diff options
| -rw-r--r-- | sysdeps/unix/sysv/linux/getsysstats.c | 139 |
1 files changed, 134 insertions, 5 deletions
diff --git a/sysdeps/unix/sysv/linux/getsysstats.c b/sysdeps/unix/sysv/linux/getsysstats.c index 1e3d88676d..15ad91cf2f 100644 --- a/sysdeps/unix/sysv/linux/getsysstats.c +++ b/sysdeps/unix/sysv/linux/getsysstats.c @@ -17,6 +17,8 @@ <https://www.gnu.org/licenses/>. */ #include <array_length.h> +#include <assert.h> +#include <ctype.h> #include <dirent.h> #include <errno.h> #include <ldsodefs.h> @@ -29,7 +31,7 @@ #include <sysdep.h> int -__get_nprocs (void) +__get_nprocs_sched (void) { enum { @@ -52,14 +54,141 @@ __get_nprocs (void) atomics are needed). */ return 2; } -libc_hidden_def (__get_nprocs) -weak_alias (__get_nprocs, get_nprocs) + +static char * +next_line (int fd, char *const buffer, char **cp, char **re, + char *const buffer_end) +{ + char *res = *cp; + char *nl = memchr (*cp, '\n', *re - *cp); + if (nl == NULL) + { + if (*cp != buffer) + { + if (*re == buffer_end) + { + memmove (buffer, *cp, *re - *cp); + *re = buffer + (*re - *cp); + *cp = buffer; + + ssize_t n = __read_nocancel (fd, *re, buffer_end - *re); + if (n < 0) + return NULL; + + *re += n; + + nl = memchr (*cp, '\n', *re - *cp); + while (nl == NULL && *re == buffer_end) + { + /* Truncate too long lines. */ + *re = buffer + 3 * (buffer_end - buffer) / 4; + n = __read_nocancel (fd, *re, buffer_end - *re); + if (n < 0) + return NULL; + + nl = memchr (*re, '\n', n); + **re = '\n'; + *re += n; + } + } + else + nl = memchr (*cp, '\n', *re - *cp); + + res = *cp; + } + + if (nl == NULL) + nl = *re - 1; + } + + *cp = nl + 1; + assert (*cp <= *re); + + return res == *re ? NULL : res; +} + int -__get_nprocs_sched (void) +__get_nprocs (void) { - return __get_nprocs (); + enum { buffer_size = 1024 }; + char buffer[buffer_size]; + char *buffer_end = buffer + buffer_size; + char *cp = buffer_end; + char *re = buffer_end; + + const int flags = O_RDONLY | O_CLOEXEC; + /* This file contains comma-separated ranges. */ + int fd = __open_nocancel ("/sys/devices/system/cpu/online", flags); + char *l; + int result = 0; + if (fd != -1) + { + l = next_line (fd, buffer, &cp, &re, buffer_end); + if (l != NULL) + do + { + char *endp; + unsigned long int n = strtoul (l, &endp, 10); + if (l == endp) + { + result = 0; + break; + } + + unsigned long int m = n; + if (*endp == '-') + { + l = endp + 1; + m = strtoul (l, &endp, 10); + if (l == endp) + { + result = 0; + break; + } + } + + result += m - n + 1; + + l = endp; + if (l < re && *l == ',') + ++l; + } + while (l < re && *l != '\n'); + + __close_nocancel_nostatus (fd); + + if (result > 0) + return result; + } + + cp = buffer_end; + re = buffer_end; + + /* Default to an SMP system in case we cannot obtain an accurate + number. */ + result = 2; + + fd = __open_nocancel ("/proc/stat", flags); + if (fd != -1) + { + result = 0; + + while ((l = next_line (fd, buffer, &cp, &re, buffer_end)) != NULL) + /* The current format of /proc/stat has all the cpu* entries + at the front. We assume here that stays this way. */ + if (strncmp (l, "cpu", 3) != 0) + break; + else if (isdigit (l[3])) + ++result; + + __close_nocancel_nostatus (fd); + } + + return result; } +libc_hidden_def (__get_nprocs) +weak_alias (__get_nprocs, get_nprocs) /* On some architectures it is possible to distinguish between configured |