mods/android/bionic/libc/bionic/sysconf.cpp - arc/arc - Git at Google

 /*
  * Copyright (C) 2008 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */

 #include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <pthread.h>
 #include <stdio.h>  // For FOPEN_MAX.
 #include <string.h>
 #include <sys/sysconf.h>
 #include <time.h>
 #include <unistd.h>

 #include "private/bionic_tls.h"
 #include "private/ScopedReaddir.h"
 // ARC MOD BEGIN
 // For implementing __sysconf_nprocessors_*() on top of the sysconf IRT.
 #if defined(HAVE_ARC)
 #include <irt_syscalls.h>
 static int __sysconf_nprocessors_onln();

 // These defines are from
 // native_client/src/trusted/service_runtime/include/sys/unistd.h. Note that
 // the sysconf IRT only supports retrieving two configurations below while
 // ARC/Android code requires a lot more. This is why we use Bionic's default
 // sysconf.cpp (this file) combined with the sysconf IRT call.
 #define NACL_ABI__SC_NPROCESSORS_ONLN 1
 #define NACL_ABI__SC_PAGESIZE 2
 #endif
 // ARC MOD END

 /* seems to be the default on Linux, per the GLibc sources and my own digging */

 #define  SYSTEM_CLK_TCK         100
 #define  SYSTEM_IOV_MAX         1024
 #define  SYSTEM_DELAYTIMER_MAX  2147483647
 #define  SYSTEM_MQ_OPEN_MAX     8
 #define  SYSTEM_MQ_PRIO_MAX     32768
 #define  SYSTEM_SEM_NSEMS_MAX   256
 #define  SYSTEM_SEM_VALUE_MAX   0x3fffffff  /* see bionic/semaphore.c */
 #define  SYSTEM_SIGQUEUE_MAX    32
 #define  SYSTEM_TIMER_MAX       32
 #define  SYSTEM_LOGIN_NAME_MAX  256
 #define  SYSTEM_TTY_NAME_MAX    32

 /* the following depends on our implementation */
 #define  SYSTEM_ATEXIT_MAX          65536    /* our implementation is unlimited */
 #define  SYSTEM_THREAD_THREADS_MAX  2048     /* really unlimited */

 #define  SYSTEM_2_C_BIND     _POSIX_VERSION  /* Posix C binding version */
 #define  SYSTEM_2_C_VER      _POSIX2_C_VERSION
 #define  SYSTEM_2_C_DEV      -1       /* Posix C development tools unsupported on the device */
 #define  SYSTEM_2_FORT_DEV   -1       /* Fortran development unsupported */
 #define  SYSTEM_2_FORT_RUN   -1       /* Fortran runtime unsupported */
 #define  SYSTEM_2_SW_DEV     -1       /* posix software dev utilities unsupported */
 #define  SYSTEM_2_LOCALEDEF  -1       /* localedef() unimplemented */
 #define  SYSTEM_2_UPE        -1       /* No UPE for you ! (User Portability Utilities) */
 #define  SYSTEM_2_VERSION    -1       /* No posix command-line tools */

 static bool __matches_cpuN(const char* s) {
   // The %c trick is to ensure that we have the anchored match "^cpu[0-9]+$".
   unsigned cpu;
   char dummy;
   return (sscanf(s, "cpu%u%c", &cpu, &dummy) == 1);
 }

 static int __sysconf_nprocessors_conf() {
   // ARC MOD BEGIN
 #if defined(HAVE_ARC)
 #if defined(__native_client__)
   // On NaCl i686/x86_64, it is safe to assume that the number of processors
   // available to the system is the same as the number of processors online.
   // On BMM ARM, we return a fixed value, as non-SFI NaCl does not
   // support sysconf.
   // TODO(crbug.com/368344): Update the comment for ARM when we add a
   // real _SC_NPROCESSORS_ONLN support.
   return __sysconf_nprocessors_onln();
 #else
   // TODO(crbug.com/368344): Implement this for BMM. For now, return the safest
   // value which does not trigger crbug.com/366079.
   return 2;
 #endif  // __native_client__
 #else
   // ARC MOD END
   // On x86 kernels you can use /proc/cpuinfo for this, but on ARM kernels offline CPUs disappear
   // from there. This method works on both.
   ScopedReaddir reader("/sys/devices/system/cpu");
   if (reader.IsBad()) {
     return 1;
   }

   int result = 0;
   dirent* entry;
   while ((entry = reader.ReadEntry()) != NULL) {
     if (entry->d_type == DT_DIR && __matches_cpuN(entry->d_name)) {
       ++result;
     }
   }
   return result;
   // ARC MOD BEGIN
 #endif // HAVE_ARC
   // ARC MOD END
 }

 static int __sysconf_nprocessors_onln() {
   // ARC MOD BEGIN
 #if defined(HAVE_ARC)
 #if defined(__native_client__)
   int value = 0;
   const int ret = __nacl_irt_sysconf(NACL_ABI__SC_NPROCESSORS_ONLN, &value);
   if (!ret)
     return value;
   errno = ret;
   return -1;
 #else
   // TODO(crbug.com/368344): Implement this for BMM. For now, return the safest
   // value which does not trigger crbug.com/366079.
   return 2;
 #endif  // __native_client__
 #else
   // ARC MOD END
   FILE* fp = fopen("/proc/stat", "r");
   if (fp == NULL) {
     return 1;
   }

   int result = 0;
   char buf[256];
   while (fgets(buf, sizeof(buf), fp) != NULL) {
     // Extract just the first word from the line.
     // 'cpu0 7976751 1364388 3116842 469770388 8629405 0 49047 0 0 0'
     char* p = strchr(buf, ' ');
     if (p != NULL) {
       *p = 0;
     }
     if (__matches_cpuN(buf)) {
       ++result;
     }
   }
   fclose(fp);
   return result;
   // ARC MOD BEGIN
 #endif // HAVE_ARC
   // ARC MOD END
 }

 static int __get_meminfo(const char* pattern) {
   FILE* fp = fopen("/proc/meminfo", "r");
   if (fp == NULL) {
     return -1;
   }

   int result = -1;
   char buf[256];
   while (fgets(buf, sizeof(buf), fp) != NULL) {
     long total;
     if (sscanf(buf, pattern, &total) == 1) {
       result = (int) (total / (PAGE_SIZE/1024));
       break;
     }
   }
   fclose(fp);
   return result;
 }

 static int __sysconf_phys_pages() {
   return __get_meminfo("MemTotal: %ld kB");
 }

 static int __sysconf_avphys_pages() {
   return __get_meminfo("MemFree: %ld kB");
 }

 static int __sysconf_monotonic_clock() {
   timespec t;
   int rc = clock_getres(CLOCK_MONOTONIC, &t);
   return (rc == -1) ? -1 : _POSIX_VERSION;
 }

 int sysconf(int name) {
     switch (name) {
 #ifdef _POSIX_ARG_MAX
     case _SC_ARG_MAX:           return _POSIX_ARG_MAX;
 #endif
 #ifdef _POSIX2_BC_BASE_MAX
     case _SC_BC_BASE_MAX:       return _POSIX2_BC_BASE_MAX;
 #endif
 #ifdef _POSIX2_BC_DIM_MAX
     case _SC_BC_DIM_MAX:        return _POSIX2_BC_DIM_MAX;
 #endif
 #ifdef _POSIX2_BC_SCALE_MAX
     case _SC_BC_SCALE_MAX:      return _POSIX2_BC_SCALE_MAX;
 #endif
 #ifdef _POSIX2_BC_STRING_MAX
     case _SC_BC_STRING_MAX:     return _POSIX2_BC_STRING_MAX;
 #endif
     case _SC_CHILD_MAX:         return CHILD_MAX;
     case _SC_CLK_TCK:           return SYSTEM_CLK_TCK;
 #ifdef _POSIX2_COLL_WEIGHTS_MASK
     case _SC_COLL_WEIGHTS_MAX:  return _POSIX2_COLL_WEIGHTS_MASK;
 #endif
 #ifdef _POSIX2_EXPR_NEST_MAX
     case _SC_EXPR_NEST_MAX:    return _POSIX2_EXPR_NEST_MAX;
 #endif
 #ifdef _POSIX2_LINE_MAX
     case _SC_LINE_MAX:          return _POSIX2_LINE_MAX;
 #endif
     case _SC_NGROUPS_MAX:       return NGROUPS_MAX;
     case _SC_OPEN_MAX:          return OPEN_MAX;
     //case _SC_PASS_MAX:          return PASS_MAX;
     case _SC_2_C_BIND:          return SYSTEM_2_C_BIND;
     case _SC_2_C_DEV:           return SYSTEM_2_C_DEV;
     case _SC_2_C_VERSION:       return SYSTEM_2_C_VER;
     //case _SC_2_CHAR_TERM:         return ;
     case _SC_2_FORT_DEV:        return SYSTEM_2_FORT_DEV;
     case _SC_2_FORT_RUN:        return SYSTEM_2_FORT_RUN;
     case _SC_2_LOCALEDEF:       return SYSTEM_2_LOCALEDEF;
     case _SC_2_SW_DEV:          return SYSTEM_2_SW_DEV;
     case _SC_2_UPE:             return SYSTEM_2_UPE;
     case _SC_2_VERSION:         return SYSTEM_2_VERSION;
 #ifdef _POSIX_JOB_CONTROL
     case _SC_JOB_CONTROL:       return _POSIX_JOB_CONTROL;
 #endif
 #ifdef _POSIX_SAVED_IDS
     case _SC_SAVED_IDS:         return _POSIX_SAVED_IDS;
 #endif
 #ifdef _POSIX_VERSION
     case _SC_VERSION:           return _POSIX_VERSION;
 #endif
     //case _SC_RE_DUP_<AX:        return ;
     case _SC_STREAM_MAX:        return FOPEN_MAX;
     //case _SC_TZNAME_MAX:        return ;
 #if _XOPEN_CRYPT
     case _SC_XOPEN_CRYPT:       return _XOPEN_CRYPT;
 #endif
 #ifdef _XOPEN_ENH_I18N
     case _SC_XOPEN_ENH_I18N:    return _XOPEN_ENH_I18N;
 #endif
 #ifdef _XOPEN_SHM
     case _SC_XOPEN_SHM:         return _XOPEN_SHM;
 #endif
 #ifdef _XOPEN_VERSION
     case _SC_XOPEN_VERSION:     return _XOPEN_VERSION;
 #endif
 #ifdef _XOPEN_XCU_VERSION
     case _SC_XOPEN_XCU_VERSION: return _XOPEN_XCU_VERSION;
 #endif
 #ifdef _XOPEN_REALTIME
     case _SC_XOPEN_REALTIME:    return _XOPEN_REALTIME;
 #endif
 #ifdef _XOPEN_REALTIME_THREADS
     case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS;
 #endif
 #ifdef _XOPEN_LEGACY
     case _SC_XOPEN_LEGACY:      return _XOPEN_LEGACY;
 #endif
     case _SC_ATEXIT_MAX:        return SYSTEM_ATEXIT_MAX;
     case _SC_IOV_MAX:           return SYSTEM_IOV_MAX;

     case _SC_PAGESIZE:
     case _SC_PAGE_SIZE:
         return PAGE_SIZE;

 #ifdef _XOPEN_UNIX
     case _SC_XOPEN_UNIX:        return _XOPEN_UNIX;
 #endif

     // XXX: TODO: XBS5 nonsense

 #ifdef AIO_LISTIO_MAX
     case _SC_AIO_LISTIO_MAX:       return AIO_LISTIO_MAX;
 #endif
 #ifdef AIO_MAX
     case _SC_AIO_MAX:              return AIO_MAX;
 #endif
 #ifdef AIO_PRIO_DELTA_MAX
     case _SC_AIO_PRIO_DELTA_MAX:   return AIO_PRIO_DELTA_MAX;
 #endif
     case _SC_DELAYTIMER_MAX:    return SYSTEM_DELAYTIMER_MAX;
     case _SC_MQ_OPEN_MAX:       return SYSTEM_MQ_OPEN_MAX;
     case _SC_MQ_PRIO_MAX:       return SYSTEM_MQ_PRIO_MAX;
     case _SC_RTSIG_MAX:         return RTSIG_MAX;
     case _SC_SEM_NSEMS_MAX:     return SYSTEM_SEM_NSEMS_MAX;
     case _SC_SEM_VALUE_MAX:     return SYSTEM_SEM_VALUE_MAX;
     case _SC_SIGQUEUE_MAX:      return SYSTEM_SIGQUEUE_MAX;
     case _SC_TIMER_MAX:         return SYSTEM_TIMER_MAX;
 #ifdef _POSIX_ASYNCHRONOUS_IO
     case _SC_ASYNCHRONOUS_IO:   return _POSIX_ASYNCHRONOUS_IO;
 #endif
 #ifdef _POSIX_FSYNC
     case _SC_FSYNC:             return _POSIX_FSYNC;
 #endif
 #ifdef _POSIX_MAPPED_FILES
     case _SC_MAPPED_FILES:      return _POSIX_MAPPED_FILES;
 #endif
 #ifdef _POSIX_MEMLOCK
     case _SC_MEMLOCK:           return _POSIX_MEMLOCK;
 #endif
 #ifdef _POSIX_MEMLOCK_RANGE
     case _SC_MEMLOCK_RANGE:     return _POSIX_MEMLOCK_RANGE
 #endif
 #ifdef _POSIX_MEMORY_PROTECTION
     case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION;
 #endif
 #ifdef _POSIX_MESSAGE_PASSING
     case _SC_MESSAGE_PASSING:   return _POSIX_MESSAGE_PASSING;
 #endif
 #ifdef _POSIX_PRIORITIZED_IO
     case _SC_PRIORITIZED_IO:    return _POSIX_PRIORITIZED_IO;
 #endif
 #ifdef _POSIX_PRIORITY_SCHEDULING
     case _SC_PRIORITY_SCHEDULING:  return _POSIX_PRIORITY_SCHEDULING;
 #endif
 #ifdef _POSIX_REALTIME_SIGNALS
     case _SC_REALTIME_SIGNALS:  return _POSIX_REALTIME_SIGNALS;
 #endif
 #ifdef _POSIX_SEMAPHORES
     case _SC_SEMAPHORES:        return _POSIX_SEMAPHORES;
 #endif
 #ifdef _POSIX_SHARED_MEMORY_OBJECTS
     case _SC_SHARED_MEMORY_OBJECTS:  return _POSIX_SHARED_MEMORY_OBJECTS;
 #endif
 #ifdef _POSIX_SYNCHRONIZED_IO
     case _SC_SYNCHRONIZED_IO:   return _POSIX_SYNCHRONIZED_IO;
 #endif
 #ifdef _POSIX_TIMERS
     case _SC_TIMERS:            return _POSIX_TIMERS;
 #endif

     case _SC_GETGR_R_SIZE_MAX: return 1024;
     case _SC_GETPW_R_SIZE_MAX: return 1024;

     case _SC_LOGIN_NAME_MAX:    return SYSTEM_LOGIN_NAME_MAX;

     case _SC_THREAD_DESTRUCTOR_ITERATIONS:
       return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;

     case _SC_THREAD_KEYS_MAX:
       return (BIONIC_TLS_SLOTS - TLS_SLOT_FIRST_USER_SLOT - BIONIC_TLS_RESERVED_SLOTS);

     case _SC_THREAD_STACK_MIN:    return PTHREAD_STACK_MIN;
     case _SC_THREAD_THREADS_MAX:  return SYSTEM_THREAD_THREADS_MAX;
     case _SC_TTY_NAME_MAX:        return SYSTEM_TTY_NAME_MAX;
 #ifdef _POSIX_THREADS
     case _SC_THREADS:             return _POSIX_THREADS;
 #endif

     case _SC_THREAD_ATTR_STACKADDR:   return -1; // Removed in POSIX 2008
     case _SC_THREAD_ATTR_STACKSIZE:   return -1; // Removed in POSIX 2008

 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
     case _SC_THREAD_PRIORITY_SCHEDULING:  return _POSIX_THREAD_PRIORITY_SCHEDULING;
 #endif
 #ifdef _POSIX_THREAD_PRIO_INHERIT
     case _SC_THREAD_PRIO_INHERIT:         return _POSIX_THREAD_PRIO_INHERIT;
 #endif
 #ifdef _POSIX_THREAD_PRIO_PROTECT
     case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT;
 #endif
 #ifdef _POSIX_THREAD_SAFE_FUNCTIONS
     case _SC_THREAD_SAFE_FUNCTIONS:  return _POSIX_THREAD_SAFE_FUNCTIONS
 #endif

     case _SC_MONOTONIC_CLOCK:   return __sysconf_monotonic_clock();
     case _SC_NPROCESSORS_CONF:  return __sysconf_nprocessors_conf();
     case _SC_NPROCESSORS_ONLN:  return __sysconf_nprocessors_onln();
     case _SC_PHYS_PAGES:        return __sysconf_phys_pages();
     case _SC_AVPHYS_PAGES:      return __sysconf_avphys_pages();

     default:
        /* Posix says EINVAL is the only error that shall be returned,
         * but GLibc uses ENOSYS */
         errno = ENOSYS;
         return -1;
     }
 }
	/*
	* Copyright (C) 2008 The Android Open Source Project
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in
	* the documentation and/or other materials provided with the
	* distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
	* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*/

	#include <ctype.h>
	#include <dirent.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <limits.h>
	#include <pthread.h>
	#include <stdio.h> // For FOPEN_MAX.
	#include <string.h>
	#include <sys/sysconf.h>
	#include <time.h>
	#include <unistd.h>

	#include "private/bionic_tls.h"
	#include "private/ScopedReaddir.h"
	// ARC MOD BEGIN
	// For implementing __sysconf_nprocessors_*() on top of the sysconf IRT.
	#if defined(HAVE_ARC)
	#include <irt_syscalls.h>
	static int __sysconf_nprocessors_onln();

	// These defines are from
	// native_client/src/trusted/service_runtime/include/sys/unistd.h. Note that
	// the sysconf IRT only supports retrieving two configurations below while
	// ARC/Android code requires a lot more. This is why we use Bionic's default
	// sysconf.cpp (this file) combined with the sysconf IRT call.
	#define NACL_ABI__SC_NPROCESSORS_ONLN 1
	#define NACL_ABI__SC_PAGESIZE 2
	#endif
	// ARC MOD END

	/* seems to be the default on Linux, per the GLibc sources and my own digging */

	#define SYSTEM_CLK_TCK 100
	#define SYSTEM_IOV_MAX 1024
	#define SYSTEM_DELAYTIMER_MAX 2147483647
	#define SYSTEM_MQ_OPEN_MAX 8
	#define SYSTEM_MQ_PRIO_MAX 32768
	#define SYSTEM_SEM_NSEMS_MAX 256
	#define SYSTEM_SEM_VALUE_MAX 0x3fffffff /* see bionic/semaphore.c */
	#define SYSTEM_SIGQUEUE_MAX 32
	#define SYSTEM_TIMER_MAX 32
	#define SYSTEM_LOGIN_NAME_MAX 256
	#define SYSTEM_TTY_NAME_MAX 32

	/* the following depends on our implementation */
	#define SYSTEM_ATEXIT_MAX 65536 /* our implementation is unlimited */
	#define SYSTEM_THREAD_THREADS_MAX 2048 /* really unlimited */

	#define SYSTEM_2_C_BIND _POSIX_VERSION /* Posix C binding version */
	#define SYSTEM_2_C_VER _POSIX2_C_VERSION
	#define SYSTEM_2_C_DEV -1 /* Posix C development tools unsupported on the device */
	#define SYSTEM_2_FORT_DEV -1 /* Fortran development unsupported */
	#define SYSTEM_2_FORT_RUN -1 /* Fortran runtime unsupported */
	#define SYSTEM_2_SW_DEV -1 /* posix software dev utilities unsupported */
	#define SYSTEM_2_LOCALEDEF -1 /* localedef() unimplemented */
	#define SYSTEM_2_UPE -1 /* No UPE for you ! (User Portability Utilities) */
	#define SYSTEM_2_VERSION -1 /* No posix command-line tools */

	static bool __matches_cpuN(const char* s) {
	// The %c trick is to ensure that we have the anchored match "^cpu[0-9]+$".
	unsigned cpu;
	char dummy;
	return (sscanf(s, "cpu%u%c", &cpu, &dummy) == 1);
	}

	static int __sysconf_nprocessors_conf() {
	// ARC MOD BEGIN
	#if defined(HAVE_ARC)
	#if defined(__native_client__)
	// On NaCl i686/x86_64, it is safe to assume that the number of processors
	// available to the system is the same as the number of processors online.
	// On BMM ARM, we return a fixed value, as non-SFI NaCl does not
	// support sysconf.
	// TODO(crbug.com/368344): Update the comment for ARM when we add a
	// real _SC_NPROCESSORS_ONLN support.
	return __sysconf_nprocessors_onln();
	#else
	// TODO(crbug.com/368344): Implement this for BMM. For now, return the safest
	// value which does not trigger crbug.com/366079.
	return 2;
	#endif // __native_client__
	#else
	// ARC MOD END
	// On x86 kernels you can use /proc/cpuinfo for this, but on ARM kernels offline CPUs disappear
	// from there. This method works on both.
	ScopedReaddir reader("/sys/devices/system/cpu");
	if (reader.IsBad()) {
	return 1;
	}

	int result = 0;
	dirent* entry;
	while ((entry = reader.ReadEntry()) != NULL) {
	if (entry->d_type == DT_DIR && __matches_cpuN(entry->d_name)) {
	++result;
	}
	}
	return result;
	// ARC MOD BEGIN
	#endif // HAVE_ARC
	// ARC MOD END
	}

	static int __sysconf_nprocessors_onln() {
	// ARC MOD BEGIN
	#if defined(HAVE_ARC)
	#if defined(__native_client__)
	int value = 0;
	const int ret = __nacl_irt_sysconf(NACL_ABI__SC_NPROCESSORS_ONLN, &value);
	if (!ret)
	return value;
	errno = ret;
	return -1;
	#else
	// TODO(crbug.com/368344): Implement this for BMM. For now, return the safest
	// value which does not trigger crbug.com/366079.
	return 2;
	#endif // __native_client__
	#else
	// ARC MOD END
	FILE* fp = fopen("/proc/stat", "r");
	if (fp == NULL) {
	return 1;
	}

	int result = 0;
	char buf[256];
	while (fgets(buf, sizeof(buf), fp) != NULL) {
	// Extract just the first word from the line.
	// 'cpu0 7976751 1364388 3116842 469770388 8629405 0 49047 0 0 0'
	char* p = strchr(buf, ' ');
	if (p != NULL) {
	*p = 0;
	}
	if (__matches_cpuN(buf)) {
	++result;
	}
	}
	fclose(fp);
	return result;
	// ARC MOD BEGIN
	#endif // HAVE_ARC
	// ARC MOD END
	}

	static int __get_meminfo(const char* pattern) {
	FILE* fp = fopen("/proc/meminfo", "r");
	if (fp == NULL) {
	return -1;
	}

	int result = -1;
	char buf[256];
	while (fgets(buf, sizeof(buf), fp) != NULL) {
	long total;
	if (sscanf(buf, pattern, &total) == 1) {
	result = (int) (total / (PAGE_SIZE/1024));
	break;
	}
	}
	fclose(fp);
	return result;
	}

	static int __sysconf_phys_pages() {
	return __get_meminfo("MemTotal: %ld kB");
	}

	static int __sysconf_avphys_pages() {
	return __get_meminfo("MemFree: %ld kB");
	}

	static int __sysconf_monotonic_clock() {
	timespec t;
	int rc = clock_getres(CLOCK_MONOTONIC, &t);
	return (rc == -1) ? -1 : _POSIX_VERSION;
	}

	int sysconf(int name) {
	switch (name) {
	#ifdef _POSIX_ARG_MAX
	case _SC_ARG_MAX: return _POSIX_ARG_MAX;
	#endif
	#ifdef _POSIX2_BC_BASE_MAX
	case _SC_BC_BASE_MAX: return _POSIX2_BC_BASE_MAX;
	#endif
	#ifdef _POSIX2_BC_DIM_MAX
	case _SC_BC_DIM_MAX: return _POSIX2_BC_DIM_MAX;
	#endif
	#ifdef _POSIX2_BC_SCALE_MAX
	case _SC_BC_SCALE_MAX: return _POSIX2_BC_SCALE_MAX;
	#endif
	#ifdef _POSIX2_BC_STRING_MAX
	case _SC_BC_STRING_MAX: return _POSIX2_BC_STRING_MAX;
	#endif
	case _SC_CHILD_MAX: return CHILD_MAX;
	case _SC_CLK_TCK: return SYSTEM_CLK_TCK;
	#ifdef _POSIX2_COLL_WEIGHTS_MASK
	case _SC_COLL_WEIGHTS_MAX: return _POSIX2_COLL_WEIGHTS_MASK;
	#endif
	#ifdef _POSIX2_EXPR_NEST_MAX
	case _SC_EXPR_NEST_MAX: return _POSIX2_EXPR_NEST_MAX;
	#endif
	#ifdef _POSIX2_LINE_MAX
	case _SC_LINE_MAX: return _POSIX2_LINE_MAX;
	#endif
	case _SC_NGROUPS_MAX: return NGROUPS_MAX;
	case _SC_OPEN_MAX: return OPEN_MAX;
	//case _SC_PASS_MAX: return PASS_MAX;
	case _SC_2_C_BIND: return SYSTEM_2_C_BIND;
	case _SC_2_C_DEV: return SYSTEM_2_C_DEV;
	case _SC_2_C_VERSION: return SYSTEM_2_C_VER;
	//case _SC_2_CHAR_TERM: return ;
	case _SC_2_FORT_DEV: return SYSTEM_2_FORT_DEV;
	case _SC_2_FORT_RUN: return SYSTEM_2_FORT_RUN;
	case _SC_2_LOCALEDEF: return SYSTEM_2_LOCALEDEF;
	case _SC_2_SW_DEV: return SYSTEM_2_SW_DEV;
	case _SC_2_UPE: return SYSTEM_2_UPE;
	case _SC_2_VERSION: return SYSTEM_2_VERSION;
	#ifdef _POSIX_JOB_CONTROL
	case _SC_JOB_CONTROL: return _POSIX_JOB_CONTROL;
	#endif
	#ifdef _POSIX_SAVED_IDS
	case _SC_SAVED_IDS: return _POSIX_SAVED_IDS;
	#endif
	#ifdef _POSIX_VERSION
	case _SC_VERSION: return _POSIX_VERSION;
	#endif
	//case _SC_RE_DUP_<AX: return ;
	case _SC_STREAM_MAX: return FOPEN_MAX;
	//case _SC_TZNAME_MAX: return ;
	#if _XOPEN_CRYPT
	case _SC_XOPEN_CRYPT: return _XOPEN_CRYPT;
	#endif
	#ifdef _XOPEN_ENH_I18N
	case _SC_XOPEN_ENH_I18N: return _XOPEN_ENH_I18N;
	#endif
	#ifdef _XOPEN_SHM
	case _SC_XOPEN_SHM: return _XOPEN_SHM;
	#endif
	#ifdef _XOPEN_VERSION
	case _SC_XOPEN_VERSION: return _XOPEN_VERSION;
	#endif
	#ifdef _XOPEN_XCU_VERSION
	case _SC_XOPEN_XCU_VERSION: return _XOPEN_XCU_VERSION;
	#endif
	#ifdef _XOPEN_REALTIME
	case _SC_XOPEN_REALTIME: return _XOPEN_REALTIME;
	#endif
	#ifdef _XOPEN_REALTIME_THREADS
	case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS;
	#endif
	#ifdef _XOPEN_LEGACY
	case _SC_XOPEN_LEGACY: return _XOPEN_LEGACY;
	#endif
	case _SC_ATEXIT_MAX: return SYSTEM_ATEXIT_MAX;
	case _SC_IOV_MAX: return SYSTEM_IOV_MAX;

	case _SC_PAGESIZE:
	case _SC_PAGE_SIZE:
	return PAGE_SIZE;

	#ifdef _XOPEN_UNIX
	case _SC_XOPEN_UNIX: return _XOPEN_UNIX;
	#endif

	// XXX: TODO: XBS5 nonsense

	#ifdef AIO_LISTIO_MAX
	case _SC_AIO_LISTIO_MAX: return AIO_LISTIO_MAX;
	#endif
	#ifdef AIO_MAX
	case _SC_AIO_MAX: return AIO_MAX;
	#endif
	#ifdef AIO_PRIO_DELTA_MAX
	case _SC_AIO_PRIO_DELTA_MAX: return AIO_PRIO_DELTA_MAX;
	#endif
	case _SC_DELAYTIMER_MAX: return SYSTEM_DELAYTIMER_MAX;
	case _SC_MQ_OPEN_MAX: return SYSTEM_MQ_OPEN_MAX;
	case _SC_MQ_PRIO_MAX: return SYSTEM_MQ_PRIO_MAX;
	case _SC_RTSIG_MAX: return RTSIG_MAX;
	case _SC_SEM_NSEMS_MAX: return SYSTEM_SEM_NSEMS_MAX;
	case _SC_SEM_VALUE_MAX: return SYSTEM_SEM_VALUE_MAX;
	case _SC_SIGQUEUE_MAX: return SYSTEM_SIGQUEUE_MAX;
	case _SC_TIMER_MAX: return SYSTEM_TIMER_MAX;
	#ifdef _POSIX_ASYNCHRONOUS_IO
	case _SC_ASYNCHRONOUS_IO: return _POSIX_ASYNCHRONOUS_IO;
	#endif
	#ifdef _POSIX_FSYNC
	case _SC_FSYNC: return _POSIX_FSYNC;
	#endif
	#ifdef _POSIX_MAPPED_FILES
	case _SC_MAPPED_FILES: return _POSIX_MAPPED_FILES;
	#endif
	#ifdef _POSIX_MEMLOCK
	case _SC_MEMLOCK: return _POSIX_MEMLOCK;
	#endif
	#ifdef _POSIX_MEMLOCK_RANGE
	case _SC_MEMLOCK_RANGE: return _POSIX_MEMLOCK_RANGE
	#endif
	#ifdef _POSIX_MEMORY_PROTECTION
	case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION;
	#endif
	#ifdef _POSIX_MESSAGE_PASSING
	case _SC_MESSAGE_PASSING: return _POSIX_MESSAGE_PASSING;
	#endif
	#ifdef _POSIX_PRIORITIZED_IO
	case _SC_PRIORITIZED_IO: return _POSIX_PRIORITIZED_IO;
	#endif
	#ifdef _POSIX_PRIORITY_SCHEDULING
	case _SC_PRIORITY_SCHEDULING: return _POSIX_PRIORITY_SCHEDULING;
	#endif
	#ifdef _POSIX_REALTIME_SIGNALS
	case _SC_REALTIME_SIGNALS: return _POSIX_REALTIME_SIGNALS;
	#endif
	#ifdef _POSIX_SEMAPHORES
	case _SC_SEMAPHORES: return _POSIX_SEMAPHORES;
	#endif
	#ifdef _POSIX_SHARED_MEMORY_OBJECTS
	case _SC_SHARED_MEMORY_OBJECTS: return _POSIX_SHARED_MEMORY_OBJECTS;
	#endif
	#ifdef _POSIX_SYNCHRONIZED_IO
	case _SC_SYNCHRONIZED_IO: return _POSIX_SYNCHRONIZED_IO;
	#endif
	#ifdef _POSIX_TIMERS
	case _SC_TIMERS: return _POSIX_TIMERS;
	#endif

	case _SC_GETGR_R_SIZE_MAX: return 1024;
	case _SC_GETPW_R_SIZE_MAX: return 1024;

	case _SC_LOGIN_NAME_MAX: return SYSTEM_LOGIN_NAME_MAX;

	case _SC_THREAD_DESTRUCTOR_ITERATIONS:
	return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;

	case _SC_THREAD_KEYS_MAX:
	return (BIONIC_TLS_SLOTS - TLS_SLOT_FIRST_USER_SLOT - BIONIC_TLS_RESERVED_SLOTS);

	case _SC_THREAD_STACK_MIN: return PTHREAD_STACK_MIN;
	case _SC_THREAD_THREADS_MAX: return SYSTEM_THREAD_THREADS_MAX;
	case _SC_TTY_NAME_MAX: return SYSTEM_TTY_NAME_MAX;
	#ifdef _POSIX_THREADS
	case _SC_THREADS: return _POSIX_THREADS;
	#endif

	case _SC_THREAD_ATTR_STACKADDR: return -1; // Removed in POSIX 2008
	case _SC_THREAD_ATTR_STACKSIZE: return -1; // Removed in POSIX 2008

	#ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
	case _SC_THREAD_PRIORITY_SCHEDULING: return _POSIX_THREAD_PRIORITY_SCHEDULING;
	#endif
	#ifdef _POSIX_THREAD_PRIO_INHERIT
	case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT;
	#endif
	#ifdef _POSIX_THREAD_PRIO_PROTECT
	case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT;
	#endif
	#ifdef _POSIX_THREAD_SAFE_FUNCTIONS
	case _SC_THREAD_SAFE_FUNCTIONS: return _POSIX_THREAD_SAFE_FUNCTIONS
	#endif

	case _SC_MONOTONIC_CLOCK: return __sysconf_monotonic_clock();
	case _SC_NPROCESSORS_CONF: return __sysconf_nprocessors_conf();
	case _SC_NPROCESSORS_ONLN: return __sysconf_nprocessors_onln();
	case _SC_PHYS_PAGES: return __sysconf_phys_pages();
	case _SC_AVPHYS_PAGES: return __sysconf_avphys_pages();

	default:
	/* Posix says EINVAL is the only error that shall be returned,
	* but GLibc uses ENOSYS */
	errno = ENOSYS;
	return -1;
	}
	}