diff options
Diffstat (limited to 'libc/sysdeps/unix/sysv/linux/prof-freq.c')
-rw-r--r-- | libc/sysdeps/unix/sysv/linux/prof-freq.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/libc/sysdeps/unix/sysv/linux/prof-freq.c b/libc/sysdeps/unix/sysv/linux/prof-freq.c new file mode 100644 index 000000000..49ec257e7 --- /dev/null +++ b/libc/sysdeps/unix/sysv/linux/prof-freq.c @@ -0,0 +1,51 @@ +/* Determine realtime clock frequency. + Copyright (C) 2003, 2004, 2006 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sys/time.h> +#include <libc-internal.h> +#include <kernel-features.h> +#include <ldsodefs.h> + + +int +__profile_frequency (void) +{ +#ifdef __ASSUME_AT_CLKTCK + return GLRO(dl_clktck); +#else + if (GLRO(dl_clktck) != 0) + return GLRO(dl_clktck); + + struct itimerval tim; + + tim.it_interval.tv_sec = 0; + tim.it_interval.tv_usec = 1; + tim.it_value.tv_sec = 0; + tim.it_value.tv_usec = 0; + + __setitimer (ITIMER_REAL, &tim, 0); + __setitimer (ITIMER_REAL, 0, &tim); + + if (tim.it_interval.tv_usec < 2) + return 0; + + return 1000000 / tim.it_interval.tv_usec; +#endif +} +libc_hidden_def (__profile_frequency) |