libsanitizer/sanitizer_common/sanitizer_thread_registry.h

   1 //===-- sanitizer_thread_registry.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 shared between sanitizer tools.
  10 //
  11 // General thread bookkeeping functionality.
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef SANITIZER_THREAD_REGISTRY_H
  15 #define SANITIZER_THREAD_REGISTRY_H
  16
  17 #include "sanitizer_common.h"
  18 #include "sanitizer_dense_map.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 enum class ThreadType {
  33   Regular, // Normal thread
  34   Worker,  // macOS Grand Central Dispatch (GCD) worker thread
  35   Fiber,   // Fiber
  36 };
  37
  38 // Generic thread context. Specific sanitizer tools may inherit from it.
  39 // If thread is dead, context may optionally be reused for a new thread.
  40 class ThreadContextBase {
  41  public:
  42   explicit ThreadContextBase(u32 tid);
  43   const u32 tid;  // Thread ID. Main thread should have tid = 0.
  44   u64 unique_id;  // Unique thread ID.
  45   u32 reuse_count;  // Number of times this tid was reused.
  46   tid_t os_id;     // PID (used for reporting).
  47   uptr user_id;   // Some opaque user thread id (e.g. pthread_t).
  48   char name[64];  // As annotated by user.
  49
  50   ThreadStatus status;
  51   bool detached;
  52   ThreadType thread_type;
  53
  54   u32 parent_tid;
  55   ThreadContextBase *next;  // For storing thread contexts in a list.
  56
  57   atomic_uint32_t thread_destroyed; // To address race of Joined vs Finished
  58
  59   void SetName(const char *new_name);
  60
  61   void SetDead();
  62   void SetJoined(void *arg);
  63   void SetFinished();
  64   void SetStarted(tid_t _os_id, ThreadType _thread_type, void *arg);
  65   void SetCreated(uptr _user_id, u64 _unique_id, bool _detached,
  66                   u32 _parent_tid, void *arg);
  67   void Reset();
  68
  69   void SetDestroyed();
  70   bool GetDestroyed();
  71
  72   // The following methods may be overriden by subclasses.
  73   // Some of them take opaque arg that may be optionally be used
  74   // by subclasses.
  75   virtual void OnDead() {}
  76   virtual void OnJoined(void *arg) {}
  77   virtual void OnFinished() {}
  78   virtual void OnStarted(void *arg) {}
  79   virtual void OnCreated(void *arg) {}
  80   virtual void OnReset() {}
  81   virtual void OnDetached(void *arg) {}
  82
  83  protected:
  84   ~ThreadContextBase();
  85 };
  86
  87 typedef ThreadContextBase* (*ThreadContextFactory)(u32 tid);
  88
  89 class SANITIZER_MUTEX ThreadRegistry {
  90  public:
  91   ThreadRegistry(ThreadContextFactory factory);
  92   ThreadRegistry(ThreadContextFactory factory, u32 max_threads,
  93                  u32 thread_quarantine_size, u32 max_reuse);
  94   void GetNumberOfThreads(uptr *total = nullptr, uptr *running = nullptr,
  95                           uptr *alive = nullptr);
  96   uptr GetMaxAliveThreads();
  97
  98   void Lock() SANITIZER_ACQUIRE() { mtx_.Lock(); }
  99   void CheckLocked() const SANITIZER_CHECK_LOCKED() { mtx_.CheckLocked(); }
 100   void Unlock() SANITIZER_RELEASE() { mtx_.Unlock(); }
 101
 102   // Should be guarded by ThreadRegistryLock.
 103   ThreadContextBase *GetThreadLocked(u32 tid) {
 104     return threads_.empty() ? nullptr : threads_[tid];
 105   }
 106
 107   u32 NumThreadsLocked() const { return threads_.size(); }
 108
 109   u32 CreateThread(uptr user_id, bool detached, u32 parent_tid, void *arg);
 110
 111   typedef void (*ThreadCallback)(ThreadContextBase *tctx, void *arg);
 112   // Invokes callback with a specified arg for each thread context.
 113   // Should be guarded by ThreadRegistryLock.
 114   void RunCallbackForEachThreadLocked(ThreadCallback cb, void *arg);
 115
 116   typedef bool (*FindThreadCallback)(ThreadContextBase *tctx, void *arg);
 117   // Finds a thread using the provided callback. Returns kInvalidTid if no
 118   // thread is found.
 119   u32 FindThread(FindThreadCallback cb, void *arg);
 120   // Should be guarded by ThreadRegistryLock. Return 0 if no thread
 121   // is found.
 122   ThreadContextBase *FindThreadContextLocked(FindThreadCallback cb,
 123                                              void *arg);
 124   ThreadContextBase *FindThreadContextByOsIDLocked(tid_t os_id);
 125
 126   void SetThreadName(u32 tid, const char *name);
 127   void SetThreadNameByUserId(uptr user_id, const char *name);
 128   void DetachThread(u32 tid, void *arg);
 129   void JoinThread(u32 tid, void *arg);
 130   // Finishes thread and returns previous status.
 131   ThreadStatus FinishThread(u32 tid);
 132   void StartThread(u32 tid, tid_t os_id, ThreadType thread_type, void *arg);
 133   u32 ConsumeThreadUserId(uptr user_id);
 134   void SetThreadUserId(u32 tid, uptr user_id);
 135
 136   // OnFork must be called in the child process after fork to purge old
 137   // threads that don't exist anymore (except for the current thread tid).
 138   // Returns number of alive threads before fork.
 139   u32 OnFork(u32 tid);
 140
 141  private:
 142   const ThreadContextFactory context_factory_;
 143   const u32 max_threads_;
 144   const u32 thread_quarantine_size_;
 145   const u32 max_reuse_;
 146
 147   Mutex mtx_;
 148
 149   u64 total_threads_;   // Total number of created threads. May be greater than
 150                         // max_threads_ if contexts were reused.
 151   uptr alive_threads_;  // Created or running.
 152   uptr max_alive_threads_;
 153   uptr running_threads_;
 154
 155   InternalMmapVector<ThreadContextBase *> threads_;
 156   IntrusiveList<ThreadContextBase> dead_threads_;
 157   IntrusiveList<ThreadContextBase> invalid_threads_;
 158   DenseMap<uptr, Tid> live_;
 159
 160   void QuarantinePush(ThreadContextBase *tctx);
 161   ThreadContextBase *QuarantinePop();
 162 };
 163
 164 typedef GenericScopedLock<ThreadRegistry> ThreadRegistryLock;
 165
 166 } // namespace __sanitizer
 167
 168 #endif // SANITIZER_THREAD_REGISTRY_H