xref: /netbsd-src/sys/external/bsd/compiler_rt/dist/lib/xray/xray_profile_collector.h (revision a7c257b03e4462df2b1020128fb82716512d7856)
1 //===-- xray_profile_collector.h -------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of XRay, a dynamic runtime instrumentation system.
11 //
12 // This file defines the interface for a data collection service, for XRay
13 // profiling. What we implement here is an in-process service where
14 // FunctionCallTrie instances can be handed off by threads, to be
15 // consolidated/collected.
16 //
17 //===----------------------------------------------------------------------===//
18 #ifndef XRAY_XRAY_PROFILE_COLLECTOR_H
19 #define XRAY_XRAY_PROFILE_COLLECTOR_H
20 
21 #include "xray_function_call_trie.h"
22 
23 #include "xray/xray_log_interface.h"
24 
25 namespace __xray {
26 
27 /// The ProfileCollectorService implements a centralised mechanism for
28 /// collecting FunctionCallTrie instances, indexed by thread ID. On demand, the
29 /// ProfileCollectorService can be queried for the most recent state of the
30 /// data, in a form that allows traversal.
31 namespace profileCollectorService {
32 
33 /// Posts the FunctionCallTrie associated with a specific Thread ID. This
34 /// will:
35 ///
36 /// Moves the collection of FunctionCallTrie, Allocators, and Buffers associated
37 /// with a thread's data to the queue. This takes ownership of the memory
38 /// associated with a thread, and manages those exclusively.
39 ///
40 void post(BufferQueue *Q, FunctionCallTrie &&T,
41           FunctionCallTrie::Allocators &&A,
42           FunctionCallTrie::Allocators::Buffers &&B, tid_t TId);
43 
44 /// The serialize will process all FunctionCallTrie instances in memory, and
45 /// turn those into specifically formatted blocks, each describing the
46 /// function call trie's contents in a compact form. In memory, this looks
47 /// like the following layout:
48 ///
49 ///   - block size (32 bits)
50 ///   - block number (32 bits)
51 ///   - thread id (64 bits)
52 ///   - list of records:
53 ///     - function ids in leaf to root order, terminated by
54 ///       0 (32 bits per function id)
55 ///     - call count (64 bit)
56 ///     - cumulative local time (64 bit)
57 ///     - record delimiter (64 bit, 0x0)
58 ///
59 void serialize();
60 
61 /// The reset function will clear out any internal memory held by the
62 /// service. The intent is to have the resetting be done in calls to the
63 /// initialization routine, or explicitly through the flush log API.
64 void reset();
65 
66 /// This nextBuffer function is meant to implement the iterator functionality,
67 /// provided in the XRay API.
68 XRayBuffer nextBuffer(XRayBuffer B);
69 
70 } // namespace profileCollectorService
71 
72 } // namespace __xray
73 
74 #endif // XRAY_XRAY_PROFILE_COLLECTOR_H
75