?? pic.c
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/* */
/* DESCRIPTION */
/* */
/* This function deletes a pipe and removes it from the list of */
/* created pipes. All tasks suspended on the pipe are */
/* resumed. Note that this function does not free the memory */
/* associated with the pipe. */
/* */
/* CALLED BY */
/* */
/* Application */
/* PICE_Delete_Pipe 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 Protect against system access*/
/* TCT_System_Unprotect Release system protection */
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* pipe_ptr Pipe 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 PIC_Delete_Pipe(NU_PIPE *pipe_ptr)
{
R1 PI_PCB *pipe; /* Pipe control block ptr */
PI_SUSPEND *suspend_ptr; /* Suspend block pointer */
PI_SUSPEND *next_ptr; /* Next suspension block ptr */
STATUS preempt; /* Status for resume call */
NU_SUPERV_USER_VARIABLES
/* Switch to supervisor mode */
NU_SUPERVISOR_MODE();
/* Move input pipe pointer into internal pointer. */
pipe = (PI_PCB *) pipe_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_PIPE_ID, (UNSIGNED) pipe,
(UNSIGNED) 0, (UNSIGNED) 0);
#endif
/* Protect against access to the pipe. */
TCT_System_Protect();
#ifdef INCLUDE_PROVIEW
_RTProf_DumpPipe(RT_PROF_DELETE_PIPE,pipe,RT_PROF_OK);
#endif /* INCLUDE_PROVIEW */
/* Clear the pipe ID. */
pipe -> pi_id = 0;
/* Release protection. */
TCT_Unprotect();
/* Protect against access to the list of created pipes. */
TCT_Protect(&PID_List_Protect);
/* Remove the pipe from the list of created pipes. */
CSC_Remove_From_List(&PID_Created_Pipes_List, &(pipe -> pi_created));
/* Decrement the total number of created pipes. */
PID_Total_Pipes--;
/* Pickup the suspended task pointer list. */
suspend_ptr = pipe -> pi_suspension_list;
/* Walk the chain task(s) currently suspended on the pipe. */
preempt = 0;
while (suspend_ptr)
{
/* Protect against system access. */
TCT_System_Protect();
/* Resume the suspended task. Insure that the status returned is
NU_PIPE_DELETED. */
suspend_ptr -> pi_return_status = NU_PIPE_DELETED;
/* Point to the next suspend structure in the link. */
next_ptr = (PI_SUSPEND *) (suspend_ptr -> pi_suspend_link.cs_next);
/* Resume the specified task. */
preempt = preempt |
TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task,
NU_PIPE_SUSPEND);
/* Determine if the next is the same as the head pointer. */
if (next_ptr == pipe -> pi_suspension_list)
/* Clear the suspension pointer to signal the end of the list
traversal. */
suspend_ptr = NU_NULL;
else
/* Setup the next suspension pointer. */
suspend_ptr = next_ptr;
/* Modify current protection. */
TCT_Set_Current_Protect(&PID_List_Protect);
/* Clear the system protection. */
TCT_System_Unprotect();
}
/* Pickup the urgent message suspension list. */
suspend_ptr = pipe -> pi_urgent_list;
/* Walk the chain task(s) currently suspended on the pipe. */
while (suspend_ptr)
{
/* Protect against system access. */
TCT_System_Protect();
/* Resume the suspended task. Insure that the status returned is
NU_PIPE_DELETED. */
suspend_ptr -> pi_return_status = NU_PIPE_DELETED;
/* Point to the next suspend structure in the link. */
next_ptr = (PI_SUSPEND *) (suspend_ptr -> pi_suspend_link.cs_next);
/* Resume the specified task. */
preempt = preempt |
TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task,
NU_PIPE_SUSPEND);
/* Determine if the next is the same as the head pointer. */
if (next_ptr == pipe -> pi_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 block. */
suspend_ptr = next_ptr;
/* Modify current protection. */
TCT_Set_Current_Protect(&PID_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 pipes. */
TCT_Unprotect();
/* Return to user mode */
NU_USER_MODE();
/* Return a successful completion. */
return(NU_SUCCESS);
}
/*************************************************************************/
/* */
/* FUNCTION */
/* */
/* PIC_Send_To_Pipe */
/* */
/* DESCRIPTION */
/* */
/* This function sends a message to the specified pipe. The */
/* message length is determined by the caller. If there are one */
/* or more tasks suspended on the pipe for a message, the message */
/* is copied into the message area of the first waiting task. If */
/* the task's request is satisfied, it is resumed. Otherwise, if */
/* the pipe cannot hold the message, suspension of the calling */
/* task is an option of the caller. */
/* */
/* CALLED BY */
/* */
/* Application */
/* PICE_Send_To_Pipe 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 pipe */
/* TCT_Unprotect Release protection */
/* */
/* INPUTS */
/* */
/* pipe_ptr Pipe 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_PIPE_FULL If pipe is currently full */
/* NU_TIMEOUT If timeout on service expires*/
/* NU_PIPE_DELETED If pipe was deleted during */
/* suspension */
/* NU_PIPE_RESET If pipe was reset 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, optimized copy loop, */
/* resulting in version 1.1 */
/* */
/* 03-18-1994 Verified version 1.1 */
/* */
/*************************************************************************/
STATUS PIC_Send_To_Pipe(NU_PIPE *pipe_ptr, VOID *message, UNSIGNED size,
UNSIGNED suspend)
{
R1 PI_PCB *pipe; /* Pipe control block ptr */
PI_SUSPEND suspend_block; /* Allocate suspension block */
PI_SUSPEND *suspend_ptr; /* Pointer to suspend block */
R2 BYTE_PTR source; /* Pointer to source */
R3 BYTE_PTR destination; /* Pointer to destination */
UNSIGNED copy_size; /* Partial copy size */
R4 INT i; /* Working counter */
UNSIGNED pad = 0; /* Number of pad bytes */
TC_TCB *task; /* Task pointer */
STATUS preempt; /* Preempt flag */
STATUS status; /* Completion status */
NU_SUPERV_USER_VARIABLES
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