qus.c
来自「nucleus 2006 source code」· C语言 代码 · 共 1,017 行 · 第 1/3 页
C
1,017 行
/*************************************************************************/
/* */
/* Copyright Mentor Graphics Corporation 2004 */
/* All Rights Reserved. */
/* */
/* THIS WORK CONTAINS TRADE SECRET AND PROPRIETARY INFORMATION WHICH IS */
/* THE PROPERTY OF MENTOR GRAPHICS CORPORATION OR ITS LICENSORS AND IS */
/* SUBJECT TO LICENSE TERMS. */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* FILE NAME VERSION */
/* */
/* qus.c Nucleus PLUS 1.15 */
/* */
/* COMPONENT */
/* */
/* QU - Queue Management */
/* */
/* DESCRIPTION */
/* */
/* This file contains supplemental routines for the Queue */
/* Management component. */
/* */
/* DATA STRUCTURES */
/* */
/* None */
/* */
/* FUNCTIONS */
/* */
/* QUS_Reset_Queue Reset a queue */
/* QUS_Send_To_Front_Of_Queue Send message to queue's front*/
/* QUS_Broadcast_To_Queue Broadcast a message to queue */
/* */
/* DEPENDENCIES */
/* */
/* cs_extr.h Common Service functions */
/* tc_extr.h Thread Control functions */
/* qu_extr.h Queue functions */
/* hi_extr.h History functions */
/* */
/*************************************************************************/
#define NU_SOURCE_FILE
#include "plus/inc/cs_extr.h" /* Common service functions */
#include "plus/inc/tc_extr.h" /* Thread control functions */
#include "plus/inc/qu_extr.h" /* Queue functions */
#include "plus/inc/hi_extr.h" /* History functions */
/* Define internal component function prototypes. */
VOID QUC_Cleanup(VOID *information);
/*************************************************************************/
/* */
/* FUNCTION */
/* */
/* QUS_Reset_Queue */
/* */
/* DESCRIPTION */
/* */
/* This function resets the specified queue back to the original */
/* state. Any messages in the queue are discarded. Also, any */
/* tasks currently suspended on the queue are resumed with the */
/* reset status. */
/* */
/* CALLED BY */
/* */
/* Application */
/* QUSE_Reset_Queue Error checking shell */
/* */
/* CALLS */
/* */
/* [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_System_Protect Protect queue data structures*/
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* queue_ptr Queue control block pointer */
/* */
/* OUTPUTS */
/* */
/* NU_SUCCESS */
/* */
/*************************************************************************/
STATUS QUS_Reset_Queue(NU_QUEUE *queue_ptr)
{
R1 QU_QCB *queue; /* Queue control block ptr */
QU_SUSPEND *suspend_ptr; /* Suspend block pointer */
QU_SUSPEND *next_ptr; /* Next suspend block pointer*/
STATUS preempt; /* Status for resume call */
NU_SUPERV_USER_VARIABLES
/* Move input queue pointer into internal pointer. */
queue = (QU_QCB *) queue_ptr;
/* Switch to supervisor mode */
NU_SUPERVISOR_MODE();
#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_RESET_QUEUE_ID, (UNSIGNED) queue,
(UNSIGNED) 0, (UNSIGNED) 0);
#endif
/* Protect against access to the queue. */
TCT_System_Protect();
/* Pickup the suspended task suspension list. */
suspend_ptr = queue -> qu_suspension_list;
/* Walk the chain task(s) currently suspended on the queue. */
preempt = 0;
while (suspend_ptr)
{
/* Resume the suspended task. Insure that the status returned is
NU_QUEUE_RESET. */
suspend_ptr -> qu_return_status = NU_QUEUE_RESET;
/* Point to the next suspend structure in the link. */
next_ptr = (QU_SUSPEND *) (suspend_ptr -> qu_suspend_link.cs_next);
/* Resume the specified task. */
preempt = preempt |
TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task,
NU_QUEUE_SUSPEND);
/* Determine if the next is the same as the head pointer. */
if (next_ptr == queue -> qu_suspension_list)
/* Clear the suspension pointer to signal the end of the list
traversal. */
suspend_ptr = NU_NULL;
else
/* Position the suspend pointer to the next suspend block. */
suspend_ptr = next_ptr;
}
/* Pickup the urgent message suspension list. */
suspend_ptr = queue -> qu_urgent_list;
/* Walk the chain task(s) currently suspended on the queue. */
while (suspend_ptr)
{
/* Resume the suspended task. Insure that the status returned is
NU_QUEUE_RESET. */
suspend_ptr -> qu_return_status = NU_QUEUE_RESET;
/* Point to the next suspend structure in the link. */
next_ptr = (QU_SUSPEND *) (suspend_ptr -> qu_suspend_link.cs_next);
/* Resume the specified task. */
preempt = preempt |
TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task,
NU_QUEUE_SUSPEND);
/* Determine if the next is the same as the head pointer. */
if (next_ptr == queue -> qu_urgent_list)
/* Clear the suspension pointer to signal the end of the list
traversal. */
suspend_ptr = NU_NULL;
else
/* Position suspend pointer to the next suspend block. */
suspend_ptr = next_ptr;
}
/* Initialize various elements of the queue. */
queue -> qu_available = queue -> qu_end - queue -> qu_start;
queue -> qu_messages = 0;
queue -> qu_read = queue -> qu_start;
queue -> qu_write = queue -> qu_start;
queue -> qu_tasks_waiting = 0;
queue -> qu_suspension_list = NU_NULL;
queue -> qu_urgent_list = NU_NULL;
#ifdef NU_PROFILE_PLUS
PRF_PLUS_QUS_RESET_QUEUE_0
#endif /* NU_PROFILE_PLUS */
/* 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 queue. */
TCT_Unprotect();
/* Return to user mode */
NU_USER_MODE();
/* Return a successful completion. */
return(NU_SUCCESS);
}
/*************************************************************************/
/* */
/* FUNCTION */
/* */
/* QUS_Send_To_Front_Of_Queue */
/* */
/* DESCRIPTION */
/* */
/* This function sends a message to the front of the specified */
/* message queue. The message length is determined by the caller. */
/* If there are any tasks suspended on the queue for a message, the */
/* message is copied into the message area of the first waiting */
/* task and that task is resumed. If there is enough room in the */
/* queue, the message is copied in front of all other messages. */
/* If there is not enough room in the queue, suspension of the */
/* caller is possible. */
/* */
/* CALLED BY */
/* */
/* Application */
/* QUSE_Send_To_Front_Of_Queue Error checking shell */
/* */
/* CALLS */
/* */
/* CSC_Place_On_List Place on suspend list */
/* CSC_Remove_From_List Remove from suspend list */
/* [HIC_Make_History_Entry] Make entry in history log */
/* TCC_Resume_Task Resume a suspended task */
/* TCC_Suspend_Task Suspend calling task */
/* [TCT_Check_Stack] Stack checking function */
/* TCT_Control_To_System Transfer control to system */
/* TCT_Current_Thread Pickup current thread pointer*/
/* TCT_System_Protect Protect queue */
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* queue_ptr Queue control block pointer */
/* message Pointer to message to send */
/* size Size of message to send */
/* suspend Suspension option if full */
/* */
/* OUTPUTS */
/* */
/* NU_SUCCESS If service is successful */
/* NU_QUEUE_FULL If queue is currently full */
/* NU_TIMEOUT If timeout on service expires*/
/* NU_QUEUE_DELETED If queue was deleted during */
/* suspension */
/* NU_QUEUE_RESET If queue was reset during */
/* suspension */
/* */
/*************************************************************************/
STATUS QUS_Send_To_Front_Of_Queue(NU_QUEUE *queue_ptr, VOID *message,
UNSIGNED size, UNSIGNED suspend)
{
R1 QU_QCB *queue; /* Queue control block ptr */
QU_SUSPEND suspend_block; /* Allocate suspension block */
QU_SUSPEND *suspend_ptr; /* Pointer to suspend block */
R3 UNSIGNED_PTR source; /* Pointer to source */
R4 UNSIGNED_PTR destination; /* Pointer to destination */
UNSIGNED copy_size; /* Partial copy size */
R2 INT i; /* Working counter */
TC_TCB *task; /* Task pointer */
STATUS preempt; /* Preempt flag */
STATUS status; /* Completion status */
NU_SUPERV_USER_VARIABLES
/* Switch to supervisor mode */
NU_SUPERVISOR_MODE();
/* Move input queue pointer into internal pointer. */
queue = (QU_QCB *) queue_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_SEND_TO_FRONT_OF_QUEUE_ID, (UNSIGNED) queue,
(UNSIGNED) message, (UNSIGNED) size);
#endif
/* Initialize the status as successful. */
status = NU_SUCCESS;
/* Protect against simultaneous access to the queue. */
TCT_System_Protect();
/* Determine if an extra word of overhead needs to be added to the
calculation. */
if (queue -> qu_fixed_size)
/* No overhead. */
i = 0;
else
{
/* Variable messages have one additional word of overhead. */
i = 1;
/* Make special check to see if a suspension needs to be
forced for a variable length message. */
if ((queue -> qu_suspension_list) && (queue -> qu_messages))
{
/* Pickup task control block pointer. */
task = (TC_TCB *) TCT_Current_Thread();
⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?