Before this commit, LibCore/System.h exposed only part of
System::stat API on Windows. Namely, users of Core::System::stat
had to #include <dirent.h> in order to check the return value of stat.
It is OK for low-level libs like LibCore/LibFileSystem, but
S_ISDIR is also used in LibWeb\Loader\GeneratedPagesLoader.cpp.
We want to avoid platform #ifdefs in LibWeb.
It fixes a bug in which ImageDecoder and RequestServer
do not exit because their connections don't close.
This makes the shutdown behavior match the Linux version,
which receives FD_READ | FD_HANGUP on socket close, and
TransportSocket::read_as_much_as_possible_without_blocking calls
schedule_shutdown when read from a socket returns 0 bytes.
On Windows, we have to explicitly call WIN32 shutdown to receive
notification FD_CLOSE.
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).
Incorrect behavior of CreateProcess:
CreateProcess("a.exe", "b c", ...) ->
a.exe::main::argv == ["b", "c"] (wrong)
CreateProcess(0, "a.exe b c", ...) ->
a.exe::main::argv == ["a.exe", "b", "c"] (right)
https://learn.microsoft.com/en-us/cpp/cpp/main-function-command-line-args
"If you use both the first and second arguments (lpApplicationName and
lpCommandLine), argv[0] may not be the executable name."
This means first argument of CreateProcess should never be used.
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Searching for executable in path is suppressed now by prepending "./"
Additional bonus of the new code: .exe extension does not need to be
specified.
_O_OBTAIN_DIR flag makes _open use FILE_FLAG_BACKUP_SEMANTICS in
CreateFile call.
FILE_FLAG_BACKUP_SEMANTICS is required to open directory handles.
For ordinary files FILE_FLAG_BACKUP_SEMANTICS overrides file security
checks when the process has SE_BACKUP_NAME and SE_RESTORE_NAME
privileges, see https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
Fonts on Windows are stored only in %WINDIR%\Fonts and
%LOCALAPPDATA%\Microsoft\Windows\Fonts, see https://stackoverflow.com/a/67078786
And system_data_directories() is not implemented on Windows yet.
A couple of reasons:
- Origin's Host (when in the tuple state) can't be null
- There's an "empty host" concept in the spec which is NOT the same as a
null Host, and that was confusing me.
