src/shims/hw_config.h

   1 /*
   2  * Copyright (c) 2011-2013 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 !TARGET_OS_WIN32
  31
  32 typedef enum {
  33         _dispatch_hw_config_logical_cpus,
  34         _dispatch_hw_config_physical_cpus,
  35         _dispatch_hw_config_active_cpus,
  36 } _dispatch_hw_config_t;
  37
  38 #if !defined(DISPATCH_HAVE_HW_CONFIG_COMMPAGE) && \
  39                 defined(_COMM_PAGE_LOGICAL_CPUS) && \
  40                 defined(_COMM_PAGE_PHYSICAL_CPUS) && defined(_COMM_PAGE_ACTIVE_CPUS)
  41 #define DISPATCH_HAVE_HW_CONFIG_COMMPAGE 1
  42 #endif
  43
  44 #if DISPATCH_HAVE_HW_CONFIG_COMMPAGE
  45
  46 DISPATCH_ALWAYS_INLINE
  47 static inline uint32_t
  48 _dispatch_hw_get_config(_dispatch_hw_config_t c)
  49 {
  50         uintptr_t p;
  51         switch (c) {
  52         case _dispatch_hw_config_logical_cpus:
  53                 p =  _COMM_PAGE_LOGICAL_CPUS; break;
  54         case _dispatch_hw_config_physical_cpus:
  55                 p = _COMM_PAGE_PHYSICAL_CPUS; break;
  56         case _dispatch_hw_config_active_cpus:
  57                 p = _COMM_PAGE_ACTIVE_CPUS; break;
  58         }
  59         return *(uint8_t*)p;
  60 }
  61
  62 #define dispatch_hw_config(c) \
  63                 _dispatch_hw_get_config(_dispatch_hw_config_##c)
  64
  65 #define DISPATCH_HW_CONFIG()
  66 #define _dispatch_hw_config_init()
  67
  68 #else // DISPATCH_HAVE_HW_CONFIG_COMMPAGE
  69
  70 extern struct _dispatch_hw_configs_s {
  71         uint32_t logical_cpus;
  72         uint32_t physical_cpus;
  73         uint32_t active_cpus;
  74 } _dispatch_hw_config;
  75
  76 #define DISPATCH_HW_CONFIG() struct _dispatch_hw_configs_s _dispatch_hw_config
  77 #define dispatch_hw_config(c) (_dispatch_hw_config.c)
  78
  79 DISPATCH_ALWAYS_INLINE
  80 static inline uint32_t
  81 _dispatch_hw_get_config(_dispatch_hw_config_t c)
  82 {
  83         uint32_t val = 1;
  84 #if defined(__linux__) && HAVE_SYSCONF
  85         switch (c) {
  86         case _dispatch_hw_config_logical_cpus:
  87         case _dispatch_hw_config_physical_cpus:
  88                 return sysconf(_SC_NPROCESSORS_CONF);
  89         case _dispatch_hw_config_active_cpus:
  90                 return sysconf(_SC_NPROCESSORS_ONLN);
  91         }
  92 #else
  93         const char *name = NULL;
  94         int r;
  95 #if defined(__APPLE__)
  96         switch (c) {
  97         case _dispatch_hw_config_logical_cpus:
  98                 name = "hw.logicalcpu_max"; break;
  99         case _dispatch_hw_config_physical_cpus:
 100                 name = "hw.physicalcpu_max"; break;
 101         case _dispatch_hw_config_active_cpus:
 102                 name = "hw.activecpu"; break;
 103         }
 104 #elif defined(__FreeBSD__)
 105          (void)c; name = "kern.smp.cpus";
 106 #endif
 107         if (name) {
 108                 size_t valsz = sizeof(val);
 109                 r = sysctlbyname(name, &val, &valsz, NULL, 0);
 110                 (void)dispatch_assume_zero(r);
 111                 dispatch_assert(valsz == sizeof(uint32_t));
 112         } else {
 113 #if HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)
 114                 r = (int)sysconf(_SC_NPROCESSORS_ONLN);
 115                 if (r > 0) val = (uint32_t)r;
 116 #endif
 117         }
 118 #endif
 119         return val;
 120 }
 121
 122 #define dispatch_hw_config_init(c) \
 123                 _dispatch_hw_get_config(_dispatch_hw_config_##c)
 124
 125 static inline void
 126 _dispatch_hw_config_init(void)
 127 {
 128         dispatch_hw_config(logical_cpus) = dispatch_hw_config_init(logical_cpus);
 129         dispatch_hw_config(physical_cpus) = dispatch_hw_config_init(physical_cpus);
 130         dispatch_hw_config(active_cpus) = dispatch_hw_config_init(active_cpus);
 131 }
 132
 133 #undef dispatch_hw_config_init
 134
 135 #endif // DISPATCH_HAVE_HW_CONFIG_COMMPAGE
 136
 137 #else // TARGET_OS_WIN32
 138
 139 static inline long
 140 _dispatch_count_bits(unsigned long value)
 141 {
 142         long bits = 0;
 143         while (value) {
 144                 bits += (value & 1);
 145                 value = value >> 1;
 146         }
 147         return bits;
 148 }
 149
 150 static inline uint32_t
 151 _dispatch_get_ncpus(void)
 152 {
 153         uint32_t val;
 154         DWORD_PTR procmask, sysmask;
 155         if (GetProcessAffinityMask(GetCurrentProcess(), &procmask, &sysmask)) {
 156                 val = _dispatch_count_bits(procmask);
 157         } else {
 158                 val = 1;
 159         }
 160         return val;
 161 }
 162 #endif // TARGET_OS_WIN32
 163
 164 #endif /* __DISPATCH_SHIMS_HW_CONFIG__ */