/* Low-level statistical profiling support function. Mostly POSIX.1 version. Copyright (C) 1996, 1997, 1998 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <sys/types.h> #include <unistd.h> #include <errno.h> #include <signal.h> #include <sys/time.h> #ifndef SIGPROF #include <sysdeps/generic/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; if (sizeof (unsigned long long int) > sizeof (size_t)) i = (unsigned long long int) i * pc_scale / 65536; else i = i / 65536 * pc_scale + i % 65536 * 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 oact; static struct itimerval otimer; struct sigaction act; struct itimerval timer; if (sample_buffer == NULL) { /* Disable profiling. */ if (samples == NULL) /* Wasn't turned on. */ return 0; if (__setitimer (ITIMER_PROF, &otimer, NULL) < 0) return -1; samples = NULL; return __sigaction (SIGPROF, &oact, NULL); } if (samples) { /* Was already turned on. Restore old timer and signal handler first. */ if (__setitimer (ITIMER_PROF, &otimer, NULL) < 0 || __sigaction (SIGPROF, &oact, NULL) < 0) return -1; } 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); } weak_alias (__profil, profil) #endif