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/*
Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file
This file is part of 0MQ.
0MQ is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
0MQ is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "clock.hpp"
#include "platform.hpp"
#include "likely.hpp"
#include "config.hpp"
#include "err.hpp"
#include "mutex.hpp"
#include <stddef.h>
#if defined _MSC_VER
#if defined _WIN32_WCE
#include <cmnintrin.h>
#else
#include <intrin.h>
#endif
#endif
#if !defined ZMQ_HAVE_WINDOWS
#include <sys/time.h>
#endif
#if defined HAVE_CLOCK_GETTIME || defined HAVE_GETHRTIME
#include <time.h>
#endif
#ifdef ZMQ_HAVE_WINDOWS
typedef ULONGLONG (*f_compatible_get_tick_count64)();
static zmq::mutex_t compatible_get_tick_count64_mutex;
ULONGLONG compatible_get_tick_count64()
{
compatible_get_tick_count64_mutex.lock();
static DWORD s_wrap = 0;
static DWORD s_last_tick = 0;
const DWORD current_tick = ::GetTickCount();
if (current_tick < s_last_tick)
++s_wrap;
s_last_tick = current_tick;
const ULONGLONG result = (static_cast<ULONGLONG>(s_wrap) << 32) + static_cast<ULONGLONG>(current_tick);
compatible_get_tick_count64_mutex.unlock();
return result;
}
f_compatible_get_tick_count64 init_compatible_get_tick_count64()
{
f_compatible_get_tick_count64 func = NULL;
HMODULE module = ::LoadLibraryA("Kernel32.dll");
if (module != NULL)
func = reinterpret_cast<f_compatible_get_tick_count64>(::GetProcAddress(module, "GetTickCount64"));
if (func == NULL)
func = compatible_get_tick_count64;
return func;
}
static f_compatible_get_tick_count64 my_get_tick_count64 = init_compatible_get_tick_count64();
#endif
zmq::clock_t::clock_t () :
last_tsc (rdtsc ()),
#ifdef ZMQ_HAVE_WINDOWS
last_time (static_cast<uint64_t>((*my_get_tick_count64)()))
#else
last_time (now_us () / 1000)
#endif
{
}
zmq::clock_t::~clock_t ()
{
}
uint64_t zmq::clock_t::now_us ()
{
#if defined ZMQ_HAVE_WINDOWS
// Get the high resolution counter's accuracy.
LARGE_INTEGER ticksPerSecond;
QueryPerformanceFrequency (&ticksPerSecond);
// What time is it?
LARGE_INTEGER tick;
QueryPerformanceCounter (&tick);
// Convert the tick number into the number of seconds
// since the system was started.
double ticks_div = ticksPerSecond.QuadPart / 1000000.0;
return (uint64_t) (tick.QuadPart / ticks_div);
#elif defined HAVE_CLOCK_GETTIME && defined CLOCK_MONOTONIC
// Use POSIX clock_gettime function to get precise monotonic time.
struct timespec tv;
int rc = clock_gettime (CLOCK_MONOTONIC, &tv);
// Fix case where system has clock_gettime but CLOCK_MONOTONIC is not supported.
// This should be a configuration check, but I looked into it and writing an
// AC_FUNC_CLOCK_MONOTONIC seems beyond my powers.
if( rc != 0) {
// Use POSIX gettimeofday function to get precise time.
struct timeval tv;
int rc = gettimeofday (&tv, NULL);
errno_assert (rc == 0);
return (tv.tv_sec * (uint64_t) 1000000 + tv.tv_usec);
}
return (tv.tv_sec * (uint64_t) 1000000 + tv.tv_nsec / 1000);
#elif defined HAVE_GETHRTIME
return (gethrtime () / 1000);
#else
// Use POSIX gettimeofday function to get precise time.
struct timeval tv;
int rc = gettimeofday (&tv, NULL);
errno_assert (rc == 0);
return (tv.tv_sec * (uint64_t) 1000000 + tv.tv_usec);
#endif
}
uint64_t zmq::clock_t::now_ms ()
{
uint64_t tsc = rdtsc ();
// If TSC is not supported, get precise time and chop off the microseconds.
if (!tsc)
{
#ifdef ZMQ_HAVE_WINDOWS
// Under Windows, now_us is not so reliable since QueryPerformanceCounter
// does not guarantee that it will use a hardware that offers a monotonic timer.
// So, lets use GetTickCount when GetTickCount64 is not available with an workaround
// to its 32 bit limitation.
return static_cast<uint64_t>((*my_get_tick_count64)());
#else
return now_us () / 1000;
#endif
}
// If TSC haven't jumped back (in case of migration to a different
// CPU core) and if not too much time elapsed since last measurement,
// we can return cached time value.
if (likely (tsc - last_tsc <= (clock_precision / 2) && tsc >= last_tsc))
return last_time;
last_tsc = tsc;
#ifdef ZMQ_HAVE_WINDOWS
last_time = static_cast<uint64_t>((*my_get_tick_count64)());
#else
last_time = now_us () / 1000;
#endif
return last_time;
}
uint64_t zmq::clock_t::rdtsc ()
{
#if (defined _MSC_VER && (defined _M_IX86 || defined _M_X64))
return __rdtsc ();
#elif (defined __GNUC__ && (defined __i386__ || defined __x86_64__))
uint32_t low, high;
__asm__ volatile ("rdtsc" : "=a" (low), "=d" (high));
return (uint64_t) high << 32 | low;
#elif (defined __SUNPRO_CC && (__SUNPRO_CC >= 0x5100) && (defined __i386 || \
defined __amd64 || defined __x86_64))
union {
uint64_t u64val;
uint32_t u32val [2];
} tsc;
asm("rdtsc" : "=a" (tsc.u32val [0]), "=d" (tsc.u32val [1]));
return tsc.u64val;
#elif defined(__s390__)
uint64_t tsc;
asm("\tstck\t%0\n" : "=Q" (tsc) : : "cc");
return(tsc);
#else
return 0;
#endif
}
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