This patch equips init with the ability to act as a server that forwards
session requests to its children. Session requests can be routed
depending of the requested service type and the session label
originating from init's parent.
The feature is configured by one or multiple <service> nodes hosted in
init's <config> node. The routing policy is selected by via the regular
server-side policy-selection mechanism, for example:
<config>
...
<service name="LOG">
<policy label="noux">
<child name="terminal_log" label="important"/>
</policy>
<default-policy> <child name="nitlog"/> </default-policy>
</service>
...
</config>
Each policy node must have a <child> sub node, which denotes name of the
server with the 'name' attribute. The optional 'label' attribute defines
the session label presented to the server, analogous to how the
rewriting of session labels works in session routes. If not specified,
the client-provided label is presented to the server as is.
Fixes#2247
This patch removes the formerly built-in policy of responding to
resource requests with handing out slack quota. Instead, resource
requests have to be answered by an update of the init configuration with
adjusted quota values.
Note that this patch may break run scripts that depend on init's
original policy. Those run scripts may be adjusted by increasing the
quota for the components that use to inflate their RAM usage during
runtime such that the specified quota suffices for the entire lifetime
of the component.
This patch destructs the environment sessions for the binary and the
dynamic linker along with the other environment sessions to avoid a
warning about reverting quota that occurs when attempting to close
these sessions too late.
This patch improves init's dynamic reconfigurability with respect to
adjustments of the RAM quota assigned to the children.
If the RAM quota is decreased, init withdraws as much quota from the
child's RAM session as possible. If the child's RAM session does not
have enough available quota, a resource-yield request is issued to
the child. Cooparative children may respond to such a request by
releasing memory.
If the RAM quota is increased, the child's RAM session is upgraded.
If the configuration exceeds init's available RAM, init re-attempts
the upgrade whenever new slack memory becomes available (e.g., by
disappearing other children).
Since init no longer provides public headers, we have to adjust the
existing users of this headers. The 'init/child_config.h' is used only
by GDB monitor. So the patch moves the header there as an interim fix.
The 'init/child_policy.h' is still used by a few components, so we have
to keep a trimmed-down version of it for now.
This patch enables init to apply changes of any server's <provides>
declarations in a differential way. Servers can in principle be extended
by new services without re-starting them. Of course, changes of the
<provides> declarations may affect clients or would-be clients as this
information is taken into account for the session routing.
This patch addresses the corner cases where an environment session
could not be routed, i.e., if an environment LOG log session is
routed to a non-existing child.
The optional 'version' attribute allows for the forced restart of a
child with an otherwise unmodified start node. The specified value is
also reflected in the state report.
This patch covers the resolution of the ROM route for child binaries
via the generic label-rewriting mechanics. Now, the <binary> node has
become merely sytactic sugar for a route like the following:
<start name="test"/>
<route>
<service name="ROM" unscoped_label="test">
<parent label="test-binary-name"/> </service>
...
</route>
...
</start>
A change of the binary name has an effect on the child's ROM route to
the binary and thereby implicitly triggers a child restart due to the
existing re-validation of the routing.
This patch extends the constructor of 'Local_connection' with an
optional 'label' argument, which was previously passed implicitly as
part of the 'args' argument. Keeping the label separate from 'args'
enables us to distinguish the client-specified label from a label that
resulted from a server-side label as it is used when rewriting a label
of an environment session (i.e., the binary name) in init's routing
policy. In principle, this patch eliminates the need for init's
explicite handling of the binary name via the '<binary>' node, or
at least allows us to simplity the binary-node handling.
With this check in place, one can safely construct an 'Xml_generator'
even if the report is disabled. This relieves the user of the reporter
from the need to distinguish enabled from disabled reports.
The initial ROMs (program and linker) are already attached to the region
map of a forked process and don't need to be obtained again from an
external ROM service when the 'Child' class asks for them. For the program
image, the local Noux ROM service already returned an invalid dataspace
capability, but not for the linker.
Instead of adding another 'magic' ROM name for the local ROM service,
this commit implements an 'empty' ROM service, which returns an
invalid dataspace for the initial ROMs.
Fixes#2272
The race may happen when element objects get destructed by another thread then
the thread handling the for_each loop. In this case it may happen that the
object is already destructed (left the ~Element destructor) but the thread
handling the loop touches the invalid memory afterwards (the Element lock).
detected during issue #2299Fixes#2320
Under certain timing conditions, the test would end up flushing the
input from the input filter in a nested way, which ultimately resulted
in lost input events of the outer nesting level. This patch eliminates
this corner case and thereby stabilizes the key-repeat test.
Transfer quota to the session local RAM session to react to the
Quota_exceeded exception properly.
The platform driver keeps a session local RAM session for each of its
clients that is used to allocate DMA memory. A client needs to transfer
some of its quota to the platform driver, which in return transfers this
quota to the session local RAM session. As it happens allocating memory
from a RAM session involves book keeping and in this case, where the
available quota in the session did not suffice and the request was only
a few KiB, the platform driver handled the exception wrongly and did not
transfer the quota.
This problem did not surface up to now because all drivers allocate DMA
memory in larger chunks and the book keeping overhead was of no
consequence as the initial quota transfer probably covered the overhead.
Fixes#2316.
