sysconf.c

Newlib 嵌入式 C库 标准实现代码

/* libc/sys/linux/sysconf.c - The sysconf function */

/* Copyright 2002, Red Hat Inc. */


#include <unistd.h>
#include <limits.h>
#include <time.h>
#include <errno.h>
#include <sys/types.h>

long int 
sysconf (int name)
{
  switch (name)
    {
    case _SC_AIO_LISTIO_MAX:
#ifdef AIO_LISTIO_MAX
      return AIO_LISTIO_MAX;
#else
      return -1;
#endif

    case _SC_AIO_MAX:
#ifdef AIO_MAX
      return AIO_MAX;
#else
      return -1;
#endif

    case _SC_AIO_PRIO_DELTA_MAX:
#ifdef AIO_PRIO_DELTA_MAX
      return AIO_PRIO_DELTA_MAX;
#else
      return -1;
#endif

    case _SC_ARG_MAX:
#ifdef ARG_MAX
      return ARG_MAX;
#else
      return -1;
#endif
    
    case _SC_CHILD_MAX:
#ifdef CHILD_MAX
      return CHILD_MAX;
#else
      return -1;
#endif

    case _SC_CLK_TCK:
      return CLK_TCK;

    case _SC_DELAYTIMER_MAX:
#ifdef DELAYTIMER_MAX
      return DELAYTIMER_MAX;
#else
      return -1;
#endif

    case _SC_GETGR_R_SIZE_MAX:
#ifdef _GETGR_R_SIZE_MAX
      return _GETGR_R_SIZE_MAX;
#else
      return -1;
#endif

    case _SC_GETPW_R_SIZE_MAX:
#ifdef _GETPW_R_SIZE_MAX
      return _GETPW_R_SIZE_MAX;
#else
      return -1;
#endif

    case _SC_LOGIN_NAME_MAX:
#ifdef LOGIN_NAME_MAX
      return LOGIN_NAME_MAX;
#else
      return -1;
#endif
   
    case _SC_MQ_OPEN_MAX:
#ifdef MQ_OPEN_MAX
      return MQ_OPEN_MAX;
#else
      return -1;
#endif
   
    case _SC_MQ_PRIO_MAX:
#ifdef MQ_PRIO_MAX
      return MQ_PRIO_MAX;
#else
      return -1;
#endif
   
    case _SC_NGROUPS_MAX:
#ifdef NGROUPS_MAX
      return NGROUPS_MAX;
#else
      return -1;
#endif
  
    case _SC_OPEN_MAX:
#ifdef OPEN_MAX
      return OPEN_MAX;
#else
      return -1;
#endif
  
    case _SC_PAGESIZE:
#ifdef PAGESIZE
      return PAGESIZE;
#else
      return -1;
#endif
  
    case _SC_RTSIG_MAX:
#ifdef RTSIG_MAX
      return RTSIG_MAX;
#else
      return -1;
#endif
  
    case _SC_SEM_NSEMS_MAX:
#ifdef SEM_NSEMS_MAX
      return SEM_NSEMS_MAX;
#else
      return -1;
#endif
  
    case _SC_SEM_VALUE_MAX:
#ifdef SEM_VALUE_MAX
      return SEM_VALUE_MAX;
#else
      return -1;
#endif
  
    case _SC_SIGQUEUE_MAX:
#ifdef SIGQUEUE_MAX
      return SIGQUEUE_MAX;
#else
      return -1;
#endif
  
    case _SC_STREAM_MAX:
#ifdef STREAM_MAX
      return STREAM_MAX;
#else
      return -1;
#endif
  
    case _SC_THREAD_DESTRUCTOR_ITERATIONS:
#ifdef PTHREAD_DESTRUCTOR_ITERATIONS
      return PTHREAD_DESTRUCTOR_ITERATIONS;
#else
      return -1;
#endif
  
    case _SC_THREAD_KEYS_MAX:
#ifdef PTHREAD_KEYS_MAX
      return PTHREAD_KEYS_MAX;
#else
      return -1;
#endif
  
    case _SC_THREAD_STACK_MIN:
#ifdef PTHREAD_STACK_MIN
      return PTHREAD_STACK_MIN;
#else
      return -1;
#endif
  
    case _SC_THREAD_THREADS_MAX:
#ifdef PTHREAD_THREADS_MAX
      return PTHREAD_THREADS_MAX;
#else
      return -1;
#endif
  
    case _SC_TIMER_MAX:
#ifdef TIMER_MAX
      return TIMER_MAX;
#else
      return -1;
#endif
  
    case _SC_TTY_NAME_MAX:
#ifdef TTY_NAME_MAX
      return TTY_NAME_MAX;
#else
      return -1;
#endif
  
    case _SC_TZNAME_MAX:
#ifdef TZNAME_MAX
      return TZNAME_MAX;
#else
      return -1;
#endif
  
    case _SC_ASYNCHRONOUS_IO:
#ifdef _POSIX_ASYNCHRONOUS_IO
      return 1;
#else
      return -1;
#endif
  
    case _SC_FSYNC:
#ifdef _POSIX_FSYNC
      return 1;
#else
      return -1;
#endif
  
    case _SC_JOB_CONTROL:
#ifdef _POSIX_JOB_CONTROL
      return 1;
#else
      return -1;
#endif
  
    case _SC_MAPPED_FILES:
#ifdef _POSIX_MAPPED_FILES
      return 1;
#else
      return -1;
#endif
  
    case _SC_MEMLOCK:
#ifdef _POSIX_MEMLOCK
      return 1;
#else
      return -1;
#endif
  
    case _SC_MEMLOCK_RANGE:
#ifdef _POSIX_MEMLOCK_RANGE
      return _POSIX_MEMLOCK_RANGE;
#else
      return -1;
#endif
  
    case _SC_MEMORY_PROTECTION:
#ifdef _POSIX_MEMORY_PROTECTION
      return 1;
#else
      return -1;
#endif
  
    case _SC_MESSAGE_PASSING:
#ifdef _POSIX_MESSAGE_PASSING
      return 1;
#else
      return -1;
#endif
  
    case _SC_PRIORITIZED_IO:
#ifdef _POSIX_PRIORITIZED_IO
      return 1;
#else
      return -1;
#endif
  
    case _SC_PRIORITY_SCHEDULING:
#ifdef _POSIX_PRIORITY_SCHEDULING
      return 1;
#else
      return -1;
#endif
  
    case _SC_REALTIME_SIGNALS:
#ifdef _POSIX_REALTIME_SIGNALS
      return 1;
#else
      return -1;
#endif
  
    case _SC_SAVED_IDS:
#ifdef _POSIX_SAVED_IDS
      return 1;
#else
      return -1;
#endif
  
    case _SC_SEMAPHORES:
#ifdef _POSIX_SEMAPHORES
      return 1;
#else
      return -1;
#endif
  
    case _SC_SHARED_MEMORY_OBJECTS:
#ifdef _POSIX_SHARED_MEMORY_OBJECTS
      return 1;
#else
      return -1;
#endif
  
    case _SC_SYNCHRONIZED_IO:
#ifdef _POSIX_SYNCHRONIZED_IO
      return 1;
#else
      return -1;
#endif
  
    case _SC_TIMERS:
#ifdef _POSIX_TIMERS
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREADS:
#ifdef _POSIX_THREADS
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREAD_ATTR_STACKADDR:
#ifdef _POSIX_THREAD_ATTR_STACKADDR
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREAD_ATTR_STACKSIZE:
#ifdef _POSIX_THREAD_ATTR_STACKSIZE
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREAD_PRIORITY_SCHEDULING:
#ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREAD_PRIO_INHERIT:
#ifdef _POSIX_THREAD_PRIO_INHERIT
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREAD_PRIO_PROTECT:
#ifdef _POSIX_THREAD_PRIO_PROTECT
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREAD_PROCESS_SHARED:
#ifdef _POSIX_THREAD_PROCESS_SHARED
      return 1;
#else
      return -1;
#endif
  
    case _SC_THREAD_SAFE_FUNCTIONS:
#ifdef _POSIX_THREAD_SAFE_FUNCTIONS
      return 1;
#else
      return -1;
#endif
  
    case _SC_VERSION:
#ifdef _POSIX_VERSION
      return _POSIX_VERSION;
#else
      return -1;
#endif

    default:
      errno = EINVAL;
      return -1;
    }

  return -1; /* can't get here */
}