1//===-- memprof_thread.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 MemProfiler, a memory profiler.
10//
11// MemProf-private header for memprof_thread.cpp.
12//===----------------------------------------------------------------------===//
13
14#ifndef MEMPROF_THREAD_H
15#define MEMPROF_THREAD_H
16
17#include "memprof_allocator.h"
18#include "memprof_internal.h"
19#include "memprof_stats.h"
20#include "sanitizer_common/sanitizer_common.h"
21#include "sanitizer_common/sanitizer_libc.h"
22#include "sanitizer_common/sanitizer_thread_registry.h"
23
24namespace __sanitizer {
25struct DTLS;
26} // namespace __sanitizer
27
28namespace __memprof {
29
30class MemprofThread;
31
32// These objects are created for every thread and are never deleted,
33// so we can find them by tid even if the thread is long dead.
34struct MemprofThreadContext final : public ThreadContextBase {
35  explicit MemprofThreadContext(int tid)
36      : ThreadContextBase(tid), announced(false),
37        destructor_iterations(GetPthreadDestructorIterations()), stack_id(0),
38        thread(nullptr) {}
39  bool announced;
40  u8 destructor_iterations;
41  u32 stack_id;
42  MemprofThread *thread;
43
44  void OnCreated(void *arg) override;
45  void OnFinished() override;
46
47  struct CreateThreadContextArgs {
48    MemprofThread *thread;
49    StackTrace *stack;
50  };
51};
52
53// MemprofThreadContext objects are never freed, so we need many of them.
54COMPILER_CHECK(sizeof(MemprofThreadContext) <= 256);
55
56// MemprofThread are stored in TSD and destroyed when the thread dies.
57class MemprofThread {
58public:
59  static MemprofThread *Create(thread_callback_t start_routine, void *arg,
60                               u32 parent_tid, StackTrace *stack,
61                               bool detached);
62  static void TSDDtor(void *tsd);
63  void Destroy();
64
65  struct InitOptions;
66  void Init(const InitOptions *options = nullptr);
67
68  thread_return_t ThreadStart(tid_t os_id,
69                              atomic_uintptr_t *signal_thread_is_registered);
70
71  uptr stack_top();
72  uptr stack_bottom();
73  uptr stack_size();
74  uptr tls_begin() { return tls_begin_; }
75  uptr tls_end() { return tls_end_; }
76  DTLS *dtls() { return dtls_; }
77  u32 tid() { return context_->tid; }
78  MemprofThreadContext *context() { return context_; }
79  void set_context(MemprofThreadContext *context) { context_ = context; }
80
81  bool AddrIsInStack(uptr addr);
82
83  // True is this thread is currently unwinding stack (i.e. collecting a stack
84  // trace). Used to prevent deadlocks on platforms where libc unwinder calls
85  // malloc internally. See PR17116 for more details.
86  bool isUnwinding() const { return unwinding_; }
87  void setUnwinding(bool b) { unwinding_ = b; }
88
89  MemprofThreadLocalMallocStorage &malloc_storage() { return malloc_storage_; }
90  MemprofStats &stats() { return stats_; }
91
92private:
93  // NOTE: There is no MemprofThread constructor. It is allocated
94  // via mmap() and *must* be valid in zero-initialized state.
95
96  void SetThreadStackAndTls(const InitOptions *options);
97
98  struct StackBounds {
99    uptr bottom;
100    uptr top;
101  };
102  StackBounds GetStackBounds() const;
103
104  MemprofThreadContext *context_;
105  thread_callback_t start_routine_;
106  void *arg_;
107
108  uptr stack_top_;
109  uptr stack_bottom_;
110
111  uptr tls_begin_;
112  uptr tls_end_;
113  DTLS *dtls_;
114
115  MemprofThreadLocalMallocStorage malloc_storage_;
116  MemprofStats stats_;
117  bool unwinding_;
118};
119
120// Returns a single instance of registry.
121ThreadRegistry &memprofThreadRegistry();
122
123// Must be called under ThreadRegistryLock.
124MemprofThreadContext *GetThreadContextByTidLocked(u32 tid);
125
126// Get the current thread. May return 0.
127MemprofThread *GetCurrentThread();
128void SetCurrentThread(MemprofThread *t);
129u32 GetCurrentTidOrInvalid();
130
131// Used to handle fork().
132void EnsureMainThreadIDIsCorrect();
133} // namespace __memprof
134
135#endif // MEMPROF_THREAD_H
136