| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #include <grpc/support/log.h> |
| #include <grpc/support/time.h> |
| #include <stdio.h> |
| |
| #include "src/core/lib/support/time_precise.h" |
| |
| #ifdef GRPC_TIMERS_RDTSC |
| #if defined(__i386__) |
| static void gpr_get_cycle_counter(int64_t int *clk) { |
| int64_t int ret; |
| __asm__ volatile("rdtsc" : "=A"(ret)); |
| *clk = ret; |
| } |
| |
| // ---------------------------------------------------------------- |
| #elif defined(__x86_64__) || defined(__amd64__) |
| static void gpr_get_cycle_counter(int64_t *clk) { |
| uint64_t low, high; |
| __asm__ volatile("rdtsc" : "=a"(low), "=d"(high)); |
| *clk = (int64_t)(high << 32) | (int64_t)low; |
| } |
| #endif |
| |
| static double cycles_per_second = 0; |
| static int64_t start_cycle; |
| void gpr_precise_clock_init(void) { |
| time_t start; |
| int64_t end_cycle; |
| gpr_log(GPR_DEBUG, "Calibrating timers"); |
| start = time(NULL); |
| while (time(NULL) == start) |
| ; |
| gpr_get_cycle_counter(&start_cycle); |
| while (time(NULL) <= start + 10) |
| ; |
| gpr_get_cycle_counter(&end_cycle); |
| cycles_per_second = (double)(end_cycle - start_cycle) / 10.0; |
| gpr_log(GPR_DEBUG, "... cycles_per_second = %f\n", cycles_per_second); |
| } |
| |
| void gpr_precise_clock_now(gpr_timespec *clk) { |
| int64_t counter; |
| double secs; |
| gpr_get_cycle_counter(&counter); |
| secs = (double)(counter - start_cycle) / cycles_per_second; |
| clk->clock_type = GPR_CLOCK_PRECISE; |
| clk->tv_sec = (int64_t)secs; |
| clk->tv_nsec = (int32_t)(1e9 * (secs - (double)clk->tv_sec)); |
| } |
| |
| #else /* GRPC_TIMERS_RDTSC */ |
| void gpr_precise_clock_init(void) {} |
| |
| void gpr_precise_clock_now(gpr_timespec *clk) { |
| *clk = gpr_now(GPR_CLOCK_REALTIME); |
| clk->clock_type = GPR_CLOCK_PRECISE; |
| } |
| #endif /* GRPC_TIMERS_RDTSC */ |