| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_SUPPORT_TIME_PRECISE_H_ |
| #define GRPC_CORE_SUPPORT_TIME_PRECISE_H_ |
| |
| #include <grpc/support/sync.h> |
| #include <grpc/support/time.h> |
| #include <stdio.h> |
| |
| #ifdef GRPC_TIMERS_RDTSC |
| #if defined(__i386__) |
| static void gpr_get_cycle_counter(long long int *clk) { |
| long long int ret; |
| __asm__ volatile("rdtsc" : "=A"(ret)); |
| *clk = ret; |
| } |
| |
| // ---------------------------------------------------------------- |
| #elif defined(__x86_64__) || defined(__amd64__) |
| static void gpr_get_cycle_counter(long long int *clk) { |
| unsigned long long low, high; |
| __asm__ volatile("rdtsc" : "=a"(low), "=d"(high)); |
| *clk = (high << 32) | low; |
| } |
| #endif |
| |
| static gpr_once precise_clock_init = GPR_ONCE_INIT; |
| static long long cycles_per_second = 0; |
| static void gpr_precise_clock_init() { |
| time_t start = time(NULL); |
| gpr_precise_clock start_cycle; |
| gpr_precise_clock end_cycle; |
| while (time(NULL) == start) |
| ; |
| gpr_get_cycle_counter(&start_cycle); |
| while (time(NULL) == start + 1) |
| ; |
| gpr_get_cycle_counter(&end_cycle); |
| cycles_per_second = end_cycle - start_cycle; |
| } |
| |
| static double grpc_precise_clock_scaling_factor() { |
| gpr_once_init(&precise_clock_init, grpc_precise_clock_init); |
| return 1e6 / cycles_per_second; |
| } |
| |
| static void gpr_precise_clock_now(gpr_timespec *clk) { |
| long long int counter; |
| gpr_get_cycle_counter(&counter); |
| clk->clock = GPR_CLOCK_REALTIME; |
| clk->tv_sec = counter / cycles_per_second; |
| clk->tv_nsec = counter % cycles_per_second; |
| } |
| |
| #else /* GRPC_TIMERS_RDTSC */ |
| static void gpr_precise_clock_now(gpr_timespec *clk) { |
| *clk = gpr_now(GPR_CLOCK_REALTIME); |
| clk->clock_type = GPR_CLOCK_PRECISE; |
| } |
| #endif /* GRPC_TIMERS_RDTSC */ |
| |
| #endif /* GRPC_CORE_SUPPORT_TIME_PRECISE_ */ |