5.3 Eventflags
The RI78V4 provides 16-bit eventflags as a queuing function for tasks, such as keeping the tasks waiting for execution, until the results of the execution of a given processing program are output.
In the RI78V4, the method of creating an eventflag is limited to "static creation by the Kernel Initialization Module".
Eventflags therefore cannot be created dynamically using a method such as issuing a service call from a processing program.
- Static create
Static eventflag creation is realized by defining Eventflag information in the system configuration file.
The RI78V4 executes eventflag creation processing based on data stored in information files, using the Kernel Initialization Module, and handles the created eventflags as management targets.
Static eventflag creation is realized by defining Eventflag information in the system configuration file.
The RI78V4 executes eventflag creation processing based on data stored in information files, using the Kernel Initialization Module, and handles the created eventflags as management targets.
In the RI78V4, eventflags created statically by the Kernel Initialization Module cannot be deleted dynamically using a method such as issuing a service call from a processing program.
- set_flg, iset_flg
These service calls set the result of ORing the bit pattern of the eventflag specified by parameter flgid and the bit pattern specified by parameter setptn as the bit pattern of the target eventflag.
If the required condition of the task queued to the target eventflag wait queue is satisfied when this service call is issued, the relevant task is unlinked from the wait queue at the same time as bit pattern setting processing.
As a result, the relevant task is moved from the WAITING state (waiting state for an eventflag) to the READY state, or from the WAITING-SUSPENDED state to the SUSPENDED state.
The following describes an example for coding this service call.
These service calls set the result of ORing the bit pattern of the eventflag specified by parameter flgid and the bit pattern specified by parameter setptn as the bit pattern of the target eventflag.
If the required condition of the task queued to the target eventflag wait queue is satisfied when this service call is issued, the relevant task is unlinked from the wait queue at the same time as bit pattern setting processing.
As a result, the relevant task is moved from the WAITING state (waiting state for an eventflag) to the READY state, or from the WAITING-SUSPENDED state to the SUSPENDED state.
The following describes an example for coding this service call.
#include <kernel.h> /*Standard header file definition*/ #include <kernel_id.h> /*System information header file definition*/ void func_task ( VP_INT exinf ) { ID flgid = ID_flgA; /*Declares and initializes variable*/ FLGPTN setptn = 0B1010; /*Declares and initializes variable*/ /* ............ */ set_flg ( flgid, setptn ); /*Set eventflag*/ /* ............ */ } |
Note 1 If the task linked in the wait queue is moved to the READY state after this service call is issued, this service call also re-queues the task at the end of the ready queue corresponding to the priority of the task.
Note 2 If the bit pattern set to the target eventflag is B'1100 and the bit pattern specified by parameter setptn is B'1010 when this service call is issued, the bit pattern of the target eventflag is set to B'1110.
- clr_flg
This service call sets the result of ANDing the bit pattern set to the eventflag specified by parameter flgid and the bit pattern specified by parameter clrptn as the bit pattern of the target eventflag.
The following describes an example for coding this service call.
This service call sets the result of ANDing the bit pattern set to the eventflag specified by parameter flgid and the bit pattern specified by parameter clrptn as the bit pattern of the target eventflag.
The following describes an example for coding this service call.
#include <kernel.h> /*Standard header file definition*/ #include <kernel_id.h> /*System information header file definition*/ void func_task ( VP_INT exinf ) { ID flgid = ID_flgA; /*Declares and initializes variable*/ FLGPTN clrptn = 0B1010; /*Declares and initializes variable*/ /* ............ */ clr_flg ( flgid, clrptn ); /*Clear eventflag*/ /* ............ */ } |
Note 1 This service call does not perform queuing of clear requests. If the bit pattern has been cleared, therefore, no processing is performed but it is not handled as an error.
Note 2 If the bit pattern set to the target eventflag is B'1100 and the bit pattern specified by parameter clrptn is B'1010 when this service call is issued, the bit pattern of the target eventflag is set to B'1110.
A bit pattern is checked (waiting forever, polling, or with timeout) by issuing the following service call from the processing program.
- wai_flg
This service call checks whether the bit pattern specified by parameter waiptn and the bit pattern that satisfies the required condition specified by parameter wfmode are set to the eventflag specified by parameter flgid.
If a bit pattern that satisfies the required condition has been set for the target eventflag, the bit pattern of the target eventflag is stored in the area specified by parameter p_flgptn.
If the bit pattern of the target eventflag does not satisfy the required condition when this service call is issued, the invoking task is queued to the target eventflag wait queue.
As a result, the invoking task is unlinked from the ready queue and is moved from the RUNNING state to the WAITING state (waiting state for an eventflag).
The waiting state for an eventflag is cancelled in the following cases, and then moved to the READY state.
This service call checks whether the bit pattern specified by parameter waiptn and the bit pattern that satisfies the required condition specified by parameter wfmode are set to the eventflag specified by parameter flgid.
If a bit pattern that satisfies the required condition has been set for the target eventflag, the bit pattern of the target eventflag is stored in the area specified by parameter p_flgptn.
If the bit pattern of the target eventflag does not satisfy the required condition when this service call is issued, the invoking task is queued to the target eventflag wait queue.
As a result, the invoking task is unlinked from the ready queue and is moved from the RUNNING state to the WAITING state (waiting state for an eventflag).
The waiting state for an eventflag is cancelled in the following cases, and then moved to the READY state.
A bit pattern that satisfies the required condition was set to the target eventflag as a result of issuing set_flg.
|
|
A bit pattern that satisfies the required condition was set to the target eventflag as a result of issuing iset_flg.
|
|
- wfmode = TWF_ANDW
Checks whether all of the bits to which 1 is set by parameter waiptn are set as the target eventflag.
Checks whether all of the bits to which 1 is set by parameter waiptn are set as the target eventflag.
- wfmode = TWF_ORW
Checks which bit, among bits to which 1 is set by parameter waiptn, is set as the target eventflag.
Checks which bit, among bits to which 1 is set by parameter waiptn, is set as the target eventflag.
#include <kernel.h> /*Standard header file definition*/ #include <kernel_id.h> /*System information header file definition*/ void func_task ( VP_INT exinf ) { ER ercd; /*Declares variable*/ ID flgid = ID_flgA; /*Declares and initializes variable*/ FLGPTN waiptn = 0B1110; /*Declares and initializes variable*/ MODE wfmode = TWF_ANDW; /*Declares and initializes variable*/ FLGPTN p_flgptn; /*Declares variable*/ /* ............ */ /*Wait for eventflag (waiting forever)*/ ercd = wai_flg ( flgid, waiptn, wfmode, &p_flgptn ); if ( ercd == E_OK ) { /* ............ */ /*Normal termination processing*/ } else if ( ercd == E_RLWAI ) { /* ............ */ /*Forced termination processing*/ } /* ............ */ } |
Note 1 In the RI78V4, the number of tasks that can be queued to the eventflag wait queue is one. If this service call is issued for the eventflag to which a task is queued, therefore, "E_ILUSE" is returned regardless of whether or not the required condition is immediately satisfied.
Note 2 The RI78V4 performs bit pattern clear processing (0x0 setting) when the required condition of the target eventflag (TA_CLR attribute) is satisfied.
- pol_flg
This service call checks whether the bit pattern specified by parameter waiptn and the bit pattern that satisfies the required condition specified by parameter wfmode are set to the eventflag specified by parameter flgid.
If the bit pattern that satisfies the required condition has been set to the target eventflag, the bit pattern of the target eventflag is stored in the area specified by parameter p_flgptn.
If the bit pattern of the target eventflag does not satisfy the required condition when this service call is issued, "E_TMOUT" is returned.
The following shows the specification format of required condition wfmode.
This service call checks whether the bit pattern specified by parameter waiptn and the bit pattern that satisfies the required condition specified by parameter wfmode are set to the eventflag specified by parameter flgid.
If the bit pattern that satisfies the required condition has been set to the target eventflag, the bit pattern of the target eventflag is stored in the area specified by parameter p_flgptn.
If the bit pattern of the target eventflag does not satisfy the required condition when this service call is issued, "E_TMOUT" is returned.
The following shows the specification format of required condition wfmode.
- wfmode = TWF_ANDW
Checks whether all of the bits to which 1 is set by parameter waiptn are set as the target eventflag.
Checks whether all of the bits to which 1 is set by parameter waiptn are set as the target eventflag.
- wfmode = TWF_ORW
Checks which bit, among bits to which 1 is set by parameter waiptn, is set as the target eventflag.
Checks which bit, among bits to which 1 is set by parameter waiptn, is set as the target eventflag.
#include <kernel.h> /*Standard header file definition*/ #include <kernel_id.h> /*System information header file definition*/ void func_task ( VP_INT exinf ) { ER ercd; /*Declares variable*/ ID flgid = ID_flgA; /*Declares and initializes variable*/ FLGPTN waiptn = 0B1110; /*Declares and initializes variable*/ MODE wfmode = TWF_ANDW; /*Declares and initializes variable*/ FLGPTN p_flgptn; /*Declares variable*/ /* ............ */ /*Wait for eventflag (polling)*/ ercd = pol_flg ( flgid, waiptn, wfmode, &p_flgptn ); if ( ercd == E_OK ) { /* ............ */ /*Polling success processing*/ } else if ( ercd == E_TMOUT ) { /* ............ */ /*Polling failure processing*/ } /* ............ */ } |
Note 1 In the RI78V4, the number of tasks that can be queued to the eventflag wait queue is one. If this service call is issued for the eventflag to which a task is queued, therefore, "E_ILUSE" is returned regardless of whether or not the required condition is immediately satisfied.
Note 2 The RI78V4 performs bit pattern clear processing (0x0 setting) when the required condition of the target eventflag (TA_CLR attribute) is satisfied.
- twai_flg
This service call checks whether the bit pattern specified by parameter waiptn and the bit pattern that satisfies the required condition specified by parameter wfmode are set to the eventflag specified by parameter flgid.
If the bit pattern that satisfies the required condition has been set to the target eventflag, the bit pattern of the target eventflag is stored in the area specified by parameter p_flgptn.
If the bit pattern of the target eventflag does not satisfy the required condition when this service call is issued, the invoking task is queued to the target eventflag wait queue.
As a result, the invoking task is unlinked from the ready queue and is moved from the RUNNING state to the WAITING state (waiting state for an eventflag).
The waiting state for an eventflag is cancelled in the following cases, and then moved to the READY state.
This service call checks whether the bit pattern specified by parameter waiptn and the bit pattern that satisfies the required condition specified by parameter wfmode are set to the eventflag specified by parameter flgid.
If the bit pattern that satisfies the required condition has been set to the target eventflag, the bit pattern of the target eventflag is stored in the area specified by parameter p_flgptn.
If the bit pattern of the target eventflag does not satisfy the required condition when this service call is issued, the invoking task is queued to the target eventflag wait queue.
As a result, the invoking task is unlinked from the ready queue and is moved from the RUNNING state to the WAITING state (waiting state for an eventflag).
The waiting state for an eventflag is cancelled in the following cases, and then moved to the READY state.
A bit pattern that satisfies the required condition was set to the target eventflag as a result of issuing set_flg.
|
|
A bit pattern that satisfies the required condition was set to the target eventflag as a result of issuing iset_flg.
|
|
- wfmode = TWF_ANDW
Checks whether all of the bits to which 1 is set by parameter waiptn are set as the target eventflag.
Checks whether all of the bits to which 1 is set by parameter waiptn are set as the target eventflag.
- wfmode = TWF_ORW
Checks which bit, among bits to which 1 is set by parameter waiptn, is set as the target eventflag.
Checks which bit, among bits to which 1 is set by parameter waiptn, is set as the target eventflag.
#include <kernel.h> /*Standard header file definition*/ #include <kernel_id.h> /*System information header file definition*/ void func_task ( VP_INT exinf ) { ER ercd; /*Declares variable*/ ID flgid = ID_flgA; /*Declares and initializes variable*/ FLGPTN waiptn = 0B1110; /*Declares and initializes variable*/ MODE wfmode = TWF_ANDW; /*Declares and initializes variable*/ FLGPTN p_flgptn; /*Declares variable*/ TMO tmout = 3600; /*Declares and initializes variable*/ /* ............ */ /*Wait for eventflag (with timeout)*/ ercd = twai_flg ( flgid, waiptn, wfmode, &p_flgptn, tmout ); if ( ercd == E_OK ) { /* ............ */ /*Normal termination processing*/ } else if ( ercd == E_RLWAI ) { /* ............ */ /*Forced termination processing*/ } else if ( ercd == E_TMOUT ) { /* ............ */ /*Timeout processing*/ } /* ............ */ } |
Note 1 In the RI78V4, the number of tasks that can be queued to the eventflag wait queue is one. If this service call is issued for the eventflag to which a task is queued, therefore, "E_ILUSE" is returned regardless of whether or not the required condition is immediately satisfied.
Note 2 The RI78V4 performs bit pattern clear processing (0x0 setting) when the required condition of the target eventflag (TA_CLR attribute) is satisfied.
Note 3 When TMO_FEVR is specified for wait time tmout, processing equivalent to wai_flg will be executed. When TMO_POL is specified, processing equivalent to pol_flg will be executed.
An eventflag status is referenced by issuing the following service call from the processing program.
- ref_flg
Stores eventflag state packet (such as existence of waiting tasks) of the eventflag specified by parameter flgid in the area specified by parameter pk_rflg.
The following describes an example for coding this service call.
Stores eventflag state packet (such as existence of waiting tasks) of the eventflag specified by parameter flgid in the area specified by parameter pk_rflg.
The following describes an example for coding this service call.
#include <kernel.h> /*Standard header file definition*/ #include <kernel_id.h> /*System information header file definition*/ void func_task ( VP_INT exinf ) { ID flgid = ID_flgA; /*Declares and initializes variable*/ T_RFLG pk_rflg; /*Declares data structure*/ ID wtskid; /*Declares variable*/ FLGPTN flgptn; /*Declares variable*/ /* ............ */ ref_flg ( flgid, &pk_rflg );/*Reference eventflag state*/ wtskid = pk_rflg.wtskid; /*Reference ID number of the task at the head of the wait queue*/ flgptn = pk_rflg.flgptn; /*Reference current bit pattern*/ /* ............ */ } |