usr/src/lib/csu/vax.pcc/gmon.c

/*-
 * Copyright (c) 1983 The Regents of the University of California.
 * All rights reserved.
 *
 * This module is believed to contain source code proprietary to AT&T.
 * Use and redistribution is subject to the Berkeley Software License
 * Agreement and your Software Agreement with AT&T (Western Electric).
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)gmon.c      5.5 (Berkeley) 4/12/91";
#endif /* LIBC_SCCS and not lint */

#ifdef DEBUG
#include <stdio.h>
#endif

#include "gmon.h"

    /*
     *  froms is actually a bunch of unsigned shorts indexing tos
     */
static int              profiling = 3;
static unsigned short   *froms;
static struct tostruct  *tos = 0;
static long             tolimit = 0;
static char             *s_lowpc = 0;
static char             *s_highpc = 0;
static unsigned long    s_textsize = 0;

static int      ssiz;
static char     *sbuf;
static int      s_scale;
    /* see profil(2) where this is describe (incorrectly) */
#define         SCALE_1_TO_1    0x10000L

#define MSG "No space for monitor buffer(s)\n"

monstartup(lowpc, highpc)
    char        *lowpc;
    char        *highpc;
{
    int                 monsize;
    char                *buffer;
    char                *sbrk();
    extern char         *minbrk;

        /*
         *      round lowpc and highpc to multiples of the density we're using
         *      so the rest of the scaling (here and in gprof) stays in ints.
         */
    lowpc = (char *)
            ROUNDDOWN((unsigned)lowpc, HISTFRACTION*sizeof(HISTCOUNTER));
    s_lowpc = lowpc;
    highpc = (char *)
            ROUNDUP((unsigned)highpc, HISTFRACTION*sizeof(HISTCOUNTER));
    s_highpc = highpc;
    s_textsize = highpc - lowpc;
    monsize = (s_textsize / HISTFRACTION) + sizeof(struct phdr);
    buffer = sbrk( monsize );
    if ( buffer == (char *) -1 ) {
        write( 2 , MSG , sizeof(MSG) - 1 );
        return;
    }
    froms = (unsigned short *) sbrk( s_textsize / HASHFRACTION );
    if ( froms == (unsigned short *) -1 ) {
        write( 2 , MSG , sizeof(MSG) - 1 );
        froms = 0;
        return;
    }
    tolimit = s_textsize * ARCDENSITY / 100;
    if ( tolimit < MINARCS ) {
        tolimit = MINARCS;
    } else if ( tolimit > 65534 ) {
        tolimit = 65534;
    }
    tos = (struct tostruct *) sbrk( tolimit * sizeof( struct tostruct ) );
    if ( tos == (struct tostruct *) -1 ) {
        write( 2 , MSG , sizeof(MSG) - 1 );
        froms = 0;
        tos = 0;
        return;
    }
    minbrk = sbrk(0);
    tos[0].link = 0;
    monitor( lowpc , highpc , buffer , monsize , tolimit );
}

_mcleanup()
{
    int                 fd;
    int                 fromindex;
    int                 endfrom;
    char                *frompc;
    int                 toindex;
    struct rawarc       rawarc;

    fd = creat( "gmon.out" , 0666 );
    if ( fd < 0 ) {
        perror( "mcount: gmon.out" );
        return;
    }
#   ifdef DEBUG
        fprintf( stderr , "[mcleanup] sbuf 0x%x ssiz %d\n" , sbuf , ssiz );
#   endif DEBUG
    write( fd , sbuf , ssiz );
    endfrom = s_textsize / (HASHFRACTION * sizeof(*froms));
    for ( fromindex = 0 ; fromindex < endfrom ; fromindex++ ) {
        if ( froms[fromindex] == 0 ) {
            continue;
        }
        frompc = s_lowpc + (fromindex * HASHFRACTION * sizeof(*froms));
        for (toindex=froms[fromindex]; toindex!=0; toindex=tos[toindex].link) {
#           ifdef DEBUG
                fprintf( stderr ,
                        "[mcleanup] frompc 0x%x selfpc 0x%x count %d\n" ,
                        frompc , tos[toindex].selfpc , tos[toindex].count );
#           endif DEBUG
            rawarc.raw_frompc = (unsigned long) frompc;
            rawarc.raw_selfpc = (unsigned long) tos[toindex].selfpc;
            rawarc.raw_count = tos[toindex].count;
            write( fd , &rawarc , sizeof rawarc );
        }
    }
    close( fd );
}

asm(".text");
asm(".align 2");
asm("#the beginning of mcount()");
asm(".data");
mcount()
{
        register char                   *selfpc;        /* r11 => r5 */
        register unsigned short         *frompcindex;   /* r10 => r4 */
        register struct tostruct        *top;           /* r9  => r3 */
        register struct tostruct        *prevtop;       /* r8  => r2 */
        register long                   toindex;        /* r7  => r1 */

        /*
         *      find the return address for mcount,
         *      and the return address for mcount's caller.
         */
        asm("   .text");                /* make sure we're in text space */
        asm("   movl (sp), r11");       /* selfpc = ... (jsb frame) */
        asm("   movl 16(fp), r10");     /* frompcindex =     (calls frame) */
        /*
         *      check that we are profiling
         *      and that we aren't recursively invoked.
         */
        if (profiling) {
                goto out;
        }
        profiling++;
        /*
         *      check that frompcindex is a reasonable pc value.
         *      for example:    signal catchers get called from the stack,
         *                      not from text space.  too bad.
         */
        frompcindex = (unsigned short *)((long)frompcindex - (long)s_lowpc);
        if ((unsigned long)frompcindex > s_textsize) {
                goto done;
        }
        frompcindex =
            &froms[((long)frompcindex) / (HASHFRACTION * sizeof(*froms))];
        toindex = *frompcindex;
        if (toindex == 0) {
                /*
                 *      first time traversing this arc
                 */
                toindex = ++tos[0].link;
                if (toindex >= tolimit) {
                        goto overflow;
                }
                *frompcindex = toindex;
                top = &tos[toindex];
                top->selfpc = selfpc;
                top->count = 1;
                top->link = 0;
                goto done;
        }
        top = &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 = ++tos[0].link;
                        if (toindex >= tolimit) {
                                goto overflow;
                        }
                        top = &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 = &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:
        profiling--;
        /* and fall through */
out:
        asm("   rsb");

overflow:
        profiling++; /* halt further profiling */
#   define      TOLIMIT "mcount: tos overflow\n"
        write(2, TOLIMIT, sizeof(TOLIMIT) - 1);
        goto out;
}
asm(".text");
asm("#the end of mcount()");
asm(".data");

/*VARARGS1*/
monitor( lowpc , highpc , buf , bufsiz , nfunc )
    char        *lowpc;
    char        *highpc;
    char        *buf;   /* declared ``short buffer[]'' in monitor(3) */
    int         bufsiz;
    int         nfunc;  /* not used, available for compatability only */
{
    register o;

    if ( lowpc == 0 ) {
        moncontrol(0);
        _mcleanup();
        return;
    }
    sbuf = buf;
    ssiz = bufsiz;
    ( (struct phdr *) buf ) -> lpc = lowpc;
    ( (struct phdr *) buf ) -> hpc = highpc;
    ( (struct phdr *) buf ) -> ncnt = ssiz;
    bufsiz -= sizeof(struct phdr);
    if ( bufsiz <= 0 )
        return;
    o = highpc - lowpc;
    if( bufsiz < o )
        s_scale = ( (float) bufsiz / o ) * SCALE_1_TO_1;
    else
        s_scale = SCALE_1_TO_1;
    moncontrol(1);
}

/*
 * Control profiling
 *      profiling is what mcount checks to see if
 *      all the data structures are ready.
 */
moncontrol(mode)
    int mode;
{
    if (mode) {
        /* start */
        profil(sbuf + sizeof(struct phdr), ssiz - sizeof(struct phdr),
                s_lowpc, s_scale);
        profiling = 0;
    } else {
        /* stop */
        profil((char *)0, 0, 0, 0);
        profiling = 3;
    }
}