1 //===-- sanitizer_thread_registry.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 shared between sanitizer tools.
11 //
12 // General thread bookkeeping functionality.
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef SANITIZER_THREAD_REGISTRY_H
16 #define SANITIZER_THREAD_REGISTRY_H
17 
18 #include "sanitizer_common.h"
19 #include "sanitizer_list.h"
20 #include "sanitizer_mutex.h"
21 
22 namespace __sanitizer {
23 
24 enum ThreadStatus {
25   ThreadStatusInvalid,   // Non-existent thread, data is invalid.
26   ThreadStatusCreated,   // Created but not yet running.
27   ThreadStatusRunning,   // The thread is currently running.
28   ThreadStatusFinished,  // Joinable thread is finished but not yet joined.
29   ThreadStatusDead       // Joined, but some info is still available.
30 };
31 
32 // Generic thread context. Specific sanitizer tools may inherit from it.
33 // If thread is dead, context may optionally be reused for a new thread.
34 class ThreadContextBase {
35  public:
36   explicit ThreadContextBase(u32 tid);
37   ~ThreadContextBase();  // Should never be called.
38 
39   const u32 tid;  // Thread ID. Main thread should have tid = 0.
40   u64 unique_id;  // Unique thread ID.
41   u32 reuse_count;  // Number of times this tid was reused.
42   uptr os_id;     // PID (used for reporting).
43   uptr user_id;   // Some opaque user thread id (e.g. pthread_t).
44   char name[64];  // As annotated by user.
45 
46   ThreadStatus status;
47   bool detached;
48 
49   u32 parent_tid;
50   ThreadContextBase *next;  // For storing thread contexts in a list.
51 
52   void SetName(const char *new_name);
53 
54   void SetDead();
55   void SetJoined(void *arg);
56   void SetFinished();
57   void SetStarted(uptr _os_id, void *arg);
58   void SetCreated(uptr _user_id, u64 _unique_id, bool _detached,
59                   u32 _parent_tid, void *arg);
60   void Reset();
61 
62   // The following methods may be overriden by subclasses.
63   // Some of them take opaque arg that may be optionally be used
64   // by subclasses.
OnDead()65   virtual void OnDead() {}
OnJoined(void * arg)66   virtual void OnJoined(void *arg) {}
OnFinished()67   virtual void OnFinished() {}
OnStarted(void * arg)68   virtual void OnStarted(void *arg) {}
OnCreated(void * arg)69   virtual void OnCreated(void *arg) {}
OnReset()70   virtual void OnReset() {}
OnDetached(void * arg)71   virtual void OnDetached(void *arg) {}
72 };
73 
74 typedef ThreadContextBase* (*ThreadContextFactory)(u32 tid);
75 
76 class ThreadRegistry {
77  public:
78   static const u32 kUnknownTid;
79 
80   ThreadRegistry(ThreadContextFactory factory, u32 max_threads,
81                  u32 thread_quarantine_size, u32 max_reuse = 0);
82   void GetNumberOfThreads(uptr *total = nullptr, uptr *running = nullptr,
83                           uptr *alive = nullptr);
84   uptr GetMaxAliveThreads();
85 
Lock()86   void Lock() { mtx_.Lock(); }
CheckLocked()87   void CheckLocked() { mtx_.CheckLocked(); }
Unlock()88   void Unlock() { mtx_.Unlock(); }
89 
90   // Should be guarded by ThreadRegistryLock.
GetThreadLocked(u32 tid)91   ThreadContextBase *GetThreadLocked(u32 tid) {
92     DCHECK_LT(tid, n_contexts_);
93     return threads_[tid];
94   }
95 
96   u32 CreateThread(uptr user_id, bool detached, u32 parent_tid, void *arg);
97 
98   typedef void (*ThreadCallback)(ThreadContextBase *tctx, void *arg);
99   // Invokes callback with a specified arg for each thread context.
100   // Should be guarded by ThreadRegistryLock.
101   void RunCallbackForEachThreadLocked(ThreadCallback cb, void *arg);
102 
103   typedef bool (*FindThreadCallback)(ThreadContextBase *tctx, void *arg);
104   // Finds a thread using the provided callback. Returns kUnknownTid if no
105   // thread is found.
106   u32 FindThread(FindThreadCallback cb, void *arg);
107   // Should be guarded by ThreadRegistryLock. Return 0 if no thread
108   // is found.
109   ThreadContextBase *FindThreadContextLocked(FindThreadCallback cb,
110                                              void *arg);
111   ThreadContextBase *FindThreadContextByOsIDLocked(uptr os_id);
112 
113   void SetThreadName(u32 tid, const char *name);
114   void SetThreadNameByUserId(uptr user_id, const char *name);
115   void DetachThread(u32 tid, void *arg);
116   void JoinThread(u32 tid, void *arg);
117   void FinishThread(u32 tid);
118   void StartThread(u32 tid, uptr os_id, void *arg);
119 
120  private:
121   const ThreadContextFactory context_factory_;
122   const u32 max_threads_;
123   const u32 thread_quarantine_size_;
124   const u32 max_reuse_;
125 
126   BlockingMutex mtx_;
127 
128   u32 n_contexts_;      // Number of created thread contexts,
129                         // at most max_threads_.
130   u64 total_threads_;   // Total number of created threads. May be greater than
131                         // max_threads_ if contexts were reused.
132   uptr alive_threads_;  // Created or running.
133   uptr max_alive_threads_;
134   uptr running_threads_;
135 
136   ThreadContextBase **threads_;  // Array of thread contexts is leaked.
137   IntrusiveList<ThreadContextBase> dead_threads_;
138   IntrusiveList<ThreadContextBase> invalid_threads_;
139 
140   void QuarantinePush(ThreadContextBase *tctx);
141   ThreadContextBase *QuarantinePop();
142 };
143 
144 typedef GenericScopedLock<ThreadRegistry> ThreadRegistryLock;
145 
146 } // namespace __sanitizer
147 
148 #endif // SANITIZER_THREAD_REGISTRY_H
149