Instead of crashing the process inside Transition on a bad state transition,
propagate an error up the stack (and crash higher up).
MozReview-Commit-ID: JJmAeq6xSfe
We can move this information into ProtocolState and save having two
virtual functions for every protocol. Moving some bits out of the
codegen'd IPC code is a nice bonus, though we keep the strange setup
where toplevel protocols have two mChannel member variables.
ProtocolName() is only used for producing error messages and annotating
crash reports. But examining actual crash reports that would have used
the result of ProtocolName() indicates that we can always tell what the
erroring protocol is due to the stack backtrace. So having this virtual
function around just provides duplicate information, and it takes up too
much space in the vtable besides. Let's get rid of it.
lower.py generates repetitious:
SetManager(...);
Register(...); // Or RegisterID.
SetIPCChannel(...);
calls, which are moderately sized, given that the above call sequence
requires virtual calls in several places. Instead of codegenning this
sequence, let's consolidate the sequence into IProtocol and change the
code generator to call into the consolidated function instead.
The reasoning here is the same as for the protocol register/lookup
functions: these functions are all basic functionality that should not
be overriden by subclasses.
This functionality is base functionality for top-level and non-toplevel
protocols; nobody overrides this stuff, so it's safe to move into
ProtocolState.
IProtocol, which is inherited by every generated IPDL protocol and every
concrete protocol implementation in-tree, has a number of virtual
methods that are only relevant when distinguishing between top-level
protocols (IToplevelProtocol) and managed protocols (everything else).
These virtual methods require pointers in every protocol's vtable, which
is wasteful, and it's also somewhat confusing that many methods exist
but don't really need to be overridable in any useful way.
Let's clean this up, by creating a ProtocolState class to hold methods
that solely differ between top-level protocols and everything else.
This commit does that work and moves Shmem-related methods into this
class as a proof that this can be done in a reasonable way.
They are not yet fully async because ContentParent::InitInternal calls
OtherPid(), which will block until the process is spawned. Deferring the calls
to OtherPid() will be a subject of a follow up patch.
MozReview-Commit-ID: 4TFkMpdQtRw
MOZ_CRASH_UNSAFE_PRINTF causes data collection because crash strings are annotated to crash-stats and are publicly visible. Firefox data stewards must do data review on usages of this macro. However, all the crash strings this patch collects with MOZ_CRASH_UNSAFE_PRINTF are already collected with NS_RUNTIMEABORT.
MozReview-Commit-ID: 5ujXa9MHH5Z
And remove unreachable code after MOZ_CRASH_UNSAFE_OOL().
MOZ_CRASH_UNSAFE_OOL causes data collection because crash strings are annotated to crash-stats and are publicly visible. Firefox data stewards must do data review on usages of this macro. However, all the crash strings this patch collects with MOZ_CRASH_UNSAFE_OOL are already collected with NS_RUNTIMEABORT.
MozReview-Commit-ID: IHmJfuxXSqw
The current IPC::Message constructor takes a large number of arguments,
three of which--the nesting level, the priority, and the
compression--are almost always constant by virtue of the vast majority
of Message construction being done by auto-generated IPDL code. But
then we take these constant values into the Message constructor, we
check them for various values, and then based on those values, we
perform a bunch of bitfield operations to store flags based on those
values. This is wasted work.
Furthermore, for replies to IPDL messages, we'll construct a Message
object, and then call mutating setters on the Message object that will
perform even more bitfield manipulations. Again, these operations are
performing tasks at runtime that are the same every single time, and use
information we already have at compile time.
The impact of these extra operations is not large, maybe 15-30K of extra
code, depending on platform. Nonetheless, we can easily make them go
away, and make everything cleaner to boot.
This patch adds a HeaderFlags class that encapsulates all the knowledge
about the various kinds of flags Message needs to know about. We can
construct HeaderFlags objects with strongly-typed enum arguments for the
various kinds of flags, and the compiler can take care of folding all of
those flags together into a constant when possible (and it is possible
for all the IPDL-generated code that instantiates Messages). The upshot
is that we do no unnecessary work in the Message constructor itself. We
can also remove various mutating operations on Message, as those
operations were only there to support post-constructor flag twiddling,
which is no longer necessary.
It's important that shmem creation/destruction messages be ordered
correctly with respect to other messages that use shmems. For example,
if we create a shmem with ID 10 and then send a message that
references shmem 10, then the creation message must be handled before
the referencing message. If shmem creation/destruction messages go in
a separate queue from other messages, this ordering may not be
preserved.
Leaving shmem creation/destruction unlabeled will give us the correct
ordering. Eventually, though, we'll need to provide a solution that
doesn't bottleneck the event queue.
MozReview-Commit-ID: 88MrslRrfnh
Using a separate error function will distinguish mismatched sentinels
from other errors, such as array length problems.
MozReview-Commit-ID: Gl8swNhqLns
Every new PBrowser, whether it's created by the parent or the child, needs
to get a TabGroup assigned to it. That way IPC messages for the PBrowser will
be dispatched to that TabGroup.
For new PBrowsers created by the child, we just create a new TabGroup or reuse
the opener's TabGroup.
For PBrowsers created by the parent, the child needs to intercept the
PBrowserConstructor message and assign a TabGroup immediately. PBrowsers created
by the parent never have an opener so we can always create a new TabGroup.
In both cases, the nsGlobalWindow::TabGroupOuter logic needs to be updated to
read the TabGroup out of the IPC code. Otherwise the DOM and IPC code will get
out of sync about TabGroups.
MozReview-Commit-ID: D5iEdgirfvK
We will use the new type for the generated IPDL message handler
prototype to make sure correct error handling method is called.
MozReview-Commit-ID: AzVbApxFGZ0
