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/cpu.h>
20 #include <grpc/support/port_platform.h>
21
22 #ifdef GPR_CPU_IPHONE
23
24 #include <sys/sysctl.h>
25
gpr_cpu_num_cores(void)26 unsigned gpr_cpu_num_cores(void) {
27 size_t len;
28 unsigned int ncpu;
29 len = sizeof(ncpu);
30 sysctlbyname("hw.ncpu", &ncpu, &len, NULL, 0);
31
32 return ncpu;
33 }
34
35 // Most code that's using this is using it to shard across work queues. So
36 // unless profiling shows it's a problem or there appears a way to detect the
37 // currently running CPU core, let's have it shard the default way.
38 // Note that the interface in cpu.h lets gpr_cpu_num_cores return 0, but doing
39 // it makes it impossible for gpr_cpu_current_cpu to satisfy its stated range,
40 // and some code might be relying on it.
gpr_cpu_current_cpu(void)41 unsigned gpr_cpu_current_cpu(void) { return 0; }
42
43 #endif // GPR_CPU_IPHONE
44