Add a new plugin for creating pipes between pairs of VFS handles. It is
intended to replace the libc_pipe plugin, one of the last remaining libc
plugins.
In contrast to the libc_pipe plugin, this plugin defers cross-handle
notification until I/O signal handling rather than block and unblock
readers using a semaphore. This is a performance regression in the case
of multiple threads blocking on a pipe, but shall be an intermediate
mechanism pending renovations within the libc VFS and threading layers.
As a side effect, threads blocked on a pipe might not be resumed until
the main thread suspends and dispatches I/O signals.
The "test-libc_pipe" test has been adjusted to use the VFS pipe plugin
and tests both local pipes and pipes hosted remotely in the VFS server.
Merge adaptations (such as EOF handling, adjustment to VFS/libc
interface changes) by Norman Feske.
Fix#2303
This patch introduces a new scheme of handling ioctl operations that
maps ioctls to pseudo-file accesses, similar to how the libc maps socket
calls to socket-fs operations.
A device file can be accompanied with a (hidden) directory that is named
after the device file and hosts pseudo files for triggering the various
device operations. For example, for accessing a terminal, the directory
structure looks like this:
/dev/terminal
/dev/.terminal/info
The 'info' file contains device information in XML format. The type of
the XML node corresponds to the device type. E.g., If the libc receives
a 'TIOCGWINSZ' ioctl for /dev/terminal, it reads the content of
/dev/.terminal/info to obtain the terminal-size information. In this
case, the 'info' file looks as follows:
<terminal rows="25" columns="80/>
Following this scheme, VFS plugins can support ioctl operations by
providing an ioctl directory in addition to the actual device file.
Internally, the mechanism uses the 'os/vfs.h' API to access pseudo
files. Hence, we need to propagate the Vfs::Env to 'vfs_plugin.cc' to
create an instance of a 'Directory' for the root for the VFS.
Issue #3519
By specifying <libc update_mtime="no"...>, the modification-time update
on VFS-sync operations (as issued whenever a written file is closed)
can explicitly be disabled.
Issue #1784
This patch replaces the naive dup2 implementation (that merely
duplicated the context pointer) by the replication of the original
FD state by re-opening the same file with the same flags and seek
position. This prevents a potential double release of the VFS handle
(the FD context). It also implements 'dup'.
Fixes#3505Fixes#3477
This patch unifies the patterns of using the 'Genode' and 'Libc'
namespaces.
Types defined in the 'internal/' headers reside in the 'Libc'
namespace. The code in the headers does not need to use the
'Libc::' prefix.
Compilation units import the 'Libc' namespace after the definition of
local types. Local types reside in the 'Libc' namespace (and should
eventually move to an 'internal/' header).
Since the 'Libc' namespace imports the 'Genode' namespace, there is
no need to use the 'Genode::' prefix. Consequently, code in the
compilation units rarely need to qualify the 'Genode' or 'Libc'
namespaces.
There are a few cases where the 'Libc', the 'Genode', and the global
(libc) namespaces are ambigious. In these cases, an explicit
clarification is needed:
- 'Genode::Allocator' differs from 'Libc::Allocator'.
- 'Genode::Env' differs from 'Libc::Env'.
- Genode's string functions (strcmp, memcpy, strcpy) conflict
with the names of the (global) libc functions.
- There exist both 'Genode::uint64_t' and the libc'c 'uint64_t'.
Issue #3497
This patch is the first step of re-organizing the internal structure of
the libc. The original version involved many direct calls of global
functions (often with side effects) across compilation units, which
made the control flow (e.g., the initialization sequence) hard to
follow.
The new version replaces those ad-hoc interactions with dedicated
interfaces (like suspend.h, resume.h, select.h, current_time.h). The
underlying facilities are provided by the central Libc::Kernel and
selectively propagated to the various compilation units. The latter is
done by a sequence of 'init_*' calls, which eventually will be replaced
by constructor calls.
The addition of new headers increases the chance for name clashes with
existing (public) headers. To disambiguate libc-internal header files
from public headers, this patch moves the former into a new 'internal/'
subdirectory. This makes the include directives easier to follow and the
libc's source-tree structure more tidy.
There are still a few legacies left, which cannot easily be removed
right now (e.g., because noux relies on them). However, the patch moves
those bad apples to legacy.h and legacy.cc, which highlights the
deprecation of those functions.
Issue #3497
Ehmry -
Norman Feske
Josef Söntgen