txe_tc.c

ThreadX优秀的硬实时操作系统.This Express Start Guide is designed to help you install and use ThreadX for the

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/*                                                                        */ 
/*            Copyright (c) 1996-2000 by Express Logic Inc.               */ 
/*                                                                        */ 
/*  This software is copyrighted by and is the sole property of Express   */ 
/*  Logic, Inc.  All rights, title, ownership, or other interests         */ 
/*  in the software remain the property of Express Logic, Inc.  This      */ 
/*  software may only be used in accordance with the corresponding        */ 
/*  license agreement.  Any unauthorized use, duplication, transmission,  */ 
/*  distribution, or disclosure of this software is expressly forbidden.  */ 
/*                                                                        */
/*  This Copyright notice may not be removed or modified without prior    */ 
/*  written consent of Express Logic, Inc.                                */ 
/*                                                                        */ 
/*  Express Logic, Inc. reserves the right to modify this software        */ 
/*  without notice.                                                       */ 
/*                                                                        */ 
/*  Express Logic, Inc.                                                   */
/*  11440 West Bernardo Court               [e-mail]         */
/*  Suite 366                               http://www.expresslogic.com   */
/*  San Diego, CA  92127                                                  */
/*                                                                        */
/**************************************************************************/


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/**                                                                       */ 
/** ThreadX Component                                                     */ 
/**                                                                       */
/**   Thread Control (THR)                                                */
/**                                                                       */
/**************************************************************************/
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#define TX_SOURCE_CODE


/* Include necessary system files.  */

#include    "tx_api.h"
#include    "tx_ini.h"
#include    "tx_thr.h"
#include    "tx_tim.h"


/**************************************************************************/ 
/*                                                                        */ 
/*  FUNCTION                                               RELEASE        */ 
/*                                                                        */ 
/*    _txe_thread_create                                  PORTABLE C      */ 
/*                                                           3.0f         */ 
/*  AUTHOR                                                                */ 
/*                                                                        */ 
/*    William E. Lamie, Express Logic, Inc.                               */ 
/*                                                                        */ 
/*  DESCRIPTION                                                           */ 
/*                                                                        */ 
/*    This function checks for errors in the thread create function call. */ 
/*                                                                        */ 
/*  INPUT                                                                 */ 
/*                                                                        */ 
/*    thread_ptr                            Thread control block pointer  */ 
/*    name                                  Pointer to thread name string */ 
/*    entry_function                        Entry function of the thread  */ 
/*    entry_input                           32-bit input value to thread  */ 
/*    stack_start                           Pointer to start of stack     */ 
/*    stack_size                            Stack size in bytes           */ 
/*    priority                              Priority of thread (0-31)     */ 
/*    preempt_threshold                     Preemption threshold          */
/*    time_slice                            Thread time-slice value       */ 
/*    auto_start                            Automatic start selection     */ 
/*                                                                        */ 
/*  OUTPUT                                                                */ 
/*                                                                        */ 
/*    TX_THREAD_ERROR                       Invalid thread pointer        */ 
/*    TX_PTR_ERROR                          Invalid entry point or stack  */ 
/*                                            address                     */ 
/*    TX_SIZE_ERROR                         Invalid stack size -too small */ 
/*    TX_PRIORITY_ERROR                     Invalid thread priority       */ 
/*    TX_THRESH_ERROR                       Invalid preemption threshold  */ 
/*    status                                Actual completion status      */ 
/*                                                                        */ 
/*  CALLS                                                                 */ 
/*                                                                        */ 
/*    _tx_thread_create                     Actual thread create function */ 
/*                                                                        */ 
/*  CALLED BY                                                             */ 
/*                                                                        */ 
/*    Application Code                                                    */ 
/*                                                                        */ 
/*  RELEASE HISTORY                                                       */ 
/*                                                                        */ 
/*    DATE              NAME                      DESCRIPTION             */ 
/*                                                                        */ 
/*  12-31-1996     William E. Lamie         Initial Version 3.0           */ 
/*  11-11-1997     William E. Lamie         Modified comment(s),          */ 
/*                                            resulting in version 3.0b.  */ 
/*  01-01-1999     William E. Lamie         Modified comment(s),          */ 
/*                                            resulting in version 3.0e.  */ 
/*  11-01-1999     William E. Lamie         Modified comment(s),          */ 
/*                                            resulting in version 3.0f.  */ 
/*                                                                        */ 
/**************************************************************************/ 
UINT    _txe_thread_create(TX_THREAD *thread_ptr, CHAR *name, 
			    VOID (*entry_function)(ULONG), ULONG entry_input,
			    VOID *stack_start, ULONG stack_size, 
			    UINT priority, UINT preempt_threshold,
			    ULONG time_slice, UINT auto_start)
{

REG_1   UINT        status;                 /* Return status           */


    /* First, check for an invalid thread pointer.  */
    if ((!thread_ptr) || (thread_ptr -> tx_thread_id == TX_THREAD_ID))
    
        /* Thread pointer is invalid, return appropriate error code.  */
        return(TX_THREAD_ERROR);

    /* Check for invalid starting address of stack or the thread entry point.  */
    if ((!stack_start) || (!entry_function))

        /* Invalid stack or entry point, return appropriate error code.  */
        return(TX_PTR_ERROR);

    /* Check the stack size.  */
    if (stack_size < TX_MINIMUM_STACK)

        /* Stack is not big enough, return appropriate error code.  */
        return(TX_SIZE_ERROR);

    /* Check the priority specified.  */
    if (priority >= TX_MAX_PRIORITIES)

        /* Invalid priority selected, return appropriate error code.  */
        return(TX_PRIORITY_ERROR);

    /* Check preemption threshold. */
    if (preempt_threshold > priority)

        /* Invalid preempt threshold, return appropriate error code.  */
        return(TX_THRESH_ERROR);

    /* Check the start selection.  */
    if (auto_start > TX_AUTO_START)

        /* Invalid auto start selection, return appropriate error code.  */
        return(TX_START_ERROR);

    /* Check for invalid caller of this function.  */
    if (((!_tx_thread_current_ptr) && (_tx_thread_system_state != TX_INITIALIZE_IN_PROGRESS)) ||
        ((_tx_thread_current_ptr) && (_tx_thread_system_state)) ||
        (_tx_thread_current_ptr == &_tx_timer_thread))

        /* Invalid caller of this function, return appropriate error code.  */
        return(TX_CALLER_ERROR);

    /* Call actual thread create function.  */
    status =  _tx_thread_create(thread_ptr, name, entry_function, entry_input,
			        stack_start, stack_size, priority, preempt_threshold,
			        time_slice, auto_start);

    /* Return actual completion status.  */
    return(status);
}