📄 mbs.c
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/*************************************************************************/
/* */
/* Copyright (c) 1993-2001 Accelerated Technology, Inc. */
/* */
/* PROPRIETARY RIGHTS of Accelerated Technology are involved in the */
/* subject matter of this material. All manufacturing, reproduction, */
/* use, and sales rights pertaining to this subject matter are governed */
/* by the license agreement. The recipient of this software implicitly */
/* accepts the terms of the license. */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* FILE NAME VERSION */
/* */
/* mbs.c PLUS 1.13 */
/* */
/* COMPONENT */
/* */
/* MB - Mailbox Management */
/* */
/* DESCRIPTION */
/* */
/* This file contains the core routines for the Mailbox management */
/* component. */
/* */
/* AUTHOR */
/* */
/* Accelerated Technology, Inc. */
/* */
/* DATA STRUCTURES */
/* */
/* None */
/* */
/* FUNCTIONS */
/* */
/* MBS_Reset_Mailbox Reset a mailbox */
/* MBS_Broadcast_To_Mailbox Broadcast a mailbox message */
/* */
/* DEPENDENCIES */
/* */
/* cs_extr.h Common Service functions */
/* tc_extr.h Thread Control functions */
/* mb_extr.h Mailbox functions */
/* hi_extr.h History functions */
/* */
/* HISTORY */
/* */
/* DATE REMARKS */
/* */
/* 03-01-1994 Initial version of supplemental */
/* mailbox service file, */
/* version 1.1 */
/* */
/* 03-18-1994 Verified version 1.1 */
/* 04-17-1996 updated to version 1.2 */
/* 03-24-1998 Released version 1.3 */
/* 04-23-2001 Fixed problem with resuming task in */
/* MBS_Broadcast_To_Mailbox */
/*************************************************************************/
#define NU_SOURCE_FILE
#include "cs_extr.h" /* Common service functions */
#include "tc_extr.h" /* Thread control functions */
#include "mb_extr.h" /* Mailbox functions */
#include "hi_extr.h" /* History functions */
/* Define internal component function prototypes. */
VOID MBC_Cleanup(VOID *information);
/*************************************************************************/
/* */
/* FUNCTION */
/* */
/* MBS_Reset_Mailbox */
/* */
/* DESCRIPTION */
/* */
/* This function resets a mailbox back to the initial state. Any */
/* message in the mailbox is discarded. Also, all tasks suspended */
/* on the mailbox are resumed with the reset completion status. */
/* */
/* AUTHOR */
/* */
/* Accelerated Technology, Inc. */
/* */
/* CALLED BY */
/* */
/* Application */
/* MBSE_Reset_Mailbox 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 mailbox */
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* mailbox_ptr Mailbox control block pointer*/
/* */
/* OUTPUTS */
/* */
/* NU_SUCCESS */
/* */
/* HISTORY */
/* */
/* NAME DATE REMARKS */
/* */
/* 03-01-1993 Created initial version 1.0 */
/* 04-19-1993 Verified version 1.0 */
/* 03-01-1994 Changed function interface to */
/* match the prototype, added */
/* register variable logic, */
/* optimized protection logic, */
/* resulting in version 1.1 */
/* */
/* 03-18-1994 Verified version 1.1 */
/* */
/*************************************************************************/
STATUS MBS_Reset_Mailbox(NU_MAILBOX *mailbox_ptr)
{
R1 MB_MCB *mailbox; /* Mailbox control block ptr */
R2 MB_SUSPEND *suspend_ptr; /* Suspend block pointer */
MB_SUSPEND *next_ptr; /* Next suspend block pointer*/
STATUS preempt; /* Status for resume call */
/* Move input mailbox pointer into internal pointer. */
mailbox = (MB_MCB *) mailbox_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_RESET_MAILBOX_ID, (UNSIGNED) mailbox,
(UNSIGNED) 0, (UNSIGNED) 0);
#endif
/* Protect against access to the mailbox. */
TCT_System_Protect();
/* Pickup the suspended task pointer list. */
suspend_ptr = mailbox -> mb_suspension_list;
/* Walk the chain task(s) currently suspended on the mailbox. */
preempt = 0;
while (suspend_ptr)
{
/* Resume the suspended task. Insure that the status returned is
NU_MAILBOX_RESET. */
suspend_ptr -> mb_return_status = NU_MAILBOX_RESET;
/* Point to the next suspend structure in the link. */
next_ptr = (MB_SUSPEND *) (suspend_ptr -> mb_suspend_link.cs_next);
/* Resume the specified task. */
preempt = preempt |
TCC_Resume_Task((NU_TASK *) suspend_ptr -> mb_suspended_task,
NU_MAILBOX_SUSPEND);
/* Determine if the next is the same as the head pointer. */
if (next_ptr == mailbox -> mb_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;
}
/* Initialize the mailbox. */
mailbox -> mb_message_present = NU_FALSE;
mailbox -> mb_tasks_waiting = 0;
mailbox -> mb_suspension_list = NU_NULL;
#ifdef INCLUDE_PROVIEW
_RTProf_DumpMailBox(RT_PROF_RESET_MAILBOX,mailbox,RT_PROF_OK);
#endif
/* Determine if preemption needs to occur. */
if (preempt)
/* Transfer control to system to facilitate preemption. */
TCT_Control_To_System();
/* Release protection. */
TCT_Unprotect();
/* Return a successful completion. */
return(NU_SUCCESS);
}
/*************************************************************************/
/* */
/* FUNCTION */
/* */
/* MBS_Broadcast_To_Mailbox */
/* */
/* DESCRIPTION */
/* */
/* This function sends a message to all tasks currently waiting for */
/* a message from the mailbox. If no tasks are waiting, this */
/* service behaves like a normal send message. */
/* */
/* AUTHOR */
/* */
/* Accelerated Technology, Inc. */
/* */
/* CALLED BY */
/* */
/* Application */
/* MBSE_Broadcast_To_Mailbox Broadcast to a mailbox */
/* */
/* CALLS */
/* */
/* CSC_Place_On_List Place on suspend list */
/* CSC_Priority_Place_On_List Place on priority 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 */
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