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         const char *name = NULL;
  85         int r;
  86 #if defined(__APPLE__)
  87         switch (c) {
  88         case _dispatch_hw_config_logical_cpus:
  89                 name = "hw.logicalcpu_max"; break;
  90         case _dispatch_hw_config_physical_cpus:
  91                 name = "hw.physicalcpu_max"; break;
  92         case _dispatch_hw_config_active_cpus:
  93                 name = "hw.activecpu"; break;
  94         }
  95 #elif defined(__FreeBSD__)
  96          (void)c; name = "kern.smp.cpus";
  97 #endif
  98         if (name) {
  99                 size_t valsz = sizeof(val);
 100                 r = sysctlbyname(name, &val, &valsz, NULL, 0);
 101                 (void)dispatch_assume_zero(r);
 102                 dispatch_assert(valsz == sizeof(uint32_t));
 103         } else {
 104 #if HAVE_SYSCONF && defined(_SC_NPROCESSORS_ONLN)
 105                 r = (int)sysconf(_SC_NPROCESSORS_ONLN);
 106                 if (r > 0) val = (uint32_t)r;
 107 #endif
 108         }
 109         return val;
 110 }
 111
 112 #define dispatch_hw_config_init(c) \
 113                 _dispatch_hw_get_config(_dispatch_hw_config_##c)
 114
 115 static inline void
 116 _dispatch_hw_config_init(void)
 117 {
 118         dispatch_hw_config(logical_cpus) = dispatch_hw_config_init(logical_cpus);
 119         dispatch_hw_config(physical_cpus) = dispatch_hw_config_init(physical_cpus);
 120         dispatch_hw_config(active_cpus) = dispatch_hw_config_init(active_cpus);
 121 }
 122
 123 #undef dispatch_hw_config_init
 124
 125 #endif // DISPATCH_HAVE_HW_CONFIG_COMMPAGE
 126
 127 #else // TARGET_OS_WIN32
 128
 129 static inline long
 130 _dispatch_count_bits(unsigned long value)
 131 {
 132         long bits = 0;
 133         while (value) {
 134                 bits += (value & 1);
 135                 value = value >> 1;
 136         }
 137         return bits;
 138 }
 139
 140 static inline uint32_t
 141 _dispatch_get_ncpus(void)
 142 {
 143         uint32_t val;
 144         DWORD_PTR procmask, sysmask;
 145         if (GetProcessAffinityMask(GetCurrentProcess(), &procmask, &sysmask)) {
 146                 val = _dispatch_count_bits(procmask);
 147         } else {
 148                 val = 1;
 149         }
 150         return val;
 151 }
 152 #endif // TARGET_OS_WIN32
 153
 154 #endif /* __DISPATCH_SHIMS_HW_CONFIG__ */