Nested interrupts

The BlackBerry 10 OS fully supports nested interrupts.

The previous scenarios describe the simplest—and most common—situation where only one interrupt occurs. Worst-case timing considerations for unmasked interrupts must take into account the time for all interrupts currently being processed, because a higher priority, unmasked interrupt will preempt an existing interrupt.

In the following diagram, Thread A is running. Interrupt IRQx causes interrupt handler Intx to run, which is preempted by IRQy and its handler Inty. Inty returns an event causing Thread B to run; Intx returns an event causing Thread C to run.

Figure showing stacked interrupts.

Last modified: 2014-05-14

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