ClickHouse/base/base/getThreadId.cpp

#include <base/getThreadId.h>

#if defined(OS_ANDROID)
    #include <sys/types.h>
    #include <unistd.h>
#elif defined(OS_LINUX)
    #include <unistd.h>
    #include <syscall.h>
#elif defined(OS_FREEBSD)
    #include <pthread_np.h>
#else
    #include <pthread.h>
    #include <stdexcept>
#endif


static thread_local uint64_t current_tid = 0;

static void setCurrentThreadId()
{
#if defined(OS_ANDROID)
    current_tid = gettid();
#elif defined(OS_LINUX)
    current_tid = static_cast<uint64_t>(syscall(SYS_gettid)); /// This call is always successful. - man gettid
#elif defined(OS_FREEBSD)
    current_tid = pthread_getthreadid_np();
#elif defined(OS_SUNOS)
    // On Solaris-derived systems, this returns the ID of the LWP, analogous
    // to a thread.
    current_tid = static_cast<uint64_t>(pthread_self());
#else
    if (0 != pthread_threadid_np(nullptr, &current_tid))
        throw std::logic_error("pthread_threadid_np returned error");
#endif
}

uint64_t getThreadId()
{
    if (!current_tid)
        setCurrentThreadId();

    return current_tid;
}

void updateCurrentThreadIdAfterFork()
{
    setCurrentThreadId();
}