Commit Graph

14 Commits

Author SHA1 Message Date
Norman Feske
4d442bca30 Streamline exception types
This patch reduces the number of exception types by facilitating
globally defined exceptions for common usage patterns shared by most
services. In particular, RPC functions that demand a session-resource
upgrade not longer reflect this condition via a session-specific
exception but via the 'Out_of_ram' or 'Out_of_caps' types.

Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable',
'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args',
'Service::Unavailable', and 'Local_service::Factory::Denied' types have
been replaced by the single 'Service_denied' exception type defined in
'session/session.h'.

This consolidation eases the error handling (there are fewer exceptions
to handle), alleviates the need to convert exceptions along the
session-creation call chain, and avoids possible aliasing problems
(catching the wrong type with the same name but living in a different
scope).
2017-05-31 13:16:07 +02:00
Norman Feske
1f4f119b1e Capability quota accounting and trading
This patch mirrors the accounting and trading scheme that Genode employs
for physical memory to the accounting of capability allocations.

Capability quotas must now be explicitly assigned to subsystems by
specifying a 'caps=<amount>' attribute to init's start nodes.
Analogously to RAM quotas, cap quotas can be traded between clients and
servers as part of the session protocol. The capability budget of each
component is maintained by the component's corresponding PD session at
core.

At the current stage, the accounting is applied to RPC capabilities,
signal-context capabilities, and dataspace capabilities. Capabilities
that are dynamically allocated via core's CPU and TRACE service are not
yet covered. Also, the capabilities allocated by resource multiplexers
outside of core (like nitpicker) must be accounted by the respective
servers, which is not covered yet.

If a component runs out of capabilities, core's PD service prints a
warning to the log. To observe the consumption of capabilities per
component in detail, the PD service is equipped with a diagnostic
mode, which can be enabled via the 'diag' attribute in the target
node of init's routing rules. E.g., the following route enables the
diagnostic mode for the PD session of the "timer" component:

  <default-route>
    <service name="PD" unscoped_label="timer">
      <parent diag="yes"/>
    </service>
    ...
  </default-route>

For subsystems based on a sub-init instance, init can be configured
to report the capability-quota information of its subsystems by
adding the attribute 'child_caps="yes"' to init's '<report>'
config node. Init's own capability quota can be reported by adding
the attribute 'init_caps="yes"'.

Fixes #2398
2017-05-31 13:16:06 +02:00
Norman Feske
c1b981ede4 Annotate session interfaces with CAP_QUOTA
The new 'CAP_QUOTA' enum value denotes the capability quota to be
transferred from the client to the server at session-creation time.

Issue #2398
2017-05-31 13:16:04 +02:00
Norman Feske
29b8d609c9 Adjust file headers to refer to the AGPLv3 2017-02-28 12:59:29 +01:00
Norman Feske
9cba459958 base: remove Child::heap
This patch improves the accounting for the backing store of
session-state meta data. Originally, the session state used to be
allocated by a child-local heap partition fed from the child's RAM
session. However, whereas this approach was somehow practical from a
runtime's (parent's) point of view, the child component could not count
on the quota in its own RAM session. I.e., if the Child::heap grew at
the parent side, the child's RAM session would magically diminish. This
caused two problems. First, it violates assumptions of components like
init that carefully manage their RAM resources (and giving most of them
away their children). Second, if a child transfers most of its RAM
session quota to another RAM session (like init does), the child's RAM
session may actually not allow the parent's heap to grow, which is a
very difficult error condition to deal with.

In the new version, there is no Child::heap anymore. Instead, session
states are allocated from the runtime's RAM session. In order to let
children pay for these costs, the parent withdraws the local session
costs from the session quota donated from the child when the child
initiates a new session. Hence, in principle, all components on the
route of the session request take a small bite from the session quota to
pay for their local book keeping

Consequently, the session quota that ends up at the server may become
depleted more or less, depending on the route. In the case where the
remaining quota is insufficient for the server, the server responds with
'QUOTA_EXCEEDED'. Since this behavior must generally be expected, this
patch equips the client-side 'Env::session' implementation with the
ability to re-issue session requests with successively growing quota
donations.

For several of core's services (ROM, IO_MEM, IRQ), the default session
quota has now increased by 2 KiB, which should suffice for session
requests to up to 3 hops as is the common case for most run scripts. For
longer routes, the retry mechanism as described above comes into effect.
For the time being, we give a warning whenever the server-side quota
check triggers the retry mechanism. The warning may eventually be
removed at a later stage.
2017-02-28 12:59:23 +01:00
Norman Feske
a7f40b24ca Warn about the use of deprecated env() function
This patch enables warnings if one of the deprecate functions that rely
in the implicit use of the global Genode::env() accessor are called.

For the time being, some places within the base framework continue
to rely on the global function while omitting the warning by calling
'env_deprecated' instead of 'env'.

Issue #1987
2017-01-13 13:07:13 +01:00
Norman Feske
cfdbccc5c2 Remove blocking calls from root and parent RPCs
This is a redesign of the root and parent interfaces to eliminate
blocking RPC calls.

- New session representation at the parent (base/session_state.h)
- base-internal root proxy mechanism as migration path
- Redesign of base/service.h
- Removes ancient 'Connection::KEEP_OPEN' feature
- Interface change of 'Child', 'Child_policy', 'Slave', 'Slave_policy'
- New 'Slave::Connection'
- Changed child-construction procedure to be compatible with the
  non-blocking parent interface and to be easier to use
- The child's initial LOG session, its binary ROM session, and the
  linker ROM session have become part of the child's envirenment.
- Session upgrading must now be performed via 'env.upgrade' instead
  of performing a sole RPC call the parent. To make RAM upgrades
  easier, the 'Connection' provides a new 'upgrade_ram' method.

Issue #2120
2016-11-25 16:06:42 +01:00
Norman Feske
82107bef9b base: buffer session args in 'Connection'
This patch is a preparation of the forthcoming async parent interface.
Note that this patch increases the size of connection objects.
Furthermore it adds a diagnostic message whenever a connection fails.

Issue #2166
2016-11-25 15:27:28 +01:00
Emery Hemingway
2b8c1af9e0 remove 'filename' from ROM sesion args
Conveying the ROM filename as the final label element simplifies
routing policy and session construction.

Annotations by nfeske:

This commit also changes the ROM session to use base/log.h instead of
base/printf.h, which produced build error of VirtualBox because the
vbox headers have a '#define Log', which collides with the content of
base/log.h. Hence, this commit has to take precautions to resolve this
conflict.

The commit alse refines the previous session-label change by adding a
new 'Session_label::prefix' method and removing the use of 'char const *'
from this part of the API.

Fixes #1787
2016-07-11 13:24:36 +02:00
Norman Feske
a7b3072cc2 Pass Env & as first argument to connection objects
This patch supplements each existing connection type with an new
constructor that is meant to replace the original one. The new
one takes a reference to the component's environment as argument and
thereby does not rely on the presence of the globally accessible
'env()' interface.

The original constructors are marked as deprecated. Once we have
completely abolished the use of the global 'env()', we will remove them.

Fixes #1960
2016-05-23 15:52:37 +02:00
Norman Feske
8d797105b3 Move Attach_*dataspace utils from os to base
Fixes #1958
2016-05-23 15:52:36 +02:00
Norman Feske
e8336acafc base,os: Coding-style unification
Fixes #1432
2015-03-13 12:17:23 +01:00
Norman Feske
56ed7addbc base: fix misleading ROM-connection error message 2015-03-04 17:32:20 +01:00
Norman Feske
ca971bbfd8 Move repositories to 'repos/' subdirectory
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.

Issue #1082
2014-05-14 16:08:00 +02:00