dmc.c

test file nucleus source

    return(NU_SUCCESS);
}


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      DMC_Delete_Memory_Pool                                           */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function deletes a dynamic memory pool and removes it from  */
/*      the list of created memory pools.  All tasks suspended on the    */
/*      memory pool are resumed with the appropriate error status.       */
/*      Note that this function does not free any memory associated with */
/*      either the pool area or the pool control block.                  */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*      DMCE_Delete_Memory_Pool             Error checking shell         */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      CSC_Remove_From_List                Remove node from list        */
/*      [HIC_Make_History_Entry]            Make entry in history log    */
/*      TCC_Resume_Task                     Resume a suspended task      */
/*      [TCT_Check_Stack]                   Stack checking function      */
/*      TCT_Control_To_System               Transfer control to system   */
/*      TCT_Protect                         Protect created list         */
/*      TCT_Set_Current_Protect             Modify current protection    */
/*      TCT_System_Protect                  Setup system protection      */
/*      TCT_System_Unprotect                Release system protection    */
/*      TCT_Unprotect                       Release protection           */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      pool_ptr                            Memory pool control block    */
/*                                            pointer                    */
/*                                                                       */
/* OUTPUTS                                                               */
/*                                                                       */
/*      NU_SUCCESS                                                       */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         DATE                    REMARKS                               */
/*                                                                       */
/*      03-01-1993      Created initial version 1.0                      */
/*      04-19-1993      Verified version 1.0                             */
/*      03-01-1994      Changed function interfaces to                   */
/*                      match those in prototype,                        */
/*                      added register options, changed                  */
/*                      protection logic to reduce                       */
/*                      overhead, resulting in                           */
/*                      version 1.1                                      */
/*                                                                       */
/*      03-18-1994      Verified version 1.1                             */
/*                                                                       */
/*************************************************************************/
STATUS  DMC_Delete_Memory_Pool(NU_MEMORY_POOL *pool_ptr)
{

R1 DM_PCB      *pool;                       /* Pool control block ptr    */
DM_SUSPEND     *suspend_ptr;                /* Suspend block pointer     */
DM_SUSPEND     *next_ptr;                   /* Next suspend block        */
STATUS          preempt;                    /* Status for resume call    */
NU_SUPERV_USER_VARIABLES

    /* Switch to supervisor mode */
    NU_SUPERVISOR_MODE();

    /* Move input pool pointer into internal pointer.  */
    pool =  (DM_PCB *) pool_ptr;

#ifdef  NU_ENABLE_STACK_CHECK

    /* Call stack checking function to check for an overflow condition.  */
    TCT_Check_Stack();

#endif

#ifdef  NU_ENABLE_HISTORY

    /* Make an entry that corresponds to this function in the system history
       log.  */
    HIC_Make_History_Entry(NU_DELETE_MEMORY_POOL_ID, (UNSIGNED) pool,
                                        (UNSIGNED) 0, (UNSIGNED) 0);

#endif

    /* Protect against simultaneous access to the memory pool.  */
    TCT_Protect(&(pool -> dm_protect));

#ifdef INCLUDE_PROVIEW
    _RTProf_DumpMemoryPool(RT_PROF_DELETE_MEMORY_POOL,pool,RT_PROF_OK);
#endif /*INCLUDE_PROVIEW*/
    /* Clear the memory pool ID.  */
    pool -> dm_id =  0;

    /* Release protection.  */
    TCT_Unprotect();

    /* Protect against access to the list of created memory pools.  */
    TCT_Protect(&DMD_List_Protect);

    /* Remove the memory pool from the list of created memory pools.  */
    CSC_Remove_From_List(&DMD_Created_Pools_List, &(pool -> dm_created));

    /* Decrement the total number of created memory pools.  */
    DMD_Total_Pools--;

    /* Pickup the suspended task pointer list.  */
    suspend_ptr =  pool -> dm_suspension_list;

    /* Walk the chain task(s) currently suspended on the memory pool.  */
    preempt =  0;
    while (suspend_ptr)
    {

        /* Protect against system access.  */
        TCT_System_Protect();

        /* Resume the suspended task.  Insure that the status returned is
           NU_POOL_DELETED.  */
        suspend_ptr -> dm_return_pointer =  NU_NULL;
        suspend_ptr -> dm_return_status =   NU_POOL_DELETED;

        /* Point to the next suspend structure in the link.  */
        next_ptr =  (DM_SUSPEND *) (suspend_ptr -> dm_suspend_link.cs_next);

        /* Resume the specified task.  */
        preempt =  preempt |
            TCC_Resume_Task((NU_TASK *) suspend_ptr -> dm_suspended_task,
                                                NU_MEMORY_SUSPEND);

        /* Determine if the next is the same as the current pointer.  */
        if (next_ptr == pool -> dm_suspension_list)

            /* Clear the suspension pointer to signal the end of the list
               traversal.  */
            suspend_ptr =  NU_NULL;
        else

            /* Move the next pointer into the suspend block pointer.  */
            suspend_ptr =  next_ptr;

        /* Modify current protection.  */
        TCT_Set_Current_Protect(&DMD_List_Protect);

        /* Clear the system protection.  */
        TCT_System_Unprotect();
    }

    /* Determine if preemption needs to occur.  */
    if (preempt)

        /* Transfer control to system to facilitate preemption.  */
        TCT_Control_To_System();

    /* Release protection against access to the list of created memory
       pools. */
    TCT_Unprotect();

    /* Return to user mode */
    NU_USER_MODE();

    /* Return a successful completion.  */
    return(NU_SUCCESS);
}


/*************************************************************************/
/*                                                                       */
/* FUNCTION                                                              */
/*                                                                       */
/*      DMC_Allocate_Memory                                              */
/*                                                                       */
/* DESCRIPTION                                                           */
/*                                                                       */
/*      This function allocates memory from the specified dynamic memory */
/*      pool.  If dynamic memory is currently available, this function   */
/*      is completed immediately.  Otherwise, if there is not enough     */
/*      memory currently available, task suspension is possible.         */
/*                                                                       */
/* CALLED BY                                                             */
/*                                                                       */
/*      Application                                                      */
/*      DMCE_Allocate_Memory                Error checking shell         */
/*                                                                       */
/* CALLS                                                                 */
/*                                                                       */
/*      CSC_Place_On_List                   Place on suspend list        */
/*      [HIC_Make_History_Entry]            Make entry in history log    */
/*      TCC_Suspend_Task                    Suspend calling task         */
/*      TCC_Task_Priority                   Pickup task priority         */
/*      [TCT_Check_Stack]                   Stack checking function      */
/*      TCT_Current_Thread                  Pickup current thread pointer*/
/*      TCT_Protect                         Protect memory pool          */
/*      TCT_Set_Suspend_Protect             Save suspend protection      */
/*      TCT_System_Protect                  Protect system structures    */
/*      TCT_Unprotect                       Release protection           */
/*      TCT_Unprotect_Specific              Release specific protection  */
/*                                                                       */
/* INPUTS                                                                */
/*                                                                       */
/*      pool_ptr                            Memory pool pointer          */
/*      return_pointer                      Pointer to the destination   */
/*                                            memory pointer             */
/*      size                                Number of bytes requested    */
/*      suspend                             Suspension option if full    */
/*                                                                       */
/* OUTPUTS                                                               */
/*                                                                       */
/*      NU_SUCCESS                          If service is successful     */
/*      NU_NO_MEMORY                        Memory not available         */
/*      NU_TIMEOUT                          If timeout on service        */
/*      NU_POOL_DELETED                     If memory pool deleted       */
/*                                            during suspension          */
/*                                                                       */
/* HISTORY                                                               */
/*                                                                       */
/*         DATE                    REMARKS                               */
/*                                                                       */
/*      03-01-1993      Created initial version 1.0                      */
/*      04-19-1993      Verified version 1.0                             */
/*      03-01-1994      Changed function interfaces to                   */
/*                      match those in prototype,                        */
/*                      added register options, changed                  */
/*                      protection logic to reduce                       */
/*                      overhead, resulting in                           */
/*                      version 1.1                                      */
/*                                                                       */
/*      03-18-1994      Verified version 1.1                             */
/*                                                                       */
/*************************************************************************/
STATUS  DMC_Allocate_Memory(NU_MEMORY_POOL *pool_ptr, VOID **return_pointer,
                                        UNSIGNED size, UNSIGNED suspend)
{

R1 DM_PCB      *pool;                       /* Pool control block ptr    */
R2 DM_SUSPEND  *suspend_ptr;                /* Pointer to suspend block  */
DM_SUSPEND      suspend_block;              /* Allocate suspension block */
R4 DM_HEADER   *memory_ptr;                 /* Pointer to memory         */
R3 DM_HEADER   *new_ptr;                    /* New split block pointer   */
UNSIGNED        free_size;                  /* Size of block found       */
TC_TCB         *task;                       /* Task pointer              */
STATUS          status;                     /* Completion status         */
NU_SUPERV_USER_VARIABLES

    /* Switch to supervisor mode */
    NU_SUPERVISOR_MODE();

    /* Move input pool pointer into internal pointer.  */
    pool =  (DM_PCB *) pool_ptr;


#ifdef  NU_ENABLE_STACK_CHECK

    /* Call stack checking function to check for an overflow condition.  */
    TCT_Check_Stack();

#endif

#ifdef  NU_ENABLE_HISTORY

    /* Make an entry that corresponds to this function in the system history
       log.  */
    HIC_Make_History_Entry(NU_ALLOCATE_MEMORY_ID, (UNSIGNED) pool,
                                (UNSIGNED) return_pointer, (UNSIGNED) size);