github.com/afumu/libc@v0.0.6/musl/src/conf/sysconf.c (about)

     1  #include <unistd.h>
     2  #include <limits.h>
     3  #include <errno.h>
     4  #include <sys/resource.h>
     5  #include <signal.h>
     6  #include <sys/sysinfo.h>
     7  #include "syscall.h"
     8  #include "libc.h"
     9  
    10  #define JT(x) (-256|(x))
    11  #define VER JT(1)
    12  #define JT_ARG_MAX JT(2)
    13  #define JT_MQ_PRIO_MAX JT(3)
    14  #define JT_PAGE_SIZE JT(4)
    15  #define JT_SEM_VALUE_MAX JT(5)
    16  #define JT_NPROCESSORS_CONF JT(6)
    17  #define JT_NPROCESSORS_ONLN JT(7)
    18  #define JT_PHYS_PAGES JT(8)
    19  #define JT_AVPHYS_PAGES JT(9)
    20  #define JT_ZERO JT(10)
    21  #define JT_DELAYTIMER_MAX JT(11)
    22  
    23  #define RLIM(x) (-32768|(RLIMIT_ ## x))
    24  
    25  long sysconf(int name)
    26  {
    27  	static const short values[] = {
    28  		[_SC_ARG_MAX] = JT_ARG_MAX,
    29  		[_SC_CHILD_MAX] = RLIM(NPROC),
    30  		[_SC_CLK_TCK] = 100,
    31  		[_SC_NGROUPS_MAX] = 32,
    32  		[_SC_OPEN_MAX] = RLIM(NOFILE),
    33  		[_SC_STREAM_MAX] = -1,
    34  		[_SC_TZNAME_MAX] = TZNAME_MAX,
    35  		[_SC_JOB_CONTROL] = 1,
    36  		[_SC_SAVED_IDS] = 1,
    37  		[_SC_REALTIME_SIGNALS] = VER,
    38  		[_SC_PRIORITY_SCHEDULING] = -1,
    39  		[_SC_TIMERS] = VER,
    40  		[_SC_ASYNCHRONOUS_IO] = VER,
    41  		[_SC_PRIORITIZED_IO] = -1,
    42  		[_SC_SYNCHRONIZED_IO] = -1,
    43  		[_SC_FSYNC] = VER,
    44  		[_SC_MAPPED_FILES] = VER,
    45  		[_SC_MEMLOCK] = VER,
    46  		[_SC_MEMLOCK_RANGE] = VER,
    47  		[_SC_MEMORY_PROTECTION] = VER,
    48  		[_SC_MESSAGE_PASSING] = VER,
    49  		[_SC_SEMAPHORES] = VER,
    50  		[_SC_SHARED_MEMORY_OBJECTS] = VER,
    51  		[_SC_AIO_LISTIO_MAX] = -1,
    52  		[_SC_AIO_MAX] = -1,
    53  		[_SC_AIO_PRIO_DELTA_MAX] = JT_ZERO, /* ?? */
    54  		[_SC_DELAYTIMER_MAX] = JT_DELAYTIMER_MAX,
    55  		[_SC_MQ_OPEN_MAX] = -1,
    56  		[_SC_MQ_PRIO_MAX] = JT_MQ_PRIO_MAX,
    57  		[_SC_VERSION] = VER,
    58  		[_SC_PAGE_SIZE] = JT_PAGE_SIZE,
    59  		[_SC_RTSIG_MAX] = _NSIG - 1 - 31 - 3,
    60  		[_SC_SEM_NSEMS_MAX] = SEM_NSEMS_MAX,
    61  		[_SC_SEM_VALUE_MAX] = JT_SEM_VALUE_MAX,
    62  		[_SC_SIGQUEUE_MAX] = -1,
    63  		[_SC_TIMER_MAX] = -1,
    64  		[_SC_BC_BASE_MAX] = _POSIX2_BC_BASE_MAX,
    65  		[_SC_BC_DIM_MAX] = _POSIX2_BC_DIM_MAX,
    66  		[_SC_BC_SCALE_MAX] = _POSIX2_BC_SCALE_MAX,
    67  		[_SC_BC_STRING_MAX] = _POSIX2_BC_STRING_MAX,
    68  		[_SC_COLL_WEIGHTS_MAX] = COLL_WEIGHTS_MAX,
    69  		[_SC_EXPR_NEST_MAX] = -1,
    70  		[_SC_LINE_MAX] = -1,
    71  		[_SC_RE_DUP_MAX] = RE_DUP_MAX,
    72  		[_SC_2_VERSION] = VER,
    73  		[_SC_2_C_BIND] = VER,
    74  		[_SC_2_C_DEV] = -1,
    75  		[_SC_2_FORT_DEV] = -1,
    76  		[_SC_2_FORT_RUN] = -1,
    77  		[_SC_2_SW_DEV] = -1,
    78  		[_SC_2_LOCALEDEF] = -1,
    79  		[_SC_IOV_MAX] = IOV_MAX,
    80  		[_SC_THREADS] = VER,
    81  		[_SC_THREAD_SAFE_FUNCTIONS] = VER,
    82  		[_SC_GETGR_R_SIZE_MAX] = -1,
    83  		[_SC_GETPW_R_SIZE_MAX] = -1,
    84  		[_SC_LOGIN_NAME_MAX] = 256,
    85  		[_SC_TTY_NAME_MAX] = TTY_NAME_MAX,
    86  		[_SC_THREAD_DESTRUCTOR_ITERATIONS] = PTHREAD_DESTRUCTOR_ITERATIONS,
    87  		[_SC_THREAD_KEYS_MAX] = PTHREAD_KEYS_MAX,
    88  		[_SC_THREAD_STACK_MIN] = PTHREAD_STACK_MIN,
    89  		[_SC_THREAD_THREADS_MAX] = -1,
    90  		[_SC_THREAD_ATTR_STACKADDR] = VER,
    91  		[_SC_THREAD_ATTR_STACKSIZE] = VER,
    92  		[_SC_THREAD_PRIORITY_SCHEDULING] = VER,
    93  		[_SC_THREAD_PRIO_INHERIT] = -1,
    94  		[_SC_THREAD_PRIO_PROTECT] = -1,
    95  		[_SC_THREAD_PROCESS_SHARED] = VER,
    96  		[_SC_NPROCESSORS_CONF] = JT_NPROCESSORS_CONF,
    97  		[_SC_NPROCESSORS_ONLN] = JT_NPROCESSORS_ONLN,
    98  		[_SC_PHYS_PAGES] = JT_PHYS_PAGES,
    99  		[_SC_AVPHYS_PAGES] = JT_AVPHYS_PAGES,
   100  		[_SC_ATEXIT_MAX] = -1,
   101  		[_SC_PASS_MAX] = -1,
   102  		[_SC_XOPEN_VERSION] = _XOPEN_VERSION,
   103  		[_SC_XOPEN_XCU_VERSION] = _XOPEN_VERSION,
   104  		[_SC_XOPEN_UNIX] = 1,
   105  		[_SC_XOPEN_CRYPT] = -1,
   106  		[_SC_XOPEN_ENH_I18N] = 1,
   107  		[_SC_XOPEN_SHM] = 1,
   108  		[_SC_2_CHAR_TERM] = -1,
   109  		[_SC_2_UPE] = -1,
   110  		[_SC_XOPEN_XPG2] = -1,
   111  		[_SC_XOPEN_XPG3] = -1,
   112  		[_SC_XOPEN_XPG4] = -1,
   113  		[_SC_NZERO] = NZERO,
   114  		[_SC_XBS5_ILP32_OFF32] = -1,
   115  		[_SC_XBS5_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : -1,
   116  		[_SC_XBS5_LP64_OFF64] = sizeof(long)==8 ? 1 : -1,
   117  		[_SC_XBS5_LPBIG_OFFBIG] = -1,
   118  		[_SC_XOPEN_LEGACY] = -1,
   119  		[_SC_XOPEN_REALTIME] = -1,
   120  		[_SC_XOPEN_REALTIME_THREADS] = -1,
   121  		[_SC_ADVISORY_INFO] = VER,
   122  		[_SC_BARRIERS] = VER,
   123  		[_SC_CLOCK_SELECTION] = VER,
   124  		[_SC_CPUTIME] = VER,
   125  		[_SC_THREAD_CPUTIME] = VER,
   126  		[_SC_MONOTONIC_CLOCK] = VER,
   127  		[_SC_READER_WRITER_LOCKS] = VER,
   128  		[_SC_SPIN_LOCKS] = VER,
   129  		[_SC_REGEXP] = 1,
   130  		[_SC_SHELL] = 1,
   131  		[_SC_SPAWN] = VER,
   132  		[_SC_SPORADIC_SERVER] = -1,
   133  		[_SC_THREAD_SPORADIC_SERVER] = -1,
   134  		[_SC_TIMEOUTS] = VER,
   135  		[_SC_TYPED_MEMORY_OBJECTS] = -1,
   136  		[_SC_2_PBS] = -1,
   137  		[_SC_2_PBS_ACCOUNTING] = -1,
   138  		[_SC_2_PBS_LOCATE] = -1,
   139  		[_SC_2_PBS_MESSAGE] = -1,
   140  		[_SC_2_PBS_TRACK] = -1,
   141  		[_SC_SYMLOOP_MAX] = SYMLOOP_MAX,
   142  		[_SC_STREAMS] = JT_ZERO,
   143  		[_SC_2_PBS_CHECKPOINT] = -1,
   144  		[_SC_V6_ILP32_OFF32] = -1,
   145  		[_SC_V6_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : -1,
   146  		[_SC_V6_LP64_OFF64] = sizeof(long)==8 ? 1 : -1,
   147  		[_SC_V6_LPBIG_OFFBIG] = -1,
   148  		[_SC_HOST_NAME_MAX] = HOST_NAME_MAX,
   149  		[_SC_TRACE] = -1,
   150  		[_SC_TRACE_EVENT_FILTER] = -1,
   151  		[_SC_TRACE_INHERIT] = -1,
   152  		[_SC_TRACE_LOG] = -1,
   153  
   154  		[_SC_IPV6] = VER,
   155  		[_SC_RAW_SOCKETS] = VER,
   156  		[_SC_V7_ILP32_OFF32] = -1,
   157  		[_SC_V7_ILP32_OFFBIG] = sizeof(long)==4 ? 1 : -1,
   158  		[_SC_V7_LP64_OFF64] = sizeof(long)==8 ? 1 : -1,
   159  		[_SC_V7_LPBIG_OFFBIG] = -1,
   160  		[_SC_SS_REPL_MAX] = -1,
   161  		[_SC_TRACE_EVENT_NAME_MAX] = -1,
   162  		[_SC_TRACE_NAME_MAX] = -1,
   163  		[_SC_TRACE_SYS_MAX] = -1,
   164  		[_SC_TRACE_USER_EVENT_MAX] = -1,
   165  		[_SC_XOPEN_STREAMS] = JT_ZERO,
   166  		[_SC_THREAD_ROBUST_PRIO_INHERIT] = -1,
   167  		[_SC_THREAD_ROBUST_PRIO_PROTECT] = -1,
   168  	};
   169  
   170  	if (name >= sizeof(values)/sizeof(values[0]) || !values[name]) {
   171  		errno = EINVAL;
   172  		return -1;
   173  	} else if (values[name] >= -1) {
   174  		return values[name];
   175  	} else if (values[name] < -256) {
   176  		struct rlimit lim;
   177  		getrlimit(values[name]&16383, &lim);
   178  		if (lim.rlim_cur == RLIM_INFINITY)
   179  			return -1;
   180  		return lim.rlim_cur > LONG_MAX ? LONG_MAX : lim.rlim_cur;
   181  	}
   182  
   183  	switch ((unsigned char)values[name]) {
   184  	case VER & 255:
   185  		return _POSIX_VERSION;
   186  	case JT_ARG_MAX & 255:
   187  		return ARG_MAX;
   188  	case JT_MQ_PRIO_MAX & 255:
   189  		return MQ_PRIO_MAX;
   190  	case JT_PAGE_SIZE & 255:
   191  		return PAGE_SIZE;
   192  	case JT_SEM_VALUE_MAX & 255:
   193  		return SEM_VALUE_MAX;
   194  	case JT_DELAYTIMER_MAX & 255:
   195  		return DELAYTIMER_MAX;
   196  	case JT_NPROCESSORS_CONF & 255:
   197  	case JT_NPROCESSORS_ONLN & 255: ;
   198  		unsigned char set[128] = {1};
   199  		int i, cnt;
   200  		__syscall(SYS_sched_getaffinity, 0, sizeof set, set);
   201  		for (i=cnt=0; i<sizeof set; i++)
   202  			for (; set[i]; set[i]&=set[i]-1, cnt++);
   203  		return cnt;
   204  	case JT_PHYS_PAGES & 255:
   205  	case JT_AVPHYS_PAGES & 255: ;
   206  		unsigned long long mem;
   207  		struct sysinfo si;
   208  		__lsysinfo(&si);
   209  		if (!si.mem_unit) si.mem_unit = 1;
   210  		if (name==_SC_PHYS_PAGES) mem = si.totalram;
   211  		else mem = si.freeram + si.bufferram;
   212  		mem *= si.mem_unit;
   213  		mem /= PAGE_SIZE;
   214  		return (mem > LONG_MAX) ? LONG_MAX : mem;
   215  	case JT_ZERO & 255:
   216  		return 0;
   217  	}
   218  	return values[name];
   219  }