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timer: prevent infinite loop on one-shot timer start #38

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Merged
merged 2 commits into from
Feb 24, 2025
Merged

timer: prevent infinite loop on one-shot timer start #38

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timer: prevent infinate loop on one-shot timer start
Feb 21, 2025
e5af1d2
Code review suggestions
aggarg Feb 24, 2025
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9 changes: 8 additions & 1 deletion FreeRTOS-Plus-POSIX/source/FreeRTOS_POSIX_timer.c
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Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,7 @@ typedef struct timer_internal
StaticTimer_t xTimerBuffer; /**< Memory that holds the FreeRTOS timer. */
struct sigevent xTimerEvent; /**< What to do when this timer expires. */
TickType_t xTimerPeriod; /**< Period of this timer. */
UBaseType_t uxTimerCallbackInvocations; /**< Number of times the timer callback has been invoked. */
} timer_internal_t;

/*-----------------------------------------------------------*/
Expand Down Expand Up @@ -94,6 +95,7 @@ void prvTimerCallback( TimerHandle_t xTimer )
pxTimer->xTimerEvent.sigev_value.sival_ptr );
}
}
pxTimer->uxTimerCallbackInvocations++;
}

/*-----------------------------------------------------------*/
Expand Down Expand Up @@ -273,6 +275,9 @@ int timer_settime( timer_t timerid,
}
}

/* Set uxTimerCallbackInvocations before timer start. */
pxTimer->uxTimerCallbackInvocations = 0

/* If xNextTimerExpiration is still 0, that means that it_value specified
* an absolute timeout in the past. Per POSIX spec, a notification should be
* triggered immediately. */
Expand All @@ -286,7 +291,9 @@ int timer_settime( timer_t timerid,
xTimerCommandSent = xTimerChangePeriod( xTimer, xNextTimerExpiration, xNextTimerExpiration );

/* Wait until the timer start command is processed. */
while( ( xTimerCommandSent != pdFAIL ) && ( xTimerIsTimerActive( xTimer ) == pdFALSE ) )
while( ( xTimerCommandSent != pdFAIL ) &&
( xTimerIsTimerActive( xTimer ) == pdFALSE ) &&
( pxTimer->uxTimerCallbackInvocations == 0 ) )
{
vTaskDelay( 1 );
}
Expand Down