This patch equips the 'Block::Connection' with a framework API for the
implementation of robust block-session clients that perform block I/O in
an asynchronous fashion.
An application-defined 'JOB' type, inherited from 'Connection::Job',
encapsulates the application's context information associated with a
block operation.
The lifecycle of the jobs is implemented by the 'Connection' and driven
by the application's invokation of 'Connection::update_jobs'. The
'update_jobs' mechanism takes three hook functions as arguments, which
implement the applications-defined policy for producing and consuming
data, and for the completion of jobs.
Issue #3283
As a preparatory step for introducing the new block-client API, we have
to turn the 'Block::Connection' into a class template. The template
argument will be used to tie an application-defined job type to the
block connection.
Issue #3283
This patch adds support for manually triggering the wakeup of the packet
sink by the source. This way, a packet source becomes able to marshal
batches of submissions or unmarshal batches of acknowledgements before
yielding the control over to the sink.
Issue #3283
This patch removes the blocking Block::Session::sync RPC function and
adds the asynchronous operations SYNC and TRIM to the block session's
packet-stream interface.
Even though the patch adjusts all block components to the interface
change, the components keep the former blocking handling of sync
internally for now because of the design of the 'Block::Driver'
interface. This old interface is not worth changing. We should instead
migrate the block servers step by step to the new
'Block::Request_stream' API.
Fixes#3274
The new request tag allows a block-session client to uniquely correlate
acknowledgements with outstanding requests. Until now, this was possible
for read and write operations by taking the value of the request's
packet-stream offset. However, SYNC and TRIM requests do not carry any
packet-stream payload and thereby lack meaningful offset values. By
introducing the notion of a 'tag', we can support multiple outstanding
requests of any type and don't need to overload the meaning of the
'offset' value.
Issue #3274
This patch splits the 'Request' definition into smaller types that are
suitable for the client-side API too.
The new 'Operation' type comprises the block operation's type (opcode)
and the operation's arguments (block number, block count).
The former 'Request::operation_defined' is now 'Operation::valid'.
The 'Request' aggregates an 'Operation', which changes its object
layout.
Note that this commit relaxes the bit-precise definition of 'Request' to
facilitate the use of 'unsigned long' where appropriate, in particular
for the request tag (which should correspond to an 'Id_space::Id'). The
originally bit-precise definition was pursued to allow the sharing of
the 'Request' type between SPARK and C++ code. However, it turns out
that defining a native type in each language and a (set of) converting
constructors is a more natural approach.
Issue #3283
This patch renames 'wakeup_client' to 'wakeup_client_if_needed' to
clarify that the method triggers signals only when needed, not on every
call.
The name 'wakeup_client' is prone to misguide users to call the function
conditionally as an optimization, thereby complicating the code, but to
no effect.
Fixes#3279
This patch replaces the formerly fixed 2 KiB data alignment within the
packet-stream buffer by a server-defined alignment. This has two
benefits.
First, when using block servers that provide small block sizes like 512
bytes, we avoid fragmenting the packet-stream buffer, which occurs when
aligning 512-byte requests at 2 KiB boundaries. This reduces meta data
costs for the packet-stream allocator and also allows fitting more
requests into the buffer.
Second, block drivers with alignment constraints dictated by the
hardware can now pass those constraints to the client, thereby easing
the use of zero-copy DMA directly into the packet stream.
The alignment is determined by the Block::Session_client at construction
time and applied by the Block::Session_client::alloc_packet method.
Block-session clients should always use this method, not the 'alloc_packet'
method of the packet stream (tx source) directly. The latter merely
applies a default alignment of 2 KiB.
At the server side, the alignment is automatically checked by
block/component.h (old API) and block/request_stream.h (new API).
Issue #3274
This patch modernizes the 'Block::Session::info' interface. Instead of
using out parameters, the 'init' RPC function returns a compound 'Info'
object now. The rather complicated 'Operations' struct is replaced by
a 'writeable' attribute in the 'Info' object.
Fixes#3275
Replace the I/O response handler that is passed to the VFS at
construction with an object that is dynamically attached to handles.
This object shall also accept read-ready notifications, and plugins are
encouraged to keep handles awaiting ready-ready notifications separate
from handles that await I/O progress.
Replace the use of handle lists in plugins with handle queues, this
makes the code easier to understand and the ordering of notifications to
the application more explicit.
These changes replace the use of the Post_signal_hook from all VFS
plugins, applications must assume that read-ready and I/O notifications
occur during I/O signal dispatch and use an Io_progress_handler at its
entrypoints to defer response until after signal dispatching.
Fix#3257
The "Vfs::Vfs_handle" type should not contain any public members that
can be initialized by the VFS internally and by the application, so
remove inheritance from the "Genode::list::Element" class. The VFS
plugins must instead use lists of "Vfs::Vfs_handle" sub-classes, the
lifetime of which are always managed by the plugin.
Ref #3036
This is a safeguard against accidentally taking the 'Ack' interface as a
value instead of a reference.
The 'Payload' interface should also not be copied (and potentially
stored) because it contains a pointer.
The new 'transfer' function interface defines how pixel/alpha values
sampled from texture are applied to a destination pixel, similar to the
role of a fragment shader in GPU-based rendering. The transfer function
can be customized by defining custom pixel types, which may be (but
don't need to be) derived from 'Pixel_rgba'.
Issue #3221
This commit removes APIs that were previously marked as deprecated. This
change has the following implications:
- The use of the global 'env()' accessor is not possible anymore.
- Boolean accessor methods are no longer prefixed with 'is_'. E.g.,
instead of 'is_valid()', use 'valid()'.
- The last traces of 'Ram_session' are gone now. The 'Env::ram()'
accessor returns the 'Ram_allocator' interface, which is a subset of
the 'Pd_session' interface.
- All connection constructors need the 'Env' as argument.
- The 'Reporter' constructor needs an 'Env' argument now because the
reporter creates a report connection.
- The old overload 'Child_policy::resolve_session_request' that returned
a 'Service' does not exist anymore.
- The base/printf.h header has been removed, use base/log.h instead.
- The old notion of 'Signal_dispatcher' is gone. Use 'Signal_handler'.
- Transitional headers like os/server.h, cap_session/,
volatile_object.h, os/attached*_dataspace.h, signal_rpc_dispatcher.h
have been removed.
- The distinction between 'Thread_state' and 'Thread_state_base' does
not exist anymore.
- The header cpu_thread/capability.h along with the type definition of
'Cpu_thread_capability' has been removed. Use the type
'Thread_capability' define in cpu_session/cpu_session.h instead.
- Several XML utilities (i.e., at os/include/decorator) could be removed
because their functionality is nowadays covered by util/xml_node.h.
- The 'os/ram_session_guard.h' has been removed.
Use 'Constrained_ram_allocator' provided by base/ram_allocator.h instead.
Issue #1987
This patch enhances the packet-stream API with the principle ability to
side-step the built-in implicity data-flow signals and manage the
signals manually. This allows for a more efficient batching of packet
processing.
Issue #3092
The 'tx_cap' RPC function is only used at session-creation time. For
this reason, it was not listed in the "official" RPC interface in
'block_session.h'. However, this makes the interface more obscure than
it needs to be. So this patch promotes it to a regular RPC function.
Issue #3092
Refactor the graphical terminal server to internally represent
characters as 16-bit codepoints and handle the duplex terminal stream as
UTF-8.
- Make the Codepoint class printable to the Output interface
- Decode data received at the Terminal session from UTF-8 to a 16-bit
character
- Pass 16-bit characters through terminal decoder and char-cell arrays
- Send Unicode through terminal session in a burst of UTF-8 bytes
Fix#3148
The situation where a 'Session_policy' is constructed for a label with
no matching policy is in almost all cases a configuration problem.
A diagnostic message eases pin-pointing such mistaks. By adding the
message to the 'Session_policy', servers don't need to manually handle
the exception to provide diagnostic information. This simplifies the
server code in many components.
Since the timer and timeout handling is part of the base library (the
dynamic linker), it belongs to the base repository.
Besides moving the timer and its related infrastructure (alarm, timeout
libs, tests) to the base repository, this patch also moves the timer
from the 'drivers' subdirectory directly to 'src' and disamibuates the
timer's build locations for the various kernels. Otherwise the different
timer implementations could interfere with each other when using one
build directory with multiple kernels.
Note that this patch changes the include paths for the former os/timer,
os/alarm.h, os/duration.h, and os/timed_semaphore.h to base/.
Issue #3101
This patch improves the window decorators in the following respects:
* Strict warnings are enabled now.
* The use of the 'List_model' makes the application of window-
layout changes more robust. This is particularly the case for
the restacking of windows.
* Display-mode changes are now supported by both decorators.
Issue #3094
Packets whose data is stored within the Packet_descriptor itself
but not as payload, .e.g Usb::Packet_descriptor, are valid packets
after all. So loosen the packet valid check for zero-sized packets
is reasonable.
Fixes#3076.
Some application code is dereferencing the pointer returned by
'packet_content' at packet streams without checking that it is valid.
Throw an exception rather than return a null pointer, except for
zero-length packets, which have somewhat implicit invalid content and
that we believe to be properly handled in all current cases.
The client-side of a packet stream cannot take corrective action if the
server-side is sending packets with invalid content, but the servers
that provide packet streams should catch this exception to detect
misbehaving clients.
Ref #3059
The bulk buffer is now 64Byte-aligned so that the allocated
packets get aligned likewise (assumed the packet allocator uses an
appropriately aligned block size). This ensures that each packet
starts at a new cache line on common platforms.
Issue #3053
This patch improves the detection of new appearing top-most windows.
Such a window should prompt the decorator to bring the corresponding
nitpicker view(s) to the front of the view stack. The original
implementation relied on hints provided by the layouter (the 'topped'
attribute). With the patch, the decorator tracks the top-most window by
itself, which improves the robustness.
As a second improvement, the patch defers the destruction of windows to
the point when all other window operations are completed. This hides
intermediate states when replacing one window by another in one step,
which is typical for console-like scenarios. Hence, this patch should
eliminate flickering artifacts when switching from one virtual console
to another.
Issue #3031
Add additional parsing modes to the sequence decoder to detect and
discard unhandled sequences for ECMA-48, DEC private, and Xterm.
Add new behavior for cursor movement, cursor hiding, character deletion,
and line-wrapping.
Fix#2923
