blob: 79d9b53387f3933d41cc420b03d259c394cba7ba [file] [log] [blame]
//===- Profile.h - XRay Profile Abstraction -------------------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Defines the XRay Profile class representing the latency profile generated by
// XRay's profiling mode.
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Error.h"
#include <list>
#include <utility>
#include <vector>
namespace llvm {
namespace xray {
class Profile;
// We forward declare the Trace type for turning a Trace into a Profile.
class Trace;
/// This function will attempt to load an XRay Profiling Mode profile from the
/// provided |Filename|.
/// For any errors encountered in the loading of the profile data from
/// |Filename|, this function will return an Error condition appropriately.
Expected<Profile> loadProfile(StringRef Filename);
/// This algorithm will merge two Profile instances into a single Profile
/// instance, aggregating blocks by Thread ID.
Profile mergeProfilesByThread(const Profile &L, const Profile &R);
/// This algorithm will merge two Profile instances into a single Profile
/// instance, aggregating blocks by function call stack.
Profile mergeProfilesByStack(const Profile &L, const Profile &R);
/// This function takes a Trace and creates a Profile instance from it.
Expected<Profile> profileFromTrace(const Trace &T);
/// Profile instances are thread-compatible.
class Profile {
using ThreadID = uint64_t;
using PathID = unsigned;
using FuncID = int32_t;
struct Data {
uint64_t CallCount;
uint64_t CumulativeLocalTime;
struct Block {
ThreadID Thread;
std::vector<std::pair<PathID, Data>> PathData;
/// Provides a sequence of function IDs from a previously interned PathID.
/// Returns an error if |P| had not been interned before into the Profile.
Expected<std::vector<FuncID>> expandPath(PathID P) const;
/// The stack represented in |P| must be in stack order (leaf to root). This
/// will always return the same PathID for |P| that has the same sequence.
PathID internPath(ArrayRef<FuncID> P);
/// Appends a fully-formed Block instance into the Profile.
/// Returns an error condition in the following cases:
/// - The PathData component of the Block is empty
Error addBlock(Block &&B);
Profile() = default;
~Profile() = default;
Profile(Profile &&O) noexcept
: Blocks(std::move(O.Blocks)), NodeStorage(std::move(O.NodeStorage)),
Roots(std::move(O.Roots)), PathIDMap(std::move(O.PathIDMap)),
NextID(O.NextID) {}
Profile &operator=(Profile &&O) noexcept {
Blocks = std::move(O.Blocks);
NodeStorage = std::move(O.NodeStorage);
Roots = std::move(O.Roots);
PathIDMap = std::move(O.PathIDMap);
NextID = O.NextID;
return *this;
Profile(const Profile &);
Profile &operator=(const Profile &);
friend void swap(Profile &L, Profile &R) {
using std::swap;
swap(L.Blocks, R.Blocks);
swap(L.NodeStorage, R.NodeStorage);
swap(L.Roots, R.Roots);
swap(L.PathIDMap, R.PathIDMap);
swap(L.NextID, R.NextID);
using BlockList = std::list<Block>;
struct TrieNode {
FuncID Func = 0;
std::vector<TrieNode *> Callees{};
TrieNode *Caller = nullptr;
PathID ID = 0;
// List of blocks associated with a Profile.
BlockList Blocks;
// List of TrieNode elements we've seen.
std::list<TrieNode> NodeStorage;
// List of call stack roots.
SmallVector<TrieNode *, 4> Roots;
// Reverse mapping between a PathID to a TrieNode*.
DenseMap<PathID, TrieNode *> PathIDMap;
// Used to identify paths.
PathID NextID = 1;
using const_iterator = BlockList::const_iterator;
const_iterator begin() const { return Blocks.begin(); }
const_iterator end() const { return Blocks.end(); }
bool empty() const { return Blocks.empty(); }
} // namespace xray
} // namespace llvm