mcount.c

来自「基于组件方式开发操作系统的OSKIT源代码」· C语言 代码 · 共 203 行

/*
 * Copyright (c) 1998, 1999 University of Utah and the Flux Group.
 * All rights reserved.
 * 
 * This file is part of the Flux OSKit.  The OSKit is free software, also known
 * as "open source;" you can redistribute it and/or modify it under the terms
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF).  To explore alternate licensing terms, contact
 * the University of Utah at [e-mail] or [phone].
 * 
 * The OSKit 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 GPL for more details.  You should have
 * received a copy of the GPL along with the OSKit; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */
/*-
 * Copyright (c) 1983, 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#ifdef GPROF
/*
 * mcount routine for kernel profiling.
 */

/*#include "config_profiling.h"*/
#define CONFIG_PROFILING
#ifdef CONFIG_PROFILING

#if DEBUG_MCOUNT
#include <stdio.h>
#endif

#define OSKIT_IN_MCOUNT

#include <oskit/types.h>
#include <oskit/c/sys/gmon.h>
#include <oskit/c/sys/profile.h>

/*
 * _mcount updates data structures that represent traversals of the
 * program's call graph edges.  frompc and selfpc are the return
 * address and function address that represents the given call graph edge.
 */
void 
_mcount( 
	unsigned long frompc, 
	unsigned long selfpc) 
{ 
	register unsigned short *frompcindex;
	register struct tostruct *top, *prevtop;
	register struct gmonparam *p;
	register long toindex;
#ifdef _KERNEL
	register int s;
#endif
	p = &_gmonparam;

	/*
	 * check that we are profiling
	 * and that we aren't recursively invoked.
	 */
	if (p->state != GMON_PROF_ON)
		return;
#ifdef _KERNEL
	MCOUNT_ENTER;
#else
	p->state = GMON_PROF_BUSY;
#endif

	/* XXX remember to have code to either disable then re-enable
	 * interrupts and possibly save and restore the eflags! 
	 */
#if DEBUG_MCOUNT
	printf("frompc = %lx, selfpc = %lx\n", frompc, selfpc);	
#endif

	/*
	 * check that frompcindex is a reasonable pc value.
	 * for example:	signal catchers get called from the stack,
	 *		not from text space.  too bad.
	 */
	frompc -= p->lowpc;
	if (frompc > p->textsize)
		goto done;

	frompcindex = &p->froms[frompc / (p->hashfraction * sizeof(*p->froms))];
	toindex = *frompcindex;
	if (toindex == 0) {
                /*
		 *	first time traversing this arc
		 */
		toindex = ++p->tos[0].link;
		if (toindex >= p->tolimit)
			/* halt further profiling */
			goto overflow;

		*frompcindex = toindex;
		top = &p->tos[toindex];
		top->selfpc = selfpc;
		top->count = 1;
		top->link = 0;
		goto done;
	}
	top = &p->tos[toindex];
	if (top->selfpc == selfpc) {
		/*
		 * arc at front of chain; usual case.
		 */
		top->count++;
		goto done;
	}
	/*
	 * have to go looking down chain for it.
	 * top points to what we are looking at,
	 * prevtop points to previous top.
	 * we know it is not at the head of the chain.
	 */
	for (; /* goto done */; ) {
		if (top->link == 0) {
			/*
			 * top is end of the chain and none of the chain
			 * had top->selfpc == selfpc.
			 * so we allocate a new tostruct
			 * and link it to the head of the chain.
			 */
			toindex = ++p->tos[0].link;
			if (toindex >= p->tolimit)
				goto overflow;

			top = &p->tos[toindex];
			top->selfpc = selfpc;
			top->count = 1;
			top->link = *frompcindex;
			*frompcindex = toindex;
			goto done;
		}
		/*
		 * otherwise, check the next arc on the chain.
		 */
		prevtop = top;
		top = &p->tos[top->link];
		if (top->selfpc == selfpc) {
			/*
			 * there it is.
			 * increment its count
			 * move it to the head of the chain.
			 */
			top->count++;
			toindex = prevtop->link;
			prevtop->link = top->link;
			top->link = *frompcindex;
			*frompcindex = toindex;
			goto done;
		}
		
	}
done:
#ifdef _KERNEL
	MCOUNT_EXIT;
#else
	p->state = GMON_PROF_ON;
#endif
	return;
overflow:
	p->state = GMON_PROF_ERROR;
#ifdef _KERNEL
	MCOUNT_EXIT;
#endif
	return;
}

#endif /* CONFIG_PROFILING */
#endif /* GPROF */