Line data    Source code

       1              : //
       2              : // Copyright (c) 2026 Michael Vandeberg
       3              : //
       4              : // Distributed under the Boost Software License, Version 1.0. (See accompanying
       5              : // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
       6              : //
       7              : // Official repository: https://github.com/cppalliance/capy
       8              : //
       9              : 
      10              : #include <boost/capy/test/thread_name.hpp>
      11              : 
      12              : #if defined(_WIN32)
      13              : 
      14              : #ifndef NOMINMAX
      15              : #define NOMINMAX
      16              : #endif
      17              : #include <windows.h>
      18              : #include <string>
      19              : 
      20              : #elif defined(__APPLE__)
      21              : 
      22              : #include <pthread.h>
      23              : #include <cstring>
      24              : 
      25              : #elif defined(__linux__) || defined(__FreeBSD__) || defined(__NetBSD__)
      26              : 
      27              : #include <pthread.h>
      28              : #include <cstring>
      29              : 
      30              : #endif
      31              : 
      32              : /*
      33              :     Platform-specific thread naming implementation.
      34              : 
      35              :     Each platform has a different API and name length limit:
      36              :     - Windows: SetThreadDescription with UTF-8 to UTF-16 conversion (no limit)
      37              :     - macOS: pthread_setname_np(name) with 63-char limit
      38              :     - Linux/BSD: pthread_setname_np(thread, name) with 15-char limit
      39              : 
      40              :     All operations are best-effort and silently fail on error, since thread
      41              :     naming is purely for debugging visibility and should never affect program
      42              :     correctness. The noexcept guarantee is maintained by catching exceptions
      43              :     from std::wstring allocation on Windows.
      44              : */
      45              : 
      46              : namespace boost {
      47              : namespace capy {
      48              : 
      49              : void
      50           41 : set_current_thread_name(char const* name) noexcept
      51              : {
      52              : #if defined(_WIN32)
      53              :     // SetThreadDescription requires Windows 10 1607+. Older Windows versions
      54              :     // are unsupported; the program may fail to link on those systems.
      55              : 
      56              :     // Query required buffer size for UTF-8 to wide conversion.
      57              :     int required = MultiByteToWideChar(CP_UTF8, 0, name, -1, nullptr, 0);
      58              :     if(required <= 0)
      59              :         return;
      60              : 
      61              :     // Allocate and convert; catch exceptions to maintain noexcept.
      62              :     std::wstring wname;
      63              :     try
      64              :     {
      65              :         wname.resize(static_cast<std::size_t>(required));
      66              :     }
      67              :     catch(...)
      68              :     {
      69              :         return;
      70              :     }
      71              : 
      72              :     if(MultiByteToWideChar(CP_UTF8, 0, name, -1, wname.data(), required) <= 0)
      73              :         return;
      74              : 
      75              :     // Ignore return value: thread naming is best-effort for debugging.
      76              :     (void)SetThreadDescription(GetCurrentThread(), wname.c_str());
      77              : #elif defined(__APPLE__)
      78              :     // macOS pthread_setname_np takes only the name (no thread handle)
      79              :     // and has a 64 char limit (63 + null terminator)
      80              :     char truncated[64];
      81              :     std::strncpy(truncated, name, 63);
      82              :     truncated[63] = '\0';
      83              : 
      84              :     // Ignore return value: thread naming is best-effort for debugging.
      85              :     (void)pthread_setname_np(truncated);
      86              : #elif defined(__linux__) || defined(__FreeBSD__) || defined(__NetBSD__)
      87              :     // pthread_setname_np has 16 char limit (15 + null terminator)
      88              :     char truncated[16];
      89           41 :     std::strncpy(truncated, name, 15);
      90           41 :     truncated[15] = '\0';
      91              : 
      92              :     // Ignore return value: thread naming is best-effort for debugging.
      93           41 :     (void)pthread_setname_np(pthread_self(), truncated);
      94              : #else
      95              :     (void)name;
      96              : #endif
      97           41 : }
      98              : 
      99              : } // capy
     100              : } // boost