source: mainline/uspace/lib/libc/generic/task.c@ 94e152a

/*
 * Copyright (c) 2006 Jakub Jermar
 * Copyright (c) 2008 Jiri Svoboda
 * 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.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */ 

#include <task.h>
#include <ipc/ipc.h>
#include <ipc/loader.h>
#include <libc.h>
#include <string.h>
#include <stdlib.h>
#include <async.h>
#include <errno.h>
#include <vfs/vfs.h>

task_id_t task_get_id(void)
{
        task_id_t task_id;

        (void) __SYSCALL1(SYS_TASK_GET_ID, (sysarg_t) &task_id);

        return task_id;
}

static int task_spawn_loader(void)
{
        int phone_id, rc;

        rc = __SYSCALL1(SYS_PROGRAM_SPAWN_LOADER, (sysarg_t) &phone_id);
        if (rc != 0)
                return rc;

        return phone_id;
}

static int loader_set_args(int phone_id, const char *argv[])
{
        aid_t req;
        ipc_call_t answer;
        ipcarg_t rc;

        const char **ap;
        char *dp;
        char *arg_buf;
        size_t buffer_size;
        size_t len;

        /* 
         * Serialize the arguments into a single array. First
         * compute size of the buffer needed.
         */
        ap = argv;
        buffer_size = 0;
        while (*ap != NULL) {
                buffer_size += strlen(*ap) + 1;
                ++ap;
        }

        arg_buf = malloc(buffer_size);
        if (arg_buf == NULL) return ENOMEM;

        /* Now fill the buffer with null-terminated argument strings */
        ap = argv;
        dp = arg_buf;
        while (*ap != NULL) {
                strcpy(dp, *ap);
                dp += strlen(*ap) + 1;

                ++ap;
        }

        /* Send serialized arguments to the loader */

        req = async_send_0(phone_id, LOADER_SET_ARGS, &answer);
        rc = ipc_data_write_start(phone_id, (void *)arg_buf, buffer_size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                return rc;
        }

        async_wait_for(req, &rc);
        if (rc != EOK) return rc;

        /* Free temporary buffer */
        free(arg_buf);

        return EOK;
}

/** Create a new task by running an executable from VFS.
 *
 * @param path  pathname of the binary to execute
 * @param argv  command-line arguments
 * @return      ID of the newly created task or zero on error.
 */
task_id_t task_spawn(const char *path, const char *argv[])
{
        int phone_id;
        ipc_call_t answer;
        aid_t req;
        int rc;
        ipcarg_t retval;

        char *pa;
        size_t pa_len;
        task_id_t task_id;

        pa = absolutize(path, &pa_len);
        if (!pa)
                return 0;

        /* Spawn a program loader */    
        phone_id = task_spawn_loader();
        if (phone_id < 0)
                return 0;

        /*
         * Say hello so that the loader knows the incoming connection's
         * phone hash.
         */
        rc = async_req_0_0(phone_id, LOADER_HELLO);
        if (rc != EOK)
                return 0;

        /* Get task ID. */
        req = async_send_0(phone_id, LOADER_GET_TASKID, &answer);
        rc = ipc_data_read_start(phone_id, &task_id, sizeof(task_id));
        if (rc != EOK) {
                async_wait_for(req, NULL);
                goto error;
        }

        async_wait_for(req, &retval);
        if (retval != EOK)
                goto error;

        /* Send program pathname */
        req = async_send_0(phone_id, LOADER_SET_PATHNAME, &answer);
        rc = ipc_data_write_start(phone_id, (void *)pa, pa_len);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                return 1;
        }

        async_wait_for(req, &retval);
        if (retval != EOK)
                goto error;

        /* Send arguments */
        rc = loader_set_args(phone_id, argv);
        if (rc != EOK)
                goto error;

        /* Request loader to start the program */       
        rc = async_req_0_0(phone_id, LOADER_RUN);
        if (rc != EOK)
                goto error;

        /* Success */
        ipc_hangup(phone_id);
        return task_id;

        /* Error exit */
error:
        ipc_hangup(phone_id);
        return 0;
}

/** @}
 */