diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/ia64/has_cpuclock.c')
-rw-r--r-- | sysdeps/unix/sysv/linux/ia64/has_cpuclock.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/ia64/has_cpuclock.c b/sysdeps/unix/sysv/linux/ia64/has_cpuclock.c new file mode 100644 index 0000000000..d9e1d353b3 --- /dev/null +++ b/sysdeps/unix/sysv/linux/ia64/has_cpuclock.c @@ -0,0 +1,51 @@ +/* Copyright (C) 2000-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <not-cancel.h> + +static int itc_usable; + +static int +has_cpuclock (void) +{ + if (__builtin_expect (itc_usable == 0, 0)) + { + int newval = 1; + int fd = open_not_cancel_2 ("/proc/sal/itc_drift", O_RDONLY); + if (__builtin_expect (fd != -1, 1)) + { + char buf[16]; + /* We expect the file to contain a single digit followed by + a newline. If the format changes we better not rely on + the file content. */ + if (read_not_cancel (fd, buf, sizeof buf) != 2 + || buf[0] != '0' || buf[1] != '\n') + newval = -1; + + close_not_cancel_no_status (fd); + } + + itc_usable = newval; + } + + return itc_usable; +} |