// Copyright (c) 2018-present The Bitcoin Core developers

// Distributed under the MIT software license, see the accompanying

// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <util/threadnames.h>

#include <util/check.h>

#include <algorithm>

#include <cstring>

#include <string>

#if (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))

#include <pthread.h>

#include <pthread_np.h>

#endif

#if __has_include(<sys/prctl.h>)

#include <sys/prctl.h>

#endif

#ifdef WIN32

#include <windows.h>

#endif

//! Set the thread's name at the process level. Does not affect the

//! internal name.

static void SetThreadName(const char* name)

{

#if defined(PR_SET_NAME)

    // Only the first 15 characters are used (16 - NUL terminator)

    ::prctl(PR_SET_NAME, name, 0, 0, 0);

#elif (defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__))

    pthread_set_name_np(pthread_self(), name);

#elif defined(__APPLE__)

    pthread_setname_np(name);

#elif defined(WIN32)

    // Thread names are ASCII-only, so widening each character is sufficient as

    // a conversion to UTF-16.

    const std::wstring wname{name, name + std::strlen(name)};

    ::SetThreadDescription(::GetCurrentThread(), wname.c_str());

#else

    // Prevent warnings for unused parameters...

    (void)name;

#endif

}

/**

 * The name of the thread. We use char array instead of std::string to avoid

 * complications with running a destructor when the thread exits. Avoid adding

 * other thread_local variables.

 * @see https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=278701

 */

static thread_local char g_thread_name[128]{'\0'};

std::string util::ThreadGetInternalName() { return g_thread_name; }

//! Set the in-memory internal name for this thread. Does not affect the process

//! name.

static void SetInternalName(const std::string& name)

{

    const size_t copy_bytes{std::min(sizeof(g_thread_name) - 1, name.length())};

    std::memcpy(g_thread_name, name.data(), copy_bytes);

    g_thread_name[copy_bytes] = '\0';

}

void util::ThreadRename(const std::string& name)

{

    Assume(name.size() <= 13); // Linux keeps 15 bytes

    SetThreadName(("b-" + name).c_str());

    SetInternalName(name);

}

void util::ThreadSetInternalName(const std::string& name)

{

    SetInternalName(name);

}