threadnames.cpp raw

   1  // Copyright (c) 2018-present The Bitcoin Core developers
   2  // Distributed under the MIT software license, see the accompanying
   3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4  
   5  #include <util/threadnames.h>
   6  #include <util/check.h>
   7  
   8  #include <algorithm>
   9  #include <cstring>
  10  #include <string>
  11  
  12  #if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
  13  #include <pthread.h>
  14  #include <pthread_np.h>
  15  #endif
  16  
  17  #if __has_include(<sys/prctl.h>)
  18  #include <sys/prctl.h>
  19  #endif
  20  
  21  //! Set the thread's name at the process level. Does not affect the
  22  //! internal name.
  23  static void SetThreadName(const char* name)
  24  {
  25  #if defined(PR_SET_NAME)
  26      // Only the first 15 characters are used (16 - NUL terminator)
  27      ::prctl(PR_SET_NAME, name, 0, 0, 0);
  28  #elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
  29      pthread_set_name_np(pthread_self(), name);
  30  #elif defined(__APPLE__)
  31      pthread_setname_np(name);
  32  #else
  33      // Prevent warnings for unused parameters...
  34      (void)name;
  35  #endif
  36  }
  37  
  38  /**
  39   * The name of the thread. We use char array instead of std::string to avoid
  40   * complications with running a destructor when the thread exits. Avoid adding
  41   * other thread_local variables.
  42   * @see https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=278701
  43   */
  44  static thread_local char g_thread_name[128]{'\0'};
  45  std::string util::ThreadGetInternalName() { return g_thread_name; }
  46  //! Set the in-memory internal name for this thread. Does not affect the process
  47  //! name.
  48  static void SetInternalName(const std::string& name)
  49  {
  50      const size_t copy_bytes{std::min(sizeof(g_thread_name) - 1, name.length())};
  51      std::memcpy(g_thread_name, name.data(), copy_bytes);
  52      g_thread_name[copy_bytes] = '\0';
  53  }
  54  
  55  void util::ThreadRename(const std::string& name)
  56  {
  57      Assume(name.size() <= 13); // Linux keeps 15 bytes
  58      SetThreadName(("b-" + name).c_str());
  59      SetInternalName(name);
  60  }
  61  
  62  void util::ThreadSetInternalName(const std::string& name)
  63  {
  64      SetInternalName(name);
  65  }
  66