sosensormanager(3)
NAME
SoSensorManager
SYNOPSIS
#include <Inventor/sensors/SoSensorManager.h>
Detailed Description
The SoSensorManager class handles the sensor queues.
There are two major sensor types in Coin, 'delay' sensors and 'timer'
sensors:.
- · Delay sensors trigger when the application is otherwise idle. In
- addition, to avoid starvation in applications that are continually
busy, the delay-sensor queue also has a timeout which, when reached, will empty the queue anyhow. - · Timer sensors are set up to trigger at specific, absolute times.
Each of these two types has its own queue, which is handled by the
SoSensorManager. The queues are kept in sorted order by SoSensorManager, either according to trigger-time (for timer sensors) or by priority (for delay sensors).
The SoSensorManager provides methods for managing these queues, by insertion and removal of sensors, and processing (emptying) of the
queues.
The sensor mechanism is crucial in Coin for a number of important
features, most notably automatic scheduling redrawal upon changes, and for making it possible to set up animations in the scenegraph which
does not need any additional book-keeping from the application code. SoSensorManager should usually be considered as an internal class in the Coin API. It is only interesting for application programmers when
implementing new windowsystem-specific libraries (like Systems in Motion's SoQt, SoXt, SoGtk, SoWin or Sc21) or wrappers. Then one has to set up code to empty the queues at the correct intervals. For detailed information on how to do that, we would advise you to look at the
implementation of said mechanisms in the So*-libraries which SIM
provides.
Please note that before Coin 2.3.1, sensors with equal priority (or the same trigger time for SoTimerQueue sensors) were processed LIFO. This
has now been changed to FIFO to be conformant to SGI Inventor.
See also: - SoSensor SoTimerQueueSensor SoDelayQueueSensor SoTimerSensor SoAlarmSensor SoIdleSensor SoDataSensor SoOneShotSensor SoPathSensor SoFieldSensor SoNodeSensor
- Public Member Functions
- SoSensorManager (void)
~SoSensorManager ()
void insertDelaySensor (SoDelayQueueSensor *s) void insertTimerSensor (SoTimerQueueSensor *s) void removeDelaySensor (SoDelayQueueSensor *s) void removeTimerSensor (SoTimerQueueSensor *s) void setChangedCallback (void(*sensorQueueChangedCB)(void *), void*data) - void rescheduleTimer (SoTimerSensor *s)
void removeRescheduledTimer (SoTimerQueueSensor *s)
void processDelayQueue (SbBool isidle)
void processImmediateQueue (void)
void processTimerQueue (void)
SbBool isDelaySensorPending (void) SbBool isTimerSensorPending (SbTime &tm) void setDelaySensorTimeout (const SbTime &t) const SbTime & getDelaySensorTimeout (void) int doSelect (int nfds, void *readfds, void *writefds, void *exceptfds,struct timeval *userTimeOut) - Friends
class SoSensorManagerP
Constructor & Destructor Documentation
- SoSensorManager::SoSensorManager (void)
- Constructor.
- SoSensorManager::~SoSensorManager ()
- Destructor.
Member Function Documentation
- void SoSensorManager::insertDelaySensor (SoDelayQueueSensor * newentry)
- Add a new entry to the queue of delay sensors.
See also:removeFromQueue() - References SbList< Type >::getLength(),
SoDelayQueueSensor::getPriority(), SbList< Type >::insert(),
SoDebugError::postInfo(), and SbTime::zero().
Referenced by SoDelayQueueSensor::schedule(). - void SoSensorManager::insertTimerSensor (SoTimerQueueSensor * newentry)
- Add a new entry to the timer queue of sensors. The queue will be sorted
in order of supposed trigger time.
See also:removeFromQueue() - References SbList< Type >::getLength(),
SoTimerQueueSensor::getTriggerTime(), SbTime::getValue(), SbList< Type >::insert(), and SoDebugError::postInfo().
Referenced by SoTimerQueueSensor::schedule(), and
SoTimerQueueSensor::setTriggerTime(). - void SoSensorManager::removeDelaySensor (SoDelayQueueSensor * entry)
- Remove an entry from the queue of prioritized sensors.
See also:addToQueue() - References SoDebugError::postWarning().
Referenced by SoDelayQueueSensor::unschedule(). - void SoSensorManager::removeTimerSensor (SoTimerQueueSensor * entry)
- Remove an entry from the queue of timer sensors.
References SoDebugError::postWarning().
Referenced by removeRescheduledTimer(),
SoTimerQueueSensor::setTriggerTime(), and
SoTimerQueueSensor::unschedule(). - void SoSensorManager::setChangedCallback (void(*)(void *) func, void *
- data)
For setting up a callback function to be invoked whenever any of the
sensor queues are changed.
This callback should typically be responsible for updating the clientside mechanism which is used for processing the queues. - void SoSensorManager::rescheduleTimer (SoTimerSensor * s)
- This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Referenced by SoTimerSensor::schedule().
- void SoSensorManager::removeRescheduledTimer (SoTimerQueueSensor * s)
- This API member is considered internal to the library, as it is not
likely to be of interest to the application programmer.
References removeTimerSensor().
Referenced by SoTimerSensor::unschedule(). - void SoSensorManager::processDelayQueue (SbBool isidle)
- Trigger all delay queue entries in priority order.
The isidle flag indicates whether or not the processing happens because the application is idle or because the delay queue timeout was reached. A delay queue sensor with priority > 0 can only be triggered once
during a call to this function. If a delay sensor is rescheduled during processDelayQueue(), it is not processed until the next time this function is called. This is done to avoid an infinite loop while
processing the sensors.
A delay queue sensor with priority 0 is called an immediate sensor.
See also:SoDB::setDelaySensorTimeout() SoSensorManager::processImmediateQueue() - References SoDebugError::postInfo(), and processImmediateQueue().
- void SoSensorManager::processImmediateQueue (void)
- Process all immediate sensors (delay sensors with priority 0).
Be aware that you might risk an infinite loop using immediate sensors. Unlike delay queue sensors, immediate sensors can be rescheduled and
triggered multiple times during immediate queue processing.
See also:SoDelayQueueSensor::setPriority() - References SoDebugError::postInfo(), SoDebugError::postWarning(), and
SoSensor::trigger().
Referenced by SoDB::endNotify(), and processDelayQueue(). - void SoSensorManager::processTimerQueue (void)
- Trigger all the timers which has expired.
References SbTime::getTimeOfDay(), and SoDebugError::postInfo(). - SbBool SoSensorManager::isDelaySensorPending (void)
- Returns TRUE if at least one delay sensor or immediate sensor is
present in the respective queue, otherwise FALSE.
Referenced by SoDB::endNotify(). - SbBool SoSensorManager::isTimerSensorPending (SbTime & tm)
- Returns TRUE if at least one timer sensor is present in the queue,
otherwise FALSE.
If sensors are pending, the time interval until the next one should be triggered will be put in the tm variable. - void SoSensorManager::setDelaySensorTimeout (const SbTime & t)
- Delay sensors are usually triggered only when the system is idle. But
when there are continuous updates to the scene graph, there's a
possibility that the delay queue will starve and sensors are never
triggered. To make sure this won't happen, this is a timeout value for the delay queue. When this timeout has been reached, the sensors in the delay queue gets processed before other sensors and events. This method will let the user set this timeout value.
The default value is 1/12 of a second.
Specifying a zero time will disable the timeout, opening for potential delay queue starvation.
See also:getDelaySensorTimeout(), SoDelayQueueSensor - References SoDebugError::postWarning(), and SbTime::zero().
Referenced by SoDB::setDelaySensorTimeout(). - const SbTime & SoSensorManager::getDelaySensorTimeout (void)
- Returns the timeout value for sensors in the delay queue.
See also:setDelaySensorTimeout(), SoDelayQueueSensor - Referenced by SoDB::getDelaySensorTimeout().
- int SoSensorManager::doSelect (int nfds, void * readfds, void * writefds,
- void * exceptfds, struct timeval * usertimeout)
NOTE: THIS METHOD IS OBSOLETED. DON'T USE IT.
This is a wrapper around the standard select(2) call, which will make
sure the sensor queues are updated while waiting for any action to
happen on the given file descriptors.
The void* arguments must be valid pointers to fd_set structures. We've changed this from the original SGI Inventor API to avoid messing up the header file with system-specific includes.
NOTE: THIS METHOD IS OBSOLETED. DON'T USE IT.
Author
- Generated automatically by Doxygen for Coin from the source code.