Memory allocations are now done through smalloc. The Buffer cc class has
been removed completely, but for backwards compatibility have left the
namespace as Buffer.
The .parent attribute is only set if the Buffer is a slice of an
allocation. Which is then set to the alloc object (not a Buffer).
The .offset attribute is now a ReadOnly set to 0, for backwards
compatibility. I'd like to remove it in the future (pre v1.0).
A few alterations have been made to how arguments are either coerced or
thrown. All primitives will now be coerced to their respective values,
and (most) all out of range index requests will throw.
The indexes that are coerced were left for backwards compatibility. For
example: Buffer slice operates more like Array slice, and coerces
instead of throwing out of range indexes. This may change in the future.
The reason for wanting to throw for out of range indexes is because
giving js access to raw memory has high potential risk. To mitigate that
it's easier to make sure the developer is always quickly alerted to the
fact that their code is attempting to access beyond memory bounds.
Because SlowBuffer will be deprecated, and simply returns a new Buffer
instance, all tests on SlowBuffer have been removed.
Heapdumps will now show usage under "smalloc" instead of "Buffer".
ParseArrayIndex was added to node_internals to support proper uint
argument checking/coercion for external array data indexes.
SlabAllocator had to be updated since handle_ no longer exists.
Remove the need to call start/stop the uv_idle spinner between
MakeCallbacks. The one place where the tick processor needs to be kicked
is where a user catches uncaughtException. For that we'll now use
setImmediate, which accomplishes the same task.
maxTickDepth checks have been removed for domains and replaced with a
flag that checks if the last callback threw. If it did then execution of
the remaining tickQueue is deferred to the spinner.
This is to prevent domains from entering a continuous loop when an error
callback also throws an error.
Removes the check for maxTickDepth for non-domain callbacks. So a user
can starve I/O by setting a recursive nextTick.
The domain case is more complex and will be addressed in another commit.
Add a watchdog class which executes a timer in a separate event loop in
a separate thread that will terminate v8 execution if it expires.
Add timeout argument to functions in vm module which use the watchdog
if a non-zero timeout is specified.
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.
This reverts commit ea1cba6246.
The offending commit was intended to land on the v0.8 branch only, but
it accidentally got merged at some point.
Closes#5054.
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.
Not necessary, since we can handle the error properly on the first tick
now, even if there are event listeners, etc.
Additionally, this removes the unnecessary "_needTickCallback" from
startup, since Module.loadMain() will kick off a nextTick callback right
after it runs the main module.
Fix#4856
It seems like a good idea on the face of it, but lowWaterMarks are
actually not useful, and in practice should always be set to zero.
It would be worthwhile for writers if we actually did some kind of
writev() type of thing, but actually this just delays calling write()
and the overhead of doing a bunch of Buffer copies is not worth the
slight benefit of calling write() fewer times.
Using external memory values allows for quick communication between js
and cc land, so we can check if the js land callback needs to be run.
(this is where I meant that manually tracking nextTickQueue.length would
be helpful)
Also did some minor cleanup of removing the old Tick and
StartTickSpinner functions, and a few unneeded comments.
Conflicts:
src/node.cc
* Callbacks from spinner now calls its own function, separate from the
tickCallback logic
* MakeCallback will call a domain specific function if a domain is
detected
* _tickCallback assumes no domains, until nextTick receives a callback
with a domain. After that _tickCallback is overridden with the domain
specific implementation.
* _needTickCallback runs in startup() instead of nextTick (isaacs)
* Fix bug in _fatalException where exit would be called twice (isaacs)
* Process.domain has a default value of null
* Manually track nextTickQueue.length (will be useful later)
* Update tests to reflect internal api changes
This reverts commit 0109a9f90a.
Also included: Port all the changes to process._makeCallback into the
C++ version. Immediate nextTick, etc.
This yields a slight boost in several benchmarks. V8 is optimizing and
deoptimizing process._makeCallback repeatedly.
If the NODE_DEBUGGER_TIMEOUT environment variable is set, then use
that as the number of ms to wait for the debugger to start.
This is primarily to work around a race condition that almost never
happens in real usage with the debugger, but happens EVERY FRACKING
TIME when the debugger tests run as part of 'make test'.
Due to the nature of asyncronous programming, it's impossible to know
what will run on the next tick. Because of this, it's not correct to
maintain domain stack state between ticks
Since the _fatalException handler is only invoked after the stack is
unwound, once it exits the tick will end. The only reasonable thing to
do in that case is to exit *all* 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
When there is an error that is thrown in a nextTick function, which is
then handled by a domain or other process.on('uncaughtException')
handler, if the error handler *also* adds a nextTick and triggers
multiple MakeCallback events (ie, by doing some I/O), then it would
skip over the tickDepth check, resulting in an infinite spin.
Solution: Check the tickDepth at the start of the tick processing, and
preserve it when we are cleaning up in the error case or exiting early
in the re-entry case.
In order to make sure that tick callbacks are *eventually* handled, any
callback triggered by the underlying spinner in libuv will be processed
as if starting from a tick depth of 0.
Trevor Norris