ctf/cvt/ctfmerge.c

	ctfmerge.c revision ae115bc77f6fcde83175c75b4206dc2e50747966
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Given several files containing CTF data, merge and uniquify that data into
 * a single CTF section in an output file.
 *
 * Merges can proceed independently.  As such, we perform the merges in parallel
 * using a worker thread model.  A given glob of CTF data (either all of the CTF
 * data from a single input file, or the result of one or more merges) can only
 * be involved in a single merge at any given time, so the process decreases in
 * parallelism, especially towards the end, as more and more files are
 * consolidated, finally resulting in a single merge of two large CTF graphs.
 * Unfortunately, the last merge is also the slowest, as the two graphs being
 * merged are each the product of merges of half of the input files.
 *
 * The algorithm consists of two phases, described in detail below.  The first
 * phase entails the merging of CTF data in groups of eight.  The second phase
 * takes the results of Phase I, and merges them two at a time.  This disparity
 * is due to an observation that the merge time increases at least quadratically
 * with the size of the CTF data being merged.  As such, merges of CTF graphs
 * newly read from input files are much faster than merges of CTF graphs that
 * are themselves the results of prior merges.
 *
 * A further complication is the need to ensure the repeatability of CTF merges.
 * That is, a merge should produce the same output every time, given the same
 * input.  In both phases, this consistency requirement is met by imposing an
 * ordering on the merge process, thus ensuring that a given set of input files
 * are merged in the same order every time.
 *
 *   Phase I
 *
 *   The main thread reads the input files one by one, transforming the CTF
 *   data they contain into tdata structures.  When a given file has been read
 *   and parsed, it is placed on the work queue for retrieval by worker threads.
 *
 *   Central to Phase I is the Work In Progress (wip) array, which is used to
 *   merge batches of files in a predictable order.  Files are read by the main
 *   thread, and are merged into wip array elements in round-robin order.  When
 *   the number of files merged into a given array slot equals the batch size,
 *   the merged CTF graph in that array is added to the done slot in order by
 *   array slot.
 *
 *   For example, consider a case where we have five input files, a batch size
 *   of two, a wip array size of two, and two worker threads (T1 and T2).
 *
 *    1. The wip array elements are assigned initial batch numbers 0 and 1.
 *    2. T1 reads an input file from the input queue (wq_queue).  This is the
 *       first input file, so it is placed into wip[0].  The second file is
 *       similarly read and placed into wip[1].  The wip array slots now contain
 *       one file each (wip_nmerged == 1).
 *    3. T1 reads the third input file, which it merges into wip[0].  The
 *       number of files in wip[0] is equal to the batch size.
 *    4. T2 reads the fourth input file, which it merges into wip[1].  wip[1]
 *       is now full too.
 *    5. T2 attempts to place the contents of wip[1] on the done queue
 *       (wq_done_queue), but it can't, since the batch ID for wip[1] is 1.
 *       Batch 0 needs to be on the done queue before batch 1 can be added, so
 *       T2 blocks on wip[1]'s cv.
 *    6. T1 attempts to place the contents of wip[0] on the done queue, and
 *       succeeds, updating wq_lastdonebatch to 0.  It clears wip[0], and sets
 *       its batch ID to 2.  T1 then signals wip[1]'s cv to awaken T2.
 *    7. T2 wakes up, notices that wq_lastdonebatch is 0, which means that
 *       batch 1 can now be added.  It adds wip[1] to the done queue, clears
 *       wip[1], and sets its batch ID to 3.  It signals wip[0]'s cv, and
 *       restarts.
 *
 *   The above process continues until all input files have been consumed.  At
 *   this point, a pair of barriers are used to allow a single thread to move
 *   any partial batches from the wip array to the done array in batch ID order.
 *   When this is complete, wq_done_queue is moved to wq_queue, and Phase II
 *   begins.
 *
 *  Locking Semantics (Phase I)
 *
 *  The input queue (wq_queue) and the done queue (wq_done_queue) are
 *  protected by separate mutexes - wq_queue_lock and wq_done_queue.  wip
 *  array slots are protected by their own mutexes, which must be grabbed
 *  before releasing the input queue lock.  The wip array lock is dropped
 *  when the thread restarts the loop.  If the array slot was full, the
 *  array lock will be held while the slot contents are added to the done
 *  queue.  The done queue lock is used to protect the wip slot cv's.
 *
 *  The pow number is protected by the queue lock.  The master batch ID
 *  and last completed batch (wq_lastdonebatch) counters are protected *in
 *  Phase I* by the done queue lock.
 *
 *   Phase II
 *
 *   When Phase II begins, the queue consists of the merged batches from the
 *   first phase.  Assume we have five batches:
 *
 *  Q:  a b c d e
 *
 *   Using the same batch ID mechanism we used in Phase I, but without the wip
 *   array, worker threads remove two entries at a time from the beginning of
 *   the queue.  These two entries are merged, and are added back to the tail
 *   of the queue, as follows:
 *
 *  Q:  a b c d e   # start
 *  Q:  c d e ab    # a, b removed, merged, added to end
 *  Q:  e ab cd     # c, d removed, merged, added to end
 *  Q:  cd eab      # e, ab removed, merged, added to end
 *  Q:  cdeab       # cd, eab removed, merged, added to end
 *
 *   When one entry remains on the queue, with no merges outstanding, Phase II
 *   finishes.  We pre-determine the stopping point by pre-calculating the
 *   number of nodes that will appear on the list.  In the example above, the
 *   number (wq_ninqueue) is 9.  When ninqueue is 1, we conclude Phase II by
 *   signaling the main thread via wq_done_cv.
 *
 *  Locking Semantics (Phase II)
 *
 *  The queue (wq_queue), ninqueue, and the master batch ID and last
 *  completed batch counters are protected by wq_queue_lock.  The done
 *  queue and corresponding lock are unused in Phase II as is the wip array.
 *
 *   Uniquification
 *
 *   We want the CTF data that goes into a given module to be as small as
 *   possible.  For example, we don't want it to contain any type data that may
 *   be present in another common module.  As such, after creating the master
 *   tdata_t for a given module, we can, if requested by the user, uniquify it
 *   against the tdata_t from another module (genunix in the case of the SunOS
 *   kernel).  We perform a merge between the tdata_t for this module and the
 *   tdata_t from genunix.  Nodes found in this module that are not present in
 *   genunix are added to a third tdata_t - the uniquified tdata_t.
 *
 *   Additive Merges
 *
 *   In some cases, for example if we are issuing a new version of a common
 *   module in a patch, we need to make sure that the CTF data already present
 *   in that module does not change.  Changes to this data would void the CTF
 *   data in any module that uniquified against the common module.  To preserve
 *   the existing data, we can perform what is known as an additive merge.  In
 *   this case, a final uniquification is performed against the CTF data in the
 *   previous version of the module.  The result will be the placement of new
 *   and changed data after the existing data, thus preserving the existing type
 *   ID space.
 *
 *   Saving the result
 *
 *   When the merges are complete, the resulting tdata_t is placed into the
 *   output file, replacing the .SUNW_ctf section (if any) already in that file.
 *
 * The person who changes the merging thread code in this file without updating
 * this comment will not live to see the stock hit five.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <assert.h>
#include <synch.h>
#include <signal.h>
#include <libgen.h>
#include <string.h>
#include <errno.h>
#include <alloca.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/sysconf.h>

#include "ctf_headers.h"
#include "ctftools.h"
#include "ctfmerge.h"
#include "traverse.h"
#include "memory.h"
#include "fifo.h"
#include "barrier.h"

#pragma init(bigheap)

#define MERGE_PHASE1_BATCH_SIZE     8
#define MERGE_PHASE1_MAX_SLOTS      5
#define MERGE_INPUT_THROTTLE_LEN    10

const char *progname;
static char *outfile = NULL;
static char *tmpname = NULL;
static int dynsym;
int debug_level = DEBUG_LEVEL;

void
usage(void)
{
    (void) fprintf(stderr,
        "Usage: %s [-fgstv] -l label | -L labelenv -o outfile file ...\n"
        "       %s [-fgstv] -l label | -L labelenv -o outfile -d uniqfile\n"
        "       %*s [-g] [-D uniqlabel] file ...\n"
        "       %s [-fgstv] -l label | -L labelenv -o outfile -w withfile "
        "file ...\n"
        "       %s [-g] -c srcfile destfile\n"
        "\n"
        "  Note: if -L labelenv is specified and labelenv is not set in\n"
        "  the environment, a default value is used.\n",
        progname, progname, strlen(progname), " ",
        progname, progname);
}

static void
bigheap(void)
{
    size_t big, *size;
    int sizes, i;
    struct memcntl_mha mha;

    /*
     * First, get the available pagesizes.
     */
    if ((sizes = getpagesizes(NULL, 0)) == -1)
        return;

    if ((size = alloca(sizeof (size_t) * sizes)) == NULL)
        return;

    if (getpagesizes(size, sizes) == -1 || sizes == 1)
        return;

    big = size[sizes - 1];
    if (big & (big - 1)) {
        /*
         * The largest page size is not a power of two for some
         * inexplicable reason; return.
         */
        return;
    }

    /*
     * Now, align our break to the largest page size.
     */
    if (brk((void *)((((uintptr_t)sbrk(0) - 1) & ~(big - 1)) + big)) != 0)
        return;

    /*
     * Finally, set our heap to use the largest page size for which the
     * MC_HAT_ADVISE doesn't return EAGAIN.
     */
    mha.mha_cmd = MHA_MAPSIZE_BSSBRK;
    mha.mha_flags = 0;

    for (i = sizes - 1; i >= 0; i--) {
        mha.mha_pagesize = size[i];

        if (memcntl(NULL, 0, MC_HAT_ADVISE, (caddr_t)&mha, 0, 0) != -1)
            break;

        if (errno != EAGAIN)
            break;
    }
}

static void
finalize_phase_one(workqueue_t *wq)
{
    int startslot, i;

    /*
     * wip slots are cleared out only when maxbatchsz td's have been merged
     * into them.  We're not guaranteed that the number of files we're
     * merging is a multiple of maxbatchsz, so there will be some partial
     * groups in the wip array.  Move them to the done queue in batch ID
     * order, starting with the slot containing the next batch that would
     * have been placed on the done queue, followed by the others.
     * One thread will be doing this while the others wait at the barrier
     * back in worker_thread(), so we don't need to worry about pesky things
     * like locks.
     */

    for (startslot = -1, i = 0; i < wq->wq_nwipslots; i++) {
        if (wq->wq_wip[i].wip_batchid == wq->wq_lastdonebatch + 1) {
            startslot = i;
            break;
        }
    }

    assert(startslot != -1);

    for (i = startslot; i < startslot + wq->wq_nwipslots; i++) {
        int slotnum = i % wq->wq_nwipslots;
        wip_t *wipslot = &wq->wq_wip[slotnum];

        if (wipslot->wip_td != NULL) {
            debug(2, "clearing slot %d (%d) (saving %d)\n",
                slotnum, i, wipslot->wip_nmerged);
        } else
            debug(2, "clearing slot %d (%d)\n", slotnum, i);

        if (wipslot->wip_td != NULL) {
            fifo_add(wq->wq_donequeue, wipslot->wip_td);
            wq->wq_wip[slotnum].wip_td = NULL;
        }
    }

    wq->wq_lastdonebatch = wq->wq_next_batchid++;

    debug(2, "phase one done: donequeue has %d items\n",
        fifo_len(wq->wq_donequeue));
}

static void
init_phase_two(workqueue_t *wq)
{
    int num;

    /*
     * We're going to continually merge the first two entries on the queue,
     * placing the result on the end, until there's nothing left to merge.
     * At that point, everything will have been merged into one.  The
     * initial value of ninqueue needs to be equal to the total number of
     * entries that will show up on the queue, both at the start of the
     * phase and as generated by merges during the phase.
     */
    wq->wq_ninqueue = num = fifo_len(wq->wq_donequeue);
    while (num != 1) {
        wq->wq_ninqueue += num / 2;
        num = num / 2 + num % 2;
    }

    /*
     * Move the done queue to the work queue.  We won't be using the done
     * queue in phase 2.
     */
    assert(fifo_len(wq->wq_queue) == 0);
    fifo_free(wq->wq_queue, NULL);
    wq->wq_queue = wq->wq_donequeue;
}

static void
wip_save_work(workqueue_t *wq, wip_t *slot, int slotnum)
{
    pthread_mutex_lock(&wq->wq_donequeue_lock);

    while (wq->wq_lastdonebatch + 1 < slot->wip_batchid)
        pthread_cond_wait(&slot->wip_cv, &wq->wq_donequeue_lock);
    assert(wq->wq_lastdonebatch + 1 == slot->wip_batchid);

    fifo_add(wq->wq_donequeue, slot->wip_td);
    wq->wq_lastdonebatch++;
    pthread_cond_signal(&wq->wq_wip[(slotnum + 1) %
        wq->wq_nwipslots].wip_cv);

    /* reset the slot for next use */
    slot->wip_td = NULL;
    slot->wip_batchid = wq->wq_next_batchid++;

    pthread_mutex_unlock(&wq->wq_donequeue_lock);
}

static void
wip_add_work(wip_t *slot, tdata_t *pow)
{
    if (slot->wip_td == NULL) {
        slot->wip_td = pow;
        slot->wip_nmerged = 1;
    } else {
        debug(2, "%d: merging %p into %p\n", pthread_self(),
            (void *)pow, (void *)slot->wip_td);

        merge_into_master(pow, slot->wip_td, NULL, 0);
        tdata_free(pow);

        slot->wip_nmerged++;
    }
}

static void
worker_runphase1(workqueue_t *wq)
{
    wip_t *wipslot;
    tdata_t *pow;
    int wipslotnum, pownum;

    for (;;) {
        pthread_mutex_lock(&wq->wq_queue_lock);

        while (fifo_empty(wq->wq_queue)) {
            if (wq->wq_nomorefiles == 1) {
                pthread_cond_broadcast(&wq->wq_work_avail);
                pthread_mutex_unlock(&wq->wq_queue_lock);

                /* on to phase 2 ... */
                return;
            }

            pthread_cond_wait(&wq->wq_work_avail,
                &wq->wq_queue_lock);
        }

        /* there's work to be done! */
        pow = fifo_remove(wq->wq_queue);
        pownum = wq->wq_nextpownum++;
        pthread_cond_broadcast(&wq->wq_work_removed);

        assert(pow != NULL);

        /* merge it into the right slot */
        wipslotnum = pownum % wq->wq_nwipslots;
        wipslot = &wq->wq_wip[wipslotnum];

        pthread_mutex_lock(&wipslot->wip_lock);

        pthread_mutex_unlock(&wq->wq_queue_lock);

        wip_add_work(wipslot, pow);

        if (wipslot->wip_nmerged == wq->wq_maxbatchsz)
            wip_save_work(wq, wipslot, wipslotnum);

        pthread_mutex_unlock(&wipslot->wip_lock);
    }
}

static void
worker_runphase2(workqueue_t *wq)
{
    tdata_t *pow1, *pow2;
    int batchid;

    for (;;) {
        pthread_mutex_lock(&wq->wq_queue_lock);

        if (wq->wq_ninqueue == 1) {
            pthread_cond_broadcast(&wq->wq_work_avail);
            pthread_mutex_unlock(&wq->wq_queue_lock);

            debug(2, "%d: entering p2 completion barrier\n",
                pthread_self());
            if (barrier_wait(&wq->wq_bar1)) {
                pthread_mutex_lock(&wq->wq_queue_lock);
                wq->wq_alldone = 1;
                pthread_cond_signal(&wq->wq_alldone_cv);
                pthread_mutex_unlock(&wq->wq_queue_lock);
            }

            return;
        }

        if (fifo_len(wq->wq_queue) < 2) {
            pthread_cond_wait(&wq->wq_work_avail,
                &wq->wq_queue_lock);
            pthread_mutex_unlock(&wq->wq_queue_lock);
            continue;
        }

        /* there's work to be done! */
        pow1 = fifo_remove(wq->wq_queue);
        pow2 = fifo_remove(wq->wq_queue);
        wq->wq_ninqueue -= 2;

        batchid = wq->wq_next_batchid++;

        pthread_mutex_unlock(&wq->wq_queue_lock);

        debug(2, "%d: merging %p into %p\n", pthread_self(),
            (void *)pow1, (void *)pow2);
        merge_into_master(pow1, pow2, NULL, 0);
        tdata_free(pow1);

        /*
         * merging is complete.  place at the tail of the queue in
         * proper order.
         */
        pthread_mutex_lock(&wq->wq_queue_lock);
        while (wq->wq_lastdonebatch + 1 != batchid) {
            pthread_cond_wait(&wq->wq_done_cv,
                &wq->wq_queue_lock);
        }

        wq->wq_lastdonebatch = batchid;

        fifo_add(wq->wq_queue, pow2);
        debug(2, "%d: added %p to queue, len now %d, ninqueue %d\n",
            pthread_self(), (void *)pow2, fifo_len(wq->wq_queue),
            wq->wq_ninqueue);
        pthread_cond_broadcast(&wq->wq_done_cv);
        pthread_cond_signal(&wq->wq_work_avail);
        pthread_mutex_unlock(&wq->wq_queue_lock);
    }
}

/*
 * Main loop for worker threads.
 */
static void
worker_thread(workqueue_t *wq)
{
    worker_runphase1(wq);

    debug(2, "%d: entering first barrier\n", pthread_self());

    if (barrier_wait(&wq->wq_bar1)) {

        debug(2, "%d: doing work in first barrier\n", pthread_self());

        finalize_phase_one(wq);

        init_phase_two(wq);

        debug(2, "%d: ninqueue is %d, %d on queue\n", pthread_self(),
            wq->wq_ninqueue, fifo_len(wq->wq_queue));
    }

    debug(2, "%d: entering second barrier\n", pthread_self());

    (void) barrier_wait(&wq->wq_bar2);

    debug(2, "%d: phase 1 complete\n", pthread_self());

    worker_runphase2(wq);
}

/*
 * Pass a tdata_t tree, built from an input file, off to the work queue for
 * consumption by worker threads.
 */
static int
merge_ctf_cb(tdata_t *td, char *name, void *arg)
{
    workqueue_t *wq = arg;

    debug(3, "Adding tdata %p for processing\n", (void *)td);

    pthread_mutex_lock(&wq->wq_queue_lock);
    while (fifo_len(wq->wq_queue) > wq->wq_ithrottle) {
        debug(2, "Throttling input (len = %d, throttle = %d)\n",
            fifo_len(wq->wq_queue), wq->wq_ithrottle);
        pthread_cond_wait(&wq->wq_work_removed, &wq->wq_queue_lock);
    }

    fifo_add(wq->wq_queue, td);
    debug(1, "Thread %d announcing %s\n", pthread_self(), name);
    pthread_cond_broadcast(&wq->wq_work_avail);
    pthread_mutex_unlock(&wq->wq_queue_lock);

    return (1);
}

/*
 * This program is intended to be invoked from a Makefile, as part of the build.
 * As such, in the event of a failure or user-initiated interrupt (^C), we need
 * to ensure that a subsequent re-make will cause ctfmerge to be executed again.
 * Unfortunately, ctfmerge will usually be invoked directly after (and as part
 * of the same Makefile rule as) a link, and will operate on the linked file
 * in place.  If we merely exit upon receipt of a SIGINT, a subsequent make
 * will notice that the *linked* file is newer than the object files, and thus
 * will not reinvoke ctfmerge.  The only way to ensure that a subsequent make
 * reinvokes ctfmerge, is to remove the file to which we are adding CTF
 * data (confusingly named the output file).  This means that the link will need
 * to happen again, but links are generally fast, and we can't allow the merge
 * to be skipped.
 *
 * Another possibility would be to block SIGINT entirely - to always run to
 * completion.  The run time of ctfmerge can, however, be measured in minutes
 * in some cases, so this is not a valid option.
 */
static void
handle_sig(int sig)
{
    terminate("Caught signal %d - exiting\n", sig);
}

static void
terminate_cleanup(void)
{
    int dounlink = getenv("CTFMERGE_TERMINATE_NO_UNLINK") ? 0 : 1;

    if (tmpname != NULL && dounlink)
        unlink(tmpname);

    if (outfile == NULL)
        return;

    if (dounlink) {
        fprintf(stderr, "Removing %s\n", outfile);
        unlink(outfile);
    }
}

static void
copy_ctf_data(char *srcfile, char *destfile, int keep_stabs)
{
    tdata_t *srctd;

    if (read_ctf(&srcfile, 1, NULL, read_ctf_save_cb, &srctd, 1) == 0)
        terminate("No CTF data found in source file %s\n", srcfile);

    tmpname = mktmpname(destfile, ".ctf");
    write_ctf(srctd, destfile, tmpname, CTF_COMPRESS | keep_stabs);
    if (rename(tmpname, destfile) != 0) {
        terminate("Couldn't rename temp file %s to %s", tmpname,
            destfile);
    }
    free(tmpname);
    tdata_free(srctd);
}

static void
wq_init(workqueue_t *wq, int nfiles)
{
    int throttle, nslots, i;

    if (getenv("CTFMERGE_MAX_SLOTS"))
        nslots = atoi(getenv("CTFMERGE_MAX_SLOTS"));
    else
        nslots = MERGE_PHASE1_MAX_SLOTS;

    if (getenv("CTFMERGE_PHASE1_BATCH_SIZE"))
        wq->wq_maxbatchsz = atoi(getenv("CTFMERGE_PHASE1_BATCH_SIZE"));
    else
        wq->wq_maxbatchsz = MERGE_PHASE1_BATCH_SIZE;

    nslots = MIN(nslots, (nfiles + wq->wq_maxbatchsz - 1) /
        wq->wq_maxbatchsz);

    wq->wq_wip = xcalloc(sizeof (wip_t) * nslots);
    wq->wq_nwipslots = nslots;
    wq->wq_nthreads = MIN(sysconf(_SC_NPROCESSORS_ONLN) * 3 / 2, nslots);

    if (getenv("CTFMERGE_INPUT_THROTTLE"))
        throttle = atoi(getenv("CTFMERGE_INPUT_THROTTLE"));
    else
        throttle = MERGE_INPUT_THROTTLE_LEN;
    wq->wq_ithrottle = throttle * wq->wq_nthreads;

    debug(1, "Using %d slots, %d threads\n", wq->wq_nwipslots,
        wq->wq_nthreads);

    wq->wq_next_batchid = 0;

    for (i = 0; i < nslots; i++) {
        pthread_mutex_init(&wq->wq_wip[i].wip_lock, NULL);
        wq->wq_wip[i].wip_batchid = wq->wq_next_batchid++;
    }

    pthread_mutex_init(&wq->wq_queue_lock, NULL);
    wq->wq_queue = fifo_new();
    pthread_cond_init(&wq->wq_work_avail, NULL);
    pthread_cond_init(&wq->wq_work_removed, NULL);
    wq->wq_ninqueue = nfiles;
    wq->wq_nextpownum = 0;

    pthread_mutex_init(&wq->wq_donequeue_lock, NULL);
    wq->wq_donequeue = fifo_new();
    wq->wq_lastdonebatch = -1;

    pthread_cond_init(&wq->wq_done_cv, NULL);

    pthread_cond_init(&wq->wq_alldone_cv, NULL);
    wq->wq_alldone = 0;

    barrier_init(&wq->wq_bar1, wq->wq_nthreads);
    barrier_init(&wq->wq_bar2, wq->wq_nthreads);

    wq->wq_nomorefiles = 0;
}

static void
start_threads(workqueue_t *wq)
{
    pthread_t thrid;
    sigset_t sets;
    int i;

    sigemptyset(&sets);
    sigaddset(&sets, SIGINT);
    sigaddset(&sets, SIGQUIT);
    sigaddset(&sets, SIGTERM);
    pthread_sigmask(SIG_BLOCK, &sets, NULL);

    for (i = 0; i < wq->wq_nthreads; i++) {
        pthread_create(&thrid, NULL, (void *(*)(void *))worker_thread,
            wq);
    }

    sigset(SIGINT, handle_sig);
    sigset(SIGQUIT, handle_sig);
    sigset(SIGTERM, handle_sig);
    pthread_sigmask(SIG_UNBLOCK, &sets, NULL);
}

static int
strcompare(const void *p1, const void *p2)
{
    char *s1 = *((char **)p1);
    char *s2 = *((char **)p2);

    return (strcmp(s1, s2));
}

int
main(int argc, char **argv)
{
    workqueue_t wq;
    tdata_t *mstrtd, *savetd;
    char *uniqfile = NULL, *uniqlabel = NULL;
    char *withfile = NULL;
    char *label = NULL;
    char **ifiles, **tifiles;
    int verbose = 0, docopy = 0;
    int write_fuzzy_match = 0;
    int keep_stabs = 0;
    int require_ctf = 0;
    int nifiles, nielems;
    int c, i, idx, tidx, err;

    progname = basename(argv[0]);

    if (getenv("CTFMERGE_DEBUG_LEVEL"))
        debug_level = atoi(getenv("CTFMERGE_DEBUG_LEVEL"));

    err = 0;
    while ((c = getopt(argc, argv, ":cd:D:fgl:L:o:tvw:s")) != EOF) {
        switch (c) {
        case 'c':
            docopy = 1;
            break;
        case 'd':
            /* Uniquify against `uniqfile' */
            uniqfile = optarg;
            break;
        case 'D':
            /* Uniquify against label `uniqlabel' in `uniqfile' */
            uniqlabel = optarg;
            break;
        case 'f':
            write_fuzzy_match = CTF_FUZZY_MATCH;
            break;
        case 'g':
            keep_stabs = CTF_KEEP_STABS;
            break;
        case 'l':
            /* Label merged types with `label' */
            label = optarg;
            break;
        case 'L':
            /* Label merged types with getenv(`label`) */
            if ((label = getenv(optarg)) == NULL)
                label = CTF_DEFAULT_LABEL;
            break;
        case 'o':
            /* Place merged types in CTF section in `outfile' */
            outfile = optarg;
            break;
        case 't':
            /* Insist *all* object files built from C have CTF */
            require_ctf = 1;
            break;
        case 'v':
            /* More debugging information */
            verbose = 1;
            break;
        case 'w':
            /* Additive merge with data from `withfile' */
            withfile = optarg;
            break;
        case 's':
            /* use the dynsym rather than the symtab */
            dynsym = CTF_USE_DYNSYM;
            break;
        default:
            usage();
            exit(2);
        }
    }

    /* Validate arguments */
    if (docopy) {
        if (uniqfile != NULL || uniqlabel != NULL || label != NULL ||
            outfile != NULL || withfile != NULL || dynsym != 0)
            err++;

        if (argc - optind != 2)
            err++;
    } else {
        if (uniqfile != NULL && withfile != NULL)
            err++;

        if (uniqlabel != NULL && uniqfile == NULL)
            err++;

        if (outfile == NULL || label == NULL)
            err++;

        if (argc - optind == 0)
            err++;
    }

    if (err) {
        usage();
        exit(2);
    }

    if (getenv("STRIPSTABS_KEEP_STABS") != NULL)
        keep_stabs = CTF_KEEP_STABS;

    if (uniqfile && access(uniqfile, R_OK) != 0) {
        warning("Uniquification file %s couldn't be opened and "
            "will be ignored.\n", uniqfile);
        uniqfile = NULL;
    }
    if (withfile && access(withfile, R_OK) != 0) {
        warning("With file %s couldn't be opened and will be "
            "ignored.\n", withfile);
        withfile = NULL;
    }
    if (outfile && access(outfile, R_OK|W_OK) != 0)
        terminate("Cannot open output file %s for r/w", outfile);

    /*
     * This is ugly, but we don't want to have to have a separate tool
     * (yet) just for copying an ELF section with our specific requirements,
     * so we shoe-horn a copier into ctfmerge.
     */
    if (docopy) {
        copy_ctf_data(argv[optind], argv[optind + 1], keep_stabs);

        exit(0);
    }

    set_terminate_cleanup(terminate_cleanup);

    /* Sort the input files and strip out duplicates */
    nifiles = argc - optind;
    ifiles = xmalloc(sizeof (char *) * nifiles);
    tifiles = xmalloc(sizeof (char *) * nifiles);

    for (i = 0; i < nifiles; i++)
        tifiles[i] = argv[optind + i];
    qsort(tifiles, nifiles, sizeof (char *), (int (*)())strcompare);

    ifiles[0] = tifiles[0];
    for (idx = 0, tidx = 1; tidx < nifiles; tidx++) {
        if (strcmp(ifiles[idx], tifiles[tidx]) != 0)
            ifiles[++idx] = tifiles[tidx];
    }
    nifiles = idx + 1;

    /* Make sure they all exist */
    if ((nielems = count_files(ifiles, nifiles)) < 0)
        terminate("Some input files were inaccessible\n");

    /* Prepare for the merge */
    wq_init(&wq, nielems);

    start_threads(&wq);

    /*
     * Start the merge
     *
     * We're reading everything from each of the object files, so we
     * don't need to specify labels.
     */
    if (read_ctf(ifiles, nifiles, NULL, merge_ctf_cb,
        &wq, require_ctf) == 0) {
        /*
         * If we're verifying that C files have CTF, it's safe to
         * assume that in this case, we're building only from assembly
         * inputs.
         */
        if (require_ctf)
            exit(0);
        terminate("No ctf sections found to merge\n");
    }

    pthread_mutex_lock(&wq.wq_queue_lock);
    wq.wq_nomorefiles = 1;
    pthread_cond_broadcast(&wq.wq_work_avail);
    pthread_mutex_unlock(&wq.wq_queue_lock);

    pthread_mutex_lock(&wq.wq_queue_lock);
    while (wq.wq_alldone == 0)
        pthread_cond_wait(&wq.wq_alldone_cv, &wq.wq_queue_lock);
    pthread_mutex_unlock(&wq.wq_queue_lock);

    /*
     * All requested files have been merged, with the resulting tree in
     * mstrtd.  savetd is the tree that will be placed into the output file.
     *
     * Regardless of whether we're doing a normal uniquification or an
     * additive merge, we need a type tree that has been uniquified
     * against uniqfile or withfile, as appropriate.
     *
     * If we're doing a uniquification, we stuff the resulting tree into
     * outfile.  Otherwise, we add the tree to the tree already in withfile.
     */
    assert(fifo_len(wq.wq_queue) == 1);
    mstrtd = fifo_remove(wq.wq_queue);

    if (verbose || debug_level) {
        debug(2, "Statistics for td %p\n", (void *)mstrtd);

        iidesc_stats(mstrtd->td_iihash);
    }

    if (uniqfile != NULL || withfile != NULL) {
        char *reffile, *reflabel = NULL;
        tdata_t *reftd;

        if (uniqfile != NULL) {
            reffile = uniqfile;
            reflabel = uniqlabel;
        } else
            reffile = withfile;

        if (read_ctf(&reffile, 1, reflabel, read_ctf_save_cb,
            &reftd, require_ctf) == 0) {
            terminate("No CTF data found in reference file %s\n",
                reffile);
        }

        savetd = tdata_new();

        if (CTF_TYPE_ISCHILD(reftd->td_nextid))
            terminate("No room for additional types in master\n");

        savetd->td_nextid = withfile ? reftd->td_nextid :
            CTF_INDEX_TO_TYPE(1, TRUE);
        merge_into_master(mstrtd, reftd, savetd, 0);

        tdata_label_add(savetd, label, CTF_LABEL_LASTIDX);

        if (withfile) {
            /*
             * savetd holds the new data to be added to the withfile
             */
            tdata_t *withtd = reftd;

            tdata_merge(withtd, savetd);

            savetd = withtd;
        } else {
            char uniqname[MAXPATHLEN];
            labelent_t *parle;

            parle = tdata_label_top(reftd);

            savetd->td_parlabel = xstrdup(parle->le_name);

            strncpy(uniqname, reffile, sizeof (uniqname));
            uniqname[MAXPATHLEN - 1] = '\0';
            savetd->td_parname = xstrdup(basename(uniqname));
        }

    } else {
        /*
         * No post processing.  Write the merged tree as-is into the
         * output file.
         */
        tdata_label_free(mstrtd);
        tdata_label_add(mstrtd, label, CTF_LABEL_LASTIDX);

        savetd = mstrtd;
    }

    tmpname = mktmpname(outfile, ".ctf");
    write_ctf(savetd, outfile, tmpname,
        CTF_COMPRESS | write_fuzzy_match | dynsym | keep_stabs);
    if (rename(tmpname, outfile) != 0)
        terminate("Couldn't rename output temp file %s", tmpname);
    free(tmpname);

    return (0);
}