257 lines
12 KiB
C
257 lines
12 KiB
C
/****************************************************************************
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* libs/libc/unistd/lib_sysconf.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <unistd.h>
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#include <sched.h>
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#include <errno.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: sysconf
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*
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* Description:
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* The sysconf() function provides a method for the application to
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* determine the current value of a configurable system limit or option
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* (variable). The implementation will support all of the variables
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* listed in the following table and may support others.
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*
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* The 'name' argument represents the system variable to be queried. The
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* following table lists the minimal set of system variables from
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* <limits.h> or <unistd.h> that can be returned by sysconf(), and the
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* symbolic constants defined in <unistd.h> that are the corresponding
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* values used for name.
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*
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* Variable Value of Name
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*
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* {AIO_LISTIO_MAX} _SC_AIO_LISTIO_MAX
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* {AIO_MAX} _SC_AIO_MAX
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* {AIO_PRIO_DELTA_MAX} _SC_AIO_PRIO_DELTA_MAX
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* {ARG_MAX} _SC_ARG_MAX
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* {ATEXIT_MAX} _SC_ATEXIT_MAX
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* {BC_BASE_MAX} _SC_BC_BASE_MAX
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* {BC_DIM_MAX} _SC_BC_DIM_MAX
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* {BC_SCALE_MAX} _SC_BC_SCALE_MAX
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* {BC_STRING_MAX} _SC_BC_STRING_MAX
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* {CHILD_MAX} _SC_CHILD_MAX
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* Clock ticks/second _SC_CLK_TCK
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* {COLL_WEIGHTS_MAX} _SC_COLL_WEIGHTS_MAX
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* {DELAYTIMER_MAX} _SC_DELAYTIMER_MAX
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* {EXPR_NEST_MAX} _SC_EXPR_NEST_MAX
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* {HOST_NAME_MAX} _SC_HOST_NAME_MAX
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* {IOV_MAX} _SC_IOV_MAX
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* {LINE_MAX} _SC_LINE_MAX
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* {LOGIN_NAME_MAX} _SC_LOGIN_NAME_MAX
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* {NGROUPS_MAX} _SC_NGROUPS_MAX
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* Maximum size of getgrgid_r() and _SC_GETGR_R_SIZE_MAX
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* getgrnam_r() data buffers
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* Maximum size of getpwuid_r() and _SC_GETPW_R_SIZE_MAX
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* getpwnam_r() data buffers
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* {MQ_OPEN_MAX} _SC_MQ_OPEN_MAX
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* {MQ_PRIO_MAX} _SC_MQ_PRIO_MAX
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* {OPEN_MAX} _SC_OPEN_MAX
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* _POSIX_ADVISORY_INFO _SC_ADVISORY_INFO
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* _POSIX_BARRIERS _SC_BARRIERS
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* _POSIX_ASYNCHRONOUS_IO _SC_ASYNCHRONOUS_IO
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* _POSIX_CLOCK_SELECTION _SC_CLOCK_SELECTION
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* _POSIX_CPUTIME _SC_CPUTIME
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* _POSIX_FSYNC _SC_FSYNC
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* _POSIX_IPV6 _SC_IPV6
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* _POSIX_JOB_CONTROL _SC_JOB_CONTROL
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* _POSIX_MAPPED_FILES _SC_MAPPED_FILES
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* _POSIX_MEMLOCK _SC_MEMLOCK
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* _POSIX_MEMLOCK_RANGE _SC_MEMLOCK_RANGE
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* _POSIX_MEMORY_PROTECTION _SC_MEMORY_PROTECTION
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* _POSIX_MESSAGE_PASSING _SC_MESSAGE_PASSING
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* _POSIX_MONOTONIC_CLOCK _SC_MONOTONIC_CLOCK
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* _POSIX_PRIORITIZED_IO _SC_PRIORITIZED_IO
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* _POSIX_PRIORITY_SCHEDULING _SC_PRIORITY_SCHEDULING
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* _POSIX_RAW_SOCKETS _SC_RAW_SOCKETS
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* _POSIX_READER_WRITER_LOCKS _SC_READER_WRITER_LOCKS
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* _POSIX_REALTIME_SIGNALS _SC_REALTIME_SIGNALS
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* _POSIX_REGEXP _SC_REGEXP
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* _POSIX_SAVED_IDS _SC_SAVED_IDS
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* _POSIX_SEMAPHORES _SC_SEMAPHORES
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* _POSIX_SHARED_MEMORY_OBJECTS _SC_SHARED_MEMORY_OBJECTS
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* _POSIX_SHELL _SC_SHELL
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* _POSIX_SPAWN _SC_SPAWN
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* _POSIX_SPIN_LOCKS _SC_SPIN_LOCKS
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* _POSIX_SPORADIC_SERVER _SC_SPORADIC_SERVER
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* _POSIX_SS_REPL_MAX _SC_SS_REPL_MAX
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* _POSIX_SYNCHRONIZED_IO _SC_SYNCHRONIZED_IO
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* _POSIX_THREAD_ATTR_STACKADDR _SC_THREAD_ATTR_STACKADDR
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* _POSIX_THREAD_ATTR_STACKSIZE _SC_THREAD_ATTR_STACKSIZE
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* _POSIX_THREAD_CPUTIME _SC_THREAD_CPUTIME
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* _POSIX_THREAD_PRIO_INHERIT _SC_THREAD_PRIO_INHERIT
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* _POSIX_THREAD_PRIO_PROTECT _SC_THREAD_PRIO_PROTECT
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* _POSIX_THREAD_PRIORITY_SCHEDULING _SC_THREAD_PRIORITY_SCHEDULING
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* _POSIX_THREAD_PROCESS_SHARED _SC_THREAD_PROCESS_SHARED
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* _POSIX_THREAD_SAFE_FUNCTIONS _SC_THREAD_SAFE_FUNCTIONS
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* _POSIX_THREAD_SPORADIC_SERVER _SC_THREAD_SPORADIC_SERVER
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* _POSIX_THREADS _SC_THREADS
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* _POSIX_TIMEOUTS _SC_TIMEOUTS
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* _POSIX_TIMERS _SC_TIMERS
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* _POSIX_TRACE _SC_TRACE
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* _POSIX_TRACE_EVENT_FILTER _SC_TRACE_EVENT_FILTER
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* _POSIX_TRACE_EVENT_NAME_MAX _SC_TRACE_EVENT_NAME_MAX
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* _POSIX_TRACE_INHERIT _SC_TRACE_INHERIT
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* _POSIX_TRACE_LOG _SC_TRACE_LOG
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* _POSIX_TRACE_NAME_MAX _SC_TRACE_NAME_MAX
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* _POSIX_TRACE_SYS_MAX _SC_TRACE_SYS_MAX
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* _POSIX_TRACE_USER_EVENT_MAX _SC_TRACE_USER_EVENT_MAX
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* _POSIX_TYPED_MEMORY_OBJECTS _SC_TYPED_MEMORY_OBJECTS
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* _POSIX_VERSION _SC_VERSION
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* _POSIX_V6_ILP32_OFF32 _SC_V6_ILP32_OFF32
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* _POSIX_V6_ILP32_OFFBIG _SC_V6_ILP32_OFFBIG
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* _POSIX_V6_LP64_OFF64 _SC_V6_LP64_OFF64
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* _POSIX_V6_LPBIG_OFFBIG _SC_V6_LPBIG_OFFBIG
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* _POSIX2_C_BIND _SC_2_C_BIND
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* _POSIX2_C_DEV _SC_2_C_DEV
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* _POSIX2_CHAR_TERM _SC_2_CHAR_TERM
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* _POSIX2_FORT_DEV _SC_2_FORT_DEV
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* _POSIX2_FORT_RUN _SC_2_FORT_RUN
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* _POSIX2_LOCALEDEF _SC_2_LOCALEDEF
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* _POSIX2_PBS _SC_2_PBS
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* _POSIX2_PBS_ACCOUNTING _SC_2_PBS_ACCOUNTING
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* _POSIX2_PBS_CHECKPOINT _SC_2_PBS_CHECKPOINT
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* _POSIX2_PBS_LOCATE _SC_2_PBS_LOCATE
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* _POSIX2_PBS_MESSAGE _SC_2_PBS_MESSAGE
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* _POSIX2_PBS_TRACK _SC_2_PBS_TRACK
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* _POSIX2_SW_DEV _SC_2_SW_DEV
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* _POSIX2_UPE _SC_2_UPE
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* _POSIX2_VERSION _SC_2_VERSION
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* {PAGE_SIZE} _SC_PAGE_SIZE
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* {PAGESIZE} _SC_PAGESIZE
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* {PTHREAD_DESTRUCTOR_ITERATIONS} _SC_THREAD_DESTRUCTOR_ITERATIONS
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* {PTHREAD_KEYS_MAX} _SC_THREAD_KEYS_MAX
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* {PTHREAD_STACK_MIN} _SC_THREAD_STACK_MIN
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* {PTHREAD_THREADS_MAX} _SC_THREAD_THREADS_MAX
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* {RE_DUP_MAX} _SC_RE_DUP_MAX
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* {RTSIG_MAX} _SC_RTSIG_MAX
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* {SEM_NSEMS_MAX} _SC_SEM_NSEMS_MAX
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* {SEM_VALUE_MAX} _SC_SEM_VALUE_MAX
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* {SIGQUEUE_MAX} _SC_SIGQUEUE_MAX
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* {STREAM_MAX} _SC_STREAM_MAX
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* {SYMLOOP_MAX} _SC_SYMLOOP_MAX
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* {TIMER_MAX} _SC_TIMER_MAX
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* {TTY_NAME_MAX} _SC_TTY_NAME_MAX
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* {TZNAME_MAX} _SC_TZNAME_MAX
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* _XBS5_ILP32_OFF32 (LEGACY) _SC_XBS5_ILP32_OFF32 (LEGACY)
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* _XBS5_ILP32_OFFBIG (LEGACY) _SC_XBS5_ILP32_OFFBIG (LEGACY)
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* _XBS5_LP64_OFF64 (LEGACY) _SC_XBS5_LP64_OFF64 (LEGACY)
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* _XBS5_LPBIG_OFFBIG (LEGACY) _SC_XBS5_LPBIG_OFFBIG (LEGACY)
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* _XOPEN_CRYPT _SC_XOPEN_CRYPT
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* _XOPEN_ENH_I18N _SC_XOPEN_ENH_I18N
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* _XOPEN_LEGACY _SC_XOPEN_LEGACY
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* _XOPEN_REALTIME _SC_XOPEN_REALTIME
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* _XOPEN_REALTIME_THREADS _SC_XOPEN_REALTIME_THREADS
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* _XOPEN_SHM _SC_XOPEN_SHM
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* _XOPEN_STREAMS _SC_XOPEN_STREAMS
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* _XOPEN_UNIX _SC_XOPEN_UNIX
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* _XOPEN_VERSION _SC_XOPEN_VERSION
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*
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* Returned Value:
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* If name is an invalid value, sysconf() will return -1 and set errno to
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* EINVAL to indicate the error. If the variable corresponding to name has
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* no limit, sysconf() will return -1 without changing the value of errno.
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* Note that indefinite limits do not imply infinite limits; see
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* <limits.h>.
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*
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* Otherwise, sysconf() will return the current variable value on the
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* system. The value returned will not be more restrictive than the
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* corresponding value described to the application when it was compiled
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* with the implementation's <limits.h> or <unistd.h>. The value will not
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* change during the lifetime of the calling process, except that
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* sysconf(_SC_OPEN_MAX) may return different values before and after a
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* call to setrlimit() which changes the RLIMIT_NOFILE soft limit.
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*
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* If the variable corresponding to name is dependent on an unsupported
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* option, the results are unspecified.
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*
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****************************************************************************/
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long sysconf(int name)
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{
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int errcode;
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/* NOTE: The initialize implementation of this interface is very sparse.
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* It was originally created to support only the functionality of
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* getdtablesize() but can be extended to support as much of the standard
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* POSIX sysconf() as is necessary.
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*/
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switch (name)
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{
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case _SC_CLK_TCK:
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return CLOCKS_PER_SEC;
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case _SC_OPEN_MAX:
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return _POSIX_OPEN_MAX;
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case _SC_ATEXIT_MAX:
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#ifdef CONFIG_SCHED_EXIT_MAX
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return CONFIG_SCHED_EXIT_MAX;
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#else
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return 0;
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#endif
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case _SC_NPROCESSORS_CONF:
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case _SC_NPROCESSORS_ONLN:
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#ifdef CONFIG_SMP_NCPUS
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return CONFIG_SMP_NCPUS;
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#else
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return 1;
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#endif
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case _SC_MONOTONIC_CLOCK:
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#ifdef CONFIG_CLOCK_MONOTONIC
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return 1;
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#else
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return 0;
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#endif
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case _SC_PAGESIZE:
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#ifdef CONFIG_MM_PGSIZE
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return CONFIG_MM_PGSIZE;
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#else
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return 1;
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#endif
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default:
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#if 0 /* Assume valid but not implemented for the time being */
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errcode = EINVAL;
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#else
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errcode = ENOSYS;
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#endif
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break;
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}
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set_errno(errcode);
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return ERROR;
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}
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