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 <bitcoin-build-config.h> // IWYU pragma: keep
6
7#include <util/threadnames.h>
8#include <util/check.h>
9
10#include <algorithm>
11#include <cstring>
12#include <string>
13
14#if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
15#include <pthread.h>
16#include <pthread_np.h>
17#endif
18
19#if __has_include(<sys/prctl.h>)
20#include <sys/prctl.h>
21#endif
22
23#ifdef HAVE_SETTHREADDESCRIPTION
24#include <windows.h>
25#endif
26
27//! Set the thread's name at the process level. Does not affect the
28//! internal name.
29static void SetThreadName(const char* name)
30{
31#if defined(PR_SET_NAME)
32    // Only the first 15 characters are used (16 - NUL terminator)
33    ::prctl(PR_SET_NAME, name, 0, 0, 0);
34#elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))
35    pthread_set_name_np(pthread_self(), name);
36#elif defined(__APPLE__)
37    pthread_setname_np(name);
38#elif defined(HAVE_SETTHREADDESCRIPTION)
39    // Thread names are ASCII-only, so widening each character is sufficient as
40    // a conversion to UTF-16.
41    const std::wstring wname{name, name + std::strlen(name)};
42    ::SetThreadDescription(::GetCurrentThread(), wname.c_str());
43#else
44    // Prevent warnings for unused parameters...
45    (void)name;
46#endif
47}
48
49/**
50 * The name of the thread. We use char array instead of std::string to avoid
51 * complications with running a destructor when the thread exits. Avoid adding
52 * other thread_local variables.
53 * @see https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=278701
54 */
55static thread_local char g_thread_name[128]{'\0'};
56std::string util::ThreadGetInternalName() { return g_thread_name; }
57//! Set the in-memory internal name for this thread. Does not affect the process
58//! name.
59static void SetInternalName(const std::string& name)
60{
61    const size_t copy_bytes{std::min(sizeof(g_thread_name) - 1, name.length())};
62    std::memcpy(g_thread_name, name.data(), copy_bytes);
63    g_thread_name[copy_bytes] = '\0';
64}
65
66void util::ThreadRename(const std::string& name)
67{
68    Assume(name.size() <= 13); // Linux keeps 15 bytes
69    SetThreadName(("b-" + name).c_str());
70    SetInternalName(name);
71}
72
73void util::ThreadSetInternalName(const std::string& name)
74{
75    SetInternalName(name);
76}
77