mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 06:20:06 +00:00
93 lines
2.4 KiB
C
93 lines
2.4 KiB
C
/* Profile PC and write result to FIFO.
|
|
Copyright (C) 1999-2014 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, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#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)
|