| /* |
| * |
| * 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 _GNU_SOURCE |
| #define _GNU_SOURCE |
| #endif /* _GNU_SOURCE */ |
| |
| #include <grpc/support/port_platform.h> |
| |
| #ifdef GPR_CPU_LINUX |
| |
| #include <errno.h> |
| #include <sched.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <grpc/support/cpu.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/sync.h> |
| |
| static int ncpus = 0; |
| |
| static void init_num_cpus() { |
| /* This must be signed. sysconf returns -1 when the number cannot be |
| determined */ |
| ncpus = (int)sysconf(_SC_NPROCESSORS_ONLN); |
| if (ncpus < 1) { |
| gpr_log(GPR_ERROR, "Cannot determine number of CPUs: assuming 1"); |
| ncpus = 1; |
| } |
| } |
| |
| unsigned gpr_cpu_num_cores(void) { |
| static gpr_once once = GPR_ONCE_INIT; |
| gpr_once_init(&once, init_num_cpus); |
| return (unsigned)ncpus; |
| } |
| |
| unsigned gpr_cpu_current_cpu(void) { |
| #ifdef __GLIBC__ |
| int cpu = sched_getcpu(); |
| if (cpu < 0) { |
| gpr_log(GPR_ERROR, "Error determining current CPU: %s\n", strerror(errno)); |
| return 0; |
| } |
| return (unsigned)cpu; |
| #else |
| // sched_getcpu() is undefined on musl |
| return 0; |
| #endif |
| } |
| |
| #endif /* GPR_CPU_LINUX */ |