Quick Start Guide for SYSTEM INTERRUPT - Critical Section Use Case

In this case we perform a critical piece of code, disabling all interrupts while a global shared flag is read.

During the critical section, no interrupts may occur.

Setup

Prerequisites

There are no special setup requirements for this use-case.

Use Case

Code

Copy-paste the following code to your user application:

    system_interrupt_enter_critical_section();

    if (is_ready == true) {
        /* Do something in response to the global shared flag */
        is_ready = false;
    }

    system_interrupt_leave_critical_section();

Workflow

1. Enter a critical section to disable global interrupts.

       system_interrupt_enter_critical_section();

   Note

   Critical sections may be nested if desired; if nested, global interrupts will only be re-enabled once the outer-most critical section has completed.

2. Check a global shared flag and perform a response. This code may be any critical code that requires exclusive access to all resources without the possibility of interruption.

       if (is_ready == true) {
           /* Do something in response to the global shared flag */
           is_ready = false;
       }

3. Exit the critical section to re-enable global interrupts.

       system_interrupt_leave_critical_section();