C++ CPU_COUNT函數代碼示例

int
main()
{
  unsigned int cpu;
  int result;
  cpu_set_t newmask;
  cpu_set_t mask;
  cpu_set_t switchmask;
  cpu_set_t flipmask;

  CPU_ZERO(&mask);
  CPU_ZERO(&switchmask);
  CPU_ZERO(&flipmask);

  for (cpu = 0; cpu < sizeof(cpu_set_t)*8; cpu += 2)
    {
	  CPU_SET(cpu, &switchmask);				/* 0b01010101010101010101010101010101 */
    }
  for (cpu = 0; cpu < sizeof(cpu_set_t)*8; cpu++)
    {
	  CPU_SET(cpu, &flipmask);					/* 0b11111111111111111111111111111111 */
    }

  assert(sched_getaffinity(0, sizeof(cpu_set_t), &newmask) == 0);
  assert(!CPU_EQUAL(&newmask, &mask));

  result = sched_setaffinity(0, sizeof(cpu_set_t), &newmask);
  if (result != 0)
	{
	  int err =
#if defined (__PTW32_USES_SEPARATE_CRT)
	  GetLastError();
#else
      errno;
#endif

	  assert(err != ESRCH);
	  assert(err != EFAULT);
	  assert(err != EPERM);
	  assert(err != EINVAL);
	  assert(err != EAGAIN);
	  assert(err == ENOSYS);
	  assert(CPU_COUNT(&mask) == 1);
	}
  else
	{
	  if (CPU_COUNT(&mask) > 1)
		{
		  CPU_AND(&newmask, &mask, &switchmask); /* Remove every other CPU */
		  assert(sched_setaffinity(0, sizeof(cpu_set_t), &newmask) == 0);
		  assert(sched_getaffinity(0, sizeof(cpu_set_t), &mask) == 0);
		  CPU_XOR(&newmask, &mask, &flipmask);  /* Switch to all alternative CPUs */
		  assert(sched_setaffinity(0, sizeof(cpu_set_t), &newmask) == 0);
		  assert(sched_getaffinity(0, sizeof(cpu_set_t), &mask) == 0);
		  assert(!CPU_EQUAL(&newmask, &mask));
		}
	}

  return 0;
}

int
test_affinity5(void)
#endif
{
  unsigned int cpu;
  pthread_t tid;
  cpu_set_t threadCpus;
  DWORD_PTR vThreadMask;
  cpu_set_t keepCpus;
  pthread_t self = pthread_self();

  CPU_ZERO(&keepCpus);
  for (cpu = 1; cpu < sizeof(cpu_set_t)*8; cpu += 2)
    {
	  CPU_SET(cpu, &keepCpus);					/* 0b10101010101010101010101010101010 */
    }

  assert(pthread_getaffinity_np(self, sizeof(cpu_set_t), &threadCpus) == 0);
  if (CPU_COUNT(&threadCpus) > 1)
    {
	  assert(pthread_create(&tid, NULL, mythread, (void*)&threadCpus) == 0);
	  assert(pthread_join(tid, NULL) == 0);
	  CPU_AND(&threadCpus, &threadCpus, &keepCpus);
	  assert(pthread_setaffinity_np(self, sizeof(cpu_set_t), &threadCpus) == 0);
	  vThreadMask = SetThreadAffinityMask(GetCurrentThread(), (*(PDWORD_PTR)&threadCpus) /* Violating Opacity */);
	  assert(vThreadMask != 0);
	  assert(memcmp(&vThreadMask, &threadCpus, sizeof(DWORD_PTR)) == 0);
	  assert(pthread_create(&tid, NULL, mythread, (void*)&threadCpus) == 0);
	  assert(pthread_join(tid, NULL) == 0);
    }

  return 0;
}

void ThreadSetDefault()
{
    if (numthreads == -1)
    {
        cpu_set_t cs;
        CPU_ZERO(&cs);
        if (sched_getaffinity(0, sizeof(cs), &cs) != 0)
        {
            numthreads = 1;
            return;
        }
        
        int count = 0;
        for (int i = 0; i < CPU_COUNT(&cs); i++)
        {
            if (CPU_ISSET(i, &cs))
                count++;
        }
        
        if (count < 1)
            numthreads = 1;
        else
            numthreads = count;
    }
}

WELS_THREAD_ERROR_CODE    WelsQueryLogicalProcessInfo (WelsLogicalProcessInfo* pInfo) {
#ifdef ANDROID_NDK
  pInfo->ProcessorCount = android_getCpuCount();
  return WELS_THREAD_ERROR_OK;
#elif defined(LINUX)

  cpu_set_t cpuset;

  CPU_ZERO (&cpuset);

  if (!sched_getaffinity (0, sizeof (cpuset), &cpuset))
    pInfo->ProcessorCount = CPU_COUNT (&cpuset);
  else
    pInfo->ProcessorCount = 1;

  return WELS_THREAD_ERROR_OK;

#else

  size_t len = sizeof (pInfo->ProcessorCount);

  if (sysctlbyname (HW_NCPU_NAME, &pInfo->ProcessorCount, &len, NULL, 0) == -1)
    pInfo->ProcessorCount = 1;

  return WELS_THREAD_ERROR_OK;

#endif//LINUX
}

unsigned long
gomp_cpuset_popcount (unsigned long cpusetsize, cpu_set_t *cpusetp)
{
#ifdef CPU_COUNT_S
  /* glibc 2.7 and above provide a macro for this.  */
  return CPU_COUNT_S (cpusetsize, cpusetp);
#else
#ifdef CPU_COUNT
  if (cpusetsize == sizeof (cpu_set_t))
    /* glibc 2.6 and above provide a macro for this.  */
    return CPU_COUNT (cpusetp);
#endif
  size_t i;
  unsigned long ret = 0;
  extern int check[sizeof (cpusetp->__bits[0]) == sizeof (unsigned long int)
		   ? 1 : -1] __attribute__((unused));

  for (i = 0; i < cpusetsize / sizeof (cpusetp->__bits[0]); i++)
    {
      unsigned long int mask = cpusetp->__bits[i];
      if (mask == 0)
	continue;
      ret += __builtin_popcountl (mask);
    }
  return ret;
#endif
}

static int get_logical_cpus(AVCodecContext *avctx)
{
    int ret, nb_cpus = 1;
#if HAVE_SCHED_GETAFFINITY && defined(CPU_COUNT)
    cpu_set_t cpuset;

    CPU_ZERO(&cpuset);

    ret = sched_getaffinity(0, sizeof(cpuset), &cpuset);
    if (!ret) {
        nb_cpus = CPU_COUNT(&cpuset);
    }
#elif HAVE_GETPROCESSAFFINITYMASK
    DWORD_PTR proc_aff, sys_aff;
    ret = GetProcessAffinityMask(GetCurrentProcess(), &proc_aff, &sys_aff);
    if (ret)
        nb_cpus = av_popcount64(proc_aff);
#elif HAVE_SYSCTL && defined(HW_NCPU)
    int mib[2] = { CTL_HW, HW_NCPU };
    size_t len = sizeof(nb_cpus);

    ret = sysctl(mib, 2, &nb_cpus, &len, NULL, 0);
    if (ret == -1)
        nb_cpus = 0;
#elif HAVE_SYSCONF && defined(_SC_NPROC_ONLN)
    nb_cpus = sysconf(_SC_NPROC_ONLN);
#elif HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)
    nb_cpus = sysconf(_SC_NPROCESSORS_ONLN);
#endif
    av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
    return nb_cpus;
}

	boost::uint32_t GetAffinity()
	{
	#if defined(__APPLE__) || defined(__FreeBSD__)
		// no-op
		return 0;

	#elif defined(WIN32)
		DWORD_PTR curMask;
		DWORD_PTR systemCpus;
		GetProcessAffinityMask(GetCurrentProcess(), &curMask, &systemCpus);
		return curMask;
	#else
		cpu_set_t curAffinity;
		CPU_ZERO(&curAffinity);
		sched_getaffinity(0, sizeof(cpu_set_t), &curAffinity);

		boost::uint32_t mask = 0;

		int numCpus = std::min(CPU_COUNT(&curAffinity), 32); // w/o the min(.., 32) `(1 << n)` could overflow!
		for (int n = numCpus - 1; n >= 0; --n) {
			if (CPU_ISSET(n, &curAffinity)) {
				mask |= (1 << n);
			}
		}

		return mask;
	#endif
	}

        /**
          * This is the actual function that the thread executes.
          * It receives a block from the scheduler, class its run() method and returns it to the scheduler.
          * The thread runs until the it is told to stop by setting the m_stop boolean flag
          */
        void operator()()
        {
            if(CPU_COUNT(&m_mask)>0)
            {
                pthread_t id = pthread_self();
               int ret = pthread_setaffinity_np(id, sizeof(m_mask), &m_mask);
                if(ret != 0)
                {
                    perror("setaffinity");
                    throw(std::runtime_error("set affinity failed"));
                }
            }
            while(!m_stop.load())
            {

                std::shared_ptr<Block>torun(m_scheduler.next_task(m_id));
                if(torun)
                {
                    torun->run();
                    m_scheduler.task_done(m_id, std::move(torun));
                }
                else
                {
                    std::this_thread::sleep_for(std::chrono::milliseconds(10));
                }
            }
            m_stop.store(false);
        }

int cpu_manager::reserve_cpu_for_thread(pthread_t tid, int suggested_cpu /* = NO_CPU */)
{
	lock();
	int cpu = g_n_thread_cpu_core;
	if (cpu != NO_CPU) { //already reserved
		unlock();
		return cpu;
	}

	cpu_set_t cpu_set;
	CPU_ZERO(&cpu_set);

	int ret = pthread_getaffinity_np(tid, sizeof(cpu_set_t), &cpu_set);
	if (ret) {
		unlock();
		__log_err("pthread_getaffinity_np failed for tid=%lu, ret=%d (errno=%d %m)", tid, ret, errno);
		return -1;
	}

	int avail_cpus = CPU_COUNT(&cpu_set);
	if (avail_cpus == 0) {
		unlock();
		__log_err("no cpu available for tid=%lu", tid);
		return -1;
	}

	if (avail_cpus == 1) { //already attached
		for (cpu = 0; cpu < MAX_CPU && !CPU_ISSET(cpu, &cpu_set); cpu++) {}
	} else { //need to choose one cpu to attach to
		int min_cpu_count = -1;
		for (int i = 0, j = 0; i < MAX_CPU && j < avail_cpus; i++) {
			if (!CPU_ISSET(i, &cpu_set)) continue;
			j++;
			if (min_cpu_count < 0 || m_cpu_thread_count[i] < min_cpu_count) {
				min_cpu_count = m_cpu_thread_count[i];
				cpu = i;
			}
		}
		if (suggested_cpu >= 0
			&& CPU_ISSET(suggested_cpu, &cpu_set)
			&& m_cpu_thread_count[suggested_cpu] <= min_cpu_count + 1 ) {
			cpu = suggested_cpu;
		}
		CPU_ZERO(&cpu_set);
		CPU_SET(cpu, &cpu_set);
		__log_dbg("attach tid=%lu running on cpu=%d to cpu=%d", tid, sched_getcpu(), cpu);
		ret = pthread_setaffinity_np(tid, sizeof(cpu_set_t), &cpu_set);
		if (ret) {
			unlock();
			__log_err("pthread_setaffinity_np failed for tid=%lu to cpu=%d, ret=%d (errno=%d %m)", tid, cpu, ret, errno);
			return -1;
		}
	}

	g_n_thread_cpu_core = cpu;
	if (cpu > NO_CPU && cpu < MAX_CPU)
		m_cpu_thread_count[cpu]++;
	unlock();
	return cpu;
}

unsigned get_cpus_online(void)
{
#ifdef _WIN32
	SYSTEM_INFO info;

	GetSystemInfo(&info);
	if((int)info.dwNumberOfProcessors > 0)
		return (unsigned)info.dwNumberOfProcessors;
#elif defined(hpux) || defined(__hpux) || defined(_hpux)
	struct pst_dynamic psd;

	if(pstat_getdynamic(&psd, sizeof(psd), (size_t)1, 0) == 1)
		return (unsigned)psd.psd_proc_cnt;
#endif
	/* CPU_COUNT is a gnu extention, avail after glibc2.6 */
#if HAVE_PTHREAD_SETAFFINITY_NP-0 == 1 && defined CPU_COUNT
	{
		/*
		 * ask the affinity stuff, we may be confined to a smaller
		 * set of CPUs then are avail in HW
		 */
		cpu_set_t cst;
		int res = pthread_getaffinity_np(pthread_self(), sizeof(cst), &cst);
		if(0 == res)
			return CPU_COUNT(&cst);
	}
#endif
#ifdef _SC_NPROCESSORS_ONLN
	{
		long ncpus;
		if((ncpus = (long)sysconf(_SC_NPROCESSORS_ONLN)) > 0)
			return (unsigned)ncpus;
	}
#elif defined HAVE_SYS_SYSCTL_H
	{
		int ncpus;
		size_t len = sizeof(ncpus);
# ifdef HAVE_SYSCTLBYNAME
		/* try the online-cpu-thingy first (only osx?) */
		if(!sysctlbyname("hw.activecpu", &ncpus, &len , NULL, 0))
			return (unsigned)ncpu;
		if(!sysctlbyname("hw.ncpu", &ncpus, &len , NULL, 0))
			return (unsigned)ncpu;
# else
		int mib[2] = {CTL_HW, HW_NCPU};
		if(!sysctl(mib, 2, &ncpus, &len, NULL, 0))
			return (unsigned)ncpus
# endif
	}
#endif
	/*
	 * if old solaris does not provide NPROCESSORS,
	 * one maybe bang on processor_info() and friends
	 * from <sys/processor.h>, see above
	 */
// TODO: warn user?
	/* we have at least one cpu, we are running on it... */
	return 1;
}

MVMuint32 MVM_platform_cpu_count(void) {
    cpu_set_t set;

    if (pthread_getaffinity_np(pthread_self(), sizeof set, &set) != 0)
        return 0;

    return CPU_COUNT(&set);
}

int
get_cpu_count(void) {
    cpu_set_t cpu_set;

    CPU_ZERO(&cpu_set);
    sched_getaffinity(0, sizeof(cpu_set), &cpu_set);

    return CPU_COUNT(&cpu_set);
}

/* req is one-based, cpu_set is zero-based */
SEXP mc_affinity(SEXP req) {
    if (req != R_NilValue && TYPEOF(req) != INTSXP && TYPEOF(req) != REALSXP)
	error(_("invalid CPU affinity specification"));
    if (TYPEOF(req) == REALSXP)
	req = coerceVector(req, INTSXP);
    if (TYPEOF(req) == INTSXP) {
	int max_cpu = 0, i, n = LENGTH(req), *v = INTEGER(req);
	for (i = 0; i < n; i++) {
	    if (v[i] > max_cpu)
		max_cpu = v[i];
	    if (v[i] < 1)
		error(_("invalid CPU affinity specification"));
	}
	/* These are both one-based */
	if (max_cpu <= CPU_SETSIZE) { /* can use static set */
	    cpu_set_t cs;
	    CPU_ZERO(&cs);
	    for (i = 0; i < n; i++)
		CPU_SET(v[i] - 1, &cs);
	    sched_setaffinity(0, sizeof(cpu_set_t), &cs);
	} else {
#ifndef CPU_ALLOC
	    error(_("requested CPU set is too large for this system"));
#else
	    size_t css = CPU_ALLOC_SIZE(max_cpu);
	    cpu_set_t *cs = CPU_ALLOC(max_cpu);
	    CPU_ZERO_S(css, cs);
	    for (i = 0; i < n; i++)
		CPU_SET_S(v[i] - 1, css, cs);
	    sched_setaffinity(0, css, cs);
#endif
	}
    }

    {
	/* FIXME: in theory we may want to use *_S versions as well,
	 but that would require some knowledge about the number of
	 available CPUs and comparing that to CPU_SETSIZE, so for now
	 we just use static cpu_set -- the mask will be still set
	 correctly, just the returned set will be truncated at
	 CPU_SETSIZE */
	cpu_set_t cs;
	CPU_ZERO(&cs);
	if (sched_getaffinity(0, sizeof(cs), &cs)) {
	    if (req == R_NilValue)
		error(_("retrieving CPU affinity set failed"));
	    return R_NilValue;
	} else {
	    SEXP res = allocVector(INTSXP, CPU_COUNT(&cs));
	    int i, *v = INTEGER(res);
	    for (i = 0; i < CPU_SETSIZE; i++)
		if (CPU_ISSET(i, &cs))
		    *(v++) = i + 1;
	    return res;
	}
    }
}

void* server_worker_t::main(void * arg)
{
    conet::init_conet_env();

    server_worker_t *self = (server_worker_t *)(arg);

    if (self->cpu_affinity && CPU_COUNT(self->cpu_affinity) > 0) {
        int ret = 0;
        pthread_t tid = pthread_self();
        ret = pthread_setaffinity_np(tid, sizeof(cpu_set_t), self->cpu_affinity);
        if (ret) {
            PLOG_ERROR("set affinity failed , ", (tid, ret));
        } else {
            PLOG_INFO("set affinity success, ", (tid));
        }
    }

    int size = self->conf.servers_size();

    for (int i=0; i<size; ++i)
    {
        RpcServer const & server_conf = self->conf.servers(i);
        rpc_pb_server_t *rpc_server =  self->build_rpc_server(server_conf);
        if (rpc_server) {
            self->rpc_servers.push_back(rpc_server);
        }
    }

    int ret = 0;
    size = self->rpc_servers.size();
    for (int i=0; i<size; ++i)
    { // 啟動server
        ret = self->rpc_servers[i]->start();
        if (ret)
        {
            PLOG_ERROR("error start");
        }
    }

    coroutine_t *exit_co = NULL;

    while (likely(!self->exit_finsished)) 
    {
        if (unlikely(self->stop_flag && exit_co == NULL)) 
        {
            exit_co = conet::alloc_coroutine(
                    conet::ptr_cast<conet::co_main_func_t>(
                        &server_worker_t::proc_server_exit), self);
            conet::resume(exit_co);
        }
        conet::dispatch();
    }
    conet::free_coroutine(exit_co);
    conet::free_conet_env();
    return NULL;
}

/* TODO: OS specific? Might be better to use different method */
int get_cpu_count(void)
{
	cpu_set_t cs;

	CPU_ZERO(&cs);
	if (sched_getaffinity(0, sizeof(cs), &cs))
		return 1;

	return CPU_COUNT(&cs);
}