source: mainline/uspace/srv/taskman/main.c@ 780c8ce

/*
 * 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 <adt/prodcons.h>
#include <assert.h>
#include <async.h>
#include <errno.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"

//TODO move to appropriate header file
extern async_sess_t *session_primary;

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

static prodcons_t sess_queue;


/*
 * Static functions
 */
static void connect_to_loader(ipc_callid_t iid, ipc_call_t *icall)
{
        /* We don't accept the connection request, we forward it instead to
         * freshly spawned loader. */
        int rc = loader_spawn("loader");
        
        if (rc != EOK) {
                printf(NAME ": %s -> %i\n", __func__, rc);
                async_answer_0(iid, 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_fast(iid, exch,
            IPC_GET_ARG2(*icall),
            IPC_GET_ARG3(*icall),
            0, IPC_FF_NONE);
        async_exchange_end(exch);

        /* After forward we can dispose all session-related resources
         * TODO later could be recycled for notification API
         */
        async_hangup(sess_ref->sess);
        free(sess_ref);

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

        /* Everything OK. */
}

static void loader_to_ns(ipc_callid_t iid, ipc_call_t *icall)
{
        /* Do no accept connection request, forward it instead. */
        async_exch_t *exch = async_exchange_begin(session_primary);
        int rc = async_forward_fast(iid, exch, 0, 0, 0, IPC_FF_NONE);
        async_exchange_end(exch);

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

static void taskman_ctl_wait(ipc_callid_t iid, 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->in_task_id;

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

static void taskman_ctl_retval(ipc_callid_t iid, ipc_call_t *icall)
{
        printf("%s:%i from %llu\n", __func__, __LINE__, icall->in_task_id);
        task_id_t sender = icall->in_task_id;
        int retval = IPC_GET_ARG1(*icall);
        bool wait_for_exit = IPC_GET_ARG2(*icall);

        int rc = task_set_retval(sender, retval, wait_for_exit);
        async_answer_0(iid, rc);
}

static void taskman_ctl_ev_callback(ipc_callid_t iid, ipc_call_t *icall)
{
        printf("%s:%i from %llu\n", __func__, __LINE__, icall->in_task_id);
        /* Atomic -- will be used for notifications only */
        async_sess_t *sess = async_callback_receive(EXCHANGE_ATOMIC);
        if (sess == NULL) {
                async_answer_0(iid, ENOMEM);
                return;
        }

        int rc = event_register_listener(icall->in_task_id, sess);
        async_answer_0(iid, rc);
}

static void task_exit_event(ipc_callid_t iid, 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);
        printf("%s:%i from %llu/%i\n", __func__, __LINE__, id, exit_reason);
        task_terminated(id, exit_reason);
}

static void task_fault_event(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        task_id_t id = MERGE_LOUP32(IPC_GET_ARG1(*icall), IPC_GET_ARG2(*icall));
        printf("%s:%i from %llu\n", __func__, __LINE__, id);
        task_failed(id);
}

static void control_connection_loop(void)
{
        while (true) {
                ipc_call_t call;
                ipc_callid_t callid = async_get_call(&call);

                if (!IPC_GET_IMETHOD(call)) {
                        /* Client disconnected */
                        break;
                }

                switch (IPC_GET_IMETHOD(call)) {
                case TASKMAN_WAIT:
                        taskman_ctl_wait(callid, &call);
                        break;
                case TASKMAN_RETVAL:
                        taskman_ctl_retval(callid, &call);
                        break;
                case TASKMAN_EVENT_CALLBACK:
                        taskman_ctl_ev_callback(callid, &call);
                        break;
                default:
                        async_answer_0(callid, ENOENT);
                }
        }
}

static void control_connection(ipc_callid_t iid, ipc_call_t *icall)
{
        /* TODO remove/redesign the workaround
         * Call task_intro here for boot-time tasks,
         * probably they should announce themselves explicitly
         * or taskman should detect them from kernel's list of tasks.
         */
        int rc = task_intro(icall, false);

        /* First, accept connection */
        async_answer_0(iid, rc);

        if (rc != EOK) {
                return;
        }

        control_connection_loop();
}

static void loader_callback(ipc_callid_t iid, ipc_call_t *icall)
{
        // 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(iid, ENOMEM);
        }

        /* Create callback connection */
        sess_ref->sess = async_callback_receive_start(EXCHANGE_ATOMIC, icall);
        if (sess_ref->sess == NULL) {
                async_answer_0(iid, EINVAL);
                return;
        }

        /* Remember task_id */
        int rc = task_intro(icall, true);

        if (rc != EOK) {
                async_answer_0(iid, rc);
                free(sess_ref);
                return;
        }
        async_answer_0(iid, EOK);

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

static void taskman_connection(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        taskman_interface_t iface = IPC_GET_ARG1(*icall);
        switch (iface) {
        case TASKMAN_CONNECT_TO_LOADER:
                connect_to_loader(iid, icall);
                break;
        case TASKMAN_LOADER_TO_NS:
                loader_to_ns(iid, icall);
                break;
        case TASKMAN_CONTROL:
                control_connection(iid, icall);
                break;
        default:
                /* Unknown interface */
                async_answer_0(iid, ENOENT);
        }
}

static void implicit_connection(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        taskman_interface_t iface = IPC_GET_ARG1(*icall);
        switch (iface) {
        case TASKMAN_LOADER_CALLBACK:
                loader_callback(iid, icall);
                control_connection_loop();
                break;
        default:
                /* Unknown interface on implicit connection */
                async_answer_0(iid, EHANGUP);
        }
}


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

        /* Initialization */
        prodcons_initialize(&sess_queue);
        int rc = task_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("Cannot register for exit events (%i).\n", rc);
                return rc;
        }

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

        /* We're service too */
        rc = service_register(SERVICE_TASKMAN);
        if (rc != EOK) {
                printf("Cannot register at naming service (%i).\n", rc);
                return rc;
        }

        /* Start sysman server */
        async_set_client_connection(taskman_connection);
        async_set_implicit_connection(implicit_connection);

        printf(NAME ": Accepting connections\n");
        //TODO task_retval(EOK);
        async_manager();

        /* not reached */
        return 0;
}

/**
 * @}
 */