?? mbc.c
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/* [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 Setup current protection ptr */
/* TCT_System_Protect Protect against system access*/
/* TCT_System_Unprotect Release system protection */
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* mailbox_ptr Mailbox 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 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 MBC_Delete_Mailbox(NU_MAILBOX *mailbox_ptr)
{
R1 MB_MCB *mailbox; /* Mailbox control block ptr */
MB_SUSPEND *suspend_ptr; /* Suspend block pointer */
MB_SUSPEND *next_ptr; /* Next suspend block pointer*/
STATUS preempt; /* Status for resume call */
NU_SUPERV_USER_VARIABLES
/* Switch to supervisor mode */
NU_SUPERVISOR_MODE();
/* 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_DELETE_MAILBOX_ID, (UNSIGNED) mailbox,
(UNSIGNED) 0, (UNSIGNED) 0);
#endif
/* Call protection just in case another thread is using the mailbox. */
TCT_System_Protect();
#ifdef INCLUDE_PROVIEW
_RTProf_DumpMailBox(RT_PROF_DELETE_MAILBOX,mailbox,RT_PROF_OK);
#endif /* INCLUDE_PROVIEW */
/* Clear the mailbox ID. */
mailbox -> mb_id = 0;
/* Clear protection. */
TCT_Unprotect();
/* Protect against access to the list of created mailboxes. */
TCT_Protect(&MBD_List_Protect);
/* Remove the mailbox from the list of created mailboxes. */
CSC_Remove_From_List(&MBD_Created_Mailboxes_List,
&(mailbox -> mb_created));
/* Decrement the total number of created mailboxes. */
MBD_Total_Mailboxes--;
/* 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)
{
/* Protect against system access. */
TCT_System_Protect();
/* Resume the suspended task. Insure that the status returned is
NU_MAILBOX_DELETED. */
suspend_ptr -> mb_return_status = NU_MAILBOX_DELETED;
/* 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;
/* Setup current protection pointer. */
TCT_Set_Current_Protect(&MBD_List_Protect);
/* Unprotect 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 mailboxes. */
TCT_Unprotect();
/* Return to user mode */
NU_USER_MODE();
/* Return a successful completion. */
return(NU_SUCCESS);
}
/*************************************************************************/
/* */
/* FUNCTION */
/* */
/* MBC_Send_To_Mailbox */
/* */
/* DESCRIPTION */
/* */
/* This function sends a 4-word message to the specified mailbox. */
/* If there are one or more tasks suspended on the mailbox for a */
/* message, the message is copied into the message area of the */
/* first task waiting and that task is resumed. If the mailbox */
/* is full, suspension of the calling task is possible. */
/* */
/* CALLED BY */
/* */
/* Application */
/* MBCE_Send_To_Mailbox Error checking shell */
/* */
/* 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 */
/* TCC_Task_Priority Pickup task's priority */
/* [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 against system access*/
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* mailbox_ptr Mailbox control block pointer*/
/* message Pointer to message to send */
/* suspend Suspension option if full */
/* */
/* OUTPUTS */
/* */
/* NU_SUCCESS If service is successful */
/* NU_MAILBOX_FULL If mailbox is currently full */
/* NU_TIMEOUT If timeout on service expires*/
/* NU_MAILBOX_DELETED If mailbox is deleted during */
/* suspension */
/* NU_MAILBOX_RESET If mailbox is 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 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 MBC_Send_To_Mailbox(NU_MAILBOX *mailbox_ptr, VOID *message,
UNSIGNED suspend)
{
R1 MB_MCB *mailbox; /* Mailbox control block ptr */
MB_SUSPEND suspend_block; /* Allocate suspension block */
R2 MB_SUSPEND *suspend_ptr; /* Pointer to suspend block */
R3 UNSIGNED *source_ptr; /* Pointer to source */
R4 UNSIGNED *destination_ptr; /* Pointer to destination */
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 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_SEND_TO_MAILBOX_ID, (UNSIGNED) mailbox,
(UNSIGNED) message, (UNSIGNED) suspend);
#endif
/* Initialize the status as successful. */
status = NU_SUCCESS;
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