Enum EventKind 

pub enum EventKind {
    VMStart {
        thread: ThreadId,
    },
    VMDeath,
    ThreadStart {
        thread: ThreadId,
    },
    ThreadDeath {
        thread: ThreadId,
    },
    ClassPrepare {
        thread: ThreadId,
        ref_type: ReferenceTypeId,
        signature: String,
        status: i32,
    },
    Breakpoint {
        thread: ThreadId,
        location: Location,
    },
    Step {
        thread: ThreadId,
        location: Location,
    },
    Exception {
        thread: ThreadId,
        location: Location,
        exception: ObjectId,
        catch_location: Option<Location>,
    },
    MethodExit {
        thread: ThreadId,
        location: Location,
        return_value: Option<Value>,
    },
    FieldAccess {
        field: FieldEvent,
    },
    FieldModification {
        field: FieldEvent,
        new_value: Value,
    },
    MonitorContendedEnter {
        monitor: MonitorEvent,
    },
    MonitorContendedEntered {
        monitor: MonitorEvent,
    },
    MonitorWait {
        monitor: MonitorEvent,
        timeout: i64,
    },
    MonitorWaited {
        monitor: MonitorEvent,
        timed_out: bool,
    },
    Unknown {
        kind: u8,
    },
}

Variants

VMStart

Fields

thread: ThreadId

VMDeath

ThreadStart

Fields

thread: ThreadId

ThreadDeath

Fields

thread: ThreadId

ClassPrepare

Fields

thread: ThreadId

ref_type: ReferenceTypeId

signature: String

status: i32

Breakpoint

Fields

thread: ThreadId

location: Location

Step

Fields

thread: ThreadId

location: Location

Exception

Fields

thread: ThreadId

location: Location

exception: ObjectId

catch_location: Option<Location>

MethodExit

A method is returning. location is the return site, so a method with several return statements says which one was taken.

There is deliberately no MethodEntry: a METHOD_ENTRY request with a ClassMatch fires on every method of every matching class — the noisiest event in JDWP — and “what calls this?” is now answered far more cheaply by a traced breakpoint’s caller chain (TRACE-5). A decoded variant nothing can arm only implies a capability that isn’t there.

Fields

thread: ThreadId

location: Location

return_value: Option<Value>

What the method is returning, present only when the request was armed as METHOD_EXIT_WITH_RETURN_VALUE (kind 42). None for a plain METHOD_EXIT (kind 41), which a JVM below JDWP 1.6 is all you can get.

FieldAccess

A watched field was read.

Fields

field: FieldEvent

FieldModification

A watched field is about to be written. The event fires before the store commits, so the field still holds its old value while the thread is suspended — that is how the old→new pair is reported.

Fields

field: FieldEvent

new_value: Value

JDWP’s valueToBe — the value the write will store.

MonitorContendedEnter

A thread has begun blocking on a monitor another thread owns (MONITOR_CONTENDED_ENTER, 43). The thread is off the pool from here until the matching MonitorContendedEntered arrives.

Fields

monitor: MonitorEvent

MonitorContendedEntered

A thread that was blocking has acquired the monitor (MONITOR_CONTENDED_ENTERED, 44).

This event carries no timing of any kind. How long the thread was blocked — the actual question a contention diagnosis asks — is on neither half of the pair, so it can only be had by timestamping the ENTER on this side and matching it here. See mcp-server’s monitor pairing and ADR-0035: the resulting figure is a debugger measurement and every reply that prints one says so.

Fields

monitor: MonitorEvent

MonitorWait

A thread is about to Object.wait() (MONITOR_WAIT, 45).

Fields

monitor: MonitorEvent

timeout: i64

JDWP’s timeout — the number of milliseconds the caller asked wait(…) for, 0 for an untimed wait. It is the argument, not a measurement: a wait(5000) that returns after 3 ms still reports 5000 here.

MonitorWaited

A thread’s Object.wait() has returned (MONITOR_WAITED, 46).

Fields

monitor: MonitorEvent

timed_out: bool

Whether the wait ended because the timeout expired rather than because of a notify. The one piece of outcome the wire does carry, and the difference between “nobody signalled it” and “it was signalled” — which are opposite diagnoses.

Unknown

Fields

kind: u8

Trait Implementations

impl Clone for EventKind

fn clone(&self) -> EventKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for EventKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for EventKind

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for EventKind

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.