We'd like to offer a way for developers to safely do asynchronous instantiations
of COM objects. This patch adds a static CreateInstance method to mscom::EnsureMTA
that facilitates this under certain conditions (as outlined in the comments).
To help ensure that this is as safe as possible, we return a MozPromise that,
once resolved, produces an AgileReference that may then be passed between
threads, and may then be resolved when a specific thread needs to access the
interface.
Differential Revision: https://phabricator.services.mozilla.com/D44519
--HG--
extra : moz-landing-system : lando
Until now we asserted that EnsureMTA was being called from the main thread
unless the current thread was already in the MTA.
This patch makes MTA thread initialization thread-safe by using a C++11
"magic static," thus allowing EnsureMTA to be safely invoked from any thread.
Differential Revision: https://phabricator.services.mozilla.com/D38422
--HG--
extra : moz-landing-system : lando
In sandboxed processes with Win32k lockdown, when we initialize COM using an MTA
on a background thread, the main thread is automatically initialized by the COM
runtime as having an implicit MTA.
This is fine, except for the fact that if we want to enqueue any work that needs
to operate specifically on the EnsureMTA thread, it won't happen.
This patch adds a flag to EnsureMTA's constructor that ensures that, even if the
current thread is in an MTA (implicit or otherwise), we still forcibly enqueue
the closure specifically to the EnsureMTA thread.
Differential Revision: https://phabricator.services.mozilla.com/D28391
--HG--
extra : moz-landing-system : lando
This patch takes care of a bunch of issues and does some cleanup:
* We rename mscom::MainThreadRuntime to mscom::ProcessRuntime, as the latter
is a more accurate name going forward.
* We make ProcessRuntime aware of the Win32k Lockdown process mitigation
policy. When Win32k is disabled, we perform process-wide COM initialization
in the multi-threaded apartment (since we cannot create an STA window).
* We refactor the mscom apartment region stuff to enable the Win32k lockdown
pieces in ProcessRuntime.
* We move some Gecko-specific stuff into MOZILLA_INTERNAL_API guards so that
ProcessRuntime is usable outside of xul.dll (I will be needing it for the
launcher process).
* Another thing that might happen with the launcher process is that, under
error conditions in the launcher, we create a ProcessRuntime object on a
background thread for the purposes of telemetry logging, but we also allow
the main thread to proceed to start as the browser. This could result in a
scenario where the main thread, as the browser process, is attempting to
instantiate its ProcessRuntime and ends up racing with the launcher process's
telemetry thread which has its own ProcessRuntime. To account for this
situation, we add mutual exclusion to the process-wide initialization code.
We host this part inside mozglue since that state is shared between both
firefox.exe and xul.dll.
* We clean up ProcessRuntime::InitializeSecurity by using Vector to set up
the EXPLICIT_ACCESS entries.
* We remove mscom::MainThreadClientInfo and replace it with a direct call to
CoGetCallerTID
* We revise all references to this class to use the new name.
Differential Revision: https://phabricator.services.mozilla.com/D19551
--HG--
rename : ipc/mscom/COMApartmentRegion.h => ipc/mscom/ApartmentRegion.h
rename : ipc/mscom/MainThreadRuntime.cpp => ipc/mscom/ProcessRuntime.cpp
rename : ipc/mscom/MainThreadRuntime.h => ipc/mscom/ProcessRuntime.h
extra : moz-landing-system : lando
This patch takes care of a bunch of issues and does some cleanup:
* We rename mscom::MainThreadRuntime to mscom::ProcessRuntime, as the latter
is a more accurate name going forward.
* We make ProcessRuntime aware of the Win32k Lockdown process mitigation
policy. When Win32k is disabled, we perform process-wide COM initialization
in the multi-threaded apartment (since we cannot create an STA window).
* We refactor the mscom apartment region stuff to enable the Win32k lockdown
pieces in ProcessRuntime.
* We move some Gecko-specific stuff into MOZILLA_INTERNAL_API guards so that
ProcessRuntime is usable outside of xul.dll (I will be needing it for the
launcher process).
* Another thing that might happen with the launcher process is that, under
error conditions in the launcher, we create a ProcessRuntime object on a
background thread for the purposes of telemetry logging, but we also allow
the main thread to proceed to start as the browser. This could result in a
scenario where the main thread, as the browser process, is attempting to
instantiate its ProcessRuntime and ends up racing with the launcher process's
telemetry thread which has its own ProcessRuntime. To account for this
situation, we add mutual exclusion to the process-wide initialization code.
We host this part inside mozglue since that state is shared between both
firefox.exe and xul.dll.
* We clean up ProcessRuntime::InitializeSecurity by using Vector to set up
the EXPLICIT_ACCESS entries.
* We remove mscom::MainThreadClientInfo and replace it with a direct call to
CoGetCallerTID
* We revise all references to this class to use the new name.
Differential Revision: https://phabricator.services.mozilla.com/D19551
--HG--
rename : ipc/mscom/COMApartmentRegion.h => ipc/mscom/ApartmentRegion.h
rename : ipc/mscom/MainThreadRuntime.cpp => ipc/mscom/ProcessRuntime.cpp
rename : ipc/mscom/MainThreadRuntime.h => ipc/mscom/ProcessRuntime.h
extra : moz-landing-system : lando
We install mozilla/mscom/Utils.h, but include it with an all-lowercased
path in some places. clang-cl warns about this, and even though this is
Windows-only code and will therefore work, it's better to make
everything consistent.
Aaron Klotz
Dorel Luca
Sylvestre Ledru
Bill McCloskey
Carsten "Tomcat" Book
Ting-Yu Chou
Nathan Froyd
Nathan Froyd