The domain module has been switched over to use the domain module API as
much as currently possible. There are still some hooks in the
EventEmitter, but hopefully we can remove those in the future.
Instead of doing all the domain handling in core, allow the domain to
set an error handler that'll take care of it all. This way the domain
error handling can be abstracted enough for any user to use it.
Change process.domain to use a getter/setter and access that property
via an array index. These are much faster to get from c++, and it can be
passed to _setupDomainUse and stored as a Persistent<Array>.
InDomain() and GetDomain() as trivial ways to access the domain
information in the native layer. Important because we'll be able to
quickly access if a domain is active. Instead of just whether the domain
module has been loaded.
Since _tickCallback and _tickDomainCallback were both called from
MakeCallback, it was possible for a callback to be called that required
a domain directly to _tickCallback.
The fix was to implement process.usingDomains(). This will set all
applicable functions to their domain counterparts, and set a flag in cc
to let MakeCallback know domain callbacks always need to be checked.
Added test in own file. It's important that the test remains isolated.
It's cleaner to only load domain ticker logic when the domains are being
used. This makes execution slightly quicker in both cases, and simpler
from the spinner since there is no need to check if the latest callback
requires use of domains.
While it's true that error objects have a history of getting snake_case
properties attached by the host system, it's a point of confusion to
Node users that comes up a lot. It's still 'experimental', so best to
change this sooner rather than later.
This adds a process._fatalException method which is called into from
C++ in order to either emit the 'uncaughtException' method, or emit
'error' on the active domain.
The 'uncaughtException' event is an implementation detail that it would
be nice to deprecate one day, so exposing it as part of the domain
machinery is not ideal.
Fix#4375
This addresses #4034. There are two problems happening:
1. The domain is not exited automatically when calling dispose() on it.
Then, since the domain is disposed, attempting to exit it again will do
nothing.
2. The active domain is stored on process.domain. Since thrown errors
call `process.emit('uncaughtException', er)`, and the process is an
event emitter with a `.domain` member, it re-enters the domain a second
time before calling the error handler, pushing it onto the stack again.
Thus, if the handler calls `domain.dispose()`, then the domain is now on
the stack twice, and cannot be exited properly. Since the domain is
disposed, any subsequent IO will be no-op'ed, since we've declared that
this context is done and best forgotten.
The solution here is twofold:
1. In EventEmitter.emit, do not enter the domain if `this===process`.
2. Automatically exit the domain when calling `domain.dispose()`.
This is a squashed commit of the main work done on the domains-wip branch.
The original commit messages are preserved for posterity:
* Implicitly add EventEmitters to active domain
* Implicitly add timers to active domain
* domain: add members, remove ctor cb
* Don't hijack bound callbacks for Domain error events
* Add dispose method
* Add domain.remove(ee) method
* A test of multiple domains in process at once
* Put the active domain on the process object
* Only intercept error arg if explicitly requested
* Typo
* Don't auto-add new domains to the current domain
While an automatic parent/child relationship is sort of neat,
and leads to some nice error-bubbling characteristics, it also
results in keeping a reference to every EE and timer created,
unless domains are explicitly disposed of.
* Explicitly adding one domain to another is still fine, of course.
* Don't allow circular domain->domain memberships
* Disposing of a domain removes it from its parent
* Domain disposal turns functions into no-ops
* More documentation of domains
* More thorough dispose() semantics
* An example using domains in an HTTP server
* Don't handle errors on a disposed domain
* Need to push, even if the same domain is entered multiple times
* Array.push is too slow for the EE Ctor
* lint domain
* domain: docs
* Also call abort and destroySoon to clean up event emitters
* domain: Wrap destroy methods in a try/catch
* Attach tick callbacks to active domain
* domain: Only implicitly bind timers, not explicitly
* domain: Don't fire timers when disposed.
* domain: Simplify naming so that MakeCallback works on Timers
* Add setInterval and nextTick to domain test
* domain: Make stack private
Trevor Norris
Forrest L Norvell
Matthew Aynalem
isaacs
Ben Noordhuis
Ryunosuke SATO
Toshihiro Nakamura
Andreas Madsen
Marc Harter