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
static void sig_handler
Handle signal static void 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.
static void Parrot_unblock_signal
unblock a signal
void Parrot_init_signals
Set up actions to handle signals.
Only SIGHUP handled at the moment.
signum.TODO - Only SIGHUP is handled at the moment for testing
Initialization
static void init_events_first
Init event system for first interpreter.
static void init_events_all
Init events for all interpreters.
void Parrot_init_events
Initialize the event system.
Event Handler Functions
void Parrot_schedule_event
Create queue entry and insert event into task queue.
static void schedule_signal_event
create and schedule a signal event
void Parrot_new_timer_event
Create a new timer event due at void Parrot_new_cb_event
Prepare and schedule a callback event.
void Parrot_del_timer_event
Deactivate the timer identified by void Parrot_new_terminate_event
Create a terminate event,
interpreter will leave the run-loop when this event arrives.
void 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.
void Parrot_kill_event_loop
Schedule event-loop terminate event.
This shuts down the event thread.
void Parrot_schedule_interp_qentry
Put a queue entry into the interpreters task queue and enable event checking for the interpreter.
void Parrot_schedule_broadcast_qentry
Broadcast an event.
diff from now,
repeated at interval and running the passed sub.
timer.
IO Thread Handling
static void store_io_event
Stores an event in the event stack.
Allocates memory if necessary.
static void io_thread_ready_rd
Takes a list of pending i/o events and a file descriptor.
If the fd is ready to read,
the event is removed from the "pending" list and moved to the "scheduled" task queue.
static void *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.
static void stop_io_thread
Tell the IO thread to stop.
void Parrot_event_add_io_event
Create new i/o event.
Event Handler Thread Functions
static QUEUE_ENTRY *dup_entry
Duplicate queue entry.
static QUEUE_ENTRY *dup_entry_interval
Duplicate timed entry and add interval to static int process_events
Do something,
when an event arrived caller has locked the mutex returns 0 if event thread terminates.
static void *event_thread
The event thread is started by the first interpreter.
It handles all events for all interpreters.
abs_time.
Sleep Handling
static opcode_t *wait_for_wakeup
Sleep on the event queue condition.
If an event arrives,
the event is processed.
Terminate the loop if sleeping is finished.
opcode_t *Parrot_sleep_on_event
Go to sleep.
This is called from the
sleep opcode.Event Handling for Run-Loops
opcode_t *Parrot_do_check_events
Explicitly static void event_to_exception
Convert event to exception and throw it.
static opcode_t *do_event
Run user code or such.
The opcode_t *Parrot_do_handle_events
Called by the
sync called by the check_event opcode from run loops.
event argument is freed after execution.TODO: Instrument with splint args so splint knows event gets released.
check_event__ opcode from run loops or from above.
When called from the check_events__ opcode,
we have to restore the op_func_table.SEE ALSO
include/parrot/events.h and docs/dev/events.pod.
