?? evc.c
字號:
/* 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_EVENT_GROUP_ID, (UNSIGNED) event_group,
(UNSIGNED) 0, (UNSIGNED) 0);
#endif
/* Protect against simultaneous access to the event group. */
TCT_System_Protect();
#ifdef INCLUDE_PROVIEW
_RTProf_DumpEventGroup(RT_PROF_DELETE_EVENT_GROUP, event_group, RT_PROF_OK);
#endif /*INCLUDE_PROVIEW*/
/* Clear the event group ID. */
event_group -> ev_id = 0;
/* Release protection. */
TCT_Unprotect();
/* Protect against access to the list of created event groups. */
TCT_Protect(&EVD_List_Protect);
/* Remove the event_group from the list of created event groups. */
CSC_Remove_From_List(&EVD_Created_Event_Groups_List,
&(event_group -> ev_created));
/* Decrement the total number of created event groups. */
EVD_Total_Event_Groups--;
/* Pickup the suspended task pointer list. */
suspend_ptr = event_group -> ev_suspension_list;
/* Walk the chain task(s) currently suspended on the event_group. */
preempt = 0;
while (suspend_ptr)
{
/* Protect against system access. */
TCT_System_Protect();
/* Resume the suspended task. Insure that the status returned is
NU_GROUP_DELETED. */
suspend_ptr -> ev_return_status = NU_GROUP_DELETED;
/* Point to the next suspend structure in the link. */
next_ptr = (EV_SUSPEND *) (suspend_ptr -> ev_suspend_link.cs_next);
/* Resume the specified task. */
preempt = preempt |
TCC_Resume_Task((NU_TASK *) suspend_ptr -> ev_suspended_task,
NU_EVENT_SUSPEND);
/* Determine if the next is the same as the current pointer. */
if (next_ptr == event_group -> ev_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(&EVD_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
event groups. */
TCT_Unprotect();
/* Return to user mode */
NU_USER_MODE();
/* Return a successful completion. */
return(NU_SUCCESS);
}
/*************************************************************************/
/* */
/* FUNCTION */
/* */
/* EVC_Set_Events */
/* */
/* DESCRIPTION */
/* */
/* This function sets event flags within the specified event flag */
/* group. Event flags may be ANDed or ORed against the current */
/* events of the group. Any task that is suspended on the group */
/* that has its request satisfied is resumed. */
/* */
/* CALLED BY */
/* */
/* Application */
/* EVCE_Set_Events Error checking shell */
/* */
/* CALLS */
/* */
/* CSC_Remove_From_List Remove from suspend 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_System_Protect Protect event group */
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* event_group_ptr Event Group control block ptr*/
/* events Event flag setting */
/* operation Operation to perform on the */
/* event flag group (AND/OR) */
/* */
/* OUTPUTS */
/* */
/* NU_SUCCESS If service is successful */
/* */
/* 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 */
/* 11-19-1996 Corrected SPR190. */
/* */
/*************************************************************************/
STATUS EVC_Set_Events(NU_EVENT_GROUP *event_group_ptr, UNSIGNED events,
OPTION operation)
{
R1 EV_GCB *event_group; /* Event control block ptr */
R2 EV_SUSPEND *suspend_ptr; /* Pointer to suspension blk */
R3 EV_SUSPEND *next_ptr; /* Pointer to next suspend */
R4 EV_SUSPEND *last_ptr; /* Last suspension block ptr */
UNSIGNED consume; /* Event flags to consume */
UNSIGNED compare; /* Event comparison variable */
INT preempt; /* Preemption required flag */
NU_SUPERV_USER_VARIABLES
/* Switch to supervisor mode */
NU_SUPERVISOR_MODE();
/* Move input event group pointer into internal pointer. */
event_group = (EV_GCB *) event_group_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_SET_EVENTS_ID, (UNSIGNED) event_group,
(UNSIGNED) events, (UNSIGNED) operation);
#endif
/* Protect against simultaneous access to the event group. */
TCT_System_Protect();
/* Perform the specified operation on the current event flags in the
group. */
if (operation & EV_AND)
/* AND the specified events with the current events. */
event_group -> ev_current_events =
event_group -> ev_current_events & events;
else
/* OR the specified events with the current events. */
event_group -> ev_current_events =
event_group -> ev_current_events | events;
#ifdef INCLUDE_PROVIEW
_RTProf_DumpEventGroup(RT_PROF_SET_EVENTS,event_group , RT_PROF_OK);
#endif /*INCLUDE_PROVIEW*/
/* Determine if there are any tasks suspended for events from this
event flag group. */
if (event_group -> ev_suspension_list)
{
/* Initialize the consumption bits to 0. */
consume = 0;
/* Now, walk the chain of tasks suspended on this event flag group to
determine if any of their requests can be satisfied. */
suspend_ptr = event_group -> ev_suspension_list;
/* Setup a pointer to the last suspension block. */
last_ptr = (EV_SUSPEND *) suspend_ptr -> ev_suspend_link.cs_previous;
/* Clear the preempt flag. */
preempt = 0;
do
{
/* Determine if this request has been satisfied. */
/* First, find the event flags in common. */
compare = event_group -> ev_current_events &
suspend_ptr -> ev_requested_events;
/* Second, determine if all the event flags must match. */
if (suspend_ptr -> ev_operation & EV_AND)
/* Yes, an AND condition is present. All requested events
must be present. */
compare = (compare == suspend_ptr -> ev_requested_events);
/* Setup the next pointer. Note that this must be done before
the suspended task is resumed, since its suspend block could
get corrupted. */
next_ptr = (EV_SUSPEND *) suspend_ptr -> ev_suspend_link.cs_next;
/* If compare is non-zero, the suspended task's event request is
satisfied. */
if (compare)
{
/* Decrement the number of tasks waiting counter. */
event_group -> ev_tasks_waiting--;
/* Determine if consumption is requested. */
if (suspend_ptr -> ev_operation & EV_CONSUME)
/* Keep track of the event flags to consume. */
consume = consume | suspend_ptr -> ev_requested_events;
/* Remove the first suspended block from the list. */
CSC_Remove_From_List((CS_NODE **)
&(event_group -> ev_suspension_list),
&(suspend_ptr -> ev_suspend_link));
/* Setup the appropriate return value. */
suspend_ptr -> ev_return_status = NU_SUCCESS;
suspend_ptr -> ev_actual_events =
event_group -> ev_current_events;
/* Resume the suspended task. */
preempt = preempt |
TCC_Resume_Task((NU_TASK *) suspend_ptr -> ev_suspended_task,
NU_EVENT_SUSPEND);
}
/* Determine if there is another suspension block to examine. */
if (suspend_ptr != last_ptr)
/* More to examine in the suspension list. Look at the
next suspend block. */
suspend_ptr = next_ptr;
else
/* End of the list has been reached. Set the suspend pointer
to NULL to end the search. */
suspend_ptr = NU_NULL;
} while (suspend_ptr);
/* Apply all of the gathered consumption bits. */
event_group -> ev_current_events =
event_group -> ev_current_events & ~consume;
/* Determine if a preempt condition is present. */
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -