

const string& tensor_name, Node** copy_node);

static Status CreateDebugNode(Graph* graph, const DeviceType device_type,

const string& src_copy_node_name,

const DataType src_dt,

const string& tensor_name,

const std::vector<string>& debug_urls,

const int debug_op_num,

const string& debug_op_name, Node** debug_node);