Line data    Source code

       1             : /*
       2             :  *
       3             :  * Copyright 2015, Google Inc.
       4             :  * All rights reserved.
       5             :  *
       6             :  * Redistribution and use in source and binary forms, with or without
       7             :  * modification, are permitted provided that the following conditions are
       8             :  * met:
       9             :  *
      10             :  *     * Redistributions of source code must retain the above copyright
      11             :  * notice, this list of conditions and the following disclaimer.
      12             :  *     * Redistributions in binary form must reproduce the above
      13             :  * copyright notice, this list of conditions and the following disclaimer
      14             :  * in the documentation and/or other materials provided with the
      15             :  * distribution.
      16             :  *     * Neither the name of Google Inc. nor the names of its
      17             :  * contributors may be used to endorse or promote products derived from
      18             :  * this software without specific prior written permission.
      19             :  *
      20             :  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      21             :  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      22             :  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      23             :  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      24             :  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      25             :  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      26             :  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      27             :  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      28             :  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      29             :  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      30             :  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      31             :  *
      32             :  */
      33             : 
      34             : #ifndef _GNU_SOURCE
      35             : #define _GNU_SOURCE
      36             : #endif /* _GNU_SOURCE */
      37             : 
      38             : #include <grpc/support/port_platform.h>
      39             : 
      40             : #ifdef GPR_CPU_LINUX
      41             : 
      42             : #include <sched.h>
      43             : #include <errno.h>
      44             : #include <unistd.h>
      45             : #include <string.h>
      46             : 
      47             : #include <grpc/support/cpu.h>
      48             : #include <grpc/support/log.h>
      49             : #include <grpc/support/sync.h>
      50             : 
      51             : static int ncpus = 0;
      52             : 
      53          15 : static void init_num_cpus() {
      54             :   /* This must be signed. sysconf returns -1 when the number cannot be
      55             :      determined */
      56          15 :   ncpus = (int)sysconf(_SC_NPROCESSORS_ONLN);
      57          15 :   if (ncpus < 1) {
      58           0 :     gpr_log(GPR_ERROR, "Cannot determine number of CPUs: assuming 1");
      59           0 :     ncpus = 1;
      60             :   }
      61          15 : }
      62             : 
      63         187 : unsigned gpr_cpu_num_cores(void) {
      64             :   static gpr_once once = GPR_ONCE_INIT;
      65         187 :   gpr_once_init(&once, init_num_cpus);
      66         187 :   return (unsigned)ncpus;
      67             : }
      68             : 
      69       12000 : unsigned gpr_cpu_current_cpu(void) {
      70       12000 :   int cpu = sched_getcpu();
      71       12000 :   if (cpu < 0) {
      72           0 :     gpr_log(GPR_ERROR, "Error determining current CPU: %s\n", strerror(errno));
      73           0 :     return 0;
      74             :   }
      75       12000 :   return (unsigned)cpu;
      76             : }
      77             : 
      78             : #endif /* GPR_CPU_LINUX */