/* Profile PC and write result to FIFO. Copyright (C) 1999, 2000 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999. 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 <errno.h> #include <fcntl.h> #include <stdint.h> #include <stdlib.h> #include <unistd.h> #include <libc-internal.h> /* Nonzero if we are actually doing something. */ static int active; /* The file descriptor of the FIFO. */ static int fd; static void __attribute__ ((constructor)) install (void) { /* See whether the environment variable `PCPROFILE_OUTPUT' is defined. If yes, it should name a FIFO. We open it and mark ourself as active. */ const char *outfile = getenv ("PCPROFILE_OUTPUT"); if (outfile != NULL && *outfile != '\0') { fd = open (outfile, O_RDWR | O_CREAT, 0666); if (fd != -1) { uint32_t word; active = 1; /* Write a magic word which tells the reader about the byte order and the size of the following entries. */ word = 0xdeb00000 | sizeof (void *); if (TEMP_FAILURE_RETRY (write (fd, &word, 4)) != 4) { /* If even this fails we shouldn't try further. */ close (fd); fd = -1; active = 0; } } } } static void __attribute__ ((destructor)) uninstall (void) { if (active) close (fd); } void __cyg_profile_func_enter (void *this_fn, void *call_site) { void *buf[2]; if (! active) return; /* Now write out the current position and that of the caller. We do this now, and don't cache the because we want real-time output. */ buf[0] = this_fn; buf[1] = call_site; write (fd, buf, sizeof buf); } /* We don't handle entry and exit differently here. */ strong_alias (__cyg_profile_func_enter, __cyg_profile_func_exit)