This commit addresses the situation where an environment session
outlives the session-providing service. In this case, the env session
got already invaidated at the destruction time of the server. However,
the underlying session-state structure continues to exist until the
client is destructed. During the eventual destruction of such a dangling
environment session, we have to be careful not to interact with the
no-longer existing service.
Ref #2197
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
This patch changes the child-construction procedure to allow the routing
of environment sessions to arbitrary servers, not only to the parent.
In particular, it restores the ability to route the LOG session of the
child to a LOG service provided by a child of init. In principle, it
becomes possible to also route the immediate child's PD, CPU, and RAM
environment sessions in arbitrary ways, which simplifies scenarios that
intercept those sessions, e.g., the CPU sampler.
Note that the latter ability should be used with great caution because
init needs to interact with these sessions to create/destruct the child.
Normally, the sessions are provided by the parent. So init is safe at
all times. If they are routed to a child however, init will naturally
become dependent on this particular child. For the LOG session, this is
actually not a problem because even though the parent creates the LOG
session as part of the child's environment, it never interacts with the
session directly.
Fixes#2197
This patch unconditionally applies the labeling of sessions and thereby
removes the most common use case of 'Child_policy::filter_session_args'.
Furthermore, the patch removes an ambiguity of the session labels of
sessions created by the parent of behalf of its child, e.g., the PD
session created as part of 'Child' now has the label "<child-name>"
whereas an unlabeled PD-session request originating from the child
has the label "<child-name> -> ". This way, the routing-policy of
'Child_policy::resolve_session_request' can differentiate both cases.
As a consequence, the stricter labeling must now be considered wherever
a precise label was specified as a key for a session route or a server-
side policy selection. The simplest way to adapt those cases is to use a
'label_prefix' instead of the 'label' attribute. Alternatively, the
'label' attribute may used by appending " -> " (note the whitespace).
Fixes#2171
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
This data structure is meant as a safe alternative for a list wherever
the list is solely used to remember objects and iterate through them in
an unspecified order. One use case is the 'Service_registry'.
This data structure allows the association of objects with IDs. IDs are
kept in an AVL tree. So in contrast to a bit allocator, the ID space can be
sparsely populated and does not need to be dimensioned. The lifetime of
an ID is bound to an 'Element' object, which relieves the programmer
from manually allocating/deallocating IDs for objects.
Issue #2120
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
Unfortunately, the volatile object does not inherit the noncopyable
attribute of the enclosed object. By making all volatile objects
noncopyable, we prevent the accidental copying of a noncopyable object
wrapped in a volatile object.
Replace 'dump()' debug utilities within Allocator_avl with Output::print
equivalents, and use the new Avl_tree::for_each utility to simplify
the implementation.
Ref #2159
This overload covers the common case for initializing a string from a
literal without employing the 'Output' mechanism. This way, such
strings can by constructed without calling virtual functions, which in
turn makes the 'String' usable for the 'init_rtld' phase of the dynamic
linker.
base generic code:
* Remove unused verbosity code from mmio framework
* Remove escape sequence end heuristic from LOG
* replace Core_console with Core_log (no format specifiers)
* move test/printf to test/log
* remove `printf()` tests from the log test
* check for exact match of the log test output
base-fiasco:
* remove unused Fiasco::print_l4_threadid function
base-nova:
* remove unused hexdump utility from core
base-hw:
* remove unused Kernel::Thread::_print_* debug utilities
* always print resource summary of core during startup
* remove Kernel::Ipc_node::pd_label (not used anymore)
base*:
* Turn `printf`,`PWRN`, etc. calls into their log equivalents
Ref #1987Fix#2119
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.
While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).
To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.
Issue #1987
- remove special handling from base-nova
- add to rpc_server where it actually should be applied to
- required to work for sel4 cancel_blocking
Issue #2044
Those headers implement a platform-specific mechanism. They are never
used by components directly.
This patch also cleans up a few other remaining platform-specific
artifact such as the Fiasco.OC-specific assert.h.
Issue #1993
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
Session_label constructor now takes a bare string rather than a
serialized argument buffer.
Replace all instances of previous constructor with 'label_from_args'
function.
Issue #1787
This patch establishes the sole use of generic headers across all
kernels. The common 'native_capability.h' is based on the version of
base-sel4. All traditional L4 kernels and Linux use the same
implementation of the capability-lifetime management. On base-hw, NOVA,
Fiasco.OC, and seL4, custom implementations (based on their original
mechanisms) are used, with the potential to unify them further in the
future.
This change achieves binary compatibility of dynamically linked programs
across all kernels.
Furthermore, the patch introduces a Native_capability::print method,
which allows the easy output of the kernel-specific capability
representation using the base/log.h API.
Issue #1993
This patch alleviates the need for a Native_capability::Dst at the API
level. The former use case of this type as argument to
Deprecated_env::reinit uses the opaque Native_capability::Raw type
instead. The 'Raw' type contains the portion of the capability that is
transferred as-is when delegating the capability (i.e., when installing
the parent capability into a new component, or when installing a new
parent capability into a new forked Noux process). This information can
be retrieved via the new Native_capability::raw method.
Furthermore, this patch moves the functions for retriving the parent
capability to base/internal/parent_cap.h, which is meant to be
implemented in platform-specific ways. It replaces the former set of
startup/internal/_main_parent_cap.h headers.
Issue #1993
The static 'Thread::mystack()' function returns the stack boundaries of
the calling thread. It is useful when a thread uses a diffent stack than
the primary one.
Fixes#2037
This patch introduces the Genode::raw function that prints output
directly via a low-level kernel mechanism, if available.
On base-linux, it replaces the former 'raw_write_str' function.
On base-hw, it replaces the former kernel/log.h interface.
Fixes#2012
The whole XML comment has to be parsed as one XML tag to support strange
but valid combinations like
<!---->
<!--invisible-tag></invisible-tag-->
Fixes#1424
Quota_exceeded message are of no use during session construction, since
the arguments of the ram_quota are used and no upgrade can take place (the
session construction failed and is so not available for upgrade)
Fixes#1983
This patch removes the outdates doc/architecture.txt since the
topics are covered by the book. We keep repos/os/doc/init.txt
because it contains a few details not present in the book (yet).
The patch streamlines the terminology a bit. Furthermore, it
slightly adjusts a few source-code comments to improve the book's
functional specification chapter.
* Adds public timeout syscalls to kernel API
* Kernel::timeout installs a timeout and binds a signal context to it that
shall trigger once the timeout expired
* With Kernel::timeout_max_us, one can get the maximum installable timeout
* Kernel::timeout_age_us returns the time that has passed since the
calling threads last timeout installation
* Removes all device specific back-ends for the base-hw timer driver and
implements a generic back-end taht uses the kernel timeout API
* Adds assertions about the kernel timer frequency that originate from the
requirements of the the kernel timeout API and adjusts all timers
accordingly by using the their internal dividers
* Introduces the Kernel::Clock class. As member of each Kernel::Cpu object
it combines the management of the timer of the CPU with a timeout scheduler.
Not only the timeout API uses the timeout scheduler but also the CPUs job
scheduler for installing scheduling timeouts.
* Introduces the Kernel::time_t type for timer tic values and values inherited
from timer tics (like microseconds).
Fixes#1972
- add a new function 'binary_ready_hook_for_gdb()' in ldso. GDB can set a
breakpoint at this function to know when ldso has loaded the binary
into memory.
- get the thread state from the NOVA kernel immediately on 'pause()'
Fixes#1968
This patch moves the thread operations from the 'Cpu_session'
to the 'Cpu_thread' interface.
A noteworthy semantic change is the meaning of the former
'exception_handler' function, which used to define both, the default
exception handler or a thread-specific signal handler. Now, the
'Cpu_session::exception_sigh' function defines the CPU-session-wide
default handler whereas the 'Cpu_thread::exception_sigh' function
defines the thread-specific one.
To retain the ability to create 'Child' objects without invoking a
capability, the child's initial thread must be created outside the
'Child::Process'. It is now represented by the 'Child::Initial_thread',
which is passed as argument to the 'Child' constructor.
Fixes#1939
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
It turns out that the name function does not have much use in practice
except for naming the thread of the component's initial entrypoint. For
dynamically linked components, this thread is created by the dynamic
linker. It is named "ep" in these cases. Considering that we will
eventually turn all regular components into dynamically linked
executables, the additional information provided by the
Component::name() function remains unused. So it is better to not bother
the component developers with adding boilerplate code.
This patch cleans up the thread API and comes with the following
noteworthy changes:
- Introduced Cpu_session::Weight type that replaces a formerly used
plain integer value to prevent the accidental mix-up of
arguments.
- The enum definition of Cpu_session::DEFAULT_WEIGHT moved to
Cpu_session::Weight::DEFAULT_WEIGHT
- New Thread constructor that takes a 'Env &' as first argument.
The original constructors are now marked as deprecated. For the
common use case where the default 'Weight' and 'Affinity' are
used, a shortcut is provided. In the long term, those two
constructors should be the only ones to remain.
- The former 'Thread<>' class template has been renamed to
'Thread_deprecated'.
- The former 'Thread_base' class is now called 'Thread'.
- The new 'name()' accessor returns the thread's name as 'Name'
object as centrally defined via 'Cpu_session::Name'. It is meant to
replace the old-fashioned 'name' method that takes a buffer and size
as arguments.
- Adaptation of the thread test to the new API
Issue #1954
This patch moves the base library from src/base to src/lib/base,
flattens the library-internal directory structure, and moves the common
parts of the library-description files to base/lib/mk/base.inc and
base/lib/mk/base-common.inc.
Furthermore, the patch fixes a few cosmetic issues (whitespace and
comments only) that I encountered while browsing the result.
Fixes#1952
Most slab allocators in core use a sliced heap as backing store. Since
sliced-heap allocations are performed at page-granularity, it is
sensible to dimension the slab blocks to fill whole pages.
This patch cleans up the implementation of the sliced heap, adds a
constructor that takes references instead of pointers, and adds the
function 'meta_data_size' to determine the meta-data overhead per block.
The latter can be used to dimension slab allocators such that slab
blocks use whole pages.
The original 'Env' interface as returned by 'Genode::env()' has been
renamed to 'Env_deprecated' and moved to deprecated/env.h. The new version
of base/env.h contains the interface passed to modern components that
use the component API via base/component.h.
Issue #1832
This patch makes the former 'Process' class private to the 'Child'
class and changes the constructor of the 'Child' in a way that
principally enables the implementation of single-threaded runtime
environments that virtualize the CPU, PD, and RAM services. The
new interfaces has become free from side effects. I.e., instead
of implicitly using Genode::env()->rm_session(), it takes the reference
to the local region map as argument. Also, the handling of the dynamic
linker via global variables is gone. Now, the linker binary must be
provided as constructor argument.
Fixes#1949
This patch replaces the former 'Pd_session::bind_thread' function by a
PD-capability argument of the 'Cpu_session::create_thread' function, and
removes the ancient thread-start protocol via 'Rm_session::add_client' and
'Cpu_session::set_pager'. Threads are now bound to PDs at their creation
time and implicitly paged according to the address space of the PD.
Note the API change:
This patch changes the signature of the 'Child' and 'Process' constructors.
There is a new 'address_space' argument, which represents the region map
representing the child's address space. It is supplied separately to the
PD session capability (which principally can be invoked to obtain the
PD's address space) to allow the population of the address space
without relying on an 'Pd_session::address_space' RPC call.
Furthermore, a new (optional) env_pd argument allows the explicit
overriding of the PD capability handed out to the child as part of its
environment. It can be used to intercept the interaction of the child
with its PD session at core. This is used by Noux.
Issue #1938
Since the dynamic linker depends on the XML utils and we plan to replace
the ancient 'Arg_string' with XML, it is time to move the 'Xml_node' and
'Xml_generator' to base/include.
We will eventually remove the delivery of the number of occurred signals
to the recipient. There haven't been any convincing use cases for this
feature. In the contrary, it actually led to wrong design choices in the
past where the rate of signals carried information (such as the progress
of time) that should better be obtained via an explicit RPC call.
The old 'Signal_rpc_member' template retains the old interface for now.
But the new 'Signal_handler' omits the 'unsigned' argument from the
handler function.
This patch integrates three region maps into each PD session to
reduce the session overhead and to simplify the PD creation procedure.
Please refer to the issue cited below for an elaborative discussion.
Note the API change:
With this patch, the semantics of core's RM service have changed. Now,
the service is merely a tool for creating and destroying managed
dataspaces, which are rarely needed. Regular components no longer need a
RM session. For this reason, the corresponding argument for the
'Process' and 'Child' constructors has been removed.
The former interface of the 'Rm_session' is not named 'Region_map'. As a
minor refinement, the 'Fault_type' enum values are now part of the
'Region_map::State' struct.
Issue #1938
The return code of assign_parent remained unused. So this patch
removes it.
The bind_thread function fails only due to platform-specific limitations
such as the exhaustion of ID name spaces, which cannot be sensibly
handled by the PD-session client. If occurred, such conditions used to
be reflected by integer return codes that were used for diagnostic
messages only. The patch removes the return codes and leaves the
diagnostic output to core.
Fixes#1842
When using the Allocator interface, one can't tell which alignment
resulting allocations fulfill. However, at least on ARM, given the
architectural alignment requirements of ARM memory accesses, one wants
memory allocations (what allocators are for in most cases) to be word
aligned automatically. Previously, at least the AVL allocator simply
called alloc_aligned without defining align in its alloc implementation.
This led to unaligned access faults (the default was 0) when using the
AVL allocator as Allocator (as done in the metadata management of a SLAB
of an AVL that uses the AVL as backing store). To avoid such pitfalls
in the future, we force users of alloc_aligned to always specify align
(why use alloc_aligned without align anyway).
Ref #1941
Besides unifying the Msgbuf_base classes across all platforms, this
patch merges the Ipc_marshaller functionality into Msgbuf_base, which
leads to several further simplifications. For example, this patch
eventually moves the Native_connection_state and removes all state
from the former Ipc_server to the actual server loop, which not only
makes the flow of control and information much more obvious, but is
also more flexible. I.e., on NOVA, we don't even have the notion of
reply-and-wait. Now, we are no longer forced to pretend otherwise.
Issue #1832
This patch unifies the CPU session interface across all platforms. The
former differences are moved to respective "native-CPU" interfaces.
NOVA is not covered by the patch and still relies on a custom version of
the core-internal 'cpu_session_component.h'. However, this will soon be
removed once the ongoing rework of pause/single-step on NOVA is
completed.
Fixes#1922
This patch changes the organization of the slab blocks within the slab
allocator. Originally, blocks were kept in a list sorted by the number
of free entries. However, it turned out that the maintenance of this
invariant involves a lot of overhead in the presence of a large number
of blocks. The new implementation manages blocks within a ring in no
particular order and maintains a pointer to the block where the next
allocation is attempted. This alleviates the need for sorting blocks
when allocating and deallocating.
Fixes#1908
This patch ensures that the 'Allocator_avl' releases all memory obtained
from the meta-data allocator at destruction time. If allocations are
still dangling, it produces a warning, hinting at possible memory leaks.
Finally, it properly reverts all 'add_range' operations.
This patch makes sure that the dataspace pool is flushed before
destructing the heap-local allocator-avl instance. With the original
destruction order, the allocator would still contain dangling
allocations on the account of the dataspace pool when destructed. In
practice, this caused no problem because the underlying backing store is
eventually freed on the destruction of the pool. But it triggers a
runtime warning of the allocator since it has become more strict with
regard to dangling allocations.
This commit introduces the new `Component` interface in the form of the
headers base/component.h and base/entrypoint.h. The os/server.h API
has become merely a compatibilty wrapper and will eventually be removed.
The same holds true for os/signal_rpc_dispatcher.h. The mechanism has
moved to base/signal.h and is now called 'Signal_handler'.
Since the patch shuffles headers around, please do a 'make clean' in the
build directory.
Issue #1832
This commit replaces the stateful 'Ipc_client' type with the plain
function 'ipc_call' that takes all the needed state as arguments.
The stateful 'Ipc_server' class is retained but it moved from the public
API to the internal ipc_server.h header. The kernel-specific
implementations were cleaned up and simplified. E.g., the 'wait'
function does no longer exist. The badge and exception code are no
longer carried in the message buffers but are handled in kernel-specific
ways.
Issue #610
Issue #1832
This patch moves details about the stack allocation and organization
the base-internal headers. Thereby, I replaced the notion of "thread
contexts" by "stacks" as this term is much more intuitive. The fact that
we place thread-specific information at the bottom of the stack is not
worth introducing new terminology.
Issue #1832
By moving the stub implementation to rm_session_client.cc, we can use
the generic base/include/rm_session/client.h for base-linux and
base-nova and merely use platform-specific implementations.
Issue #1832
This patch establishes a common organization of header files
internal to the base framework. The internal headers are located at
'<repository>/src/include/base/internal/'. This structure has been
choosen to make the nature of those headers immediately clear when
included:
#include <base/internal/lock_helper.h>
Issue #1832
This patch integrates the functionality of the former CAP session into
the PD session and unifies the approch of supplementing the generic PD
session with kernel-specific functionality. The latter is achieved by
the new 'Native_pd' interface. The kernel-specific interface can be
obtained via the Pd_session::native_pd accessor function. The
kernel-specific interfaces are named Nova_native_pd, Foc_native_pd, and
Linux_native_pd.
The latter change allowed for to deduplication of the
pd_session_component code among the various base platforms.
To retain API compatibility, we keep the 'Cap_session' and
'Cap_connection' around. But those classes have become mere wrappers
around the PD session interface.
Issue #1841
This patch removes the SIGNAL service from core and moves its
functionality to the PD session. Furthermore, it unifies the PD service
implementation and terminology across the various base platforms.
Issue #1841
This commit enables multi-processing for all Cortex A9 SoCs we currently
support. Moreover, it thereby enables the L2 cache for i.MX6 that was not
enabled until now. However, the QEMU variants hw_pbxa9 and hw_zynq still
only use 1 core, because the busy cpu synchronization used when initializing
multiple Cortex A9 cores leads to horrible boot times on QEMU.
During this work the CPU initialization in general was reworked. From now
on lots of hardware specifics were put into the 'spec' specific files, some
generic hook functions and abstractions thereby were eliminated. This
results to more lean implementations for instance on non-SMP platforms,
or in the x86 case where cache maintainance is a non-issue.
Due to the fact that memory/cache coherency and SMP are closely coupled
on ARM Cortex A9 this commit combines so different aspects.
Fix#1312Fix#1807
When unblocking a thread in Semaphore::up() while holding the fifo meta-data
lock, it might happen that the lock holder gets destroyed by the one it was
unblocking. This happened for instance in the pthread test in the past, where
thread destruction was synchronized via a semaphore. There is no need to hold
the lock during the unblock operation, so we should do it outside the critical
section.
Fix#1333
Previously we used a pretty slow external clock source for the timer. This
resulted in such a low TICS_PER_MS value that the granularity wasn't
sufficient to find a setup with a precision better than 1 second error per
minute. Now we use the so-called High Frequency Reference Clock as input
with TICS_PER_MS=33333 and the timer precision is significantly < 1 second per
minute.
Fixes#1805
'block_for_signal' and 'pending_signal' now set pending flag in signal context
in order to determine pending signal. The context list is also used by the
'Signal_receiver' during destruction.
Fixes#1738
Currently, when a signal arrives in the main thread, the signal dispatcher is
retrieved and called from the main thread, the dispatcher uses a proxy object
that in turn sends an RPC to the entry point. This becomes a problem when the
entry point destroys the dispatcher object, before the dispatch function has
been called by the main thread. Therefore, the main thread should simply send an
RPC to the entry point upon signal arrival and the dispatching should be handled
solely by the entry point.
Issue #1738
Holding the object pool's lock while trying to obtain an object's lock
can leave to dead-lock situations, when more than one thread tries to
access multiple objects at once (e.g.: when transfer_quota gets called
simultanously by the init and entrypoint thread in core). To circumvent
holding the object pool lock too long, but access object pointers safely
on the other hand, this commit updates the object pool implementation
to use weak pointers during the object retrieval.
Fix#1704
* Move the Synced_interface from os -> base
* Align the naming of "synchronized" helpers to "Synced_*"
* Move Synced_range_allocator to core's private headers
* Remove the raw() and lock() members from Synced_allocator and
Synced_range_allocator, and re-use the Synced_interface for them
* Make core's Mapped_mem_allocator a friend class of Synced_range_allocator
to enable the needed "unsafe" access of its physical and virtual allocators
Fix#1697
Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:
repos/base/include/spec
repos/base/mk/spec
repos/base/lib/mk/spec
repos/base/src/core/spec
...
Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.
Fix#1673
Instead of returning pointers to locked objects via a lookup function,
the new object pool implementation restricts object access to
functors resp. lambda expressions that are applied to the objects
within the pool itself.
Fix#884Fix#1658
Moves the Bios Data Area header from base-hw to base. Modifies the
base-nova core console that it uses the header as replacement for
the previous BDA bit logic.
Ref #1625
This commit eliminates the mutual interlaced taking of destruction lock,
list lock and weak pointer locks that could lead to a dead-lock situation
when a lock pointer was tried to construct while a weak object is in
destruction progress.
Now, all weak pointers are invalidated and dequeued at the very
beginning of the weak object's destruction. Moreover, before a weak pointer
gets invalidated during destruction of a weak object, it gets dequeued, and
the list lock is freed again to avoid the former dead-lock.
Fix#1607
Up to now it was not possible to trace threads that use a different
Cpu_session rather than env()->cpu_session() (as done by VirtualBox).
This problem is now solved by setting the Cpu_session explicitly when
creating the event logger and attaching the trace control area when
creating the thread.
Fixes#1618.
The recent change of the TRACE session interface triggered the
following warning:
/home/no/src/genode/repos/base/include/base/ipc.h:79:4: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
*reinterpret_cast<T *>(&_sndbuf[_write_offset]) = value;
^
In file included from /home/no/src/genode/repos/base/src/core/include/trace/session_component.h:19:0,
from /home/no/src/genode/repos/base/src/core/trace_session_component.cc:15:
/home/no/src/genode/repos/base/include/base/rpc_server.h:132:42: note: ‘ret’ was declared here
typename This_rpc_function::Ret_type ret;
The warning occurs for basic return types (like size_t), which are
indeed not initialized. The variable gets its value assigned by the
corresponding 'call_member' overload, to which the variable is passed as
reference. But the compiler apparently is not able to detect this assignment.
Declaring 'ret' with a C++11-style default initializer fixes the warning.
While importing trace sources as trace subjects into a TRACE session,
the session quota might become depleted. The TRACE session already keeps
track of the session quota via an allocator guard but the 'subjects' RPC
function missed to handle the out-of-memory condition. This patch
reflects the error condition as an 'Out_of_metadata' exception to the
TRACE client. It also contains an extension of the trace test to
exercise the corner case.
This patch enable clients of core's TRACE service to obtain the
execution times of trace subjects (i.e., threads). The execution time is
delivered as part of the 'Subject_info' structure.
Right now, the feature is available solely on NOVA. On all other base
platforms, the returned execution times are 0.
Issue #813
