Handling OS signals

Default behavior

• SIGINT - return trace
• SIGTERM, SIGQUIT - shutdown service
• SIGUSR1 - reopen file descriptors for log (logrotate)

User behavior

The component os_signals::ProcessorComponent stores os_signals::Processor and listens to SIGUSR1 and SIGUSR2 signals. You can use AddListener function to subscribe to these signals.

For example, we use signal SIGUSR1 in components::Logging for reopening files after executing logrotate.

Example

1. Add in private field class

os_signals::Subscriber signal_subscribe_

1. In in the component's constructor, register a signal listener. For example, components::Logging uses the following code:

Logging::Logging(const ComponentConfig& config, const ComponentContext& context)
    : signal_subscriber_(
          context.FindComponent<os_signals::ProcessorComponent>()
              .Get()
              .AddListener(this, kName, SIGUSR1, &Logging::OnLogRotate))

1. In the component's destructor, unsubscribe from the signal

  signal_subscriber_.Unsubscribe();

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