This module provides an API for managing and using timers.

Note: This is an initial version of the API that only provides support for relative timers (e.g., expires in 10 seconds). Absolute timers allow a specific time/date to be used, and will be supported in a future version of this API.

Creating/Deleting Timer Objects

Timers are created using le_timer_Create. The timer name is used for logging purposes only.

The following attributes of the timer can be set:

The repeat count defaults to 1, so that the timer is initially a one-shot timer. All the other attributes must be explicitly set. At a minimum, the interval must be set before the timer can be used. Note that these attributes can only be set if the timer is not currently running; otherwise, an error will be returned.

A timer is deleted using le_timer_Delete. If the timer is currently running, then it will be stopped first, before being deleted.

Using Timers

A timer can be started using le_timer_Start. If it's already running, then it won't be modified; instead an error will be returned. To restart a currently running timer, use le_timer_Restart.

A timer can be stopped using le_timer_Stop. If it's not currently running, an error will be returned, and nothing more will be done.

To determine if the timer is currently running, use le_timer_IsRunning.

When a timer expires, if the timer expiry handler is set by le_timer_SetHandler, the handler will be called with a reference to the expired timer. If additional data is required in the handler, le_timer_SetContextPtr can be used to set the appropriate context before starting the timer, and le_timer_GetContextPtr can be used to retrieve the context while in the handler.

The number of times that a timer has expired can be retrieved by le_timer_GetExpiryCount. This count is independent of whether there is an expiry handler for the timer.

Thread Support

A timer should only be used by the thread that created it. It's not safe for a thread to use or manipulate a timer that belongs to another thread. The timer expiry handler is called by the event loop of the thread that starts the timer.

See Event Loop API for details on running the event loop of a thread.

Fatal Errors

The process will exit under any of the following conditions:

If an invalid timer object is given to:

Troubleshooting

Timers can be traced by enabling the log trace keyword "timers" in the "framework" component.

See Log Controls for more information.

Copyright (C) Sierra Wireless Inc. Use of this work is subject to license.