This commit adds new "--inspect-wait" flag which works similarly
to "--inspect-brk" in that it waits for inspector session to be
established before running code. However it doesn't break on the first
statement of user code, but instead runs it as soon as a session
is established.
This commit completely rewrites inspector session polling.
Until now, there was a single function responsible for polling inspector
sessions which could have been called when polling the "JsRuntime"
as well as from internal inspector functions. There are some cases
where it's required to have reentrant polling of sessions (eg. when
"debugger" statement is run) which should be blocking until inspector
sends appropriate message to continue execution. This was not possible
before, because polling of sessions didn't have reentry ability.
As a consequence, session polling was split into two separate functions:
a) one to be used when polling from async context (on each tick of event
loop in "JsRuntime")
b) one to be used when polling synchronously and potentially blocking
(used by various inspector methods).
There are further cleanups and simplifications to be made in inspector
code, but this rewrite solves the problem at hand (being able to
evaluate
"debugger" JS statement and continue inspector functionality).
Co-authored-by: Bert Belder <bertbelder@gmail.com>
This commit changes "JsRuntime" to send "executionContextDestroyed"
notification when the program finishes and shows a prompt informing
that runtime is waiting for inspector to disconnect.
With trial and error I found that most debuggers expect "isDefault" to be sent
in "auxData" field of "executionContextCreated" notification. This stems from
the fact that Node.js sends this data and eg. VSCode requires it to close
connection to the debugger when the program finishes execution.
This commit rewrites "InspectorSession" to no longer implement "Future"
trait but instead implement "Stream" trait. "Stream" trait is implemented
by yielding a raw pointer to the "v8::inspector::V8InspectorSession" and
received message. In effect received messages are no longer dispatched
from within the future, but are explicitly dispatched by the caller.
This change should allow us to dispatch a message to the session when
another message is being dispatched, ie.
"V8InspectorSesssion::dispatch_protocol_message" is already on the
call stack.
This commit changes flow in inspector code to no longer require
"Runtime.runIfWaitingForDebugger" message to complete a handshake.
Even though clients like Chrome DevTools always send this message on startup,
it is against the protocol to require this message to start an inspector
session.
Instead "Runtime.runIfWaitingForDebugger" is required only when running with
"--inspect-brk" flag, which matches behavior of Node.js.
This commit moves implementation of "JsRuntimeInspector" to "deno_core" crate.
To achieve that following changes were made:
* "Worker" and "WebWorker" no longer own instance of "JsRuntimeInspector",
instead it is now owned by "deno_core::JsRuntime".
* Consequently polling of inspector is no longer done in "Worker"/"WebWorker",
instead it's done in "deno_core::JsRuntime::poll_event_loop".
* "deno_core::JsRuntime::poll_event_loop" and "deno_core::JsRuntime::run_event_loop",
now accept "wait_for_inspector" boolean that tells if event loop should still be
"pending" if there are active inspector sessions - this change fixes the problem
that inspector disconnects from the frontend and process exits once the code has
stopped executing.
