.TH "Runtime_events.Callbacks" 3 2024-02-29 OCamldoc "OCaml library"
.SH NAME
Runtime_events.Callbacks \- no description
.SH Module
Module   Runtime_events.Callbacks
.SH Documentation
.sp
Module
.BI "Callbacks"
 : 
.B sig end

.sp

.sp

.sp
.sp
.I type t 

.sp
Type of callbacks

.sp

.I val create 
: 
.B ?runtime_begin:(int ->
.B                   Runtime_events.Timestamp.t ->
.B                   Runtime_events.runtime_phase -> unit) ->
.B   ?runtime_end:(int ->
.B                 Runtime_events.Timestamp.t ->
.B                 Runtime_events.runtime_phase -> unit) ->
.B   ?runtime_counter:(int ->
.B                     Runtime_events.Timestamp.t ->
.B                     Runtime_events.runtime_counter -> int -> unit) ->
.B   ?alloc:(int -> Runtime_events.Timestamp.t -> int array -> unit) ->
.B   ?lifecycle:(int ->
.B               Runtime_events.Timestamp.t ->
.B               Runtime_events.lifecycle -> int option -> unit) ->
.B   ?lost_events:(int -> int -> unit) -> unit -> t
.sp
Create a 
.ft B
Callback
.ft R
that optionally subscribes to one or more runtime
events\&. The first int supplied to callbacks is the ring buffer index\&.
Each domain owns a single ring buffer for the duration of the domain\&'s
existence\&. After a domain terminates, a newly spawned domain may take
ownership of the ring buffer\&. A 
.ft B
runtime_begin
.ft R
callback is called when
the runtime enters a new phase (e\&.g a runtime_begin with EV_MINOR is
called at the start of a minor GC)\&. A 
.ft B
runtime_end
.ft R
callback is called
when the runtime leaves a certain phase\&. The 
.ft B
runtime_counter
.ft R
callback
is called when a counter is emitted by the runtime\&. 
.ft B
lifecycle
.ft R
callbacks
are called when the ring undergoes a change in lifecycle and a consumer
may need to respond\&. 
.ft B
alloc
.ft R
callbacks are currently only called on the
instrumented runtime\&. 
.ft B
lost_events
.ft R
callbacks are called if the consumer
code detects some unconsumed events have been overwritten\&.

.sp

.I val add_user_event 
: 
.B 'a Runtime_events.Type.t ->
.B   (int -> Runtime_events.Timestamp.t -> 'a Runtime_events.User.t -> 'a -> unit) ->
.B   t -> t
.sp

.ft B
add_user_event ty callback t
.ft R
extends 
.ft B
t
.ft R
to additionally subscribe to
user events of type 
.ft B
ty
.ft R
\&. When such an event happens, 
.ft B
callback
.ft R
is called
with the corresponding event and payload\&.

.sp