| /* Low-level statistical profiling support function. Mostly POSIX.1 version. |
| Copyright (C) 1996,1997,1998,2002,2004,2005,2006 |
| 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/types.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <signal.h> |
| #include <sys/time.h> |
| #include <libc-internal.h> |
| |
| #ifndef SIGPROF |
| |
| #include <gmon/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) |
| { |
| struct sigaction act; |
| struct itimerval timer; |
| #ifndef IS_IN_rtld |
| static struct sigaction oact; |
| static struct itimerval otimer; |
| # define oact_ptr &oact |
| # define otimer_ptr &otimer |
| |
| 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; |
| } |
| #else |
| /* In ld.so profiling should never be disabled once it runs. */ |
| //assert (sample_buffer != NULL); |
| # define oact_ptr NULL |
| # define otimer_ptr NULL |
| #endif |
| |
| 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_ptr) < 0) |
| return -1; |
| |
| timer.it_value.tv_sec = 0; |
| timer.it_value.tv_usec = 1000000 / __profile_frequency (); |
| timer.it_interval = timer.it_value; |
| return __setitimer (ITIMER_PROF, &timer, otimer_ptr); |
| } |
| weak_alias (__profil, profil) |
| |
| #endif |