tests/tasks/t_tasks.c

	t_tasks.c revision 2bdfb330af70122f9ca5aae2556a112a3010e9ef
/*
 * Copyright (C) 2004, 2005, 2007, 2009, 2011, 2013  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1998-2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: t_tasks.c,v 1.49 2011/07/27 07:45:55 marka Exp $ */

#include <config.h>

#include <stdlib.h>
#include <unistd.h>
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>   /* uintptr_t */
#endif
#include <isc/condition.h>
#include <isc/mem.h>
#include <isc/platform.h>
#include <isc/task.h>
#include <isc/time.h>
#include <isc/timer.h>
#include <isc/util.h>

#include <tests/t_api.h>


#ifdef ISC_PLATFORM_USETHREADS
isc_boolean_t threaded = ISC_TRUE;
#else
isc_boolean_t threaded = ISC_FALSE;
#endif

static int senders[4];

static void
require_threads(void) {
    t_info("This test requires threads\n");
    t_result(T_THREADONLY);
    return;
}

static void
t1_callback(isc_task_t *task, isc_event_t *event) {
    int i;
    int j;

    UNUSED(task);

    j = 0;

    for (i = 0; i < 1000000; i++)
        j += 100;

    t_info("task %s\n", (char *)event->ev_arg);
    isc_event_free(&event);
}

static void
t1_shutdown(isc_task_t *task, isc_event_t *event) {

    UNUSED(task);

    t_info("shutdown %s\n", (char *)event->ev_arg);
    isc_event_free(&event);
}

static void
my_tick(isc_task_t *task, isc_event_t *event) {

    UNUSED(task);

    t_info("%s\n", (char *)event->ev_arg);
    isc_event_free(&event);
}

/*
 * Adapted from RTH's original task_test program
 */

static int
t_tasks1(void) {
    char            *p;
    isc_mem_t       *mctx;
    isc_taskmgr_t       *manager;
    isc_task_t      *task1;
    isc_task_t      *task2;
    isc_task_t      *task3;
    isc_task_t      *task4;
    isc_event_t     *event;
    unsigned int        workers;
    isc_timermgr_t      *timgr;
    isc_timer_t     *ti1;
    isc_timer_t     *ti2;
    isc_result_t        isc_result;
    isc_time_t      absolute;
    isc_interval_t      interval;

    manager = NULL;
    task1 = NULL;
    task2 = NULL;
    task3 = NULL;
    task4 = NULL;
    mctx = NULL;

    workers = 2;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);
    if (workers < 1) {
        t_info("Bad config value for ISC_TASK_WORKERS, %d\n", workers);
        return(T_UNRESOLVED);
    }

    isc_result = isc_mem_create(0, 0, &mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    isc_result = isc_taskmgr_create(mctx, workers, 0, &manager);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_create(manager, 0, &task1);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_create(manager, 0, &task2);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_create(manager, 0, &task3);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_create(manager, 0, &task4);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_onshutdown(task1, t1_shutdown, "1");
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_onshutdown failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_onshutdown(task2, t1_shutdown, "2");
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_onshutdown failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_onshutdown(task3, t1_shutdown, "3");
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_onshutdown failed %d\n", isc_result);
        return(T_FAIL);
    }

    isc_result = isc_task_onshutdown(task4, t1_shutdown, "4");
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_onshutdown failed %d\n", isc_result);
        return(T_FAIL);
    }

    timgr = NULL;
    isc_result = isc_timermgr_create(mctx, &timgr);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_timermgr_create %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    ti1 = NULL;
    isc_time_settoepoch(&absolute);
    isc_interval_set(&interval, 1, 0);
    isc_result = isc_timer_create(timgr, isc_timertype_ticker,
                &absolute, &interval,
                task1, my_tick, "tick", &ti1);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_timer_create %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    ti2 = NULL;
    isc_time_settoepoch(&absolute);
    isc_interval_set(&interval, 1, 0);
    isc_result = isc_timer_create(timgr, isc_timertype_ticker,
                       &absolute, &interval,
                       task2, my_tick, "tock", &ti2);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_timer_create %d\n", isc_result);
        return(T_UNRESOLVED);
    }


#ifndef WIN32
    sleep(2);
#else
    Sleep(2000);
#endif

    /*
     * Note:  (void *)1 is used as a sender here, since some compilers
     * don't like casting a function pointer to a (void *).
     *
     * In a real use, it is more likely the sender would be a
     * structure (socket, timer, task, etc) but this is just a test
     * program.
     */
    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "1",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task1, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "2",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task2, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "3",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task3, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "4",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task4, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "2",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task2, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "3",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task3, &event);

    event = isc_event_allocate(mctx, (void *)1, 1, t1_callback, "4",
                   sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_task_send(task4, &event);

    (void)isc_task_purge(task3, NULL, 0, 0);

    isc_task_detach(&task1);
    isc_task_detach(&task2);
    isc_task_detach(&task3);
    isc_task_detach(&task4);

#ifndef WIN32
    sleep(10);
#else
    Sleep(10000);
#endif
    isc_timer_detach(&ti1);
    isc_timer_detach(&ti2);
    isc_timermgr_destroy(&timgr);
    isc_taskmgr_destroy(&manager);

    isc_mem_destroy(&mctx);
    return(T_PASS);
}

static const char *a1 = "The task subsystem can create and manage tasks";

static void
t1(void) {
    int result;

    t_assert("tasks", 1, T_REQUIRED, "%s", a1);
    result = t_tasks1();
    t_result(result);
}

#define         T2_NTASKS   10000

static isc_event_t  *T2_event;
static isc_taskmgr_t    *T2_manager;
static isc_mem_t    *T2_mctx;
static isc_condition_t  T2_cv;
static isc_mutex_t  T2_mx;
static int      T2_done;
static int      T2_nprobs;
static int      T2_nfails;
static int      T2_ntasks;

static void
t2_shutdown(isc_task_t *task, isc_event_t *event) {

    isc_result_t    isc_result;

    UNUSED(task);

    if (event->ev_arg != NULL) {
        isc_task_destroy((isc_task_t**) &event->ev_arg);
    }
    else {
        isc_result = isc_mutex_lock(&T2_mx);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_mutex_lock failed %d\n", isc_result);
            ++T2_nprobs;
        }

        T2_done = 1;

        isc_result = isc_condition_signal(&T2_cv);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_condition_signal failed %d\n", isc_result);
            ++T2_nprobs;
        }

        isc_result = isc_mutex_unlock(&T2_mx);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_mutex_unlock failed %d\n", isc_result);
            ++T2_nprobs;
        }

        isc_event_free(&T2_event);
        isc_taskmgr_destroy(&T2_manager);
        isc_mem_destroy(&T2_mctx);
    }
}

static void
t2_callback(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;
    isc_task_t  *newtask;

    ++T2_ntasks;

    if (T_debug && ((T2_ntasks % 100) == 0)) {
        t_info("T2_ntasks %d\n", T2_ntasks);
    }

    if (event->ev_arg) {

        event->ev_arg = (void *)(((uintptr_t) event->ev_arg) - 1);

        /*
         * Create a new task and forward the message.
         */
        newtask = NULL;
        isc_result = isc_task_create(T2_manager, 0, &newtask);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_task_create failed %d\n", isc_result);
            ++T2_nfails;
            return;
        }

        isc_result = isc_task_onshutdown(newtask, t2_shutdown,
                         (void *)task);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_task_onshutdown failed %d\n",
                        isc_result);
            ++T2_nfails;
            return;
        }

        isc_task_send(newtask, &event);
    } else {
        /*
         * Time to unwind, shutdown should perc back up.
         */
        isc_task_destroy(&task);
    }
}

static int
t_tasks2(void) {
    uintptr_t       ntasks;
    int         result;
    char            *p;
    isc_event_t     *event;
    unsigned int        workers;
    isc_result_t        isc_result;

    T2_manager = NULL;
    T2_done = 0;
    T2_nprobs = 0;
    T2_nfails = 0;
    T2_ntasks = 0;

    workers = 2;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);
    if (workers < 1) {
        t_info("Bad config value for ISC_TASK_WORKERS, %d\n", workers);
        return(T_UNRESOLVED);
    }

    p = t_getenv("ISC_TASKS_MIN");
    if (p != NULL)
        ntasks = atoi(p);
    else
        ntasks = T2_NTASKS;
    if (ntasks == 0U) {
        t_info("Bad config value for ISC_TASKS_MIN, %lu\n",
               (unsigned long)ntasks);
        return(T_UNRESOLVED);
    }

    t_info("Testing with %lu tasks\n", (unsigned long)ntasks);

    isc_result = isc_mutex_init(&T2_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_init failed %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    isc_result = isc_condition_init(&T2_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_init failed %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    isc_result = isc_mem_create(0, 0, &T2_mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    isc_result = isc_taskmgr_create(T2_mctx, workers, 0, &T2_manager);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %d\n", isc_result);
        return(T_FAIL);
    }

    T2_event = isc_event_allocate(T2_mctx, (void *)1, 1, t2_callback,
                    (void *)ntasks, sizeof(*event));
    if (T2_event == NULL) {
        t_info("isc_event_allocate failed\n");
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_lock(&T2_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    t2_callback(NULL, T2_event);

    while (T2_done == 0) {
        isc_result = isc_condition_wait(&T2_cv, &T2_mx);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_condition_wait failed %d\n", isc_result);
            return(T_UNRESOLVED);
        }
    }

    result = T_UNRESOLVED;

    if ((T2_nfails == 0) && (T2_nprobs == 0))
        result = T_PASS;
    else if (T2_nfails != 0)
        result = T_FAIL;

    return(result);
}

static const char *a2 = "The task subsystem can create ISC_TASKS_MIN tasks";

static void
t2(void) {
    t_assert("tasks", 2, T_REQUIRED, "%s", a2);

    if (threaded)
        t_result(t_tasks2());
    else
        require_threads();
}

#define T3_NEVENTS  256

static  int     T3_flag;
static  int     T3_nevents;
static  int     T3_nsdevents;
static  isc_mutex_t T3_mx;
static  isc_condition_t T3_cv;
static  int     T3_nfails;
static  int     T3_nprobs;

static void
t3_sde1(isc_task_t *task, isc_event_t *event) {

    UNUSED(task);

    if (T3_nevents != T3_NEVENTS) {
        t_info("Some events were not processed\n");
        ++T3_nprobs;
    }
    if (T3_nsdevents == 1) {
        ++T3_nsdevents;
    } else {
        t_info("Shutdown events not processed in LIFO order\n");
        ++T3_nfails;
    }
    isc_event_free(&event);
}

static void
t3_sde2(isc_task_t *task, isc_event_t *event) {

    UNUSED(task);

    if (T3_nevents != T3_NEVENTS) {
        t_info("Some events were not processed\n");
        ++T3_nprobs;
    }
    if (T3_nsdevents == 0) {
        ++T3_nsdevents;
    } else {
        t_info("Shutdown events not processed in LIFO order\n");
        ++T3_nfails;
    }
    isc_event_free(&event);
}

static void
t3_event1(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;

    UNUSED(task);

    isc_result = isc_mutex_lock(&T3_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T3_nprobs;
    }
    while (T3_flag != 1) {
        (void) isc_condition_wait(&T3_cv, &T3_mx);
    }

    isc_result = isc_mutex_unlock(&T3_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T3_nprobs;
    }
    isc_event_free(&event);
}

static void
t3_event2(isc_task_t *task, isc_event_t *event) {
    UNUSED(task);

    ++T3_nevents;
    isc_event_free(&event);
}

static int
t_tasks3(void) {
    int     cnt;
    int     result;
    char        *p;
    isc_mem_t   *mctx;
    isc_taskmgr_t   *tmgr;
    isc_task_t  *task;
    unsigned int    workers;
    isc_event_t *event;
    isc_result_t    isc_result;
    isc_eventtype_t event_type;

    T3_flag = 0;
    T3_nevents = 0;
    T3_nsdevents = 0;
    T3_nfails = 0;
    T3_nprobs = 0;

    event_type = 3;

    workers = 2;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);

    mctx = NULL;
    isc_result = isc_mem_create(0, 0, &mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %s\n",
               isc_result_totext(isc_result));
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_init(&T3_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_condition_init(&T3_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    tmgr = NULL;
    isc_result = isc_taskmgr_create(mctx, workers, 0, &tmgr);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_lock(&T3_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    task = NULL;
    isc_result = isc_task_create(tmgr, 0, &task);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %s\n",
               isc_result_totext(isc_result));
        (void) isc_mutex_unlock(&T3_mx);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    /*
     * This event causes the task to wait on T3_cv.
     */
    event = isc_event_allocate(mctx, &senders[1], event_type, t3_event1,
                   NULL, sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        (void) isc_mutex_unlock(&T3_mx);
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }
    isc_task_send(task, &event);

    /*
     * Now we fill up the task's event queue with some events.
     */
    for (cnt = 0; cnt < T3_NEVENTS; ++cnt) {
        event = isc_event_allocate(mctx, &senders[1], event_type,
                       t3_event2, NULL, sizeof(*event));
        if (event == NULL) {
            t_info("isc_event_allocate failed\n");
            (void) isc_mutex_unlock(&T3_mx);
            isc_task_destroy(&task);
            isc_taskmgr_destroy(&tmgr);
            isc_mem_destroy(&mctx);
            return(T_UNRESOLVED);
        }
        isc_task_send(task, &event);
    }

    /*
     * Now we register two shutdown events.
     */
    isc_result = isc_task_onshutdown(task, t3_sde1, NULL);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_send failed %s\n",
                isc_result_totext(isc_result));
        (void) isc_mutex_unlock(&T3_mx);
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_task_onshutdown(task, t3_sde2, NULL);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_send failed %s\n",
                isc_result_totext(isc_result));
        (void) isc_mutex_unlock(&T3_mx);
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_task_shutdown(task);

    /*
     * Now we free the task by signaling T3_cv.
     */
    T3_flag = 1;
    isc_result = isc_condition_signal(&T3_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_signal failed %s\n",
                isc_result_totext(isc_result));
        ++T3_nprobs;
    }

    isc_result = isc_mutex_unlock(&T3_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
                isc_result_totext(isc_result));
        ++T3_nprobs;
    }


    isc_task_detach(&task);
    isc_taskmgr_destroy(&tmgr);
    isc_mem_destroy(&mctx);

    if (T3_nsdevents != 2) {
        t_info("T3_nsdevents == %d, expected 2\n", T3_nsdevents);
        ++T3_nfails;
    }

    result = T_UNRESOLVED;

    if (T3_nfails != 0)
        result = T_FAIL;
    else if ((T3_nfails == 0) && (T3_nprobs == 0))
        result = T_PASS;

    return(result);
}

static const char *a3 = "When isc_task_shutdown() is called, any shutdown "
            "events that have been requested via prior "
            "isc_task_onshutdown() calls are posted in "
            "LIFO order.";
static void
t3(void) {
    t_assert("tasks", 3, T_REQUIRED, "%s", a3);

    if (threaded)
        t_result(t_tasks3());
    else
        require_threads();
}

static isc_mutex_t  T4_mx;
static isc_condition_t  T4_cv;
static int      T4_flag;
static int      T4_nprobs;
static int      T4_nfails;

static void
t4_event1(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;

    UNUSED(task);

    isc_result = isc_mutex_lock(&T4_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T4_nprobs;
    }
    while (T4_flag != 1) {
        (void) isc_condition_wait(&T4_cv, &T4_mx);
    }

    isc_result = isc_mutex_unlock(&T4_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T4_nprobs;
    }
    isc_event_free(&event);
}

static void
t4_sde(isc_task_t *task, isc_event_t *event) {
    UNUSED(task);

    /*
     * No-op.
     */

    isc_event_free(&event);
}

static int
t_tasks4(void) {
    int     result;
    char        *p;
    isc_mem_t   *mctx;
    isc_taskmgr_t   *tmgr;
    isc_task_t  *task;
    unsigned int    workers;
    isc_result_t    isc_result;
    isc_eventtype_t event_type;
    isc_event_t *event;

    T4_nprobs = 0;
    T4_nfails = 0;
    T4_flag = 0;

    event_type = 4;

    workers = 2;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);

    mctx = NULL;
    isc_result = isc_mem_create(0, 0, &mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %s\n",
               isc_result_totext(isc_result));
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_init(&T4_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_condition_init(&T4_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_init failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T4_mx);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    tmgr = NULL;
    isc_result = isc_taskmgr_create(mctx, workers, 0, &tmgr);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T4_mx);
        (void) isc_condition_destroy(&T4_cv);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_lock(&T4_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T4_mx);
        (void) isc_condition_destroy(&T4_cv);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    task = NULL;
    isc_result = isc_task_create(tmgr, 0, &task);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T4_mx);
        (void) isc_condition_destroy(&T4_cv);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    /*
     * This event causes the task to wait on T4_cv.
     */
    event = isc_event_allocate(mctx, &senders[1], event_type, t4_event1,
                   NULL, sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        DESTROYLOCK(&T4_mx);
        isc_task_destroy(&task);
        (void) isc_condition_destroy(&T4_cv);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }
    isc_task_send(task, &event);

    isc_task_shutdown(task);

    isc_result = isc_task_onshutdown(task, t4_sde, NULL);
    if (isc_result != ISC_R_SHUTTINGDOWN) {
        t_info("isc_task_onshutdown returned %s\n",
               isc_result_totext(isc_result));
        ++T4_nfails;
    }

    /*
     * Release the task.
     */
    T4_flag = 1;

    isc_result = isc_condition_signal(&T4_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_signal failed %s\n",
                isc_result_totext(isc_result));
        ++T4_nprobs;
    }

    isc_result = isc_mutex_unlock(&T4_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
                isc_result_totext(isc_result));
        ++T4_nprobs;
    }

    isc_task_detach(&task);
    isc_taskmgr_destroy(&tmgr);
    isc_mem_destroy(&mctx);
    (void) isc_condition_destroy(&T4_cv);
    DESTROYLOCK(&T4_mx);

    result = T_UNRESOLVED;

    if (T4_nfails != 0)
        result = T_FAIL;
    else if ((T4_nfails == 0) && (T4_nprobs == 0))
        result = T_PASS;

    return(result);
}

static const char *a4 =
        "After isc_task_shutdown() has been called, any call to "
        "isc_task_onshutdown() will return ISC_R_SHUTTINGDOWN.";

static void
t4(void) {
    t_assert("tasks", 4, T_REQUIRED, "%s", a4);

    if (threaded)
        t_result(t_tasks4());
    else
        require_threads();
}

static int      T7_nprobs;
static int      T7_eflag;
static int      T7_sdflag;
static isc_mutex_t  T7_mx;
static isc_condition_t  T7_cv;

static int      T7_nfails;

static void
t7_event1(isc_task_t *task, isc_event_t *event) {
    UNUSED(task);

    ++T7_eflag;

    isc_event_free(&event);
}

static void
t7_sde(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;

    UNUSED(task);

    isc_result = isc_mutex_lock(&T7_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T7_nprobs;
    }

    ++T7_sdflag;

    isc_result = isc_condition_signal(&T7_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_signal failed %s\n",
               isc_result_totext(isc_result));
        ++T7_nprobs;
    }

    isc_result = isc_mutex_unlock(&T7_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T7_nprobs;
    }

    isc_event_free(&event);
}

static int
t_tasks7(void) {
    int     result;
    char        *p;
    isc_mem_t   *mctx;
    isc_taskmgr_t   *tmgr;
    isc_task_t  *task;
    unsigned int    workers;
    isc_result_t    isc_result;
    isc_eventtype_t event_type;
    isc_event_t *event;
    isc_time_t  now;
    isc_interval_t  interval;

    T7_nprobs = 0;
    T7_nfails = 0;
    T7_sdflag = 0;
    T7_eflag = 0;

    event_type = 7;

    workers = 2;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);

    mctx = NULL;
    isc_result = isc_mem_create(0, 0, &mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %s\n",
               isc_result_totext(isc_result));
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_init(&T7_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_condition_init(&T7_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_init failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T7_mx);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    tmgr = NULL;
    isc_result = isc_taskmgr_create(mctx, workers, 0, &tmgr);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T7_mx);
        (void) isc_condition_destroy(&T7_cv);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_lock(&T7_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T7_mx);
        (void) isc_condition_destroy(&T7_cv);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_FAIL);
    }

    task = NULL;
    isc_result = isc_task_create(tmgr, 0, &task);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T7_mx);
        (void) isc_condition_destroy(&T7_cv);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_FAIL);
    }

    isc_result = isc_task_onshutdown(task, t7_sde, NULL);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_onshutdown returned %s\n",
               isc_result_totext(isc_result));
        DESTROYLOCK(&T7_mx);
        (void) isc_condition_destroy(&T7_cv);
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    event = isc_event_allocate(mctx, &senders[1], event_type, t7_event1,
                   NULL, sizeof(*event));
    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        DESTROYLOCK(&T7_mx);
        (void) isc_condition_destroy(&T7_cv);
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }
    isc_task_send(task, &event);

    isc_task_shutdown(task);

    isc_interval_set(&interval, 5, 0);

    while (T7_sdflag == 0) {
        isc_result = isc_time_nowplusinterval(&now, &interval);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_time_nowplusinterval failed %s\n",
                   isc_result_totext(isc_result));
            DESTROYLOCK(&T7_mx);
            (void) isc_condition_destroy(&T7_cv);
            isc_task_destroy(&task);
            isc_taskmgr_destroy(&tmgr);
            isc_mem_destroy(&mctx);
            return(T_UNRESOLVED);
        }

        isc_result = isc_condition_waituntil(&T7_cv, &T7_mx, &now);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_condition_waituntil returned %s\n",
                   isc_result_totext(isc_result));
            DESTROYLOCK(&T7_mx);
            (void) isc_condition_destroy(&T7_cv);
            isc_task_destroy(&task);
            isc_taskmgr_destroy(&tmgr);
            isc_mem_destroy(&mctx);
            return(T_FAIL);
        }
    }

    isc_result = isc_mutex_unlock(&T7_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T7_nprobs;
    }

    isc_task_detach(&task);
    isc_taskmgr_destroy(&tmgr);
    isc_mem_destroy(&mctx);
    (void) isc_condition_destroy(&T7_cv);
    DESTROYLOCK(&T7_mx);

    result = T_UNRESOLVED;

    if (T7_eflag == 0)
        ++T7_nfails;

    if (T7_nfails != 0)
        result = T_FAIL;
    else if ((T7_nfails == 0) && (T7_nprobs == 0))
        result = T_PASS;

    return(result);
}

static const char *a7 = "A call to isc_task_create() creates a task that can "
            "receive events.";

static void
t7(void) {
    t_assert("tasks", 7, T_REQUIRED, "%s", a7);

    if (threaded)
        t_result(t_tasks7());
    else
        require_threads();
}

#define T10_SENDERCNT   3
#define T10_TYPECNT 4
#define T10_TAGCNT  5
#define T10_NEVENTS (T10_SENDERCNT*T10_TYPECNT*T10_TAGCNT)
#define T_CONTROL   99999

static int      T10_nprobs;
static int      T10_nfails;
static int      T10_startflag;
static int      T10_shutdownflag;
static int      T10_eventcnt;
static isc_mutex_t  T10_mx;
static isc_condition_t  T10_cv;

static void     *T10_purge_sender;
static isc_eventtype_t  T10_purge_type_first;
static isc_eventtype_t  T10_purge_type_last;
static void     *T10_purge_tag;
static int      T10_testrange;

static void
t10_event1(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;

    UNUSED(task);

    isc_result = isc_mutex_lock(&T10_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T10_nprobs;
    }

    while (T10_startflag == 0) {
        isc_result = isc_condition_wait(&T10_cv, &T10_mx);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_mutex_lock failed %s\n",
                   isc_result_totext(isc_result));
            ++T10_nprobs;
        }
    }

    isc_result = isc_mutex_unlock(&T10_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T10_nprobs;
    }

    isc_event_free(&event);
}

static void
t10_event2(isc_task_t *task, isc_event_t *event) {

    int sender_match;
    int type_match;
    int tag_match;

    UNUSED(task);

    sender_match = 0;
    type_match = 0;
    tag_match = 0;

    if (T_debug) {
        t_info("Event %p,%d,%p,%s\n",
               event->ev_sender,
               (int)event->ev_type,
               event->ev_tag,
               event->ev_attributes & ISC_EVENTATTR_NOPURGE ?
               "NP" : "P");
    }

    if ((T10_purge_sender == NULL) ||
        (T10_purge_sender == event->ev_sender)) {
        sender_match = 1;
    }
    if (T10_testrange == 0) {
        if (T10_purge_type_first == event->ev_type) {
            type_match = 1;
        }
    } else {
        if ((T10_purge_type_first <= event->ev_type) &&
            (event->ev_type <= T10_purge_type_last)) {
            type_match = 1;
        }
    }
    if ((T10_purge_tag == NULL) ||
        (T10_purge_tag == event->ev_tag)) {
        tag_match = 1;
    }

    if (sender_match && type_match && tag_match) {
        if (event->ev_attributes & ISC_EVENTATTR_NOPURGE) {
            t_info("event %p,%d,%p matched but was not purgable\n",
                event->ev_sender, (int)event->ev_type,
                   event->ev_tag);
            ++T10_eventcnt;
        } else {
            t_info("*** event %p,%d,%p not purged\n",
                   event->ev_sender, (int)event->ev_type,
                   event->ev_tag);
        }
    } else {
        ++T10_eventcnt;
    }
    isc_event_free(&event);
}


static void
t10_sde(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;

    UNUSED(task);

    isc_result = isc_mutex_lock(&T10_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T10_nprobs;
    }

    ++T10_shutdownflag;

    isc_result = isc_condition_signal(&T10_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_signal failed %s\n",
               isc_result_totext(isc_result));
        ++T10_nprobs;
    }

    isc_result = isc_mutex_unlock(&T10_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T10_nprobs;
    }

    isc_event_free(&event);
}

static void
t_taskpurge_x(int sender, int type, int tag, void *purge_sender,
          int purge_type_first, int purge_type_last, void *purge_tag,
          int exp_nevents, int *nfails, int *nprobs, int testrange)
{
    char        *p;
    isc_mem_t   *mctx;
    isc_taskmgr_t   *tmgr;
    isc_task_t  *task;
    unsigned int    workers;
    isc_result_t    isc_result;
    isc_event_t *event;
    isc_time_t  now;
    isc_interval_t  interval;
    int     sender_cnt;
    int     type_cnt;
    int     tag_cnt;
    int     event_cnt;
    int     cnt;
    int     nevents;
    isc_event_t *eventtab[T10_NEVENTS];


    T10_startflag = 0;
    T10_shutdownflag = 0;
    T10_eventcnt = 0;
    T10_purge_sender = purge_sender;
    T10_purge_type_first = (isc_eventtype_t) purge_type_first;
    T10_purge_type_last = (isc_eventtype_t) purge_type_last;
    T10_purge_tag = purge_tag;
    T10_testrange = testrange;

    workers = 2;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);

    mctx = NULL;
    isc_result = isc_mem_create(0, 0, &mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %s\n",
               isc_result_totext(isc_result));
        ++*nprobs;
        return;
    }

    isc_result = isc_mutex_init(&T10_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        ++*nprobs;
        return;
    }

    isc_result = isc_condition_init(&T10_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T10_mx);
        ++*nprobs;
        return;
    }

    tmgr = NULL;
    isc_result = isc_taskmgr_create(mctx, workers, 0, &tmgr);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T10_mx);
        (void) isc_condition_destroy(&T10_cv);
        ++*nprobs;
        return;
    }

    task = NULL;
    isc_result = isc_task_create(tmgr, 0, &task);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %s\n",
               isc_result_totext(isc_result));
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T10_mx);
        (void) isc_condition_destroy(&T10_cv);
        ++*nprobs;
        return;
    }

    isc_result = isc_task_onshutdown(task, t10_sde, NULL);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_onshutdown returned %s\n",
               isc_result_totext(isc_result));
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T10_mx);
        (void) isc_condition_destroy(&T10_cv);
        ++*nprobs;
        return;
    }

    /*
     * Block the task on T10_cv.
     */
    event = isc_event_allocate(mctx, (void *)1, (isc_eventtype_t)T_CONTROL,
                   t10_event1, NULL, sizeof(*event));

    if (event == NULL) {
        t_info("isc_event_allocate failed\n");
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T10_mx);
        (void) isc_condition_destroy(&T10_cv);
        ++*nprobs;
        return;
    }
    isc_task_send(task, &event);

    /*
     * Fill the task's queue with some messages with varying
     * sender, type, tag, and purgable attribute values.
     */

    event_cnt = 0;
    for (sender_cnt = 0; sender_cnt < T10_SENDERCNT; ++sender_cnt) {
        for (type_cnt = 0; type_cnt < T10_TYPECNT; ++type_cnt) {
            for (tag_cnt = 0; tag_cnt < T10_TAGCNT; ++tag_cnt) {
                eventtab[event_cnt] =
                    isc_event_allocate(mctx,
                        &senders[sender + sender_cnt],
                        (isc_eventtype_t)(type + type_cnt),
                        t10_event2, NULL, sizeof(*event));

                if (eventtab[event_cnt] == NULL) {
                    t_info("isc_event_allocate failed\n");
                    isc_task_destroy(&task);
                    isc_taskmgr_destroy(&tmgr);
                    isc_mem_destroy(&mctx);
                    DESTROYLOCK(&T10_mx);
                    (void) isc_condition_destroy(&T10_cv);
                    ++*nprobs;
                    return;
                }

                eventtab[event_cnt]->ev_tag =
                    (void *)((uintptr_t)tag + tag_cnt);

                /*
                 * Make all odd message non-purgable.
                 */
                if ((sender_cnt % 2) && (type_cnt %2) &&
                    (tag_cnt %2))
                    eventtab[event_cnt]->ev_attributes |=
                        ISC_EVENTATTR_NOPURGE;
                ++event_cnt;
            }
        }
    }

    for (cnt = 0; cnt < event_cnt; ++cnt)
        isc_task_send(task, &eventtab[cnt]);

    if (T_debug)
        t_info("%d events queued\n", cnt);

    if (testrange == 0) {
        /*
         * We're testing isc_task_purge.
         */
        nevents = isc_task_purge(task, purge_sender,
                    (isc_eventtype_t)purge_type_first,
                    purge_tag);
        if (nevents != exp_nevents) {
            t_info("*** isc_task_purge returned %d, expected %d\n",
                nevents, exp_nevents);
            ++*nfails;
        } else if (T_debug)
            t_info("isc_task_purge returned %d\n", nevents);
    } else {
        /*
         * We're testing isc_task_purgerange.
         */
        nevents = isc_task_purgerange(task, purge_sender,
                         (isc_eventtype_t)purge_type_first,
                         (isc_eventtype_t)purge_type_last,
                         purge_tag);
        if (nevents != exp_nevents) {
            t_info("*** isc_task_purgerange returned %d, "
                   "expected %d\n", nevents, exp_nevents);
            ++*nfails;
        } else if (T_debug)
            t_info("isc_task_purgerange returned %d\n", nevents);
    }

    isc_result = isc_mutex_lock(&T10_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T10_mx);
        (void) isc_condition_destroy(&T10_cv);
        ++*nprobs;
        return;
    }

    /*
     * Unblock the task, allowing event processing.
     */
    T10_startflag = 1;
    isc_result = isc_condition_signal(&T10_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_signal failed %s\n",
               isc_result_totext(isc_result));
        ++*nprobs;
    }

    isc_task_shutdown(task);

    isc_interval_set(&interval, 5, 0);

    /*
     * Wait for shutdown processing to complete.
     */
    while (T10_shutdownflag == 0) {
        isc_result = isc_time_nowplusinterval(&now, &interval);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_time_nowplusinterval failed %s\n",
                   isc_result_totext(isc_result));
            isc_task_detach(&task);
            isc_taskmgr_destroy(&tmgr);
            isc_mem_destroy(&mctx);
            DESTROYLOCK(&T10_mx);
            (void) isc_condition_destroy(&T10_cv);
            ++*nprobs;
            return;
        }

        isc_result = isc_condition_waituntil(&T10_cv, &T10_mx, &now);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_condition_waituntil returned %s\n",
                   isc_result_totext(isc_result));
            isc_task_detach(&task);
            isc_taskmgr_destroy(&tmgr);
            isc_mem_destroy(&mctx);
            DESTROYLOCK(&T10_mx);
            (void) isc_condition_destroy(&T10_cv);
            ++*nfails;
            return;
        }
    }

    isc_result = isc_mutex_unlock(&T10_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++*nprobs;
    }

    isc_task_detach(&task);
    isc_taskmgr_destroy(&tmgr);
    isc_mem_destroy(&mctx);
    DESTROYLOCK(&T10_mx);
    (void) isc_condition_destroy(&T10_cv);

    if (T_debug)
        t_info("task processed %d events\n", T10_eventcnt);

    if ((T10_eventcnt + nevents) != event_cnt) {
        t_info("*** processed %d, purged %d, total %d\n",
               T10_eventcnt, nevents, event_cnt);
        ++*nfails;
    }
}

static int
t_tasks10(void) {
    int result;

    T10_nprobs = 0;
    T10_nfails = 0;

    /*
     * Try purging on a specific sender.
     */
    t_info("testing purge on 2,4,8 expecting 1\n");
    t_taskpurge_x(1, 4, 7, &senders[2], 4, 4, (void *)8, 1, &T10_nfails,
              &T10_nprobs, 0);

    /*
     * Try purging on all senders.
     */
    t_info("testing purge on 0,4,8 expecting 3\n");
    t_taskpurge_x(1, 4, 7, NULL, 4, 4, (void *)8, 3, &T10_nfails,
              &T10_nprobs, 0);

    /*
     * Try purging on all senders, specified type, all tags.
     */
    t_info("testing purge on 0,4,0 expecting 15\n");
    t_taskpurge_x(1, 4, 7, NULL, 4, 4, NULL, 15, &T10_nfails,
              &T10_nprobs, 0);

    /*
     * Try purging on a specified tag, no such type.
     */
    t_info("testing purge on 0,99,8 expecting 0\n");
    t_taskpurge_x(1, 4, 7, NULL, 99, 99, (void *)8, 0, &T10_nfails,
              &T10_nprobs, 0);

    /*
     * Try purging on specified sender, type, all tags.
     */
    t_info("testing purge on 0,5,0 expecting 5\n");
    t_taskpurge_x(1, 4, 7, &senders[3], 5, 5, NULL, 5, &T10_nfails,
              &T10_nprobs, 0);

    result = T_UNRESOLVED;

    if ((T10_nfails == 0) && (T10_nprobs == 0))
        result = T_PASS;
    else if (T10_nfails != 0)
        result = T_FAIL;

    return(result);
}

static const char *a10 =
            "A call to isc_task_purge(task, sender, type, tag) "
            "purges all events of type 'type' and with tag 'tag' "
            "not marked as unpurgable from sender from the task's "
            "queue and returns the number of events purged.";

static void
t10(void) {
    t_assert("tasks", 10, T_REQUIRED, "%s", a10);

    if (threaded)
        t_result(t_tasks10());
    else
        require_threads();
}

static int      T11_nprobs;
static int      T11_nfails;
static int      T11_startflag;
static int      T11_shutdownflag;
static int      T11_eventcnt;
static isc_mutex_t  T11_mx;
static isc_condition_t  T11_cv;

static void
t11_event1(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;

    UNUSED(task);

    isc_result = isc_mutex_lock(&T11_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    while (T11_startflag == 0) {
        isc_result = isc_condition_wait(&T11_cv, &T11_mx);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_mutex_lock failed %s\n",
                   isc_result_totext(isc_result));
            ++T11_nprobs;
        }
    }

    isc_result = isc_mutex_unlock(&T11_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    isc_event_free(&event);
}

static void
t11_event2(isc_task_t *task, isc_event_t *event) {
    UNUSED(task);

    ++T11_eventcnt;
    isc_event_free(&event);
}


static void
t11_sde(isc_task_t *task, isc_event_t *event) {
    isc_result_t    isc_result;

    UNUSED(task);

    isc_result = isc_mutex_lock(&T11_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    ++T11_shutdownflag;

    isc_result = isc_condition_signal(&T11_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_signal failed %s\n",
               isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    isc_result = isc_mutex_unlock(&T11_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    isc_event_free(&event);
}

static int
t_tasks11(int purgable) {
    char        *p;
    isc_mem_t   *mctx;
    isc_taskmgr_t   *tmgr;
    isc_task_t  *task;
    isc_boolean_t   rval;
    unsigned int    workers;
    isc_result_t    isc_result;
    isc_event_t *event1;
    isc_event_t *event2, *event2_clone;
    isc_time_t  now;
    isc_interval_t  interval;
    int     result;

    T11_startflag = 0;
    T11_shutdownflag = 0;
    T11_eventcnt = 0;

    workers = 2;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);

    mctx = NULL;
    isc_result = isc_mem_create(0, 0, &mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %s\n",
               isc_result_totext(isc_result));
        return(T_UNRESOLVED);
    }

    isc_result = isc_mutex_init(&T11_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        return(T_UNRESOLVED);
    }

    isc_result = isc_condition_init(&T11_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_init failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T11_mx);
        return(T_UNRESOLVED);
    }

    tmgr = NULL;
    isc_result = isc_taskmgr_create(mctx, workers, 0, &tmgr);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %s\n",
               isc_result_totext(isc_result));
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T11_mx);
        (void) isc_condition_destroy(&T11_cv);
        return(T_UNRESOLVED);
    }

    task = NULL;
    isc_result = isc_task_create(tmgr, 0, &task);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_create failed %s\n",
               isc_result_totext(isc_result));
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T11_mx);
        (void) isc_condition_destroy(&T11_cv);
        return(T_UNRESOLVED);
    }

    isc_result = isc_task_onshutdown(task, t11_sde, NULL);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_task_onshutdown returned %s\n",
               isc_result_totext(isc_result));
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T11_mx);
        (void) isc_condition_destroy(&T11_cv);
        return(T_UNRESOLVED);
    }

    /*
     * Block the task on T11_cv.
     */
    event1 = isc_event_allocate(mctx, (void *)1, (isc_eventtype_t)1,
                    t11_event1, NULL, sizeof(*event1));
    if (event1 == NULL) {
        t_info("isc_event_allocate failed\n");
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T11_mx);
        (void) isc_condition_destroy(&T11_cv);
        return(T_UNRESOLVED);
    }
    isc_task_send(task, &event1);

    event2 = isc_event_allocate(mctx, (void *)1, (isc_eventtype_t)1,
                    t11_event2, NULL, sizeof(*event2));
    if (event2 == NULL) {
        t_info("isc_event_allocate failed\n");
        isc_task_destroy(&task);
        isc_taskmgr_destroy(&tmgr);
        isc_mem_destroy(&mctx);
        DESTROYLOCK(&T11_mx);
        (void) isc_condition_destroy(&T11_cv);
        return(T_UNRESOLVED);
    }
    event2_clone = event2;
    if (purgable)
        event2->ev_attributes &= ~ISC_EVENTATTR_NOPURGE;
    else
        event2->ev_attributes |= ISC_EVENTATTR_NOPURGE;

    isc_task_send(task, &event2);

    rval = isc_task_purgeevent(task, event2_clone);
    if (rval != (purgable ? ISC_TRUE : ISC_FALSE)) {
        t_info("isc_task_purgeevent returned %s, expected %s\n",
               (rval ? "ISC_TRUE" : "ISC_FALSE"),
               (purgable ? "ISC_TRUE" : "ISC_FALSE"));
        ++T11_nfails;
    }

    isc_result = isc_mutex_lock(&T11_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_lock failed %s\n",
               isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    /*
     * Unblock the task, allowing event processing.
     */
    T11_startflag = 1;
    isc_result = isc_condition_signal(&T11_cv);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_condition_signal failed %s\n",
                isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    isc_task_shutdown(task);

    isc_interval_set(&interval, 5, 0);

    /*
     * Wait for shutdown processing to complete.
     */
    while (T11_shutdownflag == 0) {
        isc_result = isc_time_nowplusinterval(&now, &interval);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_time_nowplusinterval failed %s\n",
                   isc_result_totext(isc_result));
            ++T11_nprobs;
        }

        isc_result = isc_condition_waituntil(&T11_cv, &T11_mx, &now);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_condition_waituntil returned %s\n",
                   isc_result_totext(isc_result));
            ++T11_nprobs;
        }
    }

    isc_result = isc_mutex_unlock(&T11_mx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mutex_unlock failed %s\n",
               isc_result_totext(isc_result));
        ++T11_nprobs;
    }

    isc_task_detach(&task);
    isc_taskmgr_destroy(&tmgr);
    isc_mem_destroy(&mctx);
    DESTROYLOCK(&T11_mx);
    (void) isc_condition_destroy(&T11_cv);

    if (T11_eventcnt != (purgable ? 0 : 1)) {
        t_info("Event was %s purged\n",
               (purgable ? "not" : "unexpectedly"));
        ++T11_nfails;
    }

    result = T_UNRESOLVED;

    if ((T11_nfails == 0) && (T11_nprobs == 0))
        result = T_PASS;
    else if (T11_nfails)
        result = T_FAIL;

    return(result);
}

static const char *a11 =
        "When the event is marked as purgable, a call to "
        "isc_task_purgeevent(task, event) purges the event 'event' "
        "from the task's queue and returns ISC_TRUE.";

static void
t11(void) {
    t_assert("tasks", 11, T_REQUIRED, "%s", a11);

    if (threaded)
        t_result(t_tasks11(1));
    else
        require_threads();
}

static const char *a12 =
            "When the event is not marked as purgable, a call to "
            "isc_task_purgeevent(task, event) does not purge the "
            "event 'event' from the task's queue and returns "
            "ISC_FALSE.";

static int
t_tasks12(void) {
    return(t_tasks11(0));
}

static void
t12(void) {
    t_assert("tasks", 12, T_REQUIRED, "%s", a12);

    if (threaded)
        t_result(t_tasks12());
    else
        require_threads();
}

static int  T13_nfails;
static int  T13_nprobs;

static const char *a13 =
        "A call to "
        "isc_event_purgerange(task, sender, first, last, tag) "
        "purges all events not marked unpurgable from "
        "sender 'sender' and of type within the range 'first' "
        "to 'last' inclusive from the task's event queue and "
        "returns the number of tasks purged.";

static int
t_tasks13(void) {
    int result;

    T13_nfails = 0;
    T13_nprobs = 0;

    /*
     * First let's try the same cases we used in t10.
     */

    /*
     * Try purging on a specific sender.
     */
    t_info("testing purge on 2,4,8 expecting 1\n");
    t_taskpurge_x(1, 4, 7, &senders[2], 4, 4, (void *)8, 1,
              &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on all senders.
     */
    t_info("testing purge on 0,4,8 expecting 3\n");
    t_taskpurge_x(1, 4, 7, NULL, 4, 4, (void *)8, 3,
              &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on all senders, specified type, all tags.
     */
    t_info("testing purge on 0,4,0 expecting 15\n");
    t_taskpurge_x(1, 4, 7, NULL, 4, 4, NULL, 15, &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on a specified tag, no such type.
     */
    t_info("testing purge on 0,99,8 expecting 0\n");
    t_taskpurge_x(1, 4, 7, NULL, 99, 99, (void *)8, 0,
              &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on specified sender, type, all tags.
     */
    t_info("testing purge on 3,5,0 expecting 5\n");
    t_taskpurge_x(1, 4, 7, &senders[3], 5, 5, 0, 5, &T13_nfails, &T13_nprobs, 1);

    /*
     * Now let's try some ranges.
     */

    t_info("testing purgerange on 2,4-5,8 expecting 2\n");
    t_taskpurge_x(1, 4, 7, &senders[2], 4, 5, (void *)8, 1,
              &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on all senders.
     */
    t_info("testing purge on 0,4-5,8 expecting 5\n");
    t_taskpurge_x(1, 4, 7, NULL, 4, 5, (void *)8, 5,
              &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on all senders, specified type, all tags.
     */
    t_info("testing purge on 0,5-6,0 expecting 28\n");
    t_taskpurge_x(1, 4, 7, NULL, 5, 6, NULL, 28, &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on a specified tag, no such type.
     */
    t_info("testing purge on 0,99-101,8 expecting 0\n");
    t_taskpurge_x(1, 4, 7, NULL, 99, 101, (void *)8, 0,
              &T13_nfails, &T13_nprobs, 1);

    /*
     * Try purging on specified sender, type, all tags.
     */
    t_info("testing purge on 3,5-6,0 expecting 10\n");
    t_taskpurge_x(1, 4, 7, &senders[3], 5, 6, NULL, 10, &T13_nfails,
              &T13_nprobs, 1);

    result = T_UNRESOLVED;

    if ((T13_nfails == 0) && (T13_nprobs == 0))
        result = T_PASS;
    else if (T13_nfails)
        result = T_FAIL;

    return (result);
}

static void
t13(void) {
    t_assert("tasks", 13, T_REQUIRED, "%s", a13);

    if (threaded)
        t_result(t_tasks13());
    else
        require_threads();
}

#define T14_NTASKS 10
#define T14_EXCLTASK 6

int t14_exclusiveerror = ISC_R_SUCCESS;
int t14_error = 0;
int t14_done = 0;

int spin(int n);

int t14_active[T14_NTASKS];

static void
t14_callback(isc_task_t *task, isc_event_t *event) {
    int taskno = *(int *)(event->ev_arg);


    t_info("task enter %d\n", taskno);
    if (taskno == T14_EXCLTASK) {
        int i;
        t14_exclusiveerror = isc_task_beginexclusive(task);
        if (t14_exclusiveerror == ISC_R_SUCCESS)
            t_info("task %d got exclusive access\n", taskno);
        else
            t_info("task %d failed to got exclusive access: %d\n",
                taskno, t14_exclusiveerror);
        for (i = 0; i < T14_NTASKS; i++) {
            t_info("task %d state %d\n", i , t14_active[i]);
            if (t14_active[i])
                t14_error++;
        }
        isc_task_endexclusive(task);
        t14_done = 1;
    } else {
        t14_active[taskno]++;
        (void) spin(10000000);
        t14_active[taskno]--;
    }
    t_info("task exit %d\n", taskno);
    if (t14_done) {
        isc_mem_put(event->ev_destroy_arg, event->ev_arg, sizeof (int));
        isc_event_free(&event);
    } else {
        isc_task_send(task, &event);
    }
}

int spin(int n) {
    int i;
    int r = 0;
    for (i = 0; i < n; i++) {
        r += i;
        if (r > 1000000)
            r = 0;
    }
    return (r);
}

static int
t_tasks14(void) {
    char            *p;
    isc_mem_t       *mctx;
    isc_taskmgr_t       *manager;
    isc_task_t      *tasks[T14_NTASKS];
    unsigned int        workers;
    isc_result_t        isc_result;
    int             i;

    manager = NULL;
    mctx = NULL;

    for (i = 0; i < T14_NTASKS; i++)
        tasks[i] = NULL;

    workers = 4;
    p = t_getenv("ISC_TASK_WORKERS");
    if (p != NULL)
        workers = atoi(p);
    if (workers < 1) {
        t_info("Bad config value for ISC_TASK_WORKERS, %d\n", workers);
        return(T_UNRESOLVED);
    }

    isc_result = isc_mem_create(0, 0, &mctx);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_mem_create failed %d\n", isc_result);
        return(T_UNRESOLVED);
    }

    isc_result = isc_taskmgr_create(mctx, workers, 0, &manager);
    if (isc_result != ISC_R_SUCCESS) {
        t_info("isc_taskmgr_create failed %d\n", isc_result);
        return(T_FAIL);
    }

    for (i = 0; i < T14_NTASKS; i++) {
        isc_event_t *event;
        int *v;

        isc_result = isc_task_create(manager, 0, &tasks[i]);
        if (isc_result != ISC_R_SUCCESS) {
            t_info("isc_task_create failed %d\n", isc_result);
            return(T_FAIL);
        }

        v = isc_mem_get(mctx, sizeof *v);
        if (v == NULL) {
            isc_task_detach(&tasks[i]);
            t_info("isc_mem_get failed\n");
            return(T_FAIL);
        }
        *v = i;

        event = isc_event_allocate(mctx, NULL, 1, t14_callback,
                       v, sizeof(*event));
        if (event == NULL) {
            isc_mem_put(mctx, v, sizeof *v);
            t_info("isc_event_allocate failed\n");
            return(T_UNRESOLVED);
        }
        isc_task_send(tasks[i], &event);
    }

    for (i = 0; i < T14_NTASKS; i++) {
        isc_task_detach(&tasks[i]);
    }

    isc_taskmgr_destroy(&manager);

    if (t14_exclusiveerror != ISC_R_SUCCESS || t14_error) {
        if (t14_exclusiveerror != ISC_R_SUCCESS)
            t_info("isc_task_beginexclusive() failed\n");
        if (t14_error)
            t_info("mutual access occurred\n");
        return(T_FAIL);
    }

    isc_mem_destroy(&mctx);
    return(T_PASS);
}

static void
t14(void) {
    int result;

    t_assert("tasks", 14, T_REQUIRED, "%s",
         "isc_task_beginexclusive() gets exclusive access");
    result = t_tasks14();
    t_result(result);
}

testspec_t  T_testlist[] = {
    {   (PFV) t1,   "basic task subsystem"  },
    {   (PFV) t2,   "maxtasks"      },
    {   (PFV) t3,   "isc_task_shutdown" },
    {   (PFV) t4,   "isc_task_shutdown" },
    {   (PFV) t7,   "isc_task_create"   },
    {   (PFV) t10,  "isc_task_purge"    },
    {   (PFV) t11,  "isc_task_purgeevent"   },
    {   (PFV) t12,  "isc_task_purgeevent"   },
    {   (PFV) t13,  "isc_task_purgerange"   },
    {   (PFV) t14,  "isc_task_beginexclusive" },
    {   (PFV) 0,    NULL            }
};

#ifdef WIN32
int
main(int argc, char **argv) {
    t_settests(T_testlist);
    return (t_main(argc, argv));
}
#endif