FreeCalypso > hg > fc-tourmaline
view src/nucleus/mbc.c @ 223:740a8e8fc9d7
startup sync logic rework for the new PWON button boot scheme
Previously we added logic to the MMI task to hold off PEI init until
R2D is running, and then extended that condition to wait for FCHG
init too. However, the dependencies of MMI upon R2D and FCHG don't
start until mmiInit(), and that call is driven by Switch_ON() code,
hence the wait for R2D and FCHG init can be made in that code path
instead of the MMI task. Furthermore, with our new way of signaling
PWON button boot to MMI, we need a new wait to ensure that the MMI
task is up - previously this assurance was provided by the wait for
Kp pointers to be set.
Solution: revert our previous PEI init hold-off additions to MMI,
add a new flag indicating MMI task init done, and put the combined
wait for all needed conditions into our new PWON button boot code
in power.c.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Tue, 27 Apr 2021 06:24:52 +0000 |
| parents | 4e78acac3d88 |
| children |
line wrap: on
line source
/*************************************************************************/ /* */ /* 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 */ /* */ /* mbc.c Nucleus PLUS 1.14 */ /* */ /* COMPONENT */ /* */ /* MB - Mailbox Management */ /* */ /* DESCRIPTION */ /* */ /* This file contains the core routines for the Mailbox management */ /* component. */ /* */ /* DATA STRUCTURES */ /* */ /* None */ /* */ /* FUNCTIONS */ /* */ /* MBC_Create_Mailbox Create a mailbox */ /* MBC_Delete_Mailbox Delete a mailbox */ /* MBC_Send_To_Mailbox Send a mailbox message */ /* MBC_Receive_From_Mailbox Receive a mailbox message */ /* MBC_Cleanup Cleanup on timeout or a */ /* terminate condition */ /* */ /* DEPENDENCIES */ /* */ /* cs_extr.h Common Service functions */ /* tc_extr.h Thread Control functions */ /* mb_extr.h Mailbox 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, 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 "mb_extr.h" /* Mailbox functions */ #include "hi_extr.h" /* History functions */ #include "profiler.h" /* ProView interface */ /* Define external inner-component global data references. */ extern CS_NODE *MBD_Created_Mailboxes_List; extern UNSIGNED MBD_Total_Mailboxes; extern TC_PROTECT MBD_List_Protect; /* Define internal component function prototypes. */ VOID MBC_Cleanup(VOID *information); /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* MBC_Create_Mailbox */ /* */ /* DESCRIPTION */ /* */ /* This function creates a mailbox and then places it on the list */ /* of created mailboxes. */ /* */ /* CALLED BY */ /* */ /* Application */ /* MBCE_Create_Mailbox 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 Data structure protect */ /* TCT_Unprotect Un-protect data structure */ /* */ /* INPUTS */ /* */ /* mailbox_ptr Mailbox control block pointer*/ /* name Mailbox name */ /* 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 interface to */ /* match the prototype, added */ /* register variable logic, */ /* resulting in version 1.1 */ /* */ /* 03-18-1994 Verified version 1.1 */ /* */ /*************************************************************************/ STATUS MBC_Create_Mailbox(NU_MAILBOX *mailbox_ptr, CHAR *name, OPTION suspend_type) { R1 MB_MCB *mailbox; /* Mailbox control block ptr */ INT i; /* Working index variable */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input mailbox pointer into internal pointer. */ mailbox = (MB_MCB *) mailbox_ptr; #ifdef NU_ENABLE_STACK_CHECK /* Call stack checking function to check for an overflow condition. */ TCT_Check_Stack(); #endif #ifdef NU_ENABLE_HISTORY /* Make an entry that corresponds to this function in the system history log. */ HIC_Make_History_Entry(NU_CREATE_MAILBOX_ID, (UNSIGNED) mailbox, (UNSIGNED) name, (UNSIGNED) suspend_type); #endif /* First, clear the mailbox ID just in case it is an old Mailbox Control Block. */ mailbox -> mb_id = 0; /* Fill in the mailbox name. */ for (i = 0; i < NU_MAX_NAME; i++) mailbox -> mb_name[i] = name[i]; /* Clear the message present flag- initial it to "no message present." */ mailbox -> mb_message_present = NU_FALSE; /* Setup the mailbox suspension type. */ if (suspend_type == NU_FIFO) /* FIFO suspension is selected, setup the flag accordingly. */ mailbox -> mb_fifo_suspend = NU_TRUE; else /* Priority suspension is selected. */ mailbox -> mb_fifo_suspend = NU_FALSE; /* Clear the suspension list pointer. */ mailbox -> mb_suspension_list = NU_NULL; /* Clear the number of tasks waiting on the mailbox counter. */ mailbox -> mb_tasks_waiting = 0; /* Initialize link pointers. */ mailbox -> mb_created.cs_previous = NU_NULL; mailbox -> mb_created.cs_next = NU_NULL; /* Protect against access to the list of created mailboxes. */ TCT_Protect(&MBD_List_Protect); /* At this point the mailbox is completely built. The ID can now be set and it can be linked into the created mailbox list. */ mailbox -> mb_id = MB_MAILBOX_ID; /* Link the mailbox into the list of created mailboxes and increment the total number of mailboxes in the system. */ CSC_Place_On_List(&MBD_Created_Mailboxes_List, &(mailbox -> mb_created)); MBD_Total_Mailboxes++; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_CREATE_MAILBOX,mailbox,RT_PROF_OK); #endif /* INCLUDE_PROVIEW */ /* Release protection against access to the list of created mailboxes. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return successful completion. */ return(NU_SUCCESS); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* MBC_Delete_Mailbox */ /* */ /* DESCRIPTION */ /* */ /* This function deletes a mailbox and removes it from the list of */ /* created mailboxes. All tasks suspended on the mailbox are */ /* resumed. Note that this function does not free the memory */ /* associated with the mailbox control block. */ /* */ /* CALLED BY */ /* */ /* Application */ /* MBCE_Delete_Mailbox 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 protection ptr */ /* TCT_System_Protect Protect against system access*/ /* TCT_System_Unprotect Release system protection */ /* TCT_Unprotect Release protection */ /* */ /* INPUTS */ /* */ /* mailbox_ptr Mailbox control block pointer*/ /* */ /* OUTPUTS */ /* */ /* NU_SUCCESS */ /* */ /* HISTORY */ /* */ /* DATE REMARKS */ /* */ /* 03-01-1993 Created initial version 1.0 */ /* 04-19-1993 Verified version 1.0 */ /* 03-01-1994 Changed function interface to */ /* match the prototype, added */ /* register variable logic, */ /* optimized protection logic, */ /* resulting in version 1.1 */ /* */ /* 03-18-1994 Verified version 1.1 */ /* */ /*************************************************************************/ STATUS MBC_Delete_Mailbox(NU_MAILBOX *mailbox_ptr) { R1 MB_MCB *mailbox; /* Mailbox control block ptr */ MB_SUSPEND *suspend_ptr; /* Suspend block pointer */ MB_SUSPEND *next_ptr; /* Next suspend block pointer*/ STATUS preempt; /* Status for resume call */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input mailbox pointer into internal pointer. */ mailbox = (MB_MCB *) mailbox_ptr; #ifdef NU_ENABLE_STACK_CHECK /* Call stack checking function to check for an overflow condition. */ TCT_Check_Stack(); #endif #ifdef NU_ENABLE_HISTORY /* Make an entry that corresponds to this function in the system history log. */ HIC_Make_History_Entry(NU_DELETE_MAILBOX_ID, (UNSIGNED) mailbox, (UNSIGNED) 0, (UNSIGNED) 0); #endif /* Call protection just in case another thread is using the mailbox. */ TCT_System_Protect(); #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_DELETE_MAILBOX,mailbox,RT_PROF_OK); #endif /* INCLUDE_PROVIEW */ /* Clear the mailbox ID. */ mailbox -> mb_id = 0; /* Clear protection. */ TCT_Unprotect(); /* Protect against access to the list of created mailboxes. */ TCT_Protect(&MBD_List_Protect); /* Remove the mailbox from the list of created mailboxes. */ CSC_Remove_From_List(&MBD_Created_Mailboxes_List, &(mailbox -> mb_created)); /* Decrement the total number of created mailboxes. */ MBD_Total_Mailboxes--; /* Pickup the suspended task pointer list. */ suspend_ptr = mailbox -> mb_suspension_list; /* Walk the chain task(s) currently suspended on the mailbox. */ preempt = 0; while (suspend_ptr) { /* Protect against system access. */ TCT_System_Protect(); /* Resume the suspended task. Insure that the status returned is NU_MAILBOX_DELETED. */ suspend_ptr -> mb_return_status = NU_MAILBOX_DELETED; /* Point to the next suspend structure in the link. */ next_ptr = (MB_SUSPEND *) (suspend_ptr -> mb_suspend_link.cs_next); /* Resume the specified task. */ preempt = preempt | TCC_Resume_Task((NU_TASK *) suspend_ptr -> mb_suspended_task, NU_MAILBOX_SUSPEND); /* Determine if the next is the same as the head pointer. */ if (next_ptr == mailbox -> mb_suspension_list) /* Clear the suspension pointer to signal the end of the list traversal. */ suspend_ptr = NU_NULL; else /* Position the suspend pointer to the next suspend block. */ suspend_ptr = next_ptr; /* Setup current protection pointer. */ TCT_Set_Current_Protect(&MBD_List_Protect); /* Unprotect the system protection. */ TCT_System_Unprotect(); } /* Determine if preemption needs to occur. */ if (preempt) /* Transfer control to system to facilitate preemption. */ TCT_Control_To_System(); /* Release protection against access to the list of created mailboxes. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return a successful completion. */ return(NU_SUCCESS); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* MBC_Send_To_Mailbox */ /* */ /* DESCRIPTION */ /* */ /* This function sends a 4-word message to the specified mailbox. */ /* If there are one or more tasks suspended on the mailbox for a */ /* message, the message is copied into the message area of the */ /* first task waiting and that task is resumed. If the mailbox */ /* is full, suspension of the calling task is possible. */ /* */ /* CALLED BY */ /* */ /* Application */ /* MBCE_Send_To_Mailbox Error checking shell */ /* */ /* CALLS */ /* */ /* CSC_Place_On_List Place on suspend list */ /* CSC_Priority_Place_On_List Place on priority list */ /* CSC_Remove_From_List Remove from suspend list */ /* [HIC_Make_History_Entry] Make entry in history log */ /* TCC_Resume_Task Resume a suspended task */ /* TCC_Suspend_Task Suspend calling task */ /* TCC_Task_Priority Pickup task's priority */ /* [TCT_Check_Stack] Stack checking function */ /* TCT_Control_To_System Transfer control to system */ /* TCT_Current_Thread Pickup current thread pointer*/ /* TCT_System_Protect Protect against system access*/ /* TCT_Unprotect Release protection */ /* */ /* INPUTS */ /* */ /* mailbox_ptr Mailbox control block pointer*/ /* message Pointer to message to send */ /* suspend Suspension option if full */ /* */ /* OUTPUTS */ /* */ /* NU_SUCCESS If service is successful */ /* NU_MAILBOX_FULL If mailbox is currently full */ /* NU_TIMEOUT If timeout on service expires*/ /* NU_MAILBOX_DELETED If mailbox is deleted during */ /* suspension */ /* NU_MAILBOX_RESET If mailbox is deleted during */ /* suspension */ /* */ /* HISTORY */ /* */ /* DATE REMARKS */ /* */ /* 03-01-1993 Created initial version 1.0 */ /* 04-19-1993 Verified version 1.0 */ /* 03-01-1994 Changed function interface to */ /* match the prototype, added */ /* register variable logic, */ /* optimized protection logic, */ /* resulting in version 1.1 */ /* */ /* 03-18-1994 Verified version 1.1 */ /* */ /*************************************************************************/ STATUS MBC_Send_To_Mailbox(NU_MAILBOX *mailbox_ptr, VOID *message, UNSIGNED suspend) { R1 MB_MCB *mailbox; /* Mailbox control block ptr */ MB_SUSPEND suspend_block; /* Allocate suspension block */ R2 MB_SUSPEND *suspend_ptr; /* Pointer to suspend block */ R3 UNSIGNED *source_ptr; /* Pointer to source */ R4 UNSIGNED *destination_ptr; /* Pointer to destination */ TC_TCB *task; /* Task pointer */ STATUS preempt; /* Preempt flag */ STATUS status; /* Completion status */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input mailbox pointer into internal pointer. */ mailbox = (MB_MCB *) mailbox_ptr; #ifdef NU_ENABLE_STACK_CHECK /* Call stack checking function to check for an overflow condition. */ TCT_Check_Stack(); #endif #ifdef NU_ENABLE_HISTORY /* Make an entry that corresponds to this function in the system history log. */ HIC_Make_History_Entry(NU_SEND_TO_MAILBOX_ID, (UNSIGNED) mailbox, (UNSIGNED) message, (UNSIGNED) suspend); #endif /* Initialize the status as successful. */ status = NU_SUCCESS; /* Protect against simultaneous access to the mailbox. */ TCT_System_Protect(); /* Determine if the mailbox is empty or full. */ if (mailbox -> mb_message_present) { /* Mailbox already has a message. Determine if suspension is required. */ if (suspend) { /* Suspension is requested. */ /* Increment the number of tasks waiting. */ mailbox -> mb_tasks_waiting++; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_WAIT); #endif /* INCLUDE_PROVIEW */ /* Setup the suspend block and suspend the calling task. */ suspend_ptr = &suspend_block; suspend_ptr -> mb_mailbox = mailbox; suspend_ptr -> mb_suspend_link.cs_next = NU_NULL; suspend_ptr -> mb_suspend_link.cs_previous = NU_NULL; suspend_ptr -> mb_message_area = (UNSIGNED *) message; task = (TC_TCB *) TCT_Current_Thread(); suspend_ptr -> mb_suspended_task = task; /* Determine if priority or FIFO suspension is associated with the mailbox. */ if (mailbox -> mb_fifo_suspend) { /* FIFO suspension is required. Link the suspend block into the list of suspended tasks on this mailbox. */ CSC_Place_On_List((CS_NODE **) &(mailbox ->mb_suspension_list), &(suspend_ptr -> mb_suspend_link)); } else { /* Get the priority of the current thread so the suspend block can be placed in the appropriate place. */ suspend_ptr -> mb_suspend_link.cs_priority = TCC_Task_Priority(task); CSC_Priority_Place_On_List((CS_NODE **) &(mailbox -> mb_suspension_list), &(suspend_ptr -> mb_suspend_link)); } /* Finally, suspend the calling task. Note that the suspension call automatically clears the protection on the mailbox. */ TCC_Suspend_Task((NU_TASK *) task, NU_MAILBOX_SUSPEND, MBC_Cleanup, suspend_ptr, suspend); /* Pickup the return status. */ status = suspend_ptr -> mb_return_status; } else { /* Return a status of NU_MAILBOX_FULL because there is no room in the mailbox for the message. */ status = NU_MAILBOX_FULL; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_FAIL); #endif /* INCLUDE_PROVIEW */ } } else { /* Determine if a task is waiting on the mailbox. */ if (mailbox -> mb_suspension_list) { /* Task is waiting on mailbox for a message. */ /* Decrement the number of tasks waiting on mailbox. */ mailbox -> mb_tasks_waiting--; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_OK); #endif /* INCLUDE_PROVIEW */ /* Remove the first suspended block from the list. */ suspend_ptr = mailbox -> mb_suspension_list; CSC_Remove_From_List((CS_NODE **) &(mailbox -> mb_suspension_list), &(suspend_ptr -> mb_suspend_link)); /* Setup the source and destination pointers. */ source_ptr = (UNSIGNED *) message; destination_ptr = suspend_ptr -> mb_message_area; /* Copy the message directly into the waiting task's destination. */ *destination_ptr = *source_ptr; *(destination_ptr + 1) = *(source_ptr + 1); *(destination_ptr + 2) = *(source_ptr + 2); *(destination_ptr + 3) = *(source_ptr + 3); /* Setup the appropriate return value. */ suspend_ptr -> mb_return_status = NU_SUCCESS; /* Wakeup the waiting task and check for preemption. */ preempt = TCC_Resume_Task((NU_TASK *) suspend_ptr -> mb_suspended_task, NU_MAILBOX_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 { /* Mailbox is empty and no task is waiting. */ /* Setup the source and destination pointers. */ source_ptr = (UNSIGNED *) message; destination_ptr = &(mailbox -> mb_message_area[0]); /* Place the message in the mailbox. */ *destination_ptr = *source_ptr; *(destination_ptr + 1) = *(source_ptr + 1); *(destination_ptr + 2) = *(source_ptr + 2); *(destination_ptr + 3) = *(source_ptr + 3); /* Indicate that the mailbox has a message. */ mailbox -> mb_message_present = NU_TRUE; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_SEND_TO_MAILBOX,mailbox,RT_PROF_OK); #endif /* INCLUDE_PROVIEW */ } } /* Release protection. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return the completion status. */ return(status); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* MBC_Receive_From_Mailbox */ /* */ /* DESCRIPTION */ /* */ /* This function receives a message from the specified mailbox. */ /* If there is a message currently in the mailbox, the message is */ /* removed from the mailbox and placed in the caller's area. */ /* Otherwise, if no message is present in the mailbox, suspension */ /* of the calling task is possible. */ /* */ /* CALLED BY */ /* */ /* Application */ /* MBCE_Receive_From_Mailbox Error checking shell */ /* */ /* CALLS */ /* */ /* CSC_Place_On_List Place on suspend list */ /* CSC_Priority_Place_On_List Place on priority list */ /* CSC_Remove_From_List Remove from suspend list */ /* [HIC_Make_History_Entry] Make entry in history log */ /* TCC_Resume_Task Resume a suspended task */ /* TCC_Suspend_Task Suspend calling task */ /* TCC_Task_Priority Pickup task 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 mailbox */ /* TCT_Unprotect Release protection */ /* */ /* INPUTS */ /* */ /* mailbox_ptr Mailbox control block pointer*/ /* message Pointer to message to send */ /* suspend Suspension option if empty */ /* */ /* OUTPUTS */ /* */ /* NU_SUCCESS If service is successful */ /* NU_MAILBOX_EMPTY If mailbox is currently empty*/ /* NU_TIMEOUT If timeout on service expires*/ /* NU_MAILBOX_DELETED If mailbox is deleted during */ /* suspension */ /* NU_MAILBOX_RESET If mailbox is deleted during */ /* suspension */ /* */ /* HISTORY */ /* */ /* DATE REMARKS */ /* */ /* 03-01-1993 Created initial version 1.0 */ /* 04-19-1993 Verified version 1.0 */ /* 03-01-1994 Changed function interface to */ /* match the prototype, added */ /* register variable logic, */ /* optimized protection logic, */ /* resulting in version 1.1 */ /* */ /* 03-18-1994 Verified version 1.1 */ /* */ /*************************************************************************/ STATUS MBC_Receive_From_Mailbox(NU_MAILBOX *mailbox_ptr, VOID *message, UNSIGNED suspend) { R1 MB_MCB *mailbox; /* Mailbox control block ptr */ MB_SUSPEND suspend_block; /* Allocate suspension block */ R2 MB_SUSPEND *suspend_ptr; /* Pointer to suspend block */ R3 UNSIGNED *source_ptr; /* Pointer to source */ R4 UNSIGNED *destination_ptr; /* Pointer to destination */ TC_TCB *task; /* Task pointer */ STATUS preempt; /* Preemption flag */ STATUS status; /* Completion status */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input mailbox pointer into internal pointer. */ mailbox = (MB_MCB *) mailbox_ptr; #ifdef NU_ENABLE_STACK_CHECK /* Call stack checking function to check for an overflow condition. */ TCT_Check_Stack(); #endif #ifdef NU_ENABLE_HISTORY /* Make an entry that corresponds to this function in the system history log. */ HIC_Make_History_Entry(NU_RECEIVE_FROM_MAILBOX_ID, (UNSIGNED) mailbox, (UNSIGNED) message, (UNSIGNED) suspend); #endif /* Initialize the status as successful. */ status = NU_SUCCESS; /* Protect against simultaneous access to the mailbox. */ TCT_System_Protect(); /* Determine if the mailbox is empty or full. */ if (mailbox -> mb_message_present) { /* Copy message from mailbox into the caller's area. */ /* Setup the source and destination pointers. */ source_ptr = &(mailbox -> mb_message_area[0]); destination_ptr = (UNSIGNED *) message; /* Copy the message directly into the waiting task's destination. */ *destination_ptr = *source_ptr; *(destination_ptr + 1) = *(source_ptr + 1); *(destination_ptr + 2) = *(source_ptr + 2); *(destination_ptr + 3) = *(source_ptr + 3); /* Determine if another task is waiting to place something into the mailbox. */ if (mailbox -> mb_suspension_list) { /* Yes, another task is waiting to send something to the mailbox. */ /* Decrement the number of tasks waiting counter. */ mailbox -> mb_tasks_waiting--; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_OK); #endif /* INCLUDE_PROVIEW */ /* Remove the first suspended block from the list. */ suspend_ptr = mailbox -> mb_suspension_list; CSC_Remove_From_List((CS_NODE **) &(mailbox -> mb_suspension_list), &(suspend_ptr -> mb_suspend_link)); /* Setup the source and destination pointers. */ source_ptr = suspend_ptr -> mb_message_area; destination_ptr = &(mailbox -> mb_message_area[0]); /* Copy the message directly into the waiting task's destination. */ *destination_ptr = *source_ptr; *(destination_ptr + 1) = *(source_ptr + 1); *(destination_ptr + 2) = *(source_ptr + 2); *(destination_ptr + 3) = *(source_ptr + 3); /* Setup the appropriate return value. */ suspend_ptr -> mb_return_status = NU_SUCCESS; /* Resume the suspended task. */ preempt = TCC_Resume_Task((NU_TASK *) suspend_ptr -> mb_suspended_task, NU_MAILBOX_SUSPEND); /* 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 { /* Clear the message present flag. */ mailbox -> mb_message_present = NU_FALSE; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_OK); #endif /* INCLUDE_PROVIEW */ } } else { /* Mailbox is empty. Determine if suspension is required. */ if (suspend) { /* Suspension is required. */ /* Increment the number of tasks waiting on the mailbox counter. */ mailbox -> mb_tasks_waiting++; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_WAIT); #endif /* INCLUDE_PROVIEW */ /* Setup the suspend block and suspend the calling task. */ suspend_ptr = &suspend_block; suspend_ptr -> mb_mailbox = mailbox; suspend_ptr -> mb_suspend_link.cs_next = NU_NULL; suspend_ptr -> mb_suspend_link.cs_previous = NU_NULL; suspend_ptr -> mb_message_area = (UNSIGNED *) message; task = (TC_TCB *) TCT_Current_Thread(); suspend_ptr -> mb_suspended_task = task; /* Determine if priority or FIFO suspension is associated with the mailbox. */ if (mailbox -> mb_fifo_suspend) { /* FIFO suspension is required. Link the suspend block into the list of suspended tasks on this mailbox. */ CSC_Place_On_List((CS_NODE **) &(mailbox ->mb_suspension_list), &(suspend_ptr -> mb_suspend_link)); } else { /* Get the priority of the current thread so the suspend block can be placed in the appropriate place. */ suspend_ptr -> mb_suspend_link.cs_priority = TCC_Task_Priority(task); CSC_Priority_Place_On_List((CS_NODE **) &(mailbox -> mb_suspension_list), &(suspend_block.mb_suspend_link)); } /* Finally, suspend the calling task. Note that the suspension call automatically clears the protection on the mailbox. */ TCC_Suspend_Task((NU_TASK *) task, NU_MAILBOX_SUSPEND, MBC_Cleanup, &suspend_block, suspend); /* Pickup the return status. */ status = suspend_ptr -> mb_return_status; } else { /* Return a status of NU_MAILBOX_EMPTY because there is nothing in the mailbox. */ status = NU_MAILBOX_EMPTY; #ifdef INCLUDE_PROVIEW _RTProf_DumpMailBox(RT_PROF_RECEIVE_FROM_MAILBOX,mailbox,RT_PROF_FAIL); #endif /* INCLUDE_PROVIEW */ } } /* Release protection. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return the completion status. */ return(status); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* MBC_Cleanup */ /* */ /* DESCRIPTION */ /* */ /* This function is responsible for removing a suspension block */ /* from a mailbox. 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. */ /* */ /* 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 MBC_Cleanup(VOID *information) { MB_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 = (MB_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 -> mb_return_status = NU_TIMEOUT; /* Decrement the number of tasks waiting counter. */ (suspend_ptr -> mb_mailbox) -> mb_tasks_waiting--; /* Unlink the suspend block from the suspension list. */ CSC_Remove_From_List((CS_NODE **) &((suspend_ptr -> mb_mailbox) -> mb_suspension_list), &(suspend_ptr -> mb_suspend_link)); /* Return to user mode */ NU_USER_MODE(); }