compiler-rt/lib/xray/xray_profile_collector.h

   1 //===-- xray_profile_collector.h -------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of XRay, a dynamic runtime instrumentation system.
  10 //
  11 // This file defines the interface for a data collection service, for XRay
  12 // profiling. What we implement here is an in-process service where
  13 // FunctionCallTrie instances can be handed off by threads, to be
  14 // consolidated/collected.
  15 //
  16 //===----------------------------------------------------------------------===//
  17 #ifndef XRAY_XRAY_PROFILE_COLLECTOR_H
  18 #define XRAY_XRAY_PROFILE_COLLECTOR_H
  19
  20 #include "xray_function_call_trie.h"
  21
  22 #include "xray/xray_log_interface.h"
  23
  24 namespace __xray {
  25
  26 /// The ProfileCollectorService implements a centralised mechanism for
  27 /// collecting FunctionCallTrie instances, indexed by thread ID. On demand, the
  28 /// ProfileCollectorService can be queried for the most recent state of the
  29 /// data, in a form that allows traversal.
  30 namespace profileCollectorService {
  31
  32 /// Posts the FunctionCallTrie associated with a specific Thread ID. This
  33 /// will:
  34 ///
  35 /// Moves the collection of FunctionCallTrie, Allocators, and Buffers associated
  36 /// with a thread's data to the queue. This takes ownership of the memory
  37 /// associated with a thread, and manages those exclusively.
  38 ///
  39 void post(BufferQueue *Q, FunctionCallTrie &&T,
  40           FunctionCallTrie::Allocators &&A,
  41           FunctionCallTrie::Allocators::Buffers &&B, tid_t TId);
  42
  43 /// The serialize will process all FunctionCallTrie instances in memory, and
  44 /// turn those into specifically formatted blocks, each describing the
  45 /// function call trie's contents in a compact form. In memory, this looks
  46 /// like the following layout:
  47 ///
  48 ///   - block size (32 bits)
  49 ///   - block number (32 bits)
  50 ///   - thread id (64 bits)
  51 ///   - list of records:
  52 ///     - function ids in leaf to root order, terminated by
  53 ///       0 (32 bits per function id)
  54 ///     - call count (64 bit)
  55 ///     - cumulative local time (64 bit)
  56 ///     - record delimiter (64 bit, 0x0)
  57 ///
  58 void serialize();
  59
  60 /// The reset function will clear out any internal memory held by the
  61 /// service. The intent is to have the resetting be done in calls to the
  62 /// initialization routine, or explicitly through the flush log API.
  63 void reset();
  64
  65 /// This nextBuffer function is meant to implement the iterator functionality,
  66 /// provided in the XRay API.
  67 XRayBuffer nextBuffer(XRayBuffer B);
  68
  69 } // namespace profileCollectorService
  70
  71 } // namespace __xray
  72
  73 #endif // XRAY_XRAY_PROFILE_COLLECTOR_H