1 //
2 //
3 // Copyright 2015 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 //     http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
17 //
18 
19 #include <grpc/support/port_platform.h>
20 
21 #include <grpc/support/cpu.h>
22 
23 #ifdef GPR_CPU_IPHONE
24 
25 #include <sys/sysctl.h>
26 
gpr_cpu_num_cores(void)27 unsigned gpr_cpu_num_cores(void) {
28   size_t len;
29   unsigned int ncpu;
30   len = sizeof(ncpu);
31   sysctlbyname("hw.ncpu", &ncpu, &len, NULL, 0);
32 
33   return ncpu;
34 }
35 
36 // Most code that's using this is using it to shard across work queues. So
37 // unless profiling shows it's a problem or there appears a way to detect the
38 // currently running CPU core, let's have it shard the default way.
39 // Note that the interface in cpu.h lets gpr_cpu_num_cores return 0, but doing
40 // it makes it impossible for gpr_cpu_current_cpu to satisfy its stated range,
41 // and some code might be relying on it.
gpr_cpu_current_cpu(void)42 unsigned gpr_cpu_current_cpu(void) { return 0; }
43 
44 #endif  // GPR_CPU_IPHONE
45