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view nuc-fw/nucleus/smc.c @ 79:947b1f473960
beginning of nuc-fw
| author | Michael Spacefalcon <msokolov@ivan.Harhan.ORG> |
|---|---|
| date | Sun, 11 Aug 2013 07:17:25 +0000 |
| parents | |
| children |
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/*************************************************************************/ /* */ /* 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 */ /* */ /* smc.c Nucleus PLUS 1.14 */ /* */ /* COMPONENT */ /* */ /* SM - Semaphore Management */ /* */ /* DESCRIPTION */ /* */ /* This file contains the core routines for the Semaphore Management*/ /* component. */ /* */ /* DATA STRUCTURES */ /* */ /* None */ /* */ /* FUNCTIONS */ /* */ /* SMC_Create_Semaphore Create a semaphore */ /* SMC_Delete_Semaphore Delete a semaphore */ /* SMC_Obtain_Semaphore Obtain instance of semaphore */ /* SMC_Release_Semaphore Release instance of semaphore*/ /* SMC_Cleanup Cleanup on timeout or a */ /* terminate condition */ /* */ /* DEPENDENCIES */ /* */ /* cs_extr.h Common Service functions */ /* tc_extr.h Thread Control functions */ /* sm_extr.h Semaphore 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 "sm_extr.h" /* Semaphore functions */ #include "hi_extr.h" /* History functions */ #include "profiler.h" /* ProView interface */ /* Define external inner-component global data references. */ extern CS_NODE *SMD_Created_Semaphores_List; extern UNSIGNED SMD_Total_Semaphores; extern TC_PROTECT SMD_List_Protect; /* Define internal component function prototypes. */ VOID SMC_Cleanup(VOID *information); /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* SMC_Create_Semaphore */ /* */ /* DESCRIPTION */ /* */ /* This function creates a semaphore and then places it on the list */ /* of created semaphores. */ /* */ /* CALLED BY */ /* */ /* Application */ /* SMCE_Create_Semaphore 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 */ /* */ /* semaphore_ptr Semaphore control block ptr */ /* name Semaphore name */ /* initial_count Initial semaphore instance */ /* count */ /* 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 SMC_Create_Semaphore(NU_SEMAPHORE *semaphore_ptr, CHAR *name, UNSIGNED initial_count, OPTION suspend_type) { R1 SM_SCB *semaphore; /* Semaphore control blk ptr */ INT i; /* Working index variable */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input semaphore pointer into internal pointer. */ semaphore = (SM_SCB *) semaphore_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_SEMAPHORE_ID, (UNSIGNED) semaphore, (UNSIGNED) name, (UNSIGNED) initial_count); #endif /* First, clear the semaphore ID just in case it is an old Semaphore Control Block. */ semaphore -> sm_id = 0; /* Fill in the semaphore name. */ for (i = 0; i < NU_MAX_NAME; i++) semaphore -> sm_name[i] = name[i]; /* Setup the initial semaphore instance count. */ semaphore -> sm_semaphore_count = initial_count; /* Setup the semaphore suspension type. */ if (suspend_type == NU_FIFO) /* FIFO suspension is selected, setup the flag accordingly. */ semaphore -> sm_fifo_suspend = NU_TRUE; else /* Priority suspension is selected. */ semaphore -> sm_fifo_suspend = NU_FALSE; /* Clear the suspension list pointer. */ semaphore -> sm_suspension_list = NU_NULL; /* Clear the number of tasks waiting on the semaphore counter. */ semaphore -> sm_tasks_waiting = 0; /* Initialize link pointers. */ semaphore -> sm_created.cs_previous = NU_NULL; semaphore -> sm_created.cs_next = NU_NULL; /* Protect against access to the list of created semaphores. */ TCT_Protect(&SMD_List_Protect); /* At this point the semaphore is completely built. The ID can now be set and it can be linked into the created semaphore list. */ semaphore -> sm_id = SM_SEMAPHORE_ID; /* Link the semaphore into the list of created semaphores and increment the total number of semaphores in the system. */ CSC_Place_On_List(&SMD_Created_Semaphores_List,&(semaphore -> sm_created)); SMD_Total_Semaphores++; #ifdef INCLUDE_PROVIEW _RTProf_DumpSema(RT_PROF_CREATE_SEMAPHORE,semaphore, RT_PROF_OK); #endif /* Release protection against access to the list of created semaphores. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return successful completion. */ return(NU_SUCCESS); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* SMC_Delete_Semaphore */ /* */ /* DESCRIPTION */ /* */ /* This function deletes a semaphore and removes it from the list */ /* of created semaphores. All tasks suspended on the semaphore are */ /* resumed. Note that this function does not free the memory */ /* associated with the semaphore control block. */ /* */ /* CALLED BY */ /* */ /* Application */ /* SMCE_Delete_Semaphore 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 Setup system protection */ /* TCT_System_Unprotect Release system protection */ /* TCT_Unprotect Release protection */ /* */ /* INPUTS */ /* */ /* semaphore_ptr Semaphore control block ptr */ /* */ /* 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 SMC_Delete_Semaphore(NU_SEMAPHORE *semaphore_ptr) { R1 SM_SCB *semaphore; /* Semaphore control blk ptr */ SM_SUSPEND *suspend_ptr; /* Suspend block pointer */ SM_SUSPEND *next_ptr; /* Next suspend block */ STATUS preempt; /* Status for resume call */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input semaphore pointer into internal pointer. */ semaphore = (SM_SCB *) semaphore_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_SEMAPHORE_ID, (UNSIGNED) semaphore, (UNSIGNED) 0, (UNSIGNED) 0); #endif /* Protect against access to the semaphore. */ TCT_System_Protect(); #ifdef INCLUDE_PROVIEW _RTProf_DumpSema(RT_PROF_DELETE_SEMAPHORE,semaphore, RT_PROF_OK); #endif /* Clear the semaphore ID. */ semaphore -> sm_id = 0; /* Release protection. */ TCT_Unprotect(); /* Protect against access to the list of created semaphores. */ TCT_Protect(&SMD_List_Protect); /* Remove the semaphore from the list of created semaphores. */ CSC_Remove_From_List(&SMD_Created_Semaphores_List, &(semaphore -> sm_created)); /* Decrement the total number of created semaphores. */ SMD_Total_Semaphores--; /* Pickup the suspended task pointer list. */ suspend_ptr = semaphore -> sm_suspension_list; /* Walk the chain task(s) currently suspended on the semaphore. */ preempt = 0; while (suspend_ptr) { /* Protect against system access. */ TCT_System_Protect(); /* Resume the suspended task. Insure that the status returned is NU_SEMAPHORE_DELETED. */ suspend_ptr -> sm_return_status = NU_SEMAPHORE_DELETED; /* Point to the next suspend structure in the link. */ next_ptr = (SM_SUSPEND *) (suspend_ptr -> sm_suspend_link.cs_next); /* Resume the specified task. */ preempt = preempt | TCC_Resume_Task((NU_TASK *) suspend_ptr -> sm_suspended_task, NU_SEMAPHORE_SUSPEND); /* Determine if the next is the same as the current pointer. */ if (next_ptr == semaphore -> sm_suspension_list) /* Clear the suspension pointer to signal the end of the list traversal. */ suspend_ptr = NU_NULL; else /* Move the next pointer into the suspend block pointer. */ suspend_ptr = next_ptr; /* Modify current protection. */ TCT_Set_Current_Protect(&SMD_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 semaphores. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return a successful completion. */ return(NU_SUCCESS); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* SMC_Obtain_Semaphore */ /* */ /* DESCRIPTION */ /* */ /* This function obtains an instance of the semaphore. An instance */ /* corresponds to decrementing the counter by 1. If the counter is */ /* greater than zero at the time of this call, this function can be */ /* completed immediately. Otherwise, suspension is possible. */ /* */ /* CALLED BY */ /* */ /* Application */ /* SMCE_Obtain_Semaphore Error checking shell */ /* */ /* CALLS */ /* */ /* CSC_Place_On_List Place on suspend list */ /* CSC_Priority_Place_On_List Place on priority list */ /* [HIC_Make_History_Entry] Make entry in history log */ /* TCC_Suspend_Task Suspend calling task */ /* TCC_Task_Priority Obtain task's priority */ /* [TCT_Check_Stack] Stack checking function */ /* TCT_Current_Thread Pickup current thread pointer*/ /* TCT_System_Protect Protect semaphore */ /* TCT_Unprotect Release protection */ /* */ /* INPUTS */ /* */ /* semaphore_ptr Semaphore control block ptr */ /* suspend Suspension option if full */ /* */ /* OUTPUTS */ /* */ /* NU_SUCCESS If service is successful */ /* NU_UNAVAILABLE If an instance of the */ /* semaphore is not available */ /* NU_TIMEOUT If timeout on service */ /* NU_SEMAPHORE_DELETED If semaphore deleted during */ /* suspension */ /* NU_SEMAPHORE_RESET If semaphore 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, resulting in */ /* version 1.1 */ /* */ /* 03-18-1994 Verified version 1.1 */ /* */ /*************************************************************************/ STATUS SMC_Obtain_Semaphore(NU_SEMAPHORE *semaphore_ptr, UNSIGNED suspend) { R1 SM_SCB *semaphore; /* Semaphore control blk ptr */ R2 SM_SUSPEND *suspend_ptr; /* Suspend block pointer */ SM_SUSPEND suspend_block; /* Allocate suspension block */ TC_TCB *task; /* Task pointer */ STATUS status; /* Completion status */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input semaphore pointer into internal pointer. */ semaphore = (SM_SCB *) semaphore_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_OBTAIN_SEMAPHORE_ID, (UNSIGNED) semaphore, (UNSIGNED) suspend, (UNSIGNED) 0); #endif /* Initialize the status as successful. */ status = NU_SUCCESS; /* Protect against simultaneous access to the semaphore. */ TCT_System_Protect(); /* Determine if the semaphore has an instance (can be decremented). */ if (semaphore -> sm_semaphore_count) { /* Semaphore available. Decrement and return to the caller. */ semaphore -> sm_semaphore_count--; #ifdef INCLUDE_PROVIEW _RTProf_DumpSema(RT_PROF_OBTAIN_SEMAPHORE,semaphore, RT_PROF_OK); #endif } else { /* Semaphore is not available. Determine if suspension is required. */ if (suspend) { /* Suspension is selected. */ /* Increment the number of tasks waiting. */ semaphore -> sm_tasks_waiting++; #ifdef INCLUDE_PROVIEW _RTProf_DumpSema(RT_PROF_OBTAIN_SEMAPHORE,semaphore , RT_PROF_WAIT); #endif /* Setup the suspend block and suspend the calling task. */ suspend_ptr = &suspend_block; suspend_ptr -> sm_semaphore = semaphore; suspend_ptr -> sm_suspend_link.cs_next = NU_NULL; suspend_ptr -> sm_suspend_link.cs_previous = NU_NULL; task = (TC_TCB *) TCT_Current_Thread(); suspend_ptr -> sm_suspended_task = task; /* Determine if priority or FIFO suspension is associated with the semaphore. */ if (semaphore -> sm_fifo_suspend) { /* FIFO suspension is required. Link the suspend block into the list of suspended tasks on this semaphore. */ CSC_Place_On_List((CS_NODE **) &(semaphore -> sm_suspension_list), &(suspend_ptr -> sm_suspend_link)); } else { /* Get the priority of the current thread so the suspend block can be placed in the appropriate place. */ suspend_ptr -> sm_suspend_link.cs_priority = TCC_Task_Priority(task); CSC_Priority_Place_On_List((CS_NODE **) &(semaphore -> sm_suspension_list), &(suspend_ptr -> sm_suspend_link)); } /* Finally, suspend the calling task. Note that the suspension call automatically clears the protection on the semaphore. */ TCC_Suspend_Task((NU_TASK *) task, NU_SEMAPHORE_SUSPEND, SMC_Cleanup, suspend_ptr, suspend); /* Pickup the return status. */ status = suspend_ptr -> sm_return_status; } else { /* No suspension requested. Simply return an error status. */ status = NU_UNAVAILABLE; #ifdef INCLUDE_PROVIEW _RTProf_DumpSema(RT_PROF_OBTAIN_SEMAPHORE, semaphore,RT_PROF_FAIL); #endif } } /* Release protection against access to the semaphore. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return the completion status. */ return(status); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* SMC_Release_Semaphore */ /* */ /* DESCRIPTION */ /* */ /* This function releases a previously obtained semaphore. If one */ /* or more tasks are waiting, the first task is given the released */ /* instance of the semaphore. Otherwise, the semaphore instance */ /* counter is simply incremented. */ /* */ /* CALLED BY */ /* */ /* Application */ /* SMCE_Release_Semaphore Error checking shell */ /* */ /* CALLS */ /* */ /* CSC_Remove_From_List Remove from suspend list */ /* [HIC_Make_History_Entry] Make entry in history log */ /* TCC_Resume_Task Resume a suspended task */ /* [TCT_Check_Stack] Stack checking function */ /* TCT_Control_To_System Transfer control to system */ /* TCT_System_Protect Protect semaphore */ /* TCT_Unprotect Release protection */ /* */ /* INPUTS */ /* */ /* semaphore_ptr Semaphore control block ptr */ /* */ /* 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 SMC_Release_Semaphore(NU_SEMAPHORE *semaphore_ptr) { R1 SM_SCB *semaphore; /* Semaphore control blk ptr */ R2 SM_SUSPEND *suspend_ptr; /* Pointer to suspend block */ STATUS preempt; /* Preemption flag */ STATUS status; /* Completion status */ NU_SUPERV_USER_VARIABLES /* Switch to supervisor mode */ NU_SUPERVISOR_MODE(); /* Move input semaphore pointer into internal pointer. */ semaphore = (SM_SCB *) semaphore_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_RELEASE_SEMAPHORE_ID, (UNSIGNED) semaphore, (UNSIGNED) 0, (UNSIGNED) 0); #endif /* Initialize the status as successful. */ status = NU_SUCCESS; /* Protect against simultaneous access to the semaphore. */ TCT_System_Protect(); /* Determine if another task is waiting on the semaphore. */ if (semaphore -> sm_tasks_waiting) { /* Yes, another task is waiting for an instance of the semaphore. */ /* Decrement the number of tasks waiting counter. */ semaphore -> sm_tasks_waiting--; #ifdef INCLUDE_PROVIEW _RTProf_DumpSema(RT_PROF_RELEASE_SEMAPHORE, semaphore,RT_PROF_OK); #endif /* Remove the first suspended block from the list. */ suspend_ptr = semaphore -> sm_suspension_list; CSC_Remove_From_List((CS_NODE **) &(semaphore -> sm_suspension_list), &(suspend_ptr -> sm_suspend_link)); /* Setup the appropriate return value. */ suspend_ptr -> sm_return_status = NU_SUCCESS; /* Resume the suspended task. */ preempt = TCC_Resume_Task((NU_TASK *) suspend_ptr -> sm_suspended_task, NU_SEMAPHORE_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 { /* Increment the semaphore instance counter. */ semaphore -> sm_semaphore_count++; #ifdef INCLUDE_PROVIEW _RTProf_DumpSema(RT_PROF_RELEASE_SEMAPHORE, semaphore,RT_PROF_OK); #endif } /* Release protection against access to the semaphore. */ TCT_Unprotect(); /* Return to user mode */ NU_USER_MODE(); /* Return the completion status. */ return(status); } /*************************************************************************/ /* */ /* FUNCTION */ /* */ /* SMC_Cleanup */ /* */ /* DESCRIPTION */ /* */ /* This function is responsible for removing a suspension block */ /* from a semaphore. 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 SMC_Cleanup(VOID *information) { SM_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 = (SM_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 -> sm_return_status = NU_TIMEOUT; /* Decrement the number of tasks waiting counter. */ (suspend_ptr -> sm_semaphore) -> sm_tasks_waiting--; /* Unlink the suspend block from the suspension list. */ CSC_Remove_From_List((CS_NODE **) &((suspend_ptr -> sm_semaphore) -> sm_suspension_list), &(suspend_ptr -> sm_suspend_link)); /* Return to user mode */ NU_USER_MODE(); }