diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/unix/sysv/linux/getsysstats.c | 62 |
1 files changed, 52 insertions, 10 deletions
diff --git a/sysdeps/unix/sysv/linux/getsysstats.c b/sysdeps/unix/sysv/linux/getsysstats.c index be23753d2f..45b5eafb00 100644 --- a/sysdeps/unix/sysv/linux/getsysstats.c +++ b/sysdeps/unix/sysv/linux/getsysstats.c @@ -1,5 +1,5 @@ /* Determine various system internal values, Linux version. - Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc. + Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. @@ -19,32 +19,45 @@ Boston, MA 02111-1307, USA. */ #include <alloca.h> +#include <assert.h> #include <errno.h> #include <mntent.h> #include <paths.h> #include <stdio.h> +#include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/sysinfo.h> +#include <atomicity.h> + + +/* The default value for the /proc filesystem mount point. */ +static const char path_proc[] = "/proc"; + +/* Actual mount point of /proc filesystem. */ +static char *mount_proc; /* Determine the path to the /proc filesystem if available. */ -static char * +static const char * internal_function get_proc_path (char *buffer, size_t bufsize) { - FILE *fp; struct mntent mount_point; struct mntent *entry; - char *result = NULL; + char *result; + char *copy_result; + FILE *fp; /* First find the mount point of the proc filesystem. */ - fp = __setmntent (_PATH_MNTTAB, "r"); + fp = __setmntent (_PATH_MOUNTED, "r"); + if (fp == NULL) + fp = __setmntent (_PATH_MNTTAB, "r"); if (fp != NULL) { while ((entry = __getmntent_r (fp, &mount_point, buffer, bufsize)) != NULL) - if (strcmp (mount_point.mnt_type, "proc") == 0) + if (strcmp (mount_point.mnt_type, path_proc) == 0) { result = mount_point.mnt_dir; break; @@ -52,7 +65,28 @@ get_proc_path (char *buffer, size_t bufsize) __endmntent (fp); } - return result; + /* If we haven't found anything this is generally a bad sign but we + handle it gracefully. We return what is hopefully the right + answer (/proc) but we don't remember this. This will enable + programs which started before the system is fully running to + adjust themselves. */ + if (result == NULL) + return path_proc; + + /* Make a copy we can keep around. */ + copy_result = __strdup (result); + if (copy_result == NULL) + return result; + + /* Now strore the copied value. But do it atomically. */ + assert (sizeof (long int) == sizeof (void *)); + if (compare_and_swap ((long int *) &mount_proc, (long int) 0, + (long int) copy_result) == 0) + /* Replacing the value failed. This means another thread was + faster and we don't need the copy anymore. */ + free (copy_result); + + return mount_proc; } @@ -91,7 +125,7 @@ __get_nprocs () { FILE *fp; char buffer[8192]; - char *proc_path; + const char *proc_path; int result = 1; /* XXX Here will come a test for the new system call. */ @@ -126,7 +160,7 @@ __get_nprocs_conf () { FILE *fp; char buffer[8192]; - char *proc_path; + const char *proc_path; int result = 1; /* XXX Here will come a test for the new system call. */ @@ -166,7 +200,7 @@ phys_pages_info (const char *format) { FILE *fp; char buffer[8192]; - char *proc_path; + const char *proc_path; int result = -1; /* Get mount point of proc filesystem. */ @@ -244,3 +278,11 @@ __get_avphys_pages () return phys_pages_info ("MemFree: %d kB"); } weak_alias (__get_avphys_pages, get_avphys_pages) + + +static void +free_mem (void) +{ + free (mount_proc); +} +text_set_element (__libc_subfreeres, free_mem); |