source: mainline/uspace/srv/taskman/main.c@ 13b4504

/*
 * Copyright (c) 2015 Michal Koutny
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * Locking order:
 * - task_hash_table_lock (task.c),
 * - pending_wait_lock (event.c),
 * - listeners_lock (event.c).
 *
 * @addtogroup taskman
 * @{
 */
#include <abi/ipc/methods.h>
#include <adt/prodcons.h>
#include <assert.h>
#include <async.h>
#include <errno.h>
#include <fibril_synch.h>
#include <ipc/services.h>
#include <ipc/taskman.h>
#include <loader/loader.h>
#include <macros.h>
#include <ns.h>
#include <stdio.h>
#include <stdlib.h>

#include "event.h"
#include "task.h"
#include "taskman.h"

typedef struct {
        link_t link;
        async_sess_t *sess;
} sess_ref_t;

static prodcons_t sess_queue;

/** We keep session to NS on our own in taskman */
static async_sess_t *session_ns = NULL;

static FIBRIL_MUTEX_INITIALIZE(session_ns_mtx);
static FIBRIL_CONDVAR_INITIALIZE(session_ns_cv);

/*
 * Static functions
 */
static void connect_to_loader(ipc_call_t *icall)
{
        DPRINTF("%s:%d from %" PRIu64 "\n", __func__, __LINE__, icall->task_id);
        /*
         * We don't accept the connection request, we forward it instead to
         * freshly spawned loader.
         */
        errno_t rc = loader_spawn("loader");

        if (rc != EOK) {
                async_answer_0(icall, rc);
                return;
        }

        /* Wait until spawned task presents itself to us. */
        link_t *link = prodcons_consume(&sess_queue);
        sess_ref_t *sess_ref = list_get_instance(link, sess_ref_t, link);

        /* Forward the connection request (strip interface arg). */
        async_exch_t *exch = async_exchange_begin(sess_ref->sess);
        rc = async_forward_1(icall, exch,
            ipc_get_arg2(icall),
            ipc_get_arg3(icall),
            IPC_FF_NONE);
        async_exchange_end(exch);

        /* After forward we can dispose all session-related resources */
        //async_hangup(sess_ref->sess);
        free(sess_ref);

        if (rc != EOK) {
                async_answer_0(icall, rc);
                return;
        }

        /* Everything OK. */
}

static void connect_to_ns(ipc_call_t *icall)
{
        DPRINTF("%s:%d from %" PRIu64 "\n", __func__, __LINE__, icall->task_id);

        /* Wait until we know NS */
        fibril_mutex_lock(&session_ns_mtx);
        while (session_ns == NULL) {
                fibril_condvar_wait(&session_ns_cv, &session_ns_mtx);
        }
        fibril_mutex_unlock(&session_ns_mtx);

        /* Do not accept connection, forward it */
        async_exch_t *exch = async_exchange_begin(session_ns);
        errno_t rc = async_forward_0(icall, exch, 0, IPC_FF_NONE);
        async_exchange_end(exch);

        if (rc != EOK)
                async_answer_0(icall, rc);
}

static void taskman_new_task(ipc_call_t *icall)
{
        DPRINTF("%s:%d from %" PRIu64 "\n", __func__, __LINE__, icall->task_id);
        errno_t rc = task_intro(icall->task_id);
        if (rc == EOK) {
                async_accept_0(icall);
        } else {
                async_answer_0(icall, rc);
        }
}

static void taskman_i_am_ns(ipc_call_t *icall)
{
        DPRINTF("%s:%d from %" PRIu64 "\n", __func__, __LINE__, icall->task_id);
        errno_t rc = EOK;

        fibril_mutex_lock(&session_ns_mtx);
        if (session_ns != NULL) {
                rc = EEXIST;
                goto finish;
        }

        /* Used only for connection forwarding -- atomic */
        session_ns = async_callback_receive(EXCHANGE_ATOMIC);

        if (session_ns == NULL) {
                rc = ENOENT;
                printf("%s: Cannot connect to NS\n", NAME);
        }

        fibril_condvar_broadcast(&session_ns_cv);
finish:
        fibril_mutex_unlock(&session_ns_mtx);

        if (rc == EOK) {
                async_accept_0(icall);
        } else {
                async_answer_0(icall, rc);
        }
}

static void taskman_ctl_wait(ipc_call_t *icall)
{
        task_id_t id = (task_id_t)
            MERGE_LOUP32(ipc_get_arg1(icall), ipc_get_arg2(icall));
        int flags = ipc_get_arg3(icall);
        task_id_t waiter_id = icall->task_id;

        wait_for_task(id, flags, icall, waiter_id);
}

static void taskman_ctl_retval(ipc_call_t *icall)
{
        task_id_t sender = icall->task_id;
        int retval = ipc_get_arg1(icall);
        bool wait_for_exit = ipc_get_arg2(icall);

        DPRINTF("%s:%d from %" PRIu64 "/%i\n", __func__, __LINE__, sender, retval);

        errno_t rc = task_set_retval(sender, retval, wait_for_exit);
        async_answer_0(icall, rc);
}

static void taskman_ctl_ev_callback(ipc_call_t *icall)
{
        DPRINTF("%s:%d from %" PRIu64 "\n", __func__, __LINE__, icall->task_id);

        bool past_events = ipc_get_arg1(icall);

        /* Atomic -- will be used for notifications only */
        async_sess_t *sess = async_callback_receive(EXCHANGE_ATOMIC);
        if (sess == NULL) {
                async_answer_0(icall, ENOMEM);
                return;
        }

        event_register_listener(icall->task_id, past_events, sess, icall);
}

static void task_exit_event(ipc_call_t *icall, void *arg)
{
        task_id_t id = MERGE_LOUP32(ipc_get_arg1(icall), ipc_get_arg2(icall));
        exit_reason_t exit_reason = ipc_get_arg3(icall);
        DPRINTF("%s:%d from %" PRIu64 "/%i\n", __func__, __LINE__, id, exit_reason);
        task_terminated(id, exit_reason);
}

static void task_fault_event(ipc_call_t *icall, void *arg)
{
        task_id_t id = MERGE_LOUP32(ipc_get_arg1(icall), ipc_get_arg2(icall));
        DPRINTF("%s:%d from %" PRIu64 "\n", __func__, __LINE__, id);
        task_failed(id);
}

static void taskman_i_am_loader(ipc_call_t *icall)
{
        DPRINTF("%s:%d from %" PRIu64 "\n", __func__, __LINE__, icall->task_id);
        // TODO check that loader is expected, would probably discard prodcons
        //      scheme

        /* Preallocate session container */
        sess_ref_t *sess_ref = malloc(sizeof(sess_ref_t));
        if (sess_ref == NULL) {
                async_answer_0(icall, ENOMEM);
                return;
        }

        /* Create callback connection */
        sess_ref->sess = async_callback_receive(EXCHANGE_ATOMIC);

        /* Notify spawners */
        link_initialize(&sess_ref->link);
        prodcons_produce(&sess_queue, &sess_ref->link);
}

static void taskman_connection(ipc_call_t *icall, void *arg)
{
        /* handle new incoming IPC_M_CONNECT_ME_TO calls */
        switch (ipc_get_arg2(icall)) {
        case TASKMAN_NEW_TASK:
                taskman_new_task(icall);
                break;
        case TASKMAN_CONNECT_TO_NS:
                connect_to_ns(icall);
                break;
        case TASKMAN_CONNECT_TO_LOADER:
                connect_to_loader(icall);
                break;
        default:
                DPRINTF("%s:%d from %" PRIu64 "/%" SCNuPTR "/%" SCNuPTR "/%" SCNuPTR "\n",
                    __func__, __LINE__,
                    icall->task_id, ipc_get_imethod(icall),
                    ipc_get_arg1(icall), ipc_get_arg2(icall));
                async_answer_0(icall, ENOTSUP);
                return;
        }

        /* handle accepted calls */
        while (true) {
                ipc_call_t call;

                if (!async_get_call(&call) || !ipc_get_imethod(&call)) {
                        /* Client disconnected */
                        DPRINTF("%s:%d client disconnected\n", __func__, __LINE__);
                        break;
                }

                switch (ipc_get_imethod(&call)) {
                case TASKMAN_I_AM_NS:
                        taskman_i_am_ns(&call);
                        break;
                case TASKMAN_I_AM_LOADER:
                        taskman_i_am_loader(&call);
                        break;
                case TASKMAN_WAIT:
                        taskman_ctl_wait(&call);
                        break;
                case TASKMAN_RETVAL:
                        taskman_ctl_retval(&call);
                        break;
                case TASKMAN_EVENT_CALLBACK:
                        taskman_ctl_ev_callback(&call);
                        break;
                default:
                        DPRINTF("%s:%d from %" PRIu64 "/%" SCNuPTR "/%" SCNuPTR "/%" SCNuPTR "\n",
                            __func__, __LINE__,
                            call.task_id, ipc_get_imethod(&call),
                            ipc_get_arg1(&call), ipc_get_arg2(&call));
                        async_answer_0(&call, ENOTSUP);
                }
        }
}

int main(int argc, char *argv[])
{
        printf(NAME ": HelenOS task manager\n");

        /* Initialization */
        prodcons_initialize(&sess_queue);
        errno_t rc = tasks_init();
        if (rc != EOK) {
                return rc;
        }
        rc = event_init();
        if (rc != EOK) {
                return rc;
        }

        rc = async_event_subscribe(EVENT_EXIT, task_exit_event, NULL);
        if (rc != EOK) {
                printf(NAME ": Cannot register for exit events (%i).\n", rc);
                return rc;
        }

        rc = async_event_subscribe(EVENT_FAULT, task_fault_event, NULL);
        if (rc != EOK) {
                printf(NAME ": Cannot register for fault events (%i).\n", rc);
                return rc;
        }

        task_id_t self_id = task_get_id();
        rc = task_intro(self_id);
        if (rc != EOK) {
                printf(NAME ": Cannot register self as task (%i).\n", rc);
        }

        /* Start sysman server */
        async_set_fallback_port_handler(taskman_connection, NULL);

        printf(NAME ": Accepting connections\n");
        (void)task_set_retval(self_id, EOK, false);
        async_manager();

        /* not reached */
        return 0;
}

/**
 * @}
 */