FreeCalypso > hg > ffs-editor
diff src/nucleus/pic.c @ 0:92470e5d0b9e
src: partial import from FC Selenite
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Fri, 15 May 2020 01:28:16 +0000 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/nucleus/pic.c Fri May 15 01:28:16 2020 +0000 @@ -0,0 +1,1617 @@ +/*************************************************************************/ +/* */ +/* 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 */ +/* */ +/* pic.c Nucleus PLUS 1.14 */ +/* */ +/* COMPONENT */ +/* */ +/* PI - Pipe Management */ +/* */ +/* DESCRIPTION */ +/* */ +/* This file contains the core routines for the pipe management */ +/* component. */ +/* */ +/* DATA STRUCTURES */ +/* */ +/* None */ +/* */ +/* FUNCTIONS */ +/* */ +/* PIC_Create_Pipe Create a message pipe */ +/* PIC_Delete_Pipe Delete a message pipe */ +/* PIC_Send_To_Pipe Send message to a pipe */ +/* PIC_Receive_From_Pipe Receive a message from pipe */ +/* PIC_Cleanup Cleanup on timeout or a */ +/* terminate condition */ +/* */ +/* DEPENDENCIES */ +/* */ +/* cs_extr.h Common Service functions */ +/* tc_extr.h Thread Control functions */ +/* pi_extr.h Pipe 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 */ +/* 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 */ +/* pipe 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 */ +/* 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 "pi_extr.h" /* Pipe functions */ +#include "hi_extr.h" /* History functions */ +#include "profiler.h" /* ProView interface */ + + +/* Define external inner-component global data references. */ + +extern CS_NODE *PID_Created_Pipes_List; +extern UNSIGNED PID_Total_Pipes; +extern TC_PROTECT PID_List_Protect; + + +/* Define internal component function prototypes. */ + +VOID PIC_Cleanup(VOID *information); + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* PIC_Create_Pipe */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function creates a pipe and then places it on the list */ +/* of created pipes. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* PICE_Create_Pipe Error checking shell */ +/* */ +/* CALLS */ +/* */ +/* CSC_Place_On_List Add to node to linked-list */ +/* [HIC_Make_History_Entry] Make entry in history log */ +/* [TCT_Check_Stack] Stack checking function */ +/* TCT_Protect Data structure protect */ +/* TCT_Unprotect Un-protect data structure */ +/* */ +/* INPUTS */ +/* */ +/* pipe_ptr Pipe control block pointer */ +/* name Pipe name */ +/* start_address Starting address of actual */ +/* pipe area */ +/* pipe_size Total size of pipe in bytes */ +/* message_type Type of message supported by */ +/* the pipe (fixed/variable) */ +/* message_size Size of message. Variable */ +/* message-length pipes, 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 PIC_Create_Pipe(NU_PIPE *pipe_ptr, CHAR *name, + VOID *start_address, UNSIGNED pipe_size, + OPTION message_type, UNSIGNED message_size, + OPTION suspend_type) +{ + +R1 PI_PCB *pipe; /* Pipe control block ptr */ +INT i; /* Working index variable */ +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_CREATE_PIPE_ID, (UNSIGNED) pipe, + (UNSIGNED) name, (UNSIGNED) start_address); + +#endif + + /* First, clear the pipe ID just in case it is an old pipe + Control Block. */ + pipe -> pi_id = 0; + + /* Fill in the pipe name. */ + for (i = 0; i < NU_MAX_NAME; i++) + pipe -> pi_name[i] = name[i]; + + /* Setup the pipe suspension type. */ + if (suspend_type == NU_FIFO) + + /* FIFO suspension is selected, setup the flag accordingly. */ + pipe -> pi_fifo_suspend = NU_TRUE; + + else + + /* Priority suspension is selected. */ + pipe -> pi_fifo_suspend = NU_FALSE; + + /* Setup the pipe message type. */ + if (message_type == NU_FIXED_SIZE) + + /* Fixed-size messages are required. */ + pipe -> pi_fixed_size = NU_TRUE; + else + + /* Variable-size messages are required. */ + pipe -> pi_fixed_size = NU_FALSE; + + /* Setup the message size. */ + pipe -> pi_message_size = message_size; + + /* Clear the messages counter. */ + pipe -> pi_messages = 0; + + /* Setup the actual pipe pointers. */ + pipe -> pi_pipe_size = pipe_size; + + /* Determine if the pipe's size needs to be adjusted. */ + if (pipe -> pi_fixed_size) + + /* The size of a fixed-size message pipe must be an even multiple of + the actual message size. */ + pipe_size = (pipe_size/message_size) * message_size; + + else + + /* Insure that the size is in terms of UNSIGNED data elements. This + insures that the UNSIGNED word is never written past the end of + the pipe. */ + pipe_size = (pipe_size/sizeof(UNSIGNED)) * sizeof(UNSIGNED); + + pipe -> pi_available = pipe_size; + pipe -> pi_start = (BYTE_PTR) start_address; + pipe -> pi_end = pipe -> pi_start + pipe_size; + pipe -> pi_read = (BYTE_PTR) start_address; + pipe -> pi_write = (BYTE_PTR) start_address; + + /* Clear the suspension list pointer. */ + pipe -> pi_suspension_list = NU_NULL; + + /* Clear the number of tasks waiting on the pipe counter. */ + pipe -> pi_tasks_waiting = 0; + + /* Clear the urgent message list pointer. */ + pipe -> pi_urgent_list = NU_NULL; + + /* Initialize link pointers. */ + pipe -> pi_created.cs_previous = NU_NULL; + pipe -> pi_created.cs_next = NU_NULL; + + /* Protect against access to the list of created pipes. */ + TCT_Protect(&PID_List_Protect); + + /* At this point the pipe is completely built. The ID can now be + set and it can be linked into the created pipe list. */ + pipe -> pi_id = PI_PIPE_ID; + + /* Link the pipe into the list of created pipes and increment the + total number of pipes in the system. */ + CSC_Place_On_List(&PID_Created_Pipes_List, &(pipe -> pi_created)); + PID_Total_Pipes++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_CREATE_PIPE,pipe,RT_PROF_OK); +#endif /* INCLUDE_PROVIEW */ + + /* Release protection against access to the list of created pipes. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return successful completion. */ + return(NU_SUCCESS); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* PIC_Delete_Pipe */ +/* */ +/* 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 + + /* 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_SEND_TO_PIPE_ID, (UNSIGNED) pipe, + (UNSIGNED) message, (UNSIGNED) size); + +#endif + + /* Initialize the status as successful. */ + status = NU_SUCCESS; + + /* Protect against simultaneous access to the pipe. */ + TCT_System_Protect(); + + /* Determine if an extra word of overhead needs to be added to the + calculation. */ + if (pipe -> pi_fixed_size) + + /* No overhead. */ + i = 0; + else + { + + /* Variable messages have one additional word of overhead. */ + i = sizeof(UNSIGNED); + + /* Calculate the number of pad bytes necessary to make keep the pipe + write pointer on an UNSIGNED data element alignment. */ + pad = (((size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) * + sizeof(UNSIGNED)) - size; + + /* Insure that padding is included in the overhead. */ + i = i + ((INT) pad); + + /* Make special check to see if a suspension needs to be + forced for a variable length message. */ + if ((pipe -> pi_suspension_list) && (pipe -> pi_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 ((pipe -> pi_fifo_suspend) || + (suspend == NU_NO_SUSPEND) || + ((pipe -> pi_suspension_list) -> pi_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) pipe -> pi_available; + } + } + + /* Determine if there is enough room in the pipe for the message. */ + if (pipe -> pi_available < (size + i)) + { + + /* pipe does not have room for the message. Determine if + suspension is required. */ + if (suspend) + { + + /* Suspension is requested. */ + + /* Increment the number of tasks waiting. */ + pipe -> pi_tasks_waiting++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_SEND_TO_PIPE,pipe,RT_PROF_WAIT); +#endif /* INCLUDE_PROVIEW */ + + /* Setup the suspend block and suspend the calling task. */ + suspend_ptr = &suspend_block; + suspend_ptr -> pi_pipe = pipe; + suspend_ptr -> pi_suspend_link.cs_next = NU_NULL; + suspend_ptr -> pi_suspend_link.cs_previous= NU_NULL; + suspend_ptr -> pi_message_area = (BYTE_PTR) message; + suspend_ptr -> pi_message_size = size; + task = (TC_TCB *) TCT_Current_Thread(); + suspend_ptr -> pi_suspended_task = task; + + /* Determine if priority or FIFO suspension is associated with the + pipe. */ + if (pipe -> pi_fifo_suspend) + { + + /* FIFO suspension is required. Link the suspend block into + the list of suspended tasks on this pipe. */ + CSC_Place_On_List((CS_NODE **) &(pipe -> pi_suspension_list), + &(suspend_ptr -> pi_suspend_link)); + } + else + { + + /* Get the priority of the current thread so the suspend block + can be placed in the appropriate place. */ + suspend_ptr -> pi_suspend_link.cs_priority = + TCC_Task_Priority(task); + + CSC_Priority_Place_On_List((CS_NODE **) + &(pipe -> pi_suspension_list), + &(suspend_ptr -> pi_suspend_link)); + } + + /* Finally, suspend the calling task. Note that the suspension call + automatically clears the protection on the pipe. */ + TCC_Suspend_Task((NU_TASK *) task, NU_PIPE_SUSPEND, + PIC_Cleanup, suspend_ptr, suspend); + + /* Pickup the return status. */ + status = suspend_ptr -> pi_return_status; + } + else + { + + /* Return a status of NU_PIPE_FULL because there is no + room in the pipe for the message. */ + status = NU_PIPE_FULL; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_SEND_TO_PIPE,pipe,RT_PROF_FAIL); +#endif /* INCLUDE_PROVIEW */ + } + + } + else + { + + /* Determine if a task is waiting on an empty pipe. */ + if ((pipe -> pi_suspension_list) && (pipe -> pi_messages == 0)) + { + + /* Task is waiting on pipe for a message. */ + + /* Decrement the number of tasks waiting on pipe. */ + pipe -> pi_tasks_waiting--; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_SEND_TO_PIPE,pipe,RT_PROF_OK); +#endif /* INCLUDE_PROVIEW */ + + /* Remove the first suspended block from the list. */ + suspend_ptr = pipe -> pi_suspension_list; + CSC_Remove_From_List((CS_NODE **) &(pipe -> pi_suspension_list), + &(suspend_ptr -> pi_suspend_link)); + + /* Setup the source and destination pointers. */ + source = (BYTE_PTR) message; + destination = suspend_ptr -> pi_message_area; + + /* Initialize the return status. */ + suspend_ptr -> pi_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 -> pi_actual_size = size; + + /* Wakeup the waiting task and check for preemption. */ + preempt = + TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task, + NU_PIPE_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 pipe and no task is waiting. */ + + /* Setup the source pointer. */ + source = (BYTE_PTR) message; + destination = pipe -> pi_write; + + /* Process according to the type of message supported. */ + if (pipe -> pi_fixed_size) + { + + /* Fixed-size messages are supported by this pipe. */ + + /* Loop to copy the message into the pipe area. */ + i = (INT) size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + } + else + { + + /* Variable-size messages are supported. Processing must + check for pipe wrap-around conditions. */ + + /* Place message size in first location. */ + *((UNSIGNED *) destination) = size; + destination = destination + sizeof(UNSIGNED); + + /* Check for a wrap-around condition on the pipe. */ + if (destination >= pipe -> pi_end) + + /* Wrap the write pointer back to the top of the pipe + area. */ + destination = pipe -> pi_start; + + /* Decrement the number of bytes remaining for this + extra word of overhead. */ + pipe -> pi_available = pipe -> pi_available - + sizeof(UNSIGNED); + + /* Calculate the number of bytes remaining from the write + pointer to the bottom of the pipe. */ + copy_size = pipe -> pi_end - destination; + + /* Determine if the message needs to be wrapped around the + edge of the pipe 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 = pipe -> pi_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 >= pipe -> pi_end) + + /* Move the write pointer to the top of the pipe area. */ + destination = pipe -> pi_start; + + /* Determine if the pipe supports variable-length messages. If + so, pad bytes are needed to keep UNSIGNED alignment. */ + if (pad) + { + + /* Variable-size message. Add pad bytes to the write + pointer. */ + + /* Calculate the number of bytes remaining from the write + pointer to the bottom of the pipe. */ + copy_size = pipe -> pi_end - destination; + + /* If there is not enough room at the bottom of the pipe, the + pad bytes must be wrapped around to the top. */ + if (copy_size <= pad) + + /* Move write pointer to the top of the pipe and make the + necessary adjustment. */ + destination = pipe -> pi_start + (pad - copy_size); + else + + /* There is enough room in the pipe to simply add the + the pad bytes to the write pointer. */ + destination = destination + pad; + + /* Decrement the number of available bytes. */ + pipe -> pi_available = pipe -> pi_available - pad; + } + + /* Update the actual write pointer. */ + pipe -> pi_write = destination; + + /* Decrement the number of available bytes. */ + pipe -> pi_available = pipe -> pi_available - size; + + /* Increment the number of messages in the pipe. */ + pipe -> pi_messages++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_SEND_TO_PIPE,pipe,RT_PROF_OK); +#endif /* INCLUDE_PROVIEW */ + } + } + + /* Release protection against access to the pipe. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return the completion status. */ + return(status); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* PIC_Receive_From_Pipe */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function receives a message from the specified pipe. The */ +/* size of the message is specified by the caller. If there is a */ +/* message currently in the pipe, the message is removed from the */ +/* pipe and placed in the caller's area. Suspension is possible */ +/* if the request cannot be satisfied. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* PICE_Receive_From_Pipe Error checking shell */ +/* */ +/* CALLS */ +/* */ +/* CSC_Place_On_List Place on suspend 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 the message */ +/* actual_size Size of message received */ +/* suspend Suspension option if empty */ +/* */ +/* OUTPUTS */ +/* */ +/* NU_SUCCESS If service is successful */ +/* NU_PIPE_EMPTY If pipe is currently empty */ +/* 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_Receive_From_Pipe(NU_PIPE *pipe_ptr, VOID *message, + UNSIGNED size, UNSIGNED *actual_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 */ +TC_TCB *task; /* Task pointer */ +UNSIGNED copy_size; /* Number of bytes to copy */ +UNSIGNED pad = 0; /* Number of pad bytes */ +R4 INT i; /* Working counter */ +STATUS preempt; /* Preemption flag */ +STATUS status; /* Completion status */ +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_RECEIVE_FROM_PIPE_ID, (UNSIGNED) pipe, + (UNSIGNED) message, (UNSIGNED) size); + +#endif + + /* Initialize the status as successful. */ + status = NU_SUCCESS; + + /* Protect against simultaneous access to the pipe. */ + TCT_System_Protect(); + + /* Determine if an urgent message request is currently suspended. */ + if (pipe -> pi_urgent_list) + { + + /* If so, copy the message from the suspended request block and + resume the associated task. */ + + /* Decrement the number of tasks waiting on pipe. */ + pipe -> pi_tasks_waiting--; + + /* Remove the first suspended block from the list. */ + suspend_ptr = pipe -> pi_urgent_list; + CSC_Remove_From_List((CS_NODE **) &(pipe -> pi_urgent_list), + &(suspend_ptr -> pi_suspend_link)); + + /* Setup the source and destination pointers. */ + destination = (BYTE_PTR) message; + source = suspend_ptr -> pi_message_area; + + /* Initialize the return status. */ + suspend_ptr -> pi_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. */ + *actual_size = suspend_ptr -> pi_message_size; + + /* Wakeup the waiting task and check for preemption. */ + preempt = + TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task, + NU_PIPE_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 pipe. */ + else if (pipe -> pi_messages) + { + + /* Copy message from pipe into the caller's area. */ + + /* Setup the source and destination pointers. */ + destination = (BYTE_PTR) message; + source = pipe -> pi_read; + + /* Process according to the type of message supported by the pipe. */ + if (pipe -> pi_fixed_size) + { + + /* Pipe supports fixed-size messages. */ + + /* Copy the message from the pipe area into the destination. */ + i = (INT) size; + do + { + *(destination) = *(source++); + if ((--i) == 0) + break; + destination++; + } while (1); + } + else + { + + /* Pipe supports variable-size messages. */ + + /* Variable length message size is actually in the pipe area. */ + size = *((UNSIGNED *) source); + source = source + sizeof(UNSIGNED); + + /* Check for a wrap-around condition on the pipe. */ + if (source >= pipe -> pi_end) + + /* Wrap the read pointer back to the top of the pipe + area. */ + source = pipe -> pi_start; + + /* Increment the number of available bytes in the pipe. */ + pipe -> pi_available = pipe -> pi_available + sizeof(UNSIGNED); + + /* Calculate the number of pad bytes necessary to keep + the pipe read pointer on an UNSIGNED data element alignment.*/ + pad = (((size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) * + sizeof(UNSIGNED)) - size; + + /* Calculate the number of bytes remaining from the read pointer + to the bottom of the pipe. */ + copy_size = pipe -> pi_end - source; + + /* Determine if the message needs to be wrapped around the + edge of the pipe 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 = pipe -> pi_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 >= pipe -> pi_end) + + /* Move the read pointer to the top of the pipe area. */ + source = pipe -> pi_start; + + /* Determine if the pipe supports variable-length messages. If + so, pad bytes are needed to keep UNSIGNED alignment. */ + if (pad) + { + + /* Variable-size message. Add pad bytes to the read + pointer. */ + + /* Calculate the number of bytes remaining from the read + pointer to the bottom of the pipe. */ + copy_size = pipe -> pi_end - source; + + /* If there is not enough room at the bottom of the pipe, the + pad bytes must be wrapped around to the top. */ + if (copy_size <= pad) + + /* Move read pointer to the top of the pipe and make the + necessary adjustment. */ + source = pipe -> pi_start + (pad - copy_size); + else + + /* There is enough room in the pipe to simply add the + the pad bytes to the read pointer. */ + source = source + pad; + + /* Add pad bytes to the available bytes count. */ + pipe -> pi_available = pipe -> pi_available + pad; + } + + /* Adjust the actual read pointer. */ + pipe -> pi_read = source; + + /* Increment the number of available bytes. */ + pipe -> pi_available = pipe -> pi_available + size; + + /* Decrement the number of messages in the pipe. */ + pipe -> pi_messages--; + + /* Return the number of bytes received. */ + *actual_size = size; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_RECEIVE_FROM_PIPE,pipe,RT_PROF_OK); +#endif /* INCLUDE_PROVIEW */ + + /* Determine if any tasks suspended on a full pipe can be woken + up. */ + if (pipe -> pi_suspension_list) + { + + /* Pickup the suspension list and examine suspension blocks + to see if the message could now fit in the pipe. */ + suspend_ptr = pipe -> pi_suspension_list; + preempt = NU_FALSE; + size = suspend_ptr -> pi_message_size; + i = 0; + pad = 0; + + /* Overhead of each pipe message. */ + if (!pipe -> pi_fixed_size) + { + + /* Variable messages have one additional word of overhead. */ + i = sizeof(UNSIGNED); + + /* Calculate the number of pad bytes necessary to keep + the pipe write pointer on an UNSIGNED data element + alignment. */ + pad = (((size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) * + sizeof(UNSIGNED)) - size; + + /* Insure that padding is included in the overhead. */ + i = i + ((INT) pad); + } + + while ((suspend_ptr) && ((size + i) <= pipe -> pi_available)) + { + + /* Place the suspended task's message into the pipe. */ + + /* Setup the source and destination pointers. */ + source = suspend_ptr -> pi_message_area; + destination = pipe -> pi_write; + + /* Process according to the type of message supported. */ + if (pipe -> pi_fixed_size) + { + + /* Fixed-size messages are supported by this pipe. */ + + /* Loop to copy the message into the pipe area. */ + i = (INT) size; + do + { + *(destination++) = *(source); + if ((--i) == 0) + break; + source++; + } while (1); + } + else + { + + /* Variable-size messages are supported. Processing must + check for pipe wrap-around conditions. */ + + /* Place message size in first location. */ + *((UNSIGNED *) destination) = size; + destination = destination + sizeof(UNSIGNED); + + /* Check for a wrap-around condition on the pipe. */ + if (destination >= pipe -> pi_end) + + /* Wrap the write pointer back to the top of the pipe + area. */ + destination = pipe -> pi_start; + + /* Decrement the number of bytes remaining for this + extra word of overhead. */ + pipe -> pi_available = pipe -> pi_available - + sizeof(UNSIGNED); + + /* Calculate the number of bytes remaining from the write + pointer to the bottom of the pipe. */ + copy_size = pipe -> pi_end - destination; + + /* Determine if the message needs to be wrapped around the + edge of the pipe 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 = pipe -> pi_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 >= pipe -> pi_end) + + /* Move the write pointer to the top of the pipe area. */ + destination = pipe -> pi_start; + + /* Determine if the pipe supports variable-length messages. If + so, pad bytes are needed to keep UNSIGNED alignment. */ + if (pad) + { + + /* Variable-size message. Add pad bytes to the write + pointer. */ + + /* Calculate the number of bytes remaining from the write + pointer to the bottom of the pipe. */ + copy_size = pipe -> pi_end - destination; + + /* If there is not enough room at the bottom of the pipe, + the pad bytes must be wrapped around to the top. */ + if (copy_size <= pad) + + /* Move write pointer to the top of the pipe and make + the necessary adjustment. */ + destination = pipe -> pi_start + (pad - copy_size); + else + + /* There is enough room in the pipe to simply add + the pad bytes to the write pointer. */ + destination = destination + pad; + + /* Decrement the number of available bytes. */ + pipe -> pi_available = pipe -> pi_available - pad; + } + + /* Update the actual write pointer. */ + pipe -> pi_write = destination; + + /* Decrement the number of available bytes. */ + pipe -> pi_available = pipe -> pi_available - size; + + /* Increment the number of messages in the pipe. */ + pipe -> pi_messages++; + + /* Decrement the number of tasks waiting counter. */ + pipe -> pi_tasks_waiting--; + + /* Remove the first suspended block from the list. */ + CSC_Remove_From_List((CS_NODE **) + &(pipe -> pi_suspension_list), + &(suspend_ptr -> pi_suspend_link)); + + /* Return a successful status. */ + suspend_ptr -> pi_return_status = NU_SUCCESS; + + /* Resume the suspended task. */ + preempt = preempt | + TCC_Resume_Task((NU_TASK *) suspend_ptr -> pi_suspended_task, + NU_PIPE_SUSPEND); + + /* Setup suspend pointer to the head of the list. */ + suspend_ptr = pipe -> pi_suspension_list; + + /* Determine if there really is another suspended block. If + there is and the pipe supports variable length messages, + calculate new size and padding parameters. */ + if ((suspend_ptr) && (!pipe -> pi_fixed_size)) + { + + /* Get the next message size. */ + size = suspend_ptr -> pi_message_size; + + /* Variable messages have one additional word of + overhead. */ + i = sizeof(UNSIGNED); + + /* Calculate the number of pad bytes necessary to + keep the pipe write pointer on an UNSIGNED data element + alignment. */ + pad = (((size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) * + sizeof(UNSIGNED)) - size; + + /* Insure that padding is included in the overhead. */ + i = i + ((INT) pad); + } + } + + /* 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 + { + + /* pipe is empty. Determine if the task wants to suspend. */ + if (suspend) + { + + /* Increment the number of tasks waiting on the pipe counter. */ + pipe -> pi_tasks_waiting++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_RECEIVE_FROM_PIPE,pipe,RT_PROF_WAIT); +#endif /* INCLUDE_PROVIEW */ + + /* Setup the suspend block and suspend the calling task. */ + suspend_ptr = &suspend_block; + suspend_ptr -> pi_pipe = pipe; + suspend_ptr -> pi_suspend_link.cs_next = NU_NULL; + suspend_ptr -> pi_suspend_link.cs_previous = NU_NULL; + suspend_ptr -> pi_message_area = (BYTE_PTR) message; + suspend_ptr -> pi_message_size = size; + task = (TC_TCB *) TCT_Current_Thread(); + suspend_ptr -> pi_suspended_task = task; + + /* Determine if priority or FIFO suspension is associated with the + pipe. */ + if (pipe -> pi_fifo_suspend) + { + + /* FIFO suspension is required. Link the suspend block into + the list of suspended tasks on this pipe. */ + CSC_Place_On_List((CS_NODE **) &(pipe -> pi_suspension_list), + &(suspend_ptr -> pi_suspend_link)); + } + else + { + + /* Get the priority of the current thread so the suspend block + can be placed in the appropriate place. */ + suspend_ptr -> pi_suspend_link.cs_priority = + TCC_Task_Priority(task); + + CSC_Priority_Place_On_List((CS_NODE **) + &(pipe -> pi_suspension_list), + &(suspend_ptr -> pi_suspend_link)); + } + + /* Finally, suspend the calling task. Note that the suspension call + automatically clears the protection on the pipe. */ + TCC_Suspend_Task((NU_TASK *) task, NU_PIPE_SUSPEND, + PIC_Cleanup, suspend_ptr, suspend); + + /* Pickup the status of the request. */ + status = suspend_ptr -> pi_return_status; + *actual_size = suspend_ptr -> pi_actual_size; + } + else + { + + /* Return a status of NU_PIPE_EMPTY because there are no + messages in the pipe. */ + status = NU_PIPE_EMPTY; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpPipe(RT_PROF_RECEIVE_FROM_PIPE,pipe,RT_PROF_FAIL); +#endif /* INCLUDE_PROVIEW */ + } + } + + /* Release protection against access to the pipe. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return the completion status. */ + return(status); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* PIC_Cleanup */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for removing a suspension block */ +/* from a pipe. 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 PIC_Cleanup(VOID *information) +{ + +PI_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 = (PI_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 -> pi_return_status = NU_TIMEOUT; + + /* Decrement the number of tasks waiting counter. */ + (suspend_ptr -> pi_pipe) -> pi_tasks_waiting--; + + /* Determine if the suspend block is one the urgent list. */ + if ((suspend_ptr -> pi_pipe) -> pi_urgent_list) + { + /* Unlink the suspend block from the urgent list. */ + CSC_Remove_From_List((CS_NODE **) + &((suspend_ptr -> pi_pipe) -> pi_urgent_list), + &(suspend_ptr -> pi_suspend_link)); + } + else + { + /* Unlink the suspend block from the suspension list. */ + CSC_Remove_From_List((CS_NODE **) + &((suspend_ptr -> pi_pipe) -> pi_suspension_list), + &(suspend_ptr -> pi_suspend_link)); + } + + /* Return to user mode */ + NU_USER_MODE(); +} + + + + + + +