In order to build a dependency graph of continuation execution and data-fetching in PHP-land, we need a few instrumentation points in the asio_ext HHVM extension. There are 4 additions required:
1. Callback when a continuation finishes successfully.
2. Callback when a continuation blocks on a wait_handle.
3. Get array of WaitHandles a GenArrayWaitHandle is waiting on.
4. Get WaitHandle that the SetResultToRefWaitHandle is waiting on.
I don't think this should really affect performance, as in the normal case, nothing has changed, but you never know... I'm also not sure who should be reviewing this, so I've just added @jan for now. If you could pile other people on, that would be cool.
sandcastle appears to be broken.
ContinuationWaitHandle::start() was deprecated in favor of Awaitable
interface's getWaitHandle().
Remove ContinuationWaitHandle::start() from public API and rename it
internally to c_ContinuationWaitHandle::Create() that is called only from
Continuation's getWaitHandle(). Since it is guaranteed that the
Continuation does not have associated any wait handle, we can remove the
code that handles that case.
Add support for external thread events.
See asio_external_thread_event.h for details about usage.
This is the first version that compiled, the code was not executed even
once, but wanted to get it out early to unblock @hannesr. Thus the [RFC]
flag.
My next step is to implement asio-compatible equivalent of
fb_call_user_func_async() that will make it possible to easily test the
new functonality by simulating async stuff with sleep(), etc. on the PHP
side.
There are 2 major mostly lockless synchronization points that needs
careful review:
- queue of ready external thread events (asio_session.{cpp.h})
- shutdown cleanup (asio_external_thread_event.{cpp,h})
We store a bunch of data into an ActRec on the stack, then
call a php-level function that calls a C++ function to copy it into an
ActRec on the heap. This should hopefully be a little better.
While rewriting gen_ext_hhvm in C++ I discovered these little
anomalies: the "return" field of a function has to exist, and has to be
a dictionary.
I'm also removing the specific class name of hphp_create_continuation as
per the discussion, and removing the support for parsing
types like that.
I had to edit ##bzopen## so that it handles file handles or else the test makes files called ##Resource #5## in the current directory.
The big problem with the broken tests is we return ##NULL## on too few args and Zend returns ##false##. I want to get a feel for other extensions before changing this.
I also imported ALL the files in the directory since the ##.phpt## files overflow.
It's data, not code.
My primary motivation for doing this is to make the IDL accessible from
languages that aren't PHP. (This, in turn, is motivated by a desire to
eliminate PHP scripts from the build process.)
The unserialization of random objects may be dangerous because the destructor of the object will be called when the unserialized objects are out of scope. However, the person who wrote the class may not be aware of the danger of unserialization. Therefore, we would like to require every users of the unserialize() to provide a whitelist of the class names that are authorized to be unserialized so that we can make sure the object is safe to be unserialized.
Add a parameter 'class_whitelist' to unserialize() function to determine whether to raise warnings for unsafe unserialization. If the class to be unserialized is not an instance of Serilizable or not in the whitelist, warnings will be raised. For the detailed reason why we need this, please see http://fburl.com/SafeSerializable for more information.
Add a parameter 'all_classes_enabled' to allow those hphp functions that need to unserialize any class. For example, fb_call_user_func_async() will need to serialize and nserialize the given parameters.
This will allow for php code to better verify the async state
of the mysql connection and aid in debugging. This diff adds
mysql_async_status as well as associated constants.
While I was working on the TestCodeRun refactor I found two tests about Tainted code. I looked into it and coulnd't get HHVM to compile with TAINTED=1. Then I checked and none of the extension functions we exposed about tainting were used in WWW. Scratching my head I asked, @srenfro and @jdelong, who thought it was dead. So I killed this zombie.
Generators should specify function names as the name instead of the
full name for consistency with Zend 5.5 (and more importantly because
this breaks PHPUnit), this was exposed by the backtrace removal of
file and line info
The callback passed to asio_set_on_{failed, started}_callback was
never null because the way types for input parameters work in
extensions. Null from user PHP code was converted to a stdClass
object, triggering an exception.
The only places where ReturnStatement is constructed are:
- onReturn(check_yield=true) -> not allowed in generator
- onReturn(check_yield=false) -> coming from transform_yield_break, right after creating hphp_continuation_done()
- MethodStatement, end of function call -> hphp_continuation_done() is created at end of generator in prepare_generator()
Emitter is emitting ContExit in ReturnStatements used in generators. As
can be seen from the analysis above, it's always preceded by emitting
ContDone from hphp_continuation_done(). Let's emit ContDone inside the
ReturnStatement directly and kill usage of hphp_continuation_done().
transform_yield_break() becomes a simple onReturn(check_yield=false), so
let's inline it into onYield and create ReturnStatement directly. After
this change, check_yield flag is always true and can be killed.
ContExit was also used after emitting a generator method in case the end
of method is still reachable. ContDone is added so that the generator is
properly closed. I believe this is never actually used, as MethodStatement
creates ReturnStatement at the end of method anyway.
Unhack the parser and introduce YieldExpression that emits the
equivalent set of opcodes that were emitted by bunch of
expressions/statements generated by parser before.
YieldExpression expects evaluation stack to contain just the value
being yielded, so {,List}AssignmentExpression need to evaluate RHS
first. The previous code had the same behavior.
This will let us consolidate continuation-related opcodes and make
them less tied with continuation objects.
In Zend 5.3 they decided that closures should inherit the ##$this## from the containing scope. This brings us close to paraity with them. The remaining thing is to make
function() use ($this) {}
fatal after we purge it from WWW.
Replace "collection" with "collections" in various file names since
we typically use the plural form in conversation and documentation.
Add set() and removeAt() methods needed for collection interfaces. Also
add the KeyedIterable and KeyedIterator interfaces.
Add __construct() methods for collections
In HPHPc it didn't allow closures to be cloned but in HHVM it did. When I migrated to a C++ closure then i left the HPHPc code. Zend 5.4 allows them to be cloned so lets go with this.
Expose the following data to the PHP:
- asio_get_current_context_idx(): get current context index
- asio_get_running_in_context(): get running wait handle in a given context
- asio_get_running(): get running wait handle in a current context (renamed asio_get_current())
- WaitableWaitHandle::getContextIdx(): get context the wait handle operates in
- WaitableWaitHandle::getCreator(): get continuation wait handle that constructed this wait handle
This is the last step to being able to get rid of the c++ code
gen in hphp. "make -Chphp/system" is now a no-op.
I'll rip out the actual c++ generating code as a separate diff.
Sean Cannella