[apple/libc.git] / gmon / gmon.c

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
#if defined(PROFILE)
#error This module cannot be compiled with profiling
#endif

/*-
 * 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.
 */
/*
 * History
 *  2-Mar-90  Gregg Kellogg (gk) at NeXT
 *      Changed include of kern/mach.h to kern/mach_interface.h
 *
 *  1-May-90  Matthew Self (mself) at NeXT
 *      Added prototypes, and added casts to remove all warnings.
 *      Made all private data static.
 *      vm_deallocate old data defore vm_allocate'ing new data.
 *      Added new functions monoutput and monreset.
 *
 *  18-Dec-92 Development Environment Group at NeXT
 *      Added multiple profile areas, the ability to profile shlibs and the
 *      ability to profile rld loaded code.  Moved the machine dependent mcount
 *      routine out of this source file.
 *
 *  13-Dec-92 Development Environment Group at NeXT
 *      Added support for dynamic shared libraries.  Also removed the code that
 *      had been ifdef'ed out for profiling fixed shared libraries and
 *      objective-C.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)gmon.c      5.2 (Berkeley) 6/21/85";
#endif

/*
 * see profil(2) where this (SCALE_1_TO_1) is describe (incorrectly).
 *
 * The correct description:  scale is a fixed point value with
 * the binary point in the middle of the 32 bit value.  (Bit 16 is
 * 1, bit 15 is .5, etc.)
 *
 * Setting the scale to "1" (i.e. 0x10000), results in the kernel
 * choosing the profile bucket address 1 to 1 with the pc sampled.
 * Since buckets are shorts, if the profiling base were 0, then a pc
 * of 0 increments bucket 0, a pc of 2 increments bucket 1, and a pc
 * of 4 increments bucket 2.)  (Actually, this seems a little bogus,
 * 1 to 1 should map pc's to buckets -- that's probably what was
 * intended from the man page, but historically....
 */
#define         SCALE_1_TO_1    0x10000L

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

#include <stdio.h>
#include <libc.h>
extern const struct section *getsectbyname(
        const char *segname, 
        const char *sectname);
#include <monitor.h>
#include <sys/types.h>
#include <sys/gmon.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include <mach/mach.h>
#include <mach-o/loader.h>
#include <mach-o/dyld.h>

/*
 * These are defined in here and these declarations need to be moved to libc.h
 * where the other declarations for the monitor(3) routines are declared.
 */
extern void moninit(
    void);
extern void monaddition(
    char *lowpc,
    char *highpc);
extern void moncount(
    char *frompc,
    char *selfpc);
extern void monreset(
    void);
extern void monoutput(
    const char *filename);
extern int add_profil(char *, int, int, int);

static char profiling = -1;     /* tas (test and set) location for NeXT */
static char init = 0;           /* set while moninit() is being serviced */

static unsigned long order = 0; /* call order */

struct mon_t {
    /* the address range and size this mon struct refers to */
    char                *lowpc;
    char                *highpc;
    unsigned long       textsize;
    /* the data structures to support the arc's and their counts */
    unsigned short      *froms; /* froms is unsigned shorts indexing into tos */
    struct tostruct     *tos;
    long                tolimit;
    /* the pc-sample buffer, it's size and scale */
    char                *sbuf;
    int                 ssiz;   /* includes the gmonhdr struct */
    int                 scale;
};
static struct mon_t *mon = NULL;
static unsigned long nmon = 0;

static void monsetup(
    struct mon_t *m,
    char *lowpc,
    char *highpc);
static int getprofhz(
    void);

void
moninit(
void)
{
    const struct section *section;
    char *lowpc, *highpc;
    unsigned long i;

        monreset();
        init = 1;

        section = getsectbyname ("__TEXT", "__text");
        lowpc = (char *)section->addr,
        highpc = (char *)(section->addr + section->size);

        if(mon == NULL){
            if((mon = malloc(sizeof(struct mon_t))) == NULL){
                write(2, MSG, sizeof(MSG) - 1);
                return;
            }
            nmon = 1;
            memset(mon, '\0', sizeof(struct mon_t));
        }
        /*
         * To continue to make monstartup() and the functions that existed
         * before adding multiple profiling areas working correctly the new
         * calls to get the dyld loaded code profiled are made after
         * the first mon_t struct is allocated so that they will not use the 
         * first mon_t and the old calls will always use the first mon_t struct
         * in the list.
         */
        monsetup(mon, lowpc, highpc);

        profil(mon->sbuf + sizeof(struct gmonhdr),
               mon->ssiz - sizeof(struct gmonhdr),
               (int)mon->lowpc, mon->scale);
        for(i = 1; i < nmon; i++)
            add_profil(mon[i].sbuf + sizeof(struct gmonhdr),
                       mon[i].ssiz - sizeof(struct gmonhdr),
                       (int)mon[i].lowpc, mon[i].scale);
        init = 0;
        profiling = 0;

#if defined(__DYNAMIC__)
        /*
         * Call _dyld_moninit() if the dyld is present.  This is done after the
         * above calls so the dynamic libraries will be added after the
         * executable.
         */
        if(_dyld_present())
            _dyld_moninit(monaddition);
#endif
}

void
monstartup(
char *lowpc,
char *highpc)
{
        monreset();
        if(mon == NULL){
            if((mon = malloc(sizeof(struct mon_t))) == NULL){
                write(2, MSG, sizeof(MSG) - 1);
                return;
            }
            nmon = 1;
            memset(mon, '\0', sizeof(struct mon_t));
        }
        monsetup(mon, lowpc, highpc);
}

/*
 * monaddtion() is used for adding additional pc ranges to profile.  This is
 * used for profiling dyld loaded code.
 */
void
monaddition(
char *lowpc,
char *highpc)
{
    char save_profiling;
    struct mon_t *m;

        if(mon == NULL){
            monstartup(lowpc, highpc);
            return;
        }
        save_profiling = profiling;
        profiling = -1;
        if((mon = realloc(mon, (nmon + 1) * sizeof(struct mon_t))) == NULL){
            write(2, MSG, sizeof(MSG) - 1);
            return;
        }
        m = mon + nmon;
        memset(m, '\0', sizeof(struct mon_t));
        nmon++;
        monsetup(m, lowpc, highpc);
        profiling = save_profiling;
}

static
void
monsetup(
struct mon_t *m,
char *lowpc,
char *highpc)
{
    int monsize;
    char *buffer;
    kern_return_t ret;
    struct gmonhdr *p;
    unsigned int o;

        /*
         * 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));
        m->lowpc = lowpc;
        highpc = (char *)ROUNDUP((unsigned)highpc,
                                 HISTFRACTION * sizeof(HISTCOUNTER));
        m->highpc = highpc;

        if(m->froms)
            vm_deallocate(mach_task_self(),
                          (vm_address_t)m->froms,
                          (vm_size_t)(m->textsize / HASHFRACTION));
        m->textsize = highpc - lowpc;
        ret = vm_allocate(mach_task_self(),
                          (vm_address_t *)&m->froms,
                          (vm_size_t)(m->textsize / HASHFRACTION),
                           TRUE);
        if(ret != KERN_SUCCESS){
            write(2, MSG, sizeof(MSG) - 1);
            m->froms = 0;
            return;
        }

        if(m->sbuf)
            vm_deallocate(mach_task_self(),
                          (vm_address_t)m->sbuf,
                          (vm_size_t)m->ssiz);
        monsize = (m->textsize / HISTFRACTION) + sizeof(struct gmonhdr);
        ret = vm_allocate(mach_task_self(),
                          (vm_address_t *)&buffer,
                          (vm_size_t)monsize,
                           TRUE);
        if(ret != KERN_SUCCESS){
            write(2, MSG, sizeof(MSG) - 1);
            m->sbuf = 0;
            return;
        }

        if(m->tos)
            vm_deallocate(mach_task_self(),
                          (vm_address_t)m->tos,
                          (vm_size_t)(m->tolimit * sizeof(struct tostruct)));
        m->tolimit = m->textsize * ARCDENSITY / 100;
        if(m->tolimit < MINARCS){
            m->tolimit = MINARCS;
        }
        else if(m->tolimit > 65534){
            m->tolimit = 65534;
        }
        ret =  vm_allocate(mach_task_self(), 
                           (vm_address_t *)&m->tos,
                           (vm_size_t)(m->tolimit * sizeof(struct tostruct)),
                            TRUE);
        if(ret != KERN_SUCCESS){
            write(2, MSG, sizeof(MSG) - 1);
            m->tos = 0;
            return;
        }
        m->tos[0].link = 0; /* a nop since tos was vm_allocated and is zero */

        /*
         * If this is call to monsetup() was via monstartup() (m == mon) then
         * it is using or reusing the first pc range and then the pc sample 
         * buffer can be setup by the system call profil() via monitor() via
         * a moncontrol(1) call.
         *
         * Otherwise this is call to monsetup() was via monaddition() and a
         * new system call is needed to add an additional pc sample buffer in
         * the kernel.
         */
        if(m == mon && !init){
            monitor(lowpc, highpc, buffer, monsize, m->tolimit);
        }
        else{
            /* monitor() functionality */
            m->sbuf = buffer;
            m->ssiz = monsize;
            p = (struct gmonhdr *)m->sbuf;
            memset(p, '\0', sizeof(struct gmonhdr));
            p->lpc = (unsigned long)m->lowpc;
            p->hpc = (unsigned long)m->highpc;
            p->ncnt = m->ssiz;
            p->version = GMONVERSION;
            p->profrate = getprofhz();
            o = highpc - lowpc;
            if((monsize - sizeof(struct gmonhdr)) < o)
                m->scale = ((float) (monsize - sizeof(struct gmonhdr))/ o) *
                           SCALE_1_TO_1;
            else
                m->scale = SCALE_1_TO_1;

            /* moncontrol(mode == 1) functionality */
            if(!init)
                add_profil(m->sbuf + sizeof(struct gmonhdr),
                           m->ssiz - sizeof(struct gmonhdr),
                           (int)m->lowpc, m->scale);
        }
}

void
monreset(
void)
{
    unsigned long i;
    struct mon_t *m;
    struct gmonhdr *p;

        moncontrol(0);
        if(mon == NULL)
            return;
        for(i = 0; i < nmon; i++){
            m = mon + i;
            if(m->sbuf != NULL){
                memset(m->sbuf, '\0', m->ssiz);
                p = (struct gmonhdr *)m->sbuf;
                p->lpc = (unsigned long)m->lowpc;
                p->hpc = (unsigned long)m->highpc;
                p->ncnt = m->ssiz;
            }
            if(m->froms != NULL)
                memset(m->froms, '\0', m->textsize / HASHFRACTION);
            if(m->tos != NULL)
                memset(m->tos, '\0', m->tolimit * sizeof (struct tostruct));
        }
        order = 0;
        moncontrol(1);
}

void
monoutput(
const char *filename)
{
    int fd;
    unsigned long magic, i, fromindex, endfrom, toindex;
    struct gmon_data sample_data, arc_data, dyld_data;
    char *frompc;
    struct rawarc_order rawarc_order;
    struct mon_t *m;
    unsigned long image_count, vmaddr_slide;
    char *image_name;

        moncontrol(0);
        m = mon;
        if(m == NULL)
            return;
        fd = creat(filename, 0666);
        if(fd < 0){
            perror("mcount: gmon.out");
            return;
        }

        magic = GMON_MAGIC;
        write(fd, &magic, sizeof(unsigned long));

#if defined(__DYNAMIC__)
        if(_dyld_present()){
            image_count = _dyld_image_count();
            if(image_count > 1){
#ifdef DYLD_DEBUG
                printf("image_count = %lu\n", image_count - 1);
                for(i = 1; i < image_count; i++){
                    vmaddr_slide = _dyld_get_image_vmaddr_slide(i);
                    printf("\tvmaddr_slide 0x%x\n", (unsigned int)vmaddr_slide);
                    image_name = _dyld_get_image_name(i);
                    printf("\timage_name %s\n", image_name);
                }
#endif
                /*
                 * Calculate the dyld_data.size.
                 */
                dyld_data.type = GMONTYPE_DYLD_STATE;
                dyld_data.size = sizeof(unsigned long) +
                    sizeof(unsigned long) * (image_count - 1);
                for(i = 1; i < image_count; i++){
                    image_name = _dyld_get_image_name(i);
                    dyld_data.size += strlen(image_name) + 1;
                }

                /*
                 * Write the dyld_data.
                 */
                write(fd, &dyld_data, sizeof(struct gmon_data));
                image_count--;
                write(fd, &image_count, sizeof(unsigned long));
                image_count++;
                for(i = 1; i < image_count; i++){
                    vmaddr_slide = _dyld_get_image_vmaddr_slide(i);
                    write(fd, &vmaddr_slide, sizeof(unsigned long));
                    image_name = _dyld_get_image_name(i);
                    write(fd, image_name, strlen(image_name) + 1);
                }
            }
        }
#endif
        for(i = 0; i < nmon; i++){
            m = mon + i;
#ifdef DEBUG
            fprintf(stderr, "[monoutput] sbuf 0x%x ssiz %d\n",
                    m->sbuf, m->ssiz);
#endif
            sample_data.type = GMONTYPE_SAMPLES;
            sample_data.size = m->ssiz;
            write(fd, &sample_data, sizeof(struct gmon_data));
            /*
             * Write the gmonhdr struct and the pc-sample buffer.  Note the
             * gmonhdr struct is in sbuf at the beginning of sbuf already
             * filled in.
             */
            write(fd, m->sbuf, m->ssiz);

            /*
             * Now write out the raw arcs.
             */
            endfrom = m->textsize / (HASHFRACTION * sizeof(*m->froms));
            arc_data.type = GMONTYPE_ARCS_ORDERS;
            arc_data.size = 0;
            for(fromindex = 0; fromindex < endfrom; fromindex++){
                if(m->froms[fromindex] == 0){
                    continue;
                }
                frompc = m->lowpc +
                         (fromindex * HASHFRACTION * sizeof(*m->froms));
                for(toindex = m->froms[fromindex];
                    toindex != 0;
                    toindex = m->tos[toindex].link){
                    arc_data.size += sizeof(struct rawarc_order);
                }
            }
            write(fd, &arc_data, sizeof(struct gmon_data));

            for(fromindex = 0; fromindex < endfrom; fromindex++){
                if(m->froms[fromindex] == 0){
                    continue;
                }
                frompc = m->lowpc +
                         (fromindex * HASHFRACTION * sizeof(*m->froms));
                for(toindex = m->froms[fromindex];
                    toindex != 0;
                    toindex = m->tos[toindex].link){
#ifdef DEBUG
                    fprintf(stderr, "[monoutput] frompc 0x%x selfpc 0x%x "
                            "count %ld order %lu\n", (unsigned int)frompc,
                            (unsigned int)m->tos[toindex].selfpc,
                            m->tos[toindex].count, m->tos[toindex].order);
#endif
                    rawarc_order.raw_frompc = (unsigned long)frompc;
                    rawarc_order.raw_selfpc = (unsigned long)
                                               m->tos[toindex].selfpc;
                    rawarc_order.raw_count = m->tos[toindex].count;
                    rawarc_order.raw_order = m->tos[toindex].order;
                    write(fd, &rawarc_order, sizeof(struct rawarc_order));
                }
            }
        }
        close(fd);
}

void
monitor(
char *lowpc,
char *highpc,
char *buf,
int bufsiz,
int nfunc) /* nfunc is not used; available for compatability only. */
{
    unsigned int o;
    struct gmonhdr *p;
    struct mon_t *m;

        moncontrol(0);
        m = mon;
        if(m == NULL)
            return;
        if(lowpc == 0){
            moncontrol(0);
            monoutput("gmon.out");
            return;
        }
        m->sbuf = buf;
        m->ssiz = bufsiz;
        p = (struct gmonhdr *)buf;
        memset(p, '\0', sizeof(struct gmonhdr));
        p->lpc = (unsigned long)lowpc;
        p->hpc = (unsigned long)highpc;
        p->ncnt = m->ssiz;
        p->version = GMONVERSION;
        p->profrate = getprofhz();
        bufsiz -= sizeof(struct gmonhdr);
        if(bufsiz <= 0)
            return;
        o = highpc - lowpc;
        if(bufsiz < o)
            m->scale = ((float) bufsiz / o) * SCALE_1_TO_1;
        else
            m->scale = SCALE_1_TO_1;
        moncontrol(1);
}

/*
 * Control profiling
 *      profiling is what mcount checks to see if
 *      all the data structures are ready.
 */
void
moncontrol(
int mode)
{
    struct mon_t *m;
    unsigned long i;

        if(mode){
            /* start */
            m = mon;
            if(m != NULL){
                profil(m->sbuf + sizeof(struct gmonhdr),
                       m->ssiz - sizeof(struct gmonhdr),
                       (int)m->lowpc, m->scale);
                for(i = 1; i < nmon; i++)
                    add_profil(mon[i].sbuf + sizeof(struct gmonhdr),
                               mon[i].ssiz - sizeof(struct gmonhdr),
                               (int)mon[i].lowpc, mon[i].scale);
                profiling = 0;
            }
        }
        else{
            /* stop */
            profil((char *)0, 0, 0, 0);
            profiling = -1;
        }
}

void
moncount(
char *frompc,
char *selfpc)
{
    unsigned short *frompcindex;
    struct tostruct *top, *prevtop;
    unsigned long i, toindex;
    struct mon_t *m;

        m = mon;
        if(m == NULL)
            return;
        /*
         * Check that we are profiling and that we aren't recursively invoked.
         * This should really be a test and set instruction in changing the
         * value of profiling.
         */
        if(profiling)
            return;
        profiling++;


#ifdef DEBUG
        fprintf(stderr, "[moncount] frompc 0x%x selfpc 0x%x\n",
                (unsigned int)frompc, (unsigned int)selfpc);
#endif
        frompcindex = (unsigned short *)frompc;

        /*
         * check that frompcindex is a reasonable pc value.
         * for example: signal catchers get called from the stack,
         *              not from text space.  too bad.
         */
        for(i = 0; i < nmon; i++){
            m = mon + i;
            if((unsigned long)frompcindex >= (unsigned long)m->lowpc &&
               (unsigned long)frompcindex <  (unsigned long)m->highpc)
                break;
        }
        if(i == nmon){
            goto done;
        }
        else{
            frompcindex = (unsigned short *)
                  ((unsigned long)frompcindex - (unsigned long)m->lowpc);
        }
        frompcindex =
            &m->froms[((long)frompcindex) / (HASHFRACTION * sizeof(*m->froms))];
        toindex = *frompcindex;
        if(toindex == 0){
            /*
             *  first time traversing this arc
             */
            toindex = ++m->tos[0].link;
            if(toindex >= m->tolimit){
                goto overflow;
            }
            *frompcindex = toindex;
            top = &m->tos[toindex];
            top->selfpc = (unsigned long)selfpc;
            top->count = 1;
            top->link = 0;
            top->order = ++order;
            goto done;
        }
        top = &m->tos[toindex];
        if(top->selfpc == (unsigned long)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 = ++m->tos[0].link;
                if(toindex >= m->tolimit){
                    goto overflow;
                }
                top = &m->tos[toindex];
                top->selfpc = (unsigned long)selfpc;
                top->count = 1;
                top->link = *frompcindex;
                top->order = ++order;
                *frompcindex = toindex;
                goto done;
            }
            /*
             * otherwise, check the next arc on the chain.
             */
            prevtop = top;
            top = &m->tos[top->link];
            if(top->selfpc == (unsigned long)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--;
        return;

overflow:
        profiling++; /* halt further profiling */
#define TOLIMIT "mcount: tos overflow\n"
        write(2, TOLIMIT, sizeof(TOLIMIT) - 1);
}

/*
 * Get the profiling rate.
 */
static
int
getprofhz(void)
{
    int mib[2];
    size_t size;
    struct clockinfo clockrate;

        mib[0] = CTL_KERN;
        mib[1] = KERN_CLOCKRATE;
        clockrate.profhz = 1;
        size = sizeof(clockrate);
        if(sysctl(mib, 2, &clockrate, &size, NULL, 0) < 0)
                ;
        return(clockrate.profhz);
}