Profiling suggested that on Linux sometimes over 10% of CPU time was
being spent inside the systemtap probe entry points in the binding
layer, even when the process was not actively being traced with the
`stap` tool.
That's why this commit makes it possible to use the *_ENABLED() macros
and bail out early when we're not being traced, reducing the overhead
of unused probes to (almost) zero.
Said macros were already being generated by `dtrace -h` but were not
usable because they rely on external definitions. To remedy that, we
now generate the accompanying object files with `dtrace -G`.
This commit includes a change to libuv that has been landed upstream in
commit joyent/libuv@3c172ea.
Drop the ObjectWrap dependency in favor of an internal WeakObject class.
Let's us stop worrying about API and ABI compatibility when making
changes to the way node.js deals with weakly persistent handles
internally.
This commit makes it possible to use multiple V8 execution contexts
within a single event loop. Put another way, handle and request wrap
objects now "remember" the context they belong to and switch back to
that context when the time comes to call into JS land.
This could have been done in a quick and hacky way by calling
v8::Object::GetCreationContext() on the wrap object right before
making a callback but that leaves a fairly wide margin for bugs.
Instead, we make the context explicit through a new Environment class
that encapsulates everything (or almost everything) that belongs to
the context. Variables that used to be a static or a global are now
members of the aforementioned class. An additional benefit is that
this approach should make it relatively straightforward to add full
isolate support in due course.
There is no JavaScript API yet but that will be added in the near
future.
This work was graciously sponsored by GitHub, Inc.
As documented in #3042 and in [1], the existing vm implementation has
many problems. All of these are solved by @brianmcd's [contextify][2]
package. This commit uses contextify as a conceptual base and its code
core to overhaul the vm module and fix its many edge cases and caveats.
Functionally, this fixes #3042. In particular:
- A context is now indistinguishable from the object it is based on
(the "sandbox"). A context is simply a sandbox that has been marked
by the vm module, via `vm.createContext`, with special internal
information that allows scripts to be run inside of it.
- Consequently, items added to the context from anywhere are
immediately visible to all code that can access that context, both
inside and outside the virtual machine.
This commit also smooths over the API very slightly:
- Parameter defaults are now uniformly triggered via `undefined`, per
ES6 semantics and previous discussion at [3].
- Several undocumented and problematic features have been removed, e.g.
the conflation of `vm.Script` with `vm` itself, and the fact that
`Script` instances also had all static `vm` methods. The API is now
exactly as documented (although arguably the existence of the
`vm.Script` export is not yet documented, just the `Script` class
itself).
In terms of implementation, this replaces node_script.cc with
node_contextify.cc, which is derived originally from [4] (see [5]) but
has since undergone extensive modifications and iterations to expose
the most useful C++ API and use the coding conventions and utilities of
Node core.
The bindings exposed by `process.binding('contextify')`
(node_contextify.cc) replace those formerly exposed by
`process.binding('evals')` (node_script.cc). They are:
- ContextifyScript(code, [filename]), with methods:
- runInThisContext()
- runInContext(sandbox, [timeout])
- makeContext(sandbox)
From this, the vm.js file builds the entire documented vm module API.
node.js and module.js were modified to use this new native binding, or
the vm module itself where possible. This introduces an extra line or
two into the stack traces of module compilation (and thus into most
stack traces), explaining the changed tests.
The tests were also updated slightly, with all vm-related simple tests
consolidated as test/simple/test-vm-* (some of them were formerly
test/simple/test-script-*). At the same time they switched from
`common.debug` to `console.error` and were updated to use
`assert.throws` instead of rolling their own error-testing methods.
New tests were also added, of course, demonstrating the new
capabilities and fixes.
[1]: http://nodejs.org/docs/v0.10.16/api/vm.html#vm_caveats
[2]: https://github.com/brianmcd/contextify
[3]: https://github.com/joyent/node/issues/5323#issuecomment-20250726
[4]: bf123f3ef9/src/contextify.cc
[5]: https://gist.github.com/domenic/6068120
V8 3.20.9 enforces that external pointers are aligned on a two-byte
boundary.
We cannot portably guarantee that for the source code strings that
tools/js2c.py generates so simply stop using String::NewExternal()
altogether (and by extension String::ExternalAsciiStringResource).
Fixes the following run-time assert:
FATAL ERROR: v8::String::NewExternal() Pointer is not aligned
This incarnation of macros.py is only used to disable the (d)trace
macros. Rename it so it better reflects its purpose. A new macros.py
will be added in a follow-up commit.
It will be confusing if later on we add Buffer#dispose(), and smalloc is
its own cpp api anyways. So instead create a new require('smalloc') to
expose the previous Buffer.alloc/dispose methods, and expose copyOnto
and kMaxLength as well.
Other changes:
* Added documentation and additional tests.
* smalloc::CopyOnto has changed from using assert() to throwing errors
on bad argument values because it is not exposed to the user.
* Minor style fixes.
This is a big commit that touches just about every file in the src/
directory. The V8 API has changed in significant ways. The most
important changes are:
* Binding functions take a const v8::FunctionCallbackInfo<T>& argument
rather than a const v8::Arguments& argument.
* Binding functions return void rather than v8::Handle<v8::Value>. The
return value is returned with the args.GetReturnValue().Set() family
of functions.
* v8::Persistent<T> no longer derives from v8::Handle<T> and no longer
allows you to directly dereference the object that the persistent
handle points to. This means that the common pattern of caching
oft-used JS values in a persistent handle no longer quite works,
you first need to reconstruct a v8::Local<T> from the persistent
handle with the Local<T>::New(isolate, persistent) factory method.
A handful of (internal) convenience classes and functions have been
added to make dealing with the new API a little easier.
The most visible one is node::Cached<T>, which wraps a v8::Persistent<T>
with some template sugar. It can hold arbitrary types but so far it's
exclusively used for v8::Strings (which was by far the most commonly
cached handle type.)
Now that Buffer instantiation has improved, the SlabAllocator is an
unnecessary layer of complexity preventing further performance
optimizations.
Currently there is a small performance loss with very small stream
requests, but this will soon be addressed.
smalloc is a simple utility for quickly allocating external memory onto
js objects. This will be used to centralize how memory is managed in
node, and will become the backer for Buffers. So in the future crypto's
SlabBuffer, stream's SlabAllocator will be removed.
Note on the js API: because no arguments are optional the order of
arguments have been placed to match their cc counterparts as closely as
possible.
Split `tls.js` into `_tls_legacy.js`, containing legacy
`createSecurePair` API, and `_tls_wrap.js` containing new code based on
`tls_wrap` binding.
Remove tests that are no longer useful/valid.
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.
This change shouldn't have landed in the stable branch. It's a feature,
not a bug fix.
This reverts commit 58f93ffc4a.
This reverts commit 8c8ebe49b6.
This reverts commit ba0f7b8066.
This reverts commit 21f3c5c367.
Commit 3d67f89 ("fix generation of v8 constants on freebsd") is an
unfortunate victim of this rollback.
Revert "dtrace: fix generation of v8 constants on freebsd"
Revert "dtrace: More style"
Revert "dtrace: Make D style more D-ish"
Revert "dtrace: x64 ustack helper"
Revert "dtrace: fix style in ustack helper"
Revert "dtrace: SeqAsciiString was renamed to SeqOneByteString in v8"
This reverts commit 3d67f89552.
This reverts commit 321b8eec08.
This reverts commit 38df9d51a2.
This reverts commit f9afb3f010.
This reverts commit 13296e4b13.
This reverts commit 3b715edda9.
Improvements:
* floating point operations are approx 4x's faster
* Now write quiet NaN's
* all read/write on floating point now done in C, so no more need for
lib/buffer_ieee754.js
* float values have more accurate min/max value checks
* add additional benchmarks for buffers read/write
* created benchmark/_bench_timer.js which is a simple library that
can be included into any benchmark and provides an intelligent tracker
for sync and async tests
* add benchmarks for DataView set methods
* add checks and tests to make sure offset is greater than 0
When building custom `node` versions (e.g., floating features/fixes from
different versions) it's often useful to specify a custom tag which
easily identifies build when invoking `node -v`.
Introduce a way to specify this tag in `node_version.h` file or by
running `./configure --tag="<tag>"`. Insert it right after the patch
version (and before `-pre`, if build is not a release).
Closes #4452.
