src/shims/hw_config.h

   1 /*
   2  * Copyright (c) 2011 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 /*
  22  * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
  23  * which are subject to change in future releases of Mac OS X. Any applications
  24  * relying on these interfaces WILL break.
  25  */
  26
  27 #ifndef __DISPATCH_SHIMS_HW_CONFIG__
  28 #define __DISPATCH_SHIMS_HW_CONFIG__
  29
  30 #if defined(__APPLE__)
  31 #define DISPATCH_SYSCTL_LOGICAL_CPUS    "hw.logicalcpu_max"
  32 #define DISPATCH_SYSCTL_PHYSICAL_CPUS   "hw.physicalcpu_max"
  33 #define DISPATCH_SYSCTL_ACTIVE_CPUS             "hw.activecpu"
  34 #elif defined(__FreeBSD__)
  35 #define DISPATCH_SYSCTL_LOGICAL_CPUS    "kern.smp.cpus"
  36 #define DISPATCH_SYSCTL_PHYSICAL_CPUS   "kern.smp.cpus"
  37 #define DISPATCH_SYSCTL_ACTIVE_CPUS             "kern.smp.cpus"
  38 #endif
  39
  40 #if !TARGET_OS_WIN32
  41
  42 static inline uint32_t
  43 _dispatch_get_logicalcpu_max(void)
  44 {
  45         uint32_t val = 1;
  46 #if defined(_COMM_PAGE_LOGICAL_CPUS)
  47         uint8_t* u8val = (uint8_t*)(uintptr_t)_COMM_PAGE_LOGICAL_CPUS;
  48         val = (uint32_t)*u8val;
  49 #elif defined(DISPATCH_SYSCTL_LOGICAL_CPUS)
  50         size_t valsz = sizeof(val);
  51         int ret = sysctlbyname(DISPATCH_SYSCTL_LOGICAL_CPUS,
  52                         &val, &valsz, NULL, 0);
  53         (void)dispatch_assume_zero(ret);
  54         (void)dispatch_assume(valsz == sizeof(uint32_t));
  55 #elif HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)
  56         int ret = (int)sysconf(_SC_NPROCESSORS_ONLN);
  57         val = ret < 0 ? 1 : ret;
  58 #else
  59 #warning "no supported way to query logical CPU count"
  60 #endif
  61         return val;
  62 }
  63
  64 static inline uint32_t
  65 _dispatch_get_physicalcpu_max(void)
  66 {
  67         uint32_t val = 1;
  68 #if defined(_COMM_PAGE_PHYSICAL_CPUS)
  69         uint8_t* u8val = (uint8_t*)(uintptr_t)_COMM_PAGE_PHYSICAL_CPUS;
  70         val = (uint32_t)*u8val;
  71 #elif defined(DISPATCH_SYSCTL_PHYSICAL_CPUS)
  72         size_t valsz = sizeof(val);
  73         int ret = sysctlbyname(DISPATCH_SYSCTL_LOGICAL_CPUS,
  74                         &val, &valsz, NULL, 0);
  75         (void)dispatch_assume_zero(ret);
  76         (void)dispatch_assume(valsz == sizeof(uint32_t));
  77 #elif HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)
  78         int ret = (int)sysconf(_SC_NPROCESSORS_ONLN);
  79         val = ret < 0 ? 1 : ret;
  80 #else
  81 #warning "no supported way to query physical CPU count"
  82 #endif
  83         return val;
  84 }
  85
  86 static inline uint32_t
  87 _dispatch_get_activecpu(void)
  88 {
  89         uint32_t val = 1;
  90 #if defined(_COMM_PAGE_ACTIVE_CPUS)
  91         uint8_t* u8val = (uint8_t*)(uintptr_t)_COMM_PAGE_ACTIVE_CPUS;
  92         val = (uint32_t)*u8val;
  93 #elif defined(DISPATCH_SYSCTL_ACTIVE_CPUS)
  94         size_t valsz = sizeof(val);
  95         int ret = sysctlbyname(DISPATCH_SYSCTL_ACTIVE_CPUS,
  96                         &val, &valsz, NULL, 0);
  97         (void)dispatch_assume_zero(ret);
  98         (void)dispatch_assume(valsz == sizeof(uint32_t));
  99 #elif HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)
 100         int ret = (int)sysconf(_SC_NPROCESSORS_ONLN);
 101         val = ret < 0 ? 1 : ret;
 102 #else
 103 #warning "no supported way to query active CPU count"
 104 #endif
 105         return val;
 106 }
 107
 108 #else // TARGET_OS_WIN32
 109
 110 static inline long
 111 _dispatch_count_bits(unsigned long value)
 112 {
 113         long bits = 0;
 114         while (value) {
 115                 bits += (value & 1);
 116                 value = value >> 1;
 117         }
 118         return bits;
 119 }
 120
 121
 122 static inline uint32_t
 123 _dispatch_get_ncpus(void)
 124 {
 125         uint32_t val;
 126         DWORD_PTR procmask, sysmask;
 127         if (GetProcessAffinityMask(GetCurrentProcess(), &procmask, &sysmask)) {
 128                 val = _dispatch_count_bits(procmask);
 129         } else {
 130                 val = 1;
 131         }
 132         return val;
 133 }
 134 #endif // TARGET_OS_WIN32
 135
 136 #endif /* __DISPATCH_SHIMS_HW_CONFIG__ */