This will allow sharing e.g. document cookie versions between the UI and
WebContent processes, and safely accessing those versions.
Core::AnonymousBuffer internally creates a minimum buffer of PAGE_SIZE
bytes. This is much more than the size of a single version, but this
affords us the opportunity to share multiple versions in a single buffer
between processes. With a PAGE_SIZE of 4096, we can share up to 512
versions in a single buffer.
SocketAddressWindows.h contains a bunch of copy-pasted Windows
definitions. This started causing ad-nauseam redefinition errors when
implementing the HTTP disk cache for Windows.
Instead, let's forward-declare the types we can in SocketAddress.h and
only define the couple of constants that we need. We can then assert at
compile-time that we defined them correctly.
By defining this class entirely in the System.h header, we are relying
on ::freeaddrinfo being available. This has led to us polluting the
System.h header with system-level definitions on Windows by way of
SocketAddressWindows.h.
This macro outputs the time taken to reach the end of the current scope
to the debug console. It also shows the average time, total cumulative
time and the total number of calls.
It is also possible to limit the amount of debug output using
`REPORT_TIME_EVERY(name, n)` to only print every `n` calls.
This commit changes the event loop to use IOCPs instead of
WaitForMultipleObjects to wait on events. This is done through the Nt
kernel api NtAssociateWaitCompletionPacket which associates an event
with a completion packet. Each completion packet notifies only once, as
they are normally used to signal completion of an operation so to use
them for notifiers they are associated again after each time they are
triggered.
There are more optimizations that can be done, such as reusing the
EventLoopNotifier and EventLoopTimer structures to reduce the number of
allocations and context switches for timer and notifier registration.
To detect system time zone changes on Windows, the event we need to look
for is WM_TIMECHANGE. The problem is how the callback with said message
actually gets invoked is very particular. (1) We must have an active
message pump (event loop) for the message to ever be processed. (2) We
must be a GUI application as WM_TIMECHANGE messages are seemingly sent
to top level windows only. It doesn't say that in the docs for the
event, but attempts of creating a LibTest-based application with a
message pump and a message only window and never receiving the event
point to that probably being true.
This workaround is built off the fact that Qt's message pump defined
internally in QEventDispatcherWin32::processEvents does in fact receive
WM_TIMECHANGE events, even though it is not exposed as a QEvent::Type.
Given the requirements stated above it makes sense that it works here as
the message pump is executing in a QGuiApplication context. So we use a
native event filter to hook into the unexposed WM_TIMECHANGE event and
forward it along to the on_time_zone_changed() callback.
Note that if a Windows GUI framework is done in the future, we'll have
to re-add support to ensure the TimeZoneWatcher still gets invoked.
LibCore's list of ignored header files for Swift was missing the Apple
only files on non-Apple platforms. Additionally, any generic glue code
cannot use -fobjc-arc, so we need to rely on -fblocks only.
Windows flavor of non-blocking IO, overlapped IO, differs from that on
Linux. On Windows, the OS handles writing to overlapped buffer, while
on Linux user must do it manually.
Additionally, we can only have overlapped sockets because it is the
requirement to be able to wait on them - WSAEventSelect automatically
sets socket to nonblocking mode.
So we end up emulating Linux-nonblocking sockets with
Windows-nonblocking sockets.
Pending IO state (ERROR_IO_PENDING) must not escape read/write
functions. If that happens, all synchronization like WSAPoll and
WaitForMultipleObjects stops working (WaitForMultipleObjects stops
working because with overlapped IO you are supposed to wait on an event
in OVERLAPPED structure, while we are waiting on WSA Event, see
EventLoopImplementationWindows.cpp).
Instead of everyone overriding save_to() and set_property() and doing
a pretty asymmetric job of implementing the various properties, let's
add a bit of structure here.
Object properties are now represented by a Core::Property. Properties
are registered with a getter and setter (optional) in constructors.
I've added some convenience macros for creating and registering
properties, but this does still feel a bit bulky. We'll have to
iterate on this and see where it goes.
Now that we don't keep a C compiler around in the toolchain (to save
space) we can't have .c files in the build.
This reminds me that #362 exists and we should fix that at some point.
