/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation
 * Copyright (c) 2026-present Eclipse ThreadX contributors
 *
 * This program and the accompanying materials are made available under the
 * terms of the MIT License which is available at
 * https://opensource.org/licenses/MIT.
 *
 * SPDX-License-Identifier: MIT
 **************************************************************************/

// Portions of this file were generated with AI assistance.


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** ThreadX Component                                                     */
/**                                                                       */
/**   Thread                                                              */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define TX_SOURCE_CODE


/* Include necessary system files.  */

#include "tx_api.h"
#include "tx_trace.h"
#include "tx_thread.h"


/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _tx_thread_delete                                   PORTABLE C      */
/*                                                           6.1          */
/*  AUTHOR                                                                */
/*                                                                        */
/*    William E. Lamie, Microsoft Corporation                             */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*    This function handles application delete thread requests.  The      */
/*    thread to delete must be in a terminated or completed state,        */
/*    otherwise this function just returns an error code.                 */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    thread_ptr                            Pointer to thread to suspend  */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    status                                Return completion status      */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    None                                                                */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    Application code                                                    */
/*                                                                        */
/**************************************************************************/
UINT  _tx_thread_delete(TX_THREAD *thread_ptr)
{

TX_INTERRUPT_SAVE_AREA

TX_THREAD       *next_thread;
TX_THREAD       *previous_thread;
UINT            status;


    /* Default status to success.  */
    status =  TX_SUCCESS;

    /* Lockout interrupts while the thread is being deleted.  */
    TX_DISABLE

    /* Check for proper status of this thread to delete.  */
    if (thread_ptr -> tx_thread_state != TX_COMPLETED)
    {

        /* Now check for terminated state.  */
        if (thread_ptr -> tx_thread_state != TX_TERMINATED)
        {

            /* Restore interrupts.  */
            TX_RESTORE

            /* Thread not completed or terminated - return an error!  */
            status =  TX_DELETE_ERROR;
        }
    }

    /* The state is terminal, but a terminal state on its own is not authorization to
       release the control block.  Both paths that produce one -- thread completion in
       _tx_thread_shell_entry and thread termination in _tx_thread_terminate -- publish
       TX_COMPLETED or TX_TERMINATED, and then run this thread's exit notification
       callback, before the thread has been detached from the ready list and before
       those services have finished with the pointer they hold to it.  The suspending
       flag is set for exactly that interval, so a thread whose flag is still set is
       part-way through the transition.  */
    if (status == TX_SUCCESS)
    {

        /* Is the completion or termination transition still in progress?  */
        if (thread_ptr -> tx_thread_suspending == TX_TRUE)
        {

            /* Restore interrupts.  */
            TX_RESTORE

            /* Yes, refuse the delete rather than unlink a thread the scheduler is
               still holding.  The condition is transient: the caller may retry once
               the transition has finished.  */
            status =  TX_DELETE_ERROR;
        }
    }

    /* Determine if the delete operation is okay.  */
    if (status == TX_SUCCESS)
    {

        /* Yes, continue with deleting the thread.  */

        /* Perform any additional activities for tool or user purpose.  */
        TX_THREAD_DELETE_EXTENSION(thread_ptr)

        /* If trace is enabled, insert this event into the trace buffer.  */
        TX_TRACE_IN_LINE_INSERT(TX_TRACE_THREAD_DELETE, thread_ptr, TX_POINTER_TO_ULONG_CONVERT(&next_thread), 0, 0, TX_TRACE_THREAD_EVENTS)

        /* If trace is enabled, unregister this object.  */
        TX_TRACE_OBJECT_UNREGISTER(thread_ptr)

        /* Log this kernel call.  */
        TX_EL_THREAD_DELETE_INSERT

        /* Unregister thread in the thread array structure.  */
        TX_EL_THREAD_UNREGISTER(thread_ptr)

        /* Clear the thread ID to make it invalid.  */
        thread_ptr -> tx_thread_id =  TX_CLEAR_ID;

        /* Decrement the number of created threads.  */
        _tx_thread_created_count--;

        /* See if the thread is the only one on the list.  */
        if (_tx_thread_created_count == TX_EMPTY)
        {

            /* Only created thread, just set the created list to NULL.  */
            _tx_thread_created_ptr =  TX_NULL;
        }
        else
        {

            /* Otherwise, not the only created thread, link-up the neighbors.  */
            next_thread =                                thread_ptr -> tx_thread_created_next;
            previous_thread =                            thread_ptr -> tx_thread_created_previous;
            next_thread -> tx_thread_created_previous =  previous_thread;
            previous_thread -> tx_thread_created_next =  next_thread;

            /* See if we have to update the created list head pointer.  */
            if (_tx_thread_created_ptr == thread_ptr)
            {

                /* Yes, move the head pointer to the next link. */
                _tx_thread_created_ptr =  next_thread;
            }
        }

        /* Execute Port-Specific completion processing. If needed, it is typically defined in tx_port.h.  */
        TX_THREAD_DELETE_PORT_COMPLETION(thread_ptr)

        /* Restore interrupts.  */
        TX_RESTORE
    }

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