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QHsm Class Reference

Hierarchical State Machine class (QHsm-style state machine implementation strategy) More...

#include "qp.h"

Inheritance diagram for QHsm:
QAsm QHsmDummy

Public Member Functions

QStateHandler QHsm_childState (QHsm *const me, QStateHandler const parent)
 

Static Public Member Functions

static QStateHandler QHsm_state (QHsm const *const me)
 

Public Attributes

QAsm super
 

Protected Member Functions

void QHsm_ctor (QHsm *const me, QStateHandler const initial)
 
- Protected Member Functions inherited from QAsm
void QAsm_ctor (QAsm *const me)
 
QState QHsm_top (QHsm const *const me, QEvt const *const e)
 

Private Member Functions

void QHsm_init_ (QAsm *const me, void const *const e, uint_fast8_t const qsId)
 
void QHsm_dispatch_ (QAsm *const me, QEvt const *const e, uint_fast8_t const qsId)
 
QStateHandler QHsm_getStateHandler_ (QAsm *const me)
 
bool QHsm_isIn_ (QAsm *const me, QStateHandler const state)
 
int_fast8_t QHsm_tran_ (QAsm *const me, QStateHandler *const path, uint_fast8_t const qsId)
 

Additional Inherited Members

- Protected Attributes inherited from QAsm
struct QAsmVtable const * vptr
 
union QAsmAttr state
 
union QAsmAttr temp
 

Detailed Description

Hierarchical State Machine class (QHsm-style state machine implementation strategy)

Description
QHsm represents a Hierarchical State Machine (HSM) with full support for hierarchical nesting of states, entry/exit actions, initial transitions, and transitions to history in any composite state. This class is designed for ease of manual coding of HSMs in C, but it is also supported by the QM modeling tool.
Note
QHsm is not intended to be instantiated directly, but rather serves as the abstract base class for derivation of state machines in the QP application.
Traceability
Usage
The following example illustrates how to derive a state machine class from QHsm. Please note that the QHsm member super is defined as the FIRST member of the derived class.
typedef struct {
QHsm super; // <=== inherit QHsm
double operand1;
double operand2;
char display[DISP_WIDTH + 1];
uint8_t len;
uint8_t opKey;
} Calc;
void Calc_ctor(void) {
QHsm_ctor(&me->super, Q_STATE_CAST(&Calc_initial)); // ctor of the superclass
. . .
}
#define Q_STATE_CAST(handler_)
Definition qp.h:526
Hierarchical State Machine class (QHsm-style state machine implementation strategy)
Definition qp.h:313
void QHsm_ctor(QHsm *const me, QStateHandler const initial)
QAsm super
Definition qp.h:315

Definition at line 313 of file qp.h.

Member Function Documentation

◆ QHsm_ctor()

QHsm::QHsm_ctor ( QHsm *const me,
QStateHandler const initial )
protected

Constructor of the QHsm base class.

Description
The constructor initializes the QHsm::state. The constructor is "protected" because it is only intended to be invoked from the subclasses of the abstract base class QAsm.
Parameters
[in,out]mecurrent instance pointer (see Object Orientation)
[in]initialinitial pseudostate of the instantiated state machine

◆ QHsm_init_()

QHsm::QHsm_init_ ( QAsm *const me,
void const *const e,
uint_fast8_t const qsId )
private

Implementation of the top-most initial transition in QHsm.

Description
Synchronously executes the top-most initial transition in a state machine.
Parameters
[in,out]mecurrent instance pointer (see Object Orientation)
[in]epointer to an extra parameter (might be NULL)
[in]qsIdQS-id of this state machine (for QS local filter)
Precondition qep_msm:200
  • the virtual pointer must be initialized,
  • the top-most initial transition must be initialized,
  • the initial transition must not be taken yet.
Note
This function should be called only via the virtual table (see QASM_INIT()) and should NOT be called directly in the applications.

Definition at line 141 of file qep_hsm.c.

◆ QHsm_dispatch_()

QHsm::QHsm_dispatch_ ( QAsm *const me,
QEvt const *const e,
uint_fast8_t const qsId )
private

Implementation of dispatching events to a QHsm

Description
Synchronously dispatches an event for processing to a state machine. The processing of an event represents one run-to-completion (RTC) step.
Parameters
[in,out]mecurrent instance pointer (see Object Orientation)
[in]epointer to the event to be dispatched to the MSM
[in]qsIdQS-id of this state machine (for QS local filter)
Precondition qep_msm:302
  • current state must be initialized
  • check the internal integrity (Software Self-Monitoring (SSM))
Note
This function should be called only via the virtual table (see QASM_DISPATCH()) and should NOT be called directly in the applications.

Definition at line 268 of file qep_hsm.c.

◆ QHsm_getStateHandler_()

QHsm::QHsm_getStateHandler_ ( QAsm *const me)
private

Implementation of getting the state handler in a QHsm subclass

Parameters
[in,out]mecurrent instance pointer (see Object Orientation)
Note
This function is only called internally via the virtual table

Definition at line 476 of file qep_hsm.c.

◆ QHsm_isIn_()

QHsm::QHsm_isIn_ ( QAsm *const me,
QStateHandler const state )
private
Description
Check if a given state is part of the current active state configuration in QHsm subclasses. Please note that for a HSM, to "be in a state" means also to be in a superstate of of the state.
Parameters
[in]mecurrent instance pointer (see Object Orientation)
[in]statepointer to the state-handler function to be tested
Returns
'true' if the HSM "is in" the state and 'false' otherwise
Note
This function should be called only via the virtual table (see QASM_IS_IN()) and should NOT be called directly in the applications.
Attention
This function should be only called only when the state machine is in a "stable state configuration".
Precondition qep_hsm:602
  • internal integrity check (Software Self-Monitoring (SSM))
Traceability

Definition at line 483 of file qep_hsm.c.

◆ QHsm_state()

QHsm::QHsm_state ( QHsm const *const me)
inlinestatic

Obtain the current active state from a HSM (read only)

Parameters
[in]mecurrent instance pointer (see Object Orientation)
Returns
the current active state-handler
Note
This function is used for state history (deep history) in the auto-generated code by the QM modeling tool.

Definition at line 351 of file qp.h.

◆ QHsm_childState()

QHsm::QHsm_childState ( QHsm *const me,
QStateHandler const parent )

Obtain the current active child state of a given parent in QMsm

Description
Finds the child state of the given parent, such that this child state is an ancestor of the currently active state. The main purpose of this function is to support **shallow history*transitions in state machines derived from QMsm.
Parameters
[in]mecurrent instance pointer (see Object Orientation)
[in]parentpointer to the state-handler
Returns
the child of a given parent state-handler, which is an ancestor of the currently active state. For the corner case when the currently active state is the given parent state, function returns the parent state.
Postcondition qep_msm:890
  • the child must be found
Note
This function is used in QM for auto-generating code for state history (shallow history)

Definition at line 523 of file qep_hsm.c.

◆ QHsm_tran_()

int_fast8_t QHsm_tran_ ( QAsm *const me,
QStateHandler *const path,
uint_fast8_t const qsId )
private

Definition at line 562 of file qep_hsm.c.

Member Data Documentation

◆ super

QAsm QHsm::super

Definition at line 315 of file qp.h.


The documentation for this class was generated from the following files: