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Diffstat (limited to 'sysdeps/posix/profil.c')
-rw-r--r-- | sysdeps/posix/profil.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/sysdeps/posix/profil.c b/sysdeps/posix/profil.c new file mode 100644 index 0000000000..8e34b3564f --- /dev/null +++ b/sysdeps/posix/profil.c @@ -0,0 +1,92 @@ +/* Low-level statistical profiling support function. Mostly POSIX.1 version. +Copyright (C) 1996 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <sys/types.h> +#include <unistd.h> +#include <errno.h> +#include <signal.h> +#include <sys/time.h> + +#ifndef SIGPROF + +#include_next <profil.c> + +#else + +static u_short *samples; +static size_t nsamples; +static size_t pc_offset; +static u_int pc_scale; + +static inline void +profil_count (void *pc) +{ + size_t i = ((pc - pc_offset - (void *) 0) / 2) * pc_scale / 65536; + if (i < nsamples) + ++samples[i]; +} + +/* Get the machine-dependent definition of `profil_counter', the signal + handler for SIGPROF. It calls `profil_count' (above) with the PC of the + interrupted code. */ +#include "profil-counter.h" + +/* Enable statistical profiling, writing samples of the PC into at most + SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling + is enabled, the system examines the user PC and increments + SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero, + disable profiling. Returns zero on success, -1 on error. */ + +int +profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale) +{ + static struct sigaction act, oact; + static struct itimerval timer, otimer; + + if (sample_buffer == NULL) + { + /* Disable profiling. */ + if (samples == NULL) + /* Wasn't turned on. */ + return 0; + samples = NULL; + + if (sigaction (SIGPROF, &oact, NULL) < 0) + return -1; + return setitimer (ITIMER_PROF, &otimer, NULL); + } + + samples = sample_buffer; + nsamples = size / sizeof *samples; + pc_offset = offset; + pc_scale = scale; + + act.sa_handler = (sighandler_t) &profil_counter; + act.sa_flags = SA_RESTART; + sigfillset (&act.sa_mask); + if (sigaction (SIGPROF, &act, &oact) < 0) + return -1; + + timer.it_value.tv_sec = 0; + timer.it_value.tv_usec = 1; + timer.it_interval = timer.it_value; + return setitimer (ITIMER_PROF, &timer, &otimer); +} + +#endif |