FreeCalypso > hg > ffs-editor
diff src/nucleus/quc.c @ 0:92470e5d0b9e
src: partial import from FC Selenite
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Fri, 15 May 2020 01:28:16 +0000 |
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| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/nucleus/quc.c Fri May 15 01:28:16 2020 +0000 @@ -0,0 +1,1496 @@ +/*************************************************************************/ +/* */ +/* Copyright Mentor Graphics Corporation 2002 */ +/* 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 */ +/* */ +/* quc.c Nucleus PLUS 1.14 */ +/* */ +/* COMPONENT */ +/* */ +/* QU - Queue Management */ +/* */ +/* DESCRIPTION */ +/* */ +/* This file contains the core routines for the Queue management */ +/* component. */ +/* */ +/* DATA STRUCTURES */ +/* */ +/* None */ +/* */ +/* FUNCTIONS */ +/* */ +/* QUC_Create_Queue Create a message queue */ +/* QUC_Delete_Queue Delete a message queue */ +/* QUC_Send_To_Queue Send message to a queue */ +/* QUC_Receive_From_Queue Receive a message from queue */ +/* QUC_Cleanup Cleanup on timeout or a */ +/* terminate condition */ +/* */ +/* DEPENDENCIES */ +/* */ +/* cs_extr.h Common Service functions */ +/* tc_extr.h Thread Control functions */ +/* qu_extr.h Queue functions */ +/* hi_extr.h History functions */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* 08-09-1993 Corrected pointer retrieval */ +/* loop, resulting in version 1.0a */ +/* 08-09-1993 Verified version 1.0a */ +/* 11-01-1993 Corrected a problem with fixed- */ +/* size queues of a size equal to */ +/* one message, resulting in */ +/* version 1.0b */ +/* 11-01-1993 Verified version 1.0b */ +/* 03-01-1994 Moved non-core functions into */ +/* supplemental files, changed */ +/* function interfaces to match */ +/* those in prototype, added */ +/* register options, changed */ +/* protection logic to reduce */ +/* overhead, corrected bug in */ +/* queue reset, optimized item */ +/* copy loops, resulting in */ +/* version 1.1 */ +/* */ +/* 03-18-1994 Verified version 1.1 */ +/* 04-17-1996 updated to version 1.2 */ +/* 01-28-1998 Corrected SPR412 resulting in */ +/* version 1.2a. */ +/* 03-24-1998 Released version 1.3 */ +/* 03-26-1999 Released 1.11m (new release */ +/* numbering scheme) */ +/* 04-17-2002 Released version 1.13m */ +/* 11-07-2002 Released version 1.14 */ +/*************************************************************************/ +#define NU_SOURCE_FILE + + +#include "cs_extr.h" /* Common service functions */ +#include "tc_extr.h" /* Thread control functions */ +#include "qu_extr.h" /* Queue functions */ +#include "hi_extr.h" /* History functions */ + + +/* Define external inner-component global data references. */ + +extern CS_NODE *QUD_Created_Queues_List; +extern UNSIGNED QUD_Total_Queues; +extern TC_PROTECT QUD_List_Protect; + + +/* Define internal component function prototypes. */ + +VOID QUC_Cleanup(VOID *information); + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* QUC_Create_Queue */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function creates a queue and then places it on the list */ +/* of created queues. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* QUCE_Create_Queue Error checking shell */ +/* */ +/* CALLS */ +/* */ +/* CSC_Place_On_List Add node to linked-list */ +/* [HIC_Make_History_Entry] Make entry in history log */ +/* [TCT_Check_Stack] Stack checking function */ +/* TCT_Protect Protect created list */ +/* TCT_Unprotect Un-protect data structure */ +/* */ +/* INPUTS */ +/* */ +/* queue_ptr Queue control block pointer */ +/* name Queue name */ +/* start_address Starting address of actual */ +/* queue area */ +/* queue_size Total size of queue */ +/* message_type Type of message supported by */ +/* the queue (fixed/variable) */ +/* message_size Size of message. Variable */ +/* message-length queues, this*/ +/* represents the maximum size*/ +/* suspend_type Suspension type */ +/* */ +/* 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, */ +/* resulting in version 1.1 */ +/* */ +/* 03-18-1994 Verified version 1.1 */ +/* */ +/*************************************************************************/ +STATUS QUC_Create_Queue(NU_QUEUE *queue_ptr, CHAR *name, + VOID *start_address, UNSIGNED queue_size, + OPTION message_type, UNSIGNED message_size, + OPTION suspend_type) +{ + +R1 QU_QCB *queue; /* Queue control block ptr */ +INT i; /* Working index variable */ +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_CREATE_QUEUE_ID, (UNSIGNED) queue, + (UNSIGNED) name, (UNSIGNED) start_address); + +#endif + + /* First, clear the queue ID just in case it is an old Queue + Control Block. */ + queue -> qu_id = 0; + + /* Fill in the queue name. */ + for (i = 0; i < NU_MAX_NAME; i++) + queue -> qu_name[i] = name[i]; + + /* Setup the queue suspension type. */ + if (suspend_type == NU_FIFO) + + /* FIFO suspension is selected, setup the flag accordingly. */ + queue -> qu_fifo_suspend = NU_TRUE; + + else + + /* Priority suspension is selected. */ + queue -> qu_fifo_suspend = NU_FALSE; + + /* Setup the queue message type. */ + if (message_type == NU_FIXED_SIZE) + + /* Fixed-size messages are required. */ + queue -> qu_fixed_size = NU_TRUE; + else + + /* Variable-size messages are required. */ + queue -> qu_fixed_size = NU_FALSE; + + /* Setup the message size. */ + queue -> qu_message_size = message_size; + + /* Clear the messages counter. */ + queue -> qu_messages = 0; + + /* Setup the actual queue parameters. */ + queue -> qu_queue_size = queue_size; + + /* If the queue supports fixed-size messages, make sure that the queue + size is an even multiple of the message size. */ + if (queue -> qu_fixed_size) + + /* Adjust the area of the queue being used. */ + queue_size = (queue_size / message_size) * message_size; + + queue -> qu_available = queue_size; + queue -> qu_start = (UNSIGNED *) start_address; + queue -> qu_end = queue -> qu_start + queue_size; + queue -> qu_read = (UNSIGNED *) start_address; + queue -> qu_write = (UNSIGNED *) start_address; + + /* Clear the suspension list pointer. */ + queue -> qu_suspension_list = NU_NULL; + + /* Clear the number of tasks waiting on the queue counter. */ + queue -> qu_tasks_waiting = 0; + + /* Clear the urgent message list pointer. */ + queue -> qu_urgent_list = NU_NULL; + + /* Initialize link pointers. */ + queue -> qu_created.cs_previous = NU_NULL; + queue -> qu_created.cs_next = NU_NULL; + + /* Protect against access to the list of created queues. */ + TCT_Protect(&QUD_List_Protect); + + /* At this point the queue is completely built. The ID can now be + set and it can be linked into the created queue list. */ + queue -> qu_id = QU_QUEUE_ID; + + /* Link the queue into the list of created queues and increment the + total number of queues in the system. */ + CSC_Place_On_List(&QUD_Created_Queues_List, &(queue -> qu_created)); + QUD_Total_Queues++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_CREATE_QUEUE,queue,RT_PROF_OK); +#endif + + /* Release protection against access to the list of created queues. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return successful completion. */ + return(NU_SUCCESS); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* QUC_Delete_Queue */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function deletes a queue and removes it from the list of */ +/* created queues. All tasks suspended on the queue are */ +/* resumed. Note that this function does not free the memory */ +/* associated with the queue. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* QUCE_Delete_Queue 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 Setup current protect pointer*/ +/* TCT_System_Protect Protect against system access*/ +/* TCT_System_Unprotect Release system protection */ +/* TCT_Unprotect Release protection */ +/* */ +/* INPUTS */ +/* */ +/* queue_ptr Queue 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 QUC_Delete_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_DELETE_QUEUE_ID, (UNSIGNED) queue, + (UNSIGNED) 0, (UNSIGNED) 0); + +#endif + + /* Protect against access to the queue. */ + TCT_System_Protect(); + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_DELETE_QUEUE,queue,RT_PROF_OK); +#endif + + /* Clear the queue ID. */ + queue -> qu_id = 0; + + /* Release protection. */ + TCT_Unprotect(); + + /* Protect against access to the list of created queues. */ + TCT_Protect(&QUD_List_Protect); + + /* Remove the queue from the list of created queues. */ + CSC_Remove_From_List(&QUD_Created_Queues_List, &(queue -> qu_created)); + + /* Decrement the total number of created queues. */ + QUD_Total_Queues--; + + /* Pickup the suspended task pointer list. */ + suspend_ptr = queue -> qu_suspension_list; + + /* Walk the chain task(s) currently suspended on the queue. */ + preempt = 0; + while (suspend_ptr) + { + + /* Protect against system access. */ + TCT_System_Protect(); + + /* Resume the suspended task. Insure that the status returned is + NU_QUEUE_DELETED. */ + suspend_ptr -> qu_return_status = NU_QUEUE_DELETED; + + /* 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 suspend pointer to the next pointer. */ + suspend_ptr = next_ptr; + + /* Modify current protection. */ + TCT_Set_Current_Protect(&QUD_List_Protect); + + /* Clear the system protection. */ + TCT_System_Unprotect(); + } + + /* 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) + { + + /* Protect against system access. */ + TCT_System_Protect(); + + /* Resume the suspended task. Insure that the status returned is + NU_QUEUE_DELETED. */ + suspend_ptr -> qu_return_status = NU_QUEUE_DELETED; + + /* 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 to the next suspend block in the list. */ + suspend_ptr = next_ptr; + + /* Modify current protection. */ + TCT_Set_Current_Protect(&QUD_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 queues. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return a successful completion. */ + return(NU_SUCCESS); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* QUC_Send_To_Queue */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function sends a message to the specified queue. The */ +/* message length is determined by the caller. If there are one */ +/* or more tasks suspended on the queue 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 queue cannot hold the message, suspension of the calling */ +/* task is an option of the caller. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* QUCE_Send_To_Queue 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 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 */ +/* */ +/* 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 QUC_Send_To_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_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(); + + /* Now we know that there are other task(s) are suspended trying + to send a variable length message. Determine whether or not + a suspension should be forced. */ + if ((queue -> qu_fifo_suspend) || + (suspend == NU_NO_SUSPEND) || + ((queue -> qu_suspension_list) -> qu_suspend_link.cs_priority <= + TCC_Task_Priority(task))) + + /* Bump the computed size to avoid placing the new variable + length message ahead of the suspended tasks. */ + i = (INT) queue -> qu_available; + } + } + + /* Determine if there is enough room in the queue for the message. The + extra logic is to prevent a variable-length message from sn*/ + if (queue -> qu_available < (size + i)) + { + + /* Queue does not have room for the message. Determine if + suspension is required. */ + if (suspend) + { + + /* Suspension is requested. */ + + /* Increment the number of tasks waiting. */ + queue -> qu_tasks_waiting++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_SEND_TO_QUEUE,queue,RT_PROF_WAIT); +#endif + + /* Setup the suspend block and suspend the calling task. */ + suspend_ptr = &suspend_block; + suspend_ptr -> qu_queue = queue; + suspend_ptr -> qu_suspend_link.cs_next = NU_NULL; + suspend_ptr -> qu_suspend_link.cs_previous = NU_NULL; + suspend_ptr -> qu_message_area = (UNSIGNED_PTR) message; + suspend_ptr -> qu_message_size = size; + task = (TC_TCB *) TCT_Current_Thread(); + suspend_ptr -> qu_suspended_task = task; + + /* Determine if priority or FIFO suspension is associated with the + queue. */ + if (queue -> qu_fifo_suspend) + { + + /* FIFO suspension is required. Link the suspend block into + the list of suspended tasks on this queue. */ + CSC_Place_On_List((CS_NODE **) &(queue -> qu_suspension_list), + &(suspend_ptr -> qu_suspend_link)); + } + else + { + + /* Get the priority of the current thread so the suspend block + can be placed in the appropriate place. */ + suspend_ptr -> qu_suspend_link.cs_priority = + TCC_Task_Priority(task); + + CSC_Priority_Place_On_List((CS_NODE **) + &(queue -> qu_suspension_list), + &(suspend_ptr -> qu_suspend_link)); + } + + /* Finally, suspend the calling task. Note that the suspension call + automatically clears the protection on the queue. */ + TCC_Suspend_Task((NU_TASK *) task, NU_QUEUE_SUSPEND, + QUC_Cleanup, suspend_ptr, suspend); + + /* Pickup the return status. */ + status = suspend_ptr -> qu_return_status; + } + else + { + + /* Return a status of NU_QUEUE_FULL because there is no + room in the queue for the message. */ + status = NU_QUEUE_FULL; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_SEND_TO_QUEUE,queue,RT_PROF_FAIL); +#endif + + } + } + else + { + + /* Determine if a task is waiting on an empty queue. */ + if ((queue -> qu_suspension_list) && (queue -> qu_messages == 0)) + { + + /* Task is waiting on an empty queue for a message. */ + + /* Decrement the number of tasks waiting on queue. */ + queue -> qu_tasks_waiting--; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_SEND_TO_QUEUE,queue,RT_PROF_OK); +#endif + + /* Remove the first suspended block from the list. */ + suspend_ptr = queue -> qu_suspension_list; + CSC_Remove_From_List((CS_NODE **) &(queue -> qu_suspension_list), + &(suspend_ptr -> qu_suspend_link)); + + /* Setup the source and destination pointers. */ + source = (UNSIGNED_PTR) message; + destination = suspend_ptr -> qu_message_area; + + /* Initialize the return status. */ + suspend_ptr -> qu_return_status = NU_SUCCESS; + + /* Loop to actually copy the message. */ + i = (INT) size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + + /* Return the size of the message copied. */ + suspend_ptr -> qu_actual_size = size; + + /* Wakeup the waiting task and check for preemption. */ + preempt = + TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task, + NU_QUEUE_SUSPEND); + + /* Determine if preemption needs to take place. */ + if (preempt) + + /* Transfer control to the system if the resumed task function + detects a preemption condition. */ + TCT_Control_To_System(); + } + else + { + + /* There is enough room in the queue and no task is waiting. */ + + /* Setup the source pointer. */ + source = (UNSIGNED_PTR) message; + destination = queue -> qu_write; + + /* Process according to the type of message supported. */ + if (queue -> qu_fixed_size) + { + + /* Fixed-size messages are supported by this queue. */ + + /* Loop to copy the message into the queue area. */ + i = (INT) size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + } + else + { + + /* Variable-size messages are supported. Processing must + check for queue wrap-around conditions. */ + + /* Place message size in first location. */ + *(destination++) = size; + + /* Check for a wrap-around condition on the queue. */ + if (destination >= queue -> qu_end) + + /* Wrap the write pointer back to the top of the queue + area. */ + destination = queue -> qu_start; + + /* Decrement the number of words remaining by 1 for this + extra word of overhead. */ + queue -> qu_available--; + + /* Calculate the number of words remaining from the write + pointer to the bottom of the queue. */ + copy_size = queue -> qu_end - destination; + + /* Determine if the message needs to be wrapped around the + edge of the queue area. */ + if (copy_size >= size) + { + + /* Copy the whole message at once. */ + i = (INT) size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + } + else + { + + /* Copy the first half of the message. */ + i = (INT) copy_size; + do + { + *(destination) = *(source++); + if ((--i) == 0) + break; + destination++; + } while (1); + + /* Copy the second half of the message. */ + destination = queue -> qu_start; + i = (INT) (size - copy_size); + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + } + } + + /* Check again for wrap-around condition on the write pointer. */ + if (destination >= queue -> qu_end) + + /* Move the write pointer to the top of the queue area. */ + queue -> qu_write = queue -> qu_start; + else + + /* Simply copy the last position of the destination pointer + into the write pointer. */ + queue -> qu_write = destination; + + /* Decrement the number of available words. */ + queue -> qu_available = queue -> qu_available - size; + + /* Increment the number of messages in the queue. */ + queue -> qu_messages++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_SEND_TO_QUEUE,queue,RT_PROF_OK); +#endif + + } + } + + /* Release protection against access to the queue. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return the completion status. */ + return(status); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* QUC_Receive_From_Queue */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function receives a message from the specified queue. The */ +/* size of the message is specified by the caller. If there is a */ +/* message currently in the queue, the message is removed from the */ +/* queue and placed in the caller's area. Suspension is possible */ +/* if the request cannot be satisfied. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* QUCE_Receive_From_Queue 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 queue */ +/* TCT_Unprotect Release protection */ +/* */ +/* INPUTS */ +/* */ +/* queue_ptr Queue control block pointer */ +/* message Pointer to message to send */ +/* size Size of the message */ +/* actual_size Size of message received */ +/* suspend Suspension option if empty */ +/* */ +/* OUTPUTS */ +/* */ +/* NU_SUCCESS If service is successful */ +/* NU_QUEUE_EMPTY If queue is currently empty */ +/* 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 */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* 11-01-1993 Corrected a problem resuming a */ +/* task suspended on a full queue */ +/* that only has a capacity of a */ +/* single message, resulting in */ +/* version 1.0b */ +/* 11-01-1993 Verified version 1.0b */ +/* 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 */ +/* 01-28-1998 Corrected SPR412. */ +/* */ +/*************************************************************************/ +STATUS QUC_Receive_From_Queue(NU_QUEUE *queue_ptr, VOID *message, + UNSIGNED size, UNSIGNED *actual_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 */ +TC_TCB *task; /* Task pointer */ +UNSIGNED copy_size; /* Number of words to copy */ +R2 INT i; /* Working counter */ +STATUS preempt; /* Preemption flag */ +STATUS status; /* Completion status */ +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_RECEIVE_FROM_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 urgent message request is currently suspended. */ + if (queue -> qu_urgent_list) + { + + /* If so, copy the message from the suspended request block and + resume the associated task. */ + + /* Decrement the number of tasks waiting on queue. */ + queue -> qu_tasks_waiting--; + + /* Remove the first suspended block from the list. */ + suspend_ptr = queue -> qu_urgent_list; + CSC_Remove_From_List((CS_NODE **) &(queue -> qu_urgent_list), + &(suspend_ptr -> qu_suspend_link)); + + /* Setup the source and destination pointers. */ + destination = (UNSIGNED_PTR) message; + source = suspend_ptr -> qu_message_area; + + /* Initialize the return status. */ + suspend_ptr -> qu_return_status = NU_SUCCESS; + + /* Loop to actually copy the message. */ + i = (INT) suspend_ptr -> qu_message_size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + + /* Return the size of the message copied. */ + *actual_size = suspend_ptr -> qu_message_size; + + /* Wakeup the waiting task and check for preemption. */ + preempt = + TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task, + NU_QUEUE_SUSPEND); + + /* Determine if preemption needs to take place. */ + if (preempt) + + /* Transfer control to the system if the resumed task function + detects a preemption condition. */ + TCT_Control_To_System(); + } + + /* Determine if there are messages in the queue. */ + else if (queue -> qu_messages) + { + + /* Copy message from queue into the caller's area. */ + + /* Setup the source and destination pointers. */ + source = queue -> qu_read; + destination = (UNSIGNED_PTR) message; + + /* Process according to the type of message supported by the queue. */ + if (queue -> qu_fixed_size) + { + + /* Queue supports fixed-size messages. */ + + /* Copy the message from the queue area into the destination. */ + i = (INT) size; + do + { + *(destination) = *(source++); + if ((--i) == 0) + break; + destination++; + } while (1); + } + else + { + + /* Queue supports variable-size messages. */ + + /* Variable length message size is actually in the queue area. */ + size = *(source++); + + /* Check for a wrap-around condition on the queue. */ + if (source >= queue -> qu_end) + + /* Wrap the read pointer back to the top of the queue + area. */ + source = queue -> qu_start; + + /* Increment the number of available words in the queue. */ + queue -> qu_available++; + + /* Calculate the number of words remaining from the read pointer + to the bottom of the queue. */ + copy_size = queue -> qu_end - source; + + /* Determine if the message needs to be wrapped around the + edge of the queue area. */ + if (copy_size >= size) + { + + /* Copy the whole message at once. */ + i = (INT) size; + do + { + *(destination) = *(source++); + if ((--i) == 0) + break; + destination++; + } while (1); + } + else + { + + /* Copy the first half of the message. */ + i = (INT) copy_size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + + /* Copy the second half of the message. */ + source = queue -> qu_start; + i = (INT) (size - copy_size); + do + { + *(destination) = *(source++); + if ((--i) == 0) + break; + destination++; + } while (1); + } + } + + /* Check again for wrap-around condition on the read pointer. */ + if (source >= queue -> qu_end) + + /* Move the read pointer to the top of the queue area. */ + queue -> qu_read = queue -> qu_start; + else + + /* Move the read pointer to where the copy left off. */ + queue -> qu_read = source; + + /* Increment the number of available words. */ + queue -> qu_available = queue -> qu_available + size; + + /* Decrement the number of messages in the queue. */ + queue -> qu_messages--; + + /* Return the number of words received. */ + *actual_size = size; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_RECEIVE_FROM_QUEUE,queue,RT_PROF_OK); +#endif + + /* Determine if any tasks suspended on a full queue can be woken + up. */ + if (queue -> qu_suspension_list) + { + + /* Overhead of each queue message. */ + if (!queue -> qu_fixed_size) + + i = 1; + else + + i = 0; + + /* Pickup the suspension list and examine suspension blocks + to see if the message could now fit in the queue. */ + suspend_ptr = queue -> qu_suspension_list; + preempt = NU_FALSE; + while ((suspend_ptr) && + ((suspend_ptr -> qu_message_size + i) <= queue -> qu_available)) + { + + /* Place the suspended task's message into the queue. */ + + /* Setup the source and destination pointers. */ + source = suspend_ptr -> qu_message_area; + destination = queue -> qu_write; + size = suspend_ptr -> qu_message_size; + + /* Process according to the type of message supported. */ + if (queue -> qu_fixed_size) + { + + /* Fixed-size messages are supported by this queue. */ + + /* Loop to copy the message into the queue area. */ + i = (INT) size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + } + else + { + + /* Variable-size messages are supported. Processing must + check for queue wrap-around conditions. */ + + /* Place message size in first location. */ + *(destination++) = size; + + /* Check for a wrap-around condition on the queue. */ + if (destination >= queue -> qu_end) + + /* Wrap the write pointer back to the top of the queue + area. */ + destination = queue -> qu_start; + + /* Decrement the number of words remaining by 1 for this + extra word of overhead. */ + queue -> qu_available--; + + /* Calculate the number of words remaining from the write + pointer to the bottom of the queue. */ + copy_size = queue -> qu_end - destination; + + /* Determine if the message needs to be wrapped around the + edge of the queue area. */ + if (copy_size >= size) + { + + /* Copy the whole message at once. */ + i = (INT) size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while(1); + } + else + { + + /* Copy the first half of the message. */ + i = (INT) copy_size; + do + { + *(destination) = *(source++); + if ((--i) == 0) + break; + destination++; + } while (1); + + /* Copy the second half of the message. */ + destination = queue -> qu_start; + i = (INT) (size - copy_size); + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + } + } + + /* Check again for wrap-around condition on the write + pointer. */ + if (destination >= queue -> qu_end) + + /* Move the write pointer to the top of the queue area. */ + queue -> qu_write = queue -> qu_start; + else + + /* Simply copy the last position of the destination pointer + into the write pointer. */ + queue -> qu_write = destination; + + /* Decrement the number of available words. */ + queue -> qu_available = queue -> qu_available - size; + + /* Increment the number of messages in the queue. */ + queue -> qu_messages++; + + /* Decrement the number of tasks waiting counter. */ + queue -> qu_tasks_waiting--; + + /* Remove the first suspended block from the list. */ + CSC_Remove_From_List((CS_NODE **) + &(queue -> qu_suspension_list), + &(suspend_ptr -> qu_suspend_link)); + + /* Return a successful status. */ + suspend_ptr -> qu_return_status = NU_SUCCESS; + + /* Resume the suspended task. */ + preempt = preempt | + TCC_Resume_Task((NU_TASK *) suspend_ptr -> qu_suspended_task, + NU_QUEUE_SUSPEND); + + /* Setup suspend pointer to the head of the list. */ + suspend_ptr = queue -> qu_suspension_list; + + /* Overhead of each queue message. */ + if (!queue -> qu_fixed_size) + + i = 1; + else + + i = 0; + } + + /* Determine if a preempt condition is present. */ + if (preempt) + + /* Transfer control to the system if the resumed task function + detects a preemption condition. */ + TCT_Control_To_System(); + } + } + else + { + + /* Queue is empty. Determine if the task wants to suspend. */ + if (suspend) + { + + /* Increment the number of tasks waiting on the queue counter. */ + queue -> qu_tasks_waiting++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_RECEIVE_FROM_QUEUE,queue,RT_PROF_WAIT); +#endif + + /* Setup the suspend block and suspend the calling task. */ + suspend_ptr = &suspend_block; + suspend_ptr -> qu_queue = queue; + suspend_ptr -> qu_suspend_link.cs_next = NU_NULL; + suspend_ptr -> qu_suspend_link.cs_previous = NU_NULL; + suspend_ptr -> qu_message_area = (UNSIGNED_PTR) message; + suspend_ptr -> qu_message_size = size; + task = (TC_TCB *) TCT_Current_Thread(); + suspend_ptr -> qu_suspended_task = task; + + /* Determine if priority or FIFO suspension is associated with the + queue. */ + if (queue -> qu_fifo_suspend) + { + + /* FIFO suspension is required. Link the suspend block into + the list of suspended tasks on this queue. */ + CSC_Place_On_List((CS_NODE **) &(queue -> qu_suspension_list), + &(suspend_ptr -> qu_suspend_link)); + } + else + { + + /* Get the priority of the current thread so the suspend block + can be placed in the appropriate place. */ + suspend_ptr -> qu_suspend_link.cs_priority = + TCC_Task_Priority(task); + + CSC_Priority_Place_On_List((CS_NODE **) + &(queue -> qu_suspension_list), + &(suspend_ptr -> qu_suspend_link)); + } + + /* Finally, suspend the calling task. Note that the suspension call + automatically clears the protection on the queue. */ + TCC_Suspend_Task((NU_TASK *) task, NU_QUEUE_SUSPEND, + QUC_Cleanup, suspend_ptr, suspend); + + /* Pickup the status of the request. */ + status = suspend_ptr -> qu_return_status; + *actual_size = suspend_ptr -> qu_actual_size; + } + else + { + + /* Return a status of NU_QUEUE_EMPTY because there are no + messages in the queue. */ + status = NU_QUEUE_EMPTY; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpQueue(RT_PROF_RECEIVE_FROM_QUEUE,queue,RT_PROF_FAIL); +#endif + + } + } + + /* Release protection against access to the queue. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return the completion status. */ + return(status); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* QUC_Cleanup */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for removing a suspension block */ +/* from a queue. It is not called unless a timeout or a task */ +/* terminate is in progress. Note that protection is already in */ +/* effect - the same protection at suspension time. This routine */ +/* must be called from Supervisor mode in Supervisor/User mode */ +/* switching kernels. */ +/* */ +/* CALLED BY */ +/* */ +/* TCC_Timeout Task timeout */ +/* TCC_Terminate Task terminate */ +/* */ +/* CALLS */ +/* */ +/* CSC_Remove_From_List Remove suspend block from */ +/* the suspension list */ +/* */ +/* INPUTS */ +/* */ +/* information Pointer to suspend block */ +/* */ +/* OUTPUTS */ +/* */ +/* None */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* */ +/*************************************************************************/ +VOID QUC_Cleanup(VOID *information) +{ + +QU_SUSPEND *suspend_ptr; /* Suspension block pointer */ +NU_SUPERV_USER_VARIABLES + + /* Switch to supervisor mode */ + NU_SUPERVISOR_MODE(); + + /* Use the information pointer as a suspend pointer. */ + suspend_ptr = (QU_SUSPEND *) information; + + /* By default, indicate that the service timed-out. It really does not + matter if this function is called from a terminate request since + the task does not resume. */ + suspend_ptr -> qu_return_status = NU_TIMEOUT; + + /* Decrement the number of tasks waiting counter. */ + (suspend_ptr -> qu_queue) -> qu_tasks_waiting--; + + /* Unlink the suspend block from the suspension list. */ + if ((suspend_ptr -> qu_queue) -> qu_urgent_list) + { + /* Unlink the suspend block from the suspension list. */ + CSC_Remove_From_List((CS_NODE **) + &((suspend_ptr -> qu_queue) -> qu_urgent_list), + &(suspend_ptr -> qu_suspend_link)); + } + else + { + /* Unlink the suspend block from the suspension list. */ + CSC_Remove_From_List((CS_NODE **) + &((suspend_ptr -> qu_queue) -> qu_suspension_list), + &(suspend_ptr -> qu_suspend_link)); + } + + /* Return to user mode */ + NU_USER_MODE(); +} + + + + + +