NAME

src/events.c - Event handling stuff

DESCRIPTION

An event_thread handles async events for all interpreters. When events are due, they are placed in per interpreter task_queues, where they are handled then by the check_event* opcodes.

IO events and signals are caught in the io_thread, which again dispatches these to one or all interpreters.

Signal Handling

sig_handler: Handle signal signum.; TODO - Only SIGHUP is handled at the moment for testing
Parrot_sigaction: Signal handlers are common to all threads, signal block masks are specific, so we install one handler then block that signal and unblock it in the thread, that will receive that signal.

Initialization

init_events_first: Init event system for first interpreter.
init_events_all: Init events for all interpreters.
Parrot_init_events: Initialize the event system.

Event Handler Functions

Parrot_schedule_event: Create queue entry and insert event into task queue.
Parrot_new_timer_event: Create a new timer event due at diff from now, repeated at interval and running the passed sub.
Parrot_new_cb_event: Prepare and schedule a callback event.
Parrot_del_timer_event: Deactivate the timer identified by timer.
Parrot_new_terminate_event: Create a terminate event, interpreter will leave the run-loop when this event arrives.
Parrot_new_suspend_for_gc_event: Create a suspend-for-GC event, interpreter will wait on a condition variable for GC to finish when the event arrives.
Parrot_kill_event_loop: Schedule event-loop terminate event. This shuts down the event thread.
Parrot_schedule_interp_qentry: Put a queue entry into the interpreters task queue and enable event checking for the interpreter.
Parrot_schedule_broadcast_qentry: Broadcast an event.

IO Thread Handling

io_thread: The IO thread uses select/poll to handle IO events and signals.; It waits on input from the message pipe to insert file descriptors in the wait sets.
stop_io_thread: Tell the IO thread to stop.

Event Handler Thread Functions

dup_entry: Duplicate queue entry.
dup_entry_interval: Duplicate timed entry and add interval to abs_time.
process_events: Do something, when an event arrived caller has locked the mutex returns 0 if event thread terminates.
event_thread: The event thread is started by the first interpreter. It handles all events for all interpreters.

Sleep Handling

wait_for_wakeup: Sleep on the event queue condition. If an event arrives, the event is processed. Terminate the loop if sleeping is finished.
Parrot_sleep_on_event: Go to sleep. This is called from the sleep opcode.

Event Handling for Run-Loops

Parrot_do_check_events: Explicitly sync called by the check_event opcode from run loops.
event_to_exception: Convert event to exception and throw it.
do_event: Run user code or such.
Parrot_do_handle_events: Called by the check_event__ opcode from run loops or from above. When called from the check_events__ opcode, we have to restore the op_func_table.