[apple/xnu.git] / osfmk / kern / profile.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This 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 OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

/*
 */
#include        <mach_prof.h>

#include        <mach/task_server.h>
#include        <mach/thread_act_server.h>

#if MACH_PROF
#include        <cpus.h>
#include        <kern/thread.h>
#include        <kern/thread_swap.h>
#include        <kern/queue.h>
#include        <kern/profile.h>
#include        <kern/sched_prim.h>
#include        <kern/spl.h>
#include        <kern/misc_protos.h>
#include        <ipc/ipc_space.h>
#include        <machine/machparam.h>
#include        <mach/prof.h>

thread_t profile_thread_id = THREAD_NULL;
int profile_sample_count = 0;   /* Provided for looking at from kdb. */
extern kern_return_t task_suspend(task_t task); /* ack */

/* Forwards */
prof_data_t     pbuf_alloc(void);
void            pbuf_free(
                        prof_data_t     pbuf);
void            profile_thread(void);
void            send_last_sample_buf(
                        prof_data_t     pbuf);

/*
 *****************************************************************************
 * profile_thread is the profile/trace kernel support thread. It is started
 * by a server/user request through task_sample, or thread_sample. The profile
 * thread dequeues messages and sends them to the receive_prof thread, in the
 * server, via the send_samples and send_notices mig interface functions. If
 * there are no messages in the queue profile thread blocks until wakened by
 * profile (called in from mach_clock), or last_sample (called by thread/task_
 * sample).
*/

void
profile_thread(void)
{
    spl_t           s;
    buffer_t        buf_entry;
    queue_entry_t   prof_queue_entry;
    prof_data_t     pbuf;
    kern_return_t   kr;
    int             j;

    thread_swappable(current_act(), FALSE);

    /* Initialise the queue header for the prof_queue */
    mpqueue_init(&prof_queue);

    while (TRUE) {

        /* Dequeue the first buffer. */
        s = splsched();
        mpdequeue_head(&prof_queue, &prof_queue_entry);
        splx(s);

        if ((buf_entry = (buffer_t) prof_queue_entry) == NULLPBUF) { 
            assert_wait((event_t) profile_thread, THREAD_UNINT);
            thread_block((void (*)(void)) 0);
            if (current_thread()->wait_result != THREAD_AWAKENED)
                break;
        } else 
        {
            int             dropped;

            pbuf = buf_entry->p_prof;
            kr = send_samples(pbuf->prof_port, (void *)buf_entry->p_zone,
                        (mach_msg_type_number_t)buf_entry->p_index);
            profile_sample_count += buf_entry->p_index;
            if (kr != KERN_SUCCESS)
              printf("send_samples(%x, %x, %d) error %x\n",
                        pbuf->prof_port, buf_entry->p_zone, buf_entry->p_index, kr); 
            dropped = buf_entry->p_dropped;
            if (dropped > 0) {
                printf("kernel: profile dropped %d sample%s\n", dropped,
                       dropped == 1 ? "" : "s");
                buf_entry->p_dropped = 0;
            }

            /* Indicate you've finished the dirty job */
            buf_entry->p_full = FALSE;
            if (buf_entry->p_wakeme)
              thread_wakeup((event_t) &buf_entry->p_wakeme);
        }

    }
    /* The profile thread has been signalled to exit.  Any threads waiting
       for the last buffer of samples to be acknowledged should be woken
       up now.  */
    profile_thread_id = THREAD_NULL;
    while (1) {
        s = splsched();
        mpdequeue_head(&prof_queue, &prof_queue_entry);
        splx(s);
        if ((buf_entry = (buffer_t) prof_queue_entry) == NULLPBUF)
            break;
        if (buf_entry->p_wakeme)
            thread_wakeup((event_t) &buf_entry->p_wakeme);
    }
#if 0   /* XXXXX */
    thread_halt_self();
#else
        panic("profile_thread(): halt_self");
#endif  /* XXXXX */
}

/*
 *****************************************************************************
 * send_last_sample is the drain mechanism to allow partial profiled buffers
 * to be sent to the receive_prof thread in the server.
 *****************************************************************************
*/

void
send_last_sample_buf(prof_data_t pbuf)
{
    spl_t    s;
    buffer_t buf_entry;

    if (pbuf == NULLPROFDATA)
        return;

    /* Ask for the sending of the last PC buffer.
     * Make a request to the profile_thread by inserting
     * the buffer in the send queue, and wake it up. 
     * The last buffer must be inserted at the head of the
     * send queue, so the profile_thread handles it immediatly. 
     */ 
    buf_entry = pbuf->prof_area + pbuf->prof_index;
    buf_entry->p_prof = pbuf;

    /* 
       Watch out in case profile thread exits while we are about to
       queue data for it.
     */
    s = splsched();
    if (profile_thread_id == THREAD_NULL)
        splx(s);
    else {
        buf_entry->p_wakeme = 1;
        mpenqueue_tail(&prof_queue, &buf_entry->p_list);
        thread_wakeup((event_t) profile_thread);
        assert_wait((event_t) &buf_entry->p_wakeme, THREAD_ABORTSAFE);
        splx(s); 
        thread_block((void (*)(void)) 0);
    }
}


/*
 *****************************************************************************
 * add clock tick parameters to profile/trace buffers. Called from the mach_
 * clock heritz_tick function. DCI version stores thread, sp, and pc values
 * into the profile/trace buffers. MACH_PROF version just stores pc values.
 *****************************************************************************
 */

void
profile(natural_t       pc,
        prof_data_t     pbuf)
{
    natural_t inout_val = pc; 
    buffer_t buf_entry;

    if (pbuf == NULLPROFDATA)
        return;
    
    /* Inserts the PC value in the buffer of the thread */
    set_pbuf_value(pbuf, &inout_val); 
    switch((int)inout_val) {
    case 0: 
        if (profile_thread_id == THREAD_NULL) {
          reset_pbuf_area(pbuf);
        }
        break;
    case 1: 
        /* Normal case, value successfully inserted */
        break;
    case 2 : 
        /*
         * The value we have just inserted caused the
         * buffer to be full, and ready to be sent.
         * If profile_thread_id is null, the profile
         * thread has been killed.  Since this generally
         * happens only when the O/S server task of which
         * it is a part is killed, it is not a great loss
         * to throw away the data.
         */
        if (profile_thread_id == THREAD_NULL) {
          reset_pbuf_area(pbuf);
          break;
        }

        buf_entry = (buffer_t) &pbuf->prof_area[pbuf->prof_index];
        buf_entry->p_prof = pbuf;
        mpenqueue_tail(&prof_queue, &buf_entry->p_list);
        
        /* Switch to another buffer */
        reset_pbuf_area(pbuf);
        
        /* Wake up the profile thread */
        if (profile_thread_id != THREAD_NULL)
          thread_wakeup((event_t) profile_thread);
        break;
      
      default: 
        printf("profile : unexpected case\n"); 
    }
}

/*
 *****************************************************************************
 * pbuf_alloc creates a profile/trace buffer and assoc. zones for storing
 * profiled items.
 *****************************************************************************
 */

prof_data_t
pbuf_alloc(void)
{
        register prof_data_t pbuf;
        register int i;
        register natural_t *zone;

        pbuf = (prof_data_t)kalloc(sizeof(struct prof_data));
        if (!pbuf)
                return(NULLPROFDATA);
        pbuf->prof_port = MACH_PORT_NULL;
        for (i=0; i< NB_PROF_BUFFER; i++) {
                zone = (natural_t *)kalloc(SIZE_PROF_BUFFER*sizeof(natural_t));
                if (!zone) {
                        i--;
                        while (i--)
                                kfree((vm_offset_t)pbuf->prof_area[i].p_zone,
                                      SIZE_PROF_BUFFER*sizeof(natural_t));
                        kfree((vm_offset_t)pbuf, sizeof(struct prof_data));
                        return(NULLPROFDATA);
                }
                pbuf->prof_area[i].p_zone = zone;
                pbuf->prof_area[i].p_full = FALSE;
        }
        pbuf->prof_port = MACH_PORT_NULL;
        return(pbuf);
}

/*
 *****************************************************************************
 * pbuf_free free memory allocated for storing profile/trace items. Called
 * when a task is no longer profiled/traced. Pbuf_free tears down the memory
 * alloced in pbuf_alloc. It does not check to see if the structures are valid
 * since it is only called by functions in this file.
 *****************************************************************************
 */
void
pbuf_free(
        prof_data_t     pbuf)
{
        register int i;

        if (pbuf->prof_port)
                ipc_port_release_send(pbuf->prof_port);
        
        for(i=0; i < NB_PROF_BUFFER ; i++)
                kfree((vm_offset_t)pbuf->prof_area[i].p_zone,
                      SIZE_PROF_BUFFER*sizeof(natural_t));
        kfree((vm_offset_t)pbuf, sizeof(struct prof_data));
}

#endif /* MACH_PROF */

/*
 *****************************************************************************
 * Thread_sample is used by MACH_PROF to profile a single thread, and is only
 * stub in DCI.
 *****************************************************************************
 */

kern_return_t
thread_sample(
        thread_act_t    thr_act,
        ipc_port_t      reply)
{
    /* 
     * This routine is called every time that a new thread has made
     * a request for the sampling service. We must keep track of the 
     * correspondance between its identity (thread) and the port
     * we are going to use as a reply port to send out the samples resulting 
     * from its execution. 
     */
#if !MACH_PROF
    return KERN_FAILURE;
#else 
    prof_data_t     pbuf;
    vm_offset_t     vmpbuf;

    if (reply != MACH_PORT_NULL) {
        if (thr_act->act_profiled)      /* yuck! */
                return KERN_INVALID_ARGUMENT;
        /* Start profiling this activation, do the initialization. */
        pbuf = pbuf_alloc();
        if ((thr_act->profil_buffer = pbuf) == NULLPROFDATA) {
            printf("thread_sample: cannot allocate pbuf\n");
            return KERN_RESOURCE_SHORTAGE;
        } 
        else {
            if (!set_pbuf_nb(pbuf, NB_PROF_BUFFER-1)) {
                printf("mach_sample_thread: cannot set pbuf_nb\n");
                return KERN_FAILURE;
            }
            reset_pbuf_area(pbuf);
        }
        pbuf->prof_port = reply;
        thr_act->act_profiled = TRUE;
        thr_act->act_profiled_own = TRUE;
        if (profile_thread_id == THREAD_NULL)
            profile_thread_id = kernel_thread(kernel_task, profile_thread);
    } else {
        if (!thr_act->act_profiled)
                return(KERN_INVALID_ARGUMENT);

        thr_act->act_profiled = FALSE;
        /* do not stop sampling if thread is not profiled by its own */

        if (!thr_act->act_profiled_own)
            return KERN_SUCCESS;
        else
            thr_act->act_profiled_own = FALSE;

        send_last_sample_buf(thr_act->profil_buffer);
        pbuf_free(thr_act->profil_buffer);
        thr_act->profil_buffer = NULLPROFDATA;
    }
    return KERN_SUCCESS;
#endif /* MACH_PROF */
}

/*
 *****************************************************************************
 * Task_sample is used to profile/trace tasks - all thread within a task using
 * a common profile buffer to collect items generated by the hertz_tick. For
 * each task profiled a profile buffer is created that associates a reply port
 * (used to send the data to a server thread), task (used for throttling), and
 * a zone area (used to store profiled/traced items).
 *****************************************************************************
 */

kern_return_t
task_sample(
        task_t          task,
        ipc_port_t      reply)
{
#if !MACH_PROF
    return KERN_FAILURE;
#else
    prof_data_t     pbuf=task->profil_buffer;
    vm_offset_t     vmpbuf;
    boolean_t       turnon = (reply != MACH_PORT_NULL);

    if (task == TASK_NULL)
            return KERN_INVALID_ARGUMENT;
    if (turnon)                 /* Do we want to profile this task? */
    {
        pbuf = pbuf_alloc();    /* allocate a profile buffer */
        task_lock(task);
        if (task->task_profiled) { /* if it is already profiled return so */
                task_unlock(task);
                if (pbuf != NULLPROFDATA)
                    pbuf_free(pbuf);
                return(KERN_INVALID_ARGUMENT);
        }
        if (pbuf == NULLPROFDATA) {
            task_unlock(task);
            return KERN_RESOURCE_SHORTAGE; /* can't allocate a buffer, quit */
        }
        task->profil_buffer = pbuf;
        
        if (!set_pbuf_nb(pbuf, NB_PROF_BUFFER-1)) {
            pbuf_free(pbuf);
            task_unlock(task);
            return KERN_FAILURE;
        }
        reset_pbuf_area(pbuf);
        pbuf->prof_port = reply; /* assoc. buffer with reply port */
    } else {                    /* We want to stop profiling/tracing */
        task_lock(task);
        if (!task->task_profiled) { /* but this task is not being profiled */
            task_unlock(task);
            return(KERN_INVALID_ARGUMENT);
        }
    }

    /*
     * turnon = FALSE && task_profile = TRUE ||
     * turnon = TRUE  && task_profile = FALSE
     */

    if (turnon != task->task_profiled) {
        int actual, i;
        thread_act_t thr_act;

        if (turnon && profile_thread_id == THREAD_NULL) /* 1st time thru? */
            profile_thread_id = /* then start profile thread. */
                kernel_thread(kernel_task, profile_thread);
        task->task_profiled = turnon;  
        actual = task->thr_act_count; 
        for (i = 0, thr_act = (thread_act_t)queue_first(&task->thr_acts);
             i < actual;
             i++, thr_act = (thread_act_t)queue_next(&thr_act->thr_acts)) {
                  if (!thr_act->act_profiled_own) {
                    thr_act->act_profiled = turnon;
                    if (turnon) {
                        thr_act->profil_buffer = task->profil_buffer;
                        thr_act->act_profiled = TRUE;
                    } else {
                        thr_act->act_profiled = FALSE;
                        thr_act->profil_buffer = NULLPROFDATA;
                    }
                  }
        }
        if (!turnon) {          /* drain buffers and clean-up */
            send_last_sample_buf(task->profil_buffer);
            pbuf_free(task->profil_buffer);
            task->profil_buffer = NULLPROFDATA;
        }
    }

    task_unlock(task);
    return KERN_SUCCESS;
#endif /* MACH_PROF */
}