1 //===-- tsan_trace.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 ThreadSanitizer (TSan), a race detector.
10 //
11 //===----------------------------------------------------------------------===//
12 #ifndef TSAN_TRACE_H
13 #define TSAN_TRACE_H
14 
15 #include "tsan_defs.h"
16 #include "tsan_mutex.h"
17 #include "tsan_stack_trace.h"
18 #include "tsan_mutexset.h"
19 
20 namespace __tsan {
21 
22 const int kTracePartSizeBits = 13;
23 const int kTracePartSize = 1 << kTracePartSizeBits;
24 const int kTraceParts = 2 * 1024 * 1024 / kTracePartSize;
25 const int kTraceSize = kTracePartSize * kTraceParts;
26 
27 // Must fit into 3 bits.
28 enum EventType {
29   EventTypeMop,
30   EventTypeFuncEnter,
31   EventTypeFuncExit,
32   EventTypeLock,
33   EventTypeUnlock,
34   EventTypeRLock,
35   EventTypeRUnlock
36 };
37 
38 // Represents a thread event (from most significant bit):
39 // u64 typ  : 3;   // EventType.
40 // u64 addr : 61;  // Associated pc.
41 typedef u64 Event;
42 
43 const uptr kEventPCBits = 61;
44 
45 struct TraceHeader {
46 #if !SANITIZER_GO
47   BufferedStackTrace stack0;  // Start stack for the trace.
48 #else
49   VarSizeStackTrace stack0;
50 #endif
51   u64        epoch0;  // Start epoch for the trace.
52   MutexSet   mset0;
53 
TraceHeaderTraceHeader54   TraceHeader() : stack0(), epoch0() {}
55 };
56 
57 struct Trace {
58   Mutex mtx;
59 #if !SANITIZER_GO
60   // Must be last to catch overflow as paging fault.
61   // Go shadow stack is dynamically allocated.
62   uptr shadow_stack[kShadowStackSize];
63 #endif
64   // Must be the last field, because we unmap the unused part in
65   // CreateThreadContext.
66   TraceHeader headers[kTraceParts];
67 
TraceTrace68   Trace()
69     : mtx(MutexTypeTrace, StatMtxTrace) {
70   }
71 };
72 
73 }  // namespace __tsan
74 
75 #endif  // TSAN_TRACE_H
76