* added global offset table relative loading for global symbols
* removed 'initial_sp' and 'initial_x0' because they are currently not
used on this platform. If required they are easy to resurrect.
issue #3260
Components like kernel, core, and bootstrap that are built for a
specific board need to reside inside the same architectural dependent
build directory. For instance there are sel4, foc, and hw kernel builds
for imx6q_sabrelite and imx7d_sabre, which have to reside inside the same
arm_v7 build directory.
This commit names those components explicitely, and adapts the run-tool to it.
Fix#3316
Previously, only Invalid_dataspace, Region_conflict, and Out_of_ram were
handled for both allocate and attach with the same handlers. However,
both operations can also throw Out_of_caps and for all exceptions during
attach, the dataspace must be freed again whereas this is not the case
when the exception occured during allocate.
Issue #2953
Instead of retieving the information about the underlying platform from
the configuration, check the running kernel from the platform_info. This
commit removes the undocumented "acpi" config attribute.
* Make target binaries independent of board SPECS
* Name binaries of one architecture unambigously
* Extend include path to match board specifics
* Adapt run-scripts to use the right binary
Ref #2190
Ref #3180
With the new fact that plain time values are always 64 bit unsigned, the
timestamp type is never bigger than the plain time type. Therefore, a code path
in the curr_time interpolation that treated this condition is not neccessary
anymore.
Ref #3208
This enforces the use of unsigned 64-bit values for time in the duration type,
the timeout framework, the timer session, the userland timer-drivers, and the
alarm framework on all platforms. The commit also adapts the code that uses
these tools accross all basic repositories (base, base-*, os. gems, libports,
ports, dde_*) to use unsigned 64-bit values for time as well as far as this
does not imply profound modifications.
Fixes#3208
Issue #3111
remove_range may deny to the job on memory pressure or insane ranges,
which ends up in an endless loop when the Avl allocator is in destruction.
Since the Avl gets destructed, solely the memory free up is of importance,
not the correct range adjustments during remove_range.
Track the dataspaces used by attach and add handling of flushing VM space
when dataspace gets destroyed (not triggered via the vm_session interface).
Issue #3111
Handles corner case when addr + size becomes exactly 0. Before the commit
the function returned that sum is not part of the range, which is wrong.
Issue #3111
The old inline assembly provided two output operands that were afterwards
combined for a return value. However, the second output operand isn't
necessary when using the "Acquiring a Lock" example-code of the ARM manual
"Barrier Litmus Tests and Cookbook". This saves two logical operations
per acquisition try. Additionally better documentation is now provided.
Fixes#1292
This patch adds the items necessary for building Genode components with
stack protection enabled, but it is not initialized at runtime. They are
provided at the moment as a convenience and do not implement a security
feature.
Fix#3066
If a component is being destroyed just before it calls `exit()` at its
parent, the `exit()` call causes an `Ipc_error` exception, which leads to
an `abort()` loop with repeated error messages, because `abort()` calls
`exit()` too. Catching the exception in `Expanding_parent_client::exit()`
avoids this problem.
Fixes#3228
* Introduces pending_signal syscall to check for new signals for the
calling thread without blocking
* Implements pending_signal in the base-library specific for hw to use the
new syscall
Fix#3217
The "schedule_post_signal_hook" method of the Genode::Entrypoint class
is problematic because the signal hook can be scheduled and replaced
multiple times during the signal dispatch cycle. Add an alternative to
this method with "register_io_progress_handler" and the "Post_signal_
hook" class with "Io_progress_handler". The difference being an
"Io_progress_handler" may be registered once during the lifetime of an
entrypoint to prevent arbitrary libraries from replacing a pending hook.
The "register_io_progress_handler" remains as a deprecated API, and is
now invoked for every I/O signal received and only for I/O signals
rather than for any signal.
Ref #3132
The zynq nic_drv also depends on hw, we therefore adapted the folder
structure for clarity. Also renamed the binary to 'zynq_nic_drv' to
prevent conflicts and to allow removing the cadence_gem spec.
Issue #3179
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 is a follow-up commit of "base/core: use references instead of
pointers". Because the 'Rm_root::_upgrade_session' implementation
lacked the 'override' keyword, my overzealous change of the pointer
argument went unnoticed.
This commit fixes the depot_rom (cached_fs_rom) failure in Sculpt.
When cached_fs_rom attempted to create a new managed dataspace while the
RM session quota was depleted, it tried to upgrade the session (via
Rm_connection::create). However, the upgraded resources never reached
the actual session because the default 'Root_component::_upgrade_session'
was called instead of 'Rm_root::_upgrade_session'.
Issue #3135
This patch adjusts the implementation of the base library and core such
that the code no longer relies on deprecated APIs except for very few
cases, mainly to keep those deprecated APIs in tact for now.
The most prominent changes are:
- Removing the use of base/printf.h
- Removing of the log backend for printf. The 'Console' with the
format-string parser is still there along with 'snprintf.h' because
the latter is still used at a few places, most prominently the
'Connection' classes.
- Removing the notion of a RAM session, which does not exist in
Genode anymore. Still the types were preserved (by typedefs to
PD session) to keep up compatibility. But this transition should
come to an end now.
- Slight rennovation of core's tracing service, e.g., the use of an
Attached_dataspace as the Argument_buffer.
- Reducing the reliance on global accessors like deprecated_env() or
core_env(). Still there is a longish way to go to eliminate all such
calls. A useful pattern (or at least a stop-gap solution) is to
pass the 'Env' to the individual compilation units via init functions.
- Avoiding the use of the old 'Child_policy::resolve_session_request'
interface that returned a 'Service' instead of a 'Route'.
Issue #1987
The notion of a RAM session does not exist anymore. Hence, we have to
adjust the name of 'init_env_ram_session'. Since this change modifies
the ABI, it comes as separate commit.
Issue #2407
- support to create multiple vCPUs
- support to implement Vm_session methods client side within base library
- adjust muen specific virtualbox4 version to compile/link
Issue #3111
The minimal-footprint Ada runtime for implementing library-like
functionality in SPARK is now called "spark" runtime.
The full Ada runtime for entire components written in Ada and using the
libc as glue to the underlying system will move to the world repository
as "ada" runtime.
Issue #3144
This patch replaces the former prominent use of pointers by references
wherever feasible. This has the following benefits:
* The contract between caller and callee becomes more obvious. When
passing a reference, the contract says that the argument cannot be
a null pointer. The caller is responsible to ensure that. Therefore,
the use of reference eliminates the need to add defensive null-pointer
checks at the callee site, which sometimes merely exist to be on the
safe side. The bottom line is that the code becomes easier to follow.
* Reference members must be initialized via an object initializer,
which promotes a programming style that avoids intermediate object-
construction states. Within core, there are still a few pointers
as member variables left though. E.g., caused by the late association
of 'Platform_thread' objects with their 'Platform_pd' objects.
* If no pointers are present as member variables, we don't need to
manually provide declarations of a private copy constructor and
an assignment operator to avoid -Weffc++ errors "class ... has
pointer data members [-Werror=effc++]".
This patch also changes a few system bindings on NOVA and Fiasco.OC,
e.g., the return value of the global 'cap_map' accessor has become a
reference. Hence, the patch touches a few places outside of core.
Fixes#3135
The new method allows for the construction of a meta-data object inside
the reserved space of the allocator's meta data. It thereby alleviates
the need to copy the meta data object (via the assignment operator) as
done by the traditional 'metadata' setter method. This, in turn, allows
one to use non-copyable objects (like objects with constant member
variables) as meta data.
This patch moves the removal of the signal context from the
'_platform_finish_dissolve' to the '_platform_begin_dissolve'
method. This is needed because the removal involves taking
the signal-registry lock. The latter must adhere the same
locking order as the code path used for signal delivery.
Fixes#3109
The former 'Genode::Timed_semaphore' mechanism is moved to the private
part of the two remaining users, namely dde_rump and the libc. Note
there are now two private copies of 'timed_semaphore.h'. This should be
regarded as an interim step until the use of this mechanism is removed
from both users.
This patch also cleans up the mechanism from legacy Genode API calls and
global side effects (alarm-thread singleton). The test/timed_semaphore
is now located at the libports repository as it now tests a mechanism of
the libc. The former timed_semaphore library is no more.
Fixes#3121
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
The new 'apply_first' method enables users of the list model to manually
traverse the list model via the 'Element::next' method instead of
iterating via 'for_each'. This is needed in situations where the
list-model elements are visited via recursion, not via a loop.
Issue #3094
This commit solves several issues:
* correct calculation of overlap region when detaching regions
in managed dataspaces
* prevent unmap of Fiasco.OC's core log buffer
* calculate the core-local address of regions in managed dataspaces
if possible at all and use it to unmap on kernels where this is
needed
Fix#976Fix#3082
This can happen, for example, during 'dlopen' if unresolved symbols are
present.
* Unload already loaded shared libraries
* Delete dependencies
* Flush initializer list (ctors)
fixes#3073
'SANITIZE_UNDEFINED = yes' in 'target.mk' adds the '-fsanitize=undefined'
compiler flag and links the program with libubsan and libsanitizer_common.
Issue #3072
Due to the changing environment this test is executed (like depot_autopilot)
the binary test-rm_fault used to check ROM dataspace's read-only property
does not suit anymore. This commit changes the binary to ld.lib.so that is
normally still provided as a ROM dataspace.
Ref #3027
* In base-foc/recipes/src/ replace base-foc with base-foc-pc
* To base-foc/recipes/src add base-foc-arndale, base-foc-pbxa9
* Ensure that the correct base-foc recipe is choosen by the run module
'boot_dir/foc'
This fixes the region-map component implementation in core, which uses a
'Genode::Weak_ptr<Genode::Region_map_component> _faulting_region_map'
member. This member is assigned a valid weak_ptr or an invalid weak_ptr
according to the state machine.
Fixes#3012
The new 'conditional' method simplifies the typical use case for
'Constructible' objects where the constructed/destructed state depends
on a configuration parameter. The method alleviates the need to
re-implement the logic again and again.
The patch also removes the 'Reconstructible' constructor arguments
because they are unused.
Fixes#3006
Ensure that a '\0' always appears at the end of the ouput of the XML
generator. Previously, exceptions during the Node(...) constructor
might have prevented this. This commit also extends the xml_generator
test to drive a harder test on exceptions in the Xml_generator.
Issue #2953
When the functor provided to the Node constructor throws an exception,
do revert all changes in reverse order. Previously, the changes made
to the parent node were not considered by the exception handler which
caused unnecessary characters to remain in the out buffer for each
reverted node.
Issue #2953
1) The loop for determining the line length read from a character offset
before checking whether the offset is smaller than the given string
length. This could have caused access outside the string buffer.
2) The routine for determining the line length first seeked for the
offset of the last real character of the line and than added one for
getting the length but only if the following character was '\n'. This
has to be done for any other line-terminating character too. The only
case where you don't want to do this is when the end of the whole
string is reached.
Issue #2967
This patch fixes a problem in the non-const 'for_each' method of the
'Registry' data structure. If an exception was thrown from within the
functor of the 'for_each' operation, the not yet processed items of the
registry were dropped from the registry, which is not expected.
The new base/xsd/config.inc defines generic XSD types such as 'Boolean' or
'Session_label'. It can be included in config XSD files by using:
! <xs:include schemaLocation="file://${GENODE_CONFIG_INC}"/>
The string ${GENODE_CONFIG_INC} is replaced by the run tool with the
above mentionened file path.
Issue #2897
By adding a sanity check for the validity of the PD session targeted by
a transfer_quota operation, the corner case of an incomplete PD session
of a child can no longer trigger an 'Invalid_session' exception.
This patch removes the detection of statically linked executables from
the base framework. It thereby fixes the corner cases encountered with
Sculpt when obtaining the binaries of the runtime from the depot_rom
service that is hosted within the runtime.
Statically linked binaries and hybrid Linux/Genode (lx_hybrid) binaries
can still be started by relabeling the ROM-session route of "ld.lib.so"
to the binary name, pretending that the binary is the dynamic linker.
This can be achieved via init's label rewriting mechanism:
<route>
<service name="ROM" unscoped_label="ld.lib.so">
<parent label="test-platform"/> </service>
</route>
However, as this is quite cryptic and would need to be applied for all
lx_hybrid components, the patch adds a shortcut to init's configuration.
One can simply add the 'ld="no"' attribute to the <start> node of the
corresponding component:
<start name="test-platform" ld="no"/>
Fixes#2866
Previously, the trace control of a thread was initialized in its
constructor (which is generic for all components). This has the
disadvantage that the CPU-session-pointer member of the thread might not
be valid at this point. And it cannot be replaced by using the
"deprecated_env" CPU session neither as constructing the deprecated
environment in causes troubles in Core. But as the trace control
shouldn't be needed in Core anyway, the initialization can be moved to
the Thread::start implementation of non-core components. This code
already takes care of the CPU session pointer.
Fixes#2901
This patch addresses a corner case revealed by the resource_request test
on seL4 after changing the child-destruction handling with commit "base:
close PD on 'close_all_sessions'". During the destruction of the PD
session, the backing store (session-local RAM dataspace factory) of the
signal broker's slab was destroyed before destructing the signal broker.
Instantiating the signal broker after the RAM dataspace factory fixes
the destruction order.
This patch improves the handling of the corner case where a client
vanishes while a session request is in flight (CREATE_REQUESTED but
not yet AVAILABLE). This corner case could be sporadically observed with
the init_loop test on base-linux.
In the original version, the session would eventually be delivered but
never picked up by anyone. Such a stale session still uses resources that
should better be released. In the new version, the parent checks for the
liveliness of the client whenever a session is delivered. If there is no
client of the session, a close request is immediately issued to the
server. The session state must be preserved until the close requests has
been answered.
This patch moves the closing of a child's PD session from the 'Child'
destructor to the 'close_all_sessions' method. This way, the child's
PD quota is immediately returned as soon as init flags a child as
'abandoned', which removes jitter from init's RAM-state reports.
The patch is supposed to make the 'init_loop.run' test much happier.
This patch ensures that session-create requests are handled after close
requests, which solves the corner case where one single-session server
receives a close and create request at the same time. E.g., when
expanding a partition with Sculpt, the gpt-write tool is removed and
part_blk is started (to execute resize2fs on top) in one step. Both
interact with the USB-block driver, which is a single-session server.
Fixes#2877
Internally, Genode::Session_label has a typedef from String<capacity()> to
String. To have this typedef public is especially useful when reading a
label from an XML node. This can then be written as
! Session_label label = node.attribute_value("label", Session_label::String());
instead of
! Session_label label = node.attribute_value("label", String<160>());
which would be less generic (Session_label cannot be used directly as there
is no appropriate ascii_to implementation).
Issue #2840
Whenever an environment session was provided by an asynchronous service,
e.g., the depot_rom of the sculpt scenario, the session quota was not
transferred to the server at session-creation time. This resulted in a
slow depletion of the server's quota over time. This patch ensures that
the delivery of session quota is consistent with the information
reported to the server as session argument.
The 'Child::_revert_quota_and_destroy' assumes to be called from the
client's context, which is normally the case when destroying sessions.
However, if a client's session outlives the client (because the
asynchronous close request to the server is still pending), the session
cleanup is performed in the context of the server. Here, the
'session_response' implementation wrongly called
'_revert_quota_and_destroy' to the effect that the session quota was
withdrawn from the server (good) but subsequently transferred back to
the server (bad). The patch replaces the call of
'_revert_quota_and_destroy' with only the first - correct - part of the
transaction.
In case of an Alloc_return error, don't free the address at 0. If this
is a managed dataspace, there could be valid attachments which then gets
lost.
Make decreasing alignment search working. Continue with lower alignment
restrictions in case the optimal alignment wish can't be fulfilled.
When an environment session is provided by a async service such as a
sibling component, the session metadata must be preserved until end of
the lifetime of the session at the server has been acknowledged by the
server. Since the session meta data of env sessions are always part of
the 'Child' object, the destruction of this object must be deferred
until this point.
This patch makes the 'List_model' utility robust against duplicated
occurrences of node IDs in the supplied XML data. If two or more XML
nodes correspond to the same model element, the existing element is
updated with the information of the subsequent XML nodes.
Issue #2778
The "create_grub2" script functionality is moved to the g2fg contrib sources
and also the GRUB2 head image (tool/grub2-head.img). The head image is now
partitioned as GPT and bootable in BIOS legacy mode.
The sole existence of shared-object dependencies lead to fatal
static-constructor errors before. Now, ldso checks if the ctors section
of objects in the init list are non-empty before whining.
Issue #2759
When the former trace buffer implementation wrapped, the last entry
according to commit order couldn't be detected anymore. Now, the last
committed entry is always followed by an entry with length 0.
As a downside of this, there are now two meanings of "last" entry: It
means either that the entry marks the empty padding after the entry with
the highest memory address or that it actually marks the end of the
buffer according to commit order. This is an example state of the buffer
with the two types of "last" entry:
last last
+-------------+------------+---+---------+-------------+------------+---+-------+
| len3 data3 | len4 data4 | 0 | empty | len1 data1 | len2 data2 | 0 | empty |
+-------------+------------+---+---------+-------------+------------+---+-------+
If the entry with the highest memory address fits perfectly, the first
type of "last" entry is not needed:
last
+------------+--------------------+---+-------+-------------+-------------------+
| len3 data3 | len4 data4 | 0 | empty | len1 data1 | len2 data2 |
+------------+--------------------+---+-------+-------------+-------------------+
If the buffer didn't wrap so far, there is only one "last" entry that
has both meanings:
last
+--------------------------+------------+-------------+---+---------------------+
| len1 data1 | len2 data2 | len3 data3 | 0 | empty |
+--------------------------+------------+-------------+---+---------------------+
Issue #2735
Co-authored-by: Martin Stein <martin.stein@genode-labs.com>
The Ada runtime can now be set with the ADA_RTS variable. The ada
library builds a (currently) minimal runtime from the gcc sources that
come with Genode (to stay consistent with the used compiler) and sets
the runtime path accordingly. It is build as a shared library ada.lib.so
which needs to be added to the build files.
I split the existing Ada test into program and library, and moved it
to libports as it depends on the runtime library residing in this
repository too.
Fixes#2748
Integrate the code of the Alarm framework directly into the Timeout
framework. The former Alarm-framework methods are all private to the
corresponding classes of the Timeout framework and get prefixed with
'_alarm__'. The latter avoids name clashes and makes it easier to
simplify the code later.
Issue #2704
Switch port I/O based PCI config space access to memory-mapped IO. The
base address of the PCI configuration space is acquired by mapping the
ACPI ROM and reading the first <bdf> node. An exception is thrown if the
first <bdf> node is not for PCI domain zero or if multiple <bdf> nodes
exist. This is to reduce complexity and also because multiple PCI
domains are rare.
The PCI configuration space is accessed via I/O mem dataspace which is
created in the platform_drv root and then passed on to the PCI session,
device components and finally to the actual PCI config access instances.
The memory access code is implemented in a way to make it work with Muen
subject monitor (SM) device emulation and also general x86 targets. On
Muen, the simplified device emulation code (which works also for Linux)
always returns 0xffff in EAX to indicate a non-existing device.
Therefore, EAX is enforced in the assembly templates.
Fixes#2547
AVL trees can't be copied with the default copy constructor as the
parent pointer of the first item of both of the resulting trees would
point to the original tree. Copying an AVL node, however, generally
violates the integrity of the corresponding tree. The copy constructor
of Avl_tree is used in some places but in those places it can be
replaced easily. So, this commit deletes the copy constructor of
Avl_node_base which makes Avl_node and Avl_tree non-copyable.
Issue #2654
On platforms without nic or audio driver support, the corresponding
functions to return the correct names should return a meaningful
name instead of an empty list. Otherwise, in an erroneous run-script
that calls those functions to append names to the boot modules
the whole 'bin' directory is appended instead, which leads to big
image files or errors when linking the boot modules to core.
Previously, base/trace/buffer.h included base/thread.h which includes
base/trace/logger.h which includes base/trace/buffer.h.
Removed the base/thread.h include in base/trace/buffer.h as it is not
needed.
Issue #2654
With this patch, init responds to the exit of a child by closing all
sessions of the child. E.g., if a child is a GUI application, its
nitpicker session is closed at the time of exit, not at the time when
the start node disappears from init's configuration.
Since this change requires a modification of the 'Genode::Child' class,
it takes the chance to make the child-destruction less brutal. The
new version ensures that all threads of the destructed subsystem are
destructed before other sessions, in particular PD sessions. This
eliminates spurious page-fault warnings during the child destruction.
On Fiasco.OC, closing the CPU session of a thread while being called by
the thread causes a deadlock. Hence, we skip the eager destruction of
CPU sessions on this kernel.
Related to issue #2659
Previously, the dst_len value was not decreased after each character that was
written to the dst buffer. This way, if the content length was greater than
dst_len, decoded_content wrote to memory out of bounds.
Issue #2644
Do not leave space for a terminating '0' at the end of the dst buffer in
decoded_content as the method does not write this '0'. The caller of the
method shall take care of it instead.
Issue #2644
This patch enables the warnings -Wextra, -Weffc++, and -Werror for
compiling Genode components. It thereby helps us to detect bugs like
uninitialized member variables or missing virtual destructors at compile
time. The warning level is defined via the new 'CC_CXX_WARN_STRICT'
variable. For targets that compile 3rd-party code where this warning
level is not applicable, the variable may be explictly set to an empty
value in the corresponding build-description file.
Issue #465
The patch adjust the code of the base, base-<kernel>, and os repository.
To adapt existing components to fix violations of the best practices
suggested by "Effective C++" as reported by the -Weffc++ compiler
argument. The changes follow the patterns outlined below:
* A class with virtual functions can no longer publicly inherit base
classed without a vtable. The inherited object may either be moved
to a member variable, or inherited privately. The latter would be
used for classes that inherit 'List::Element' or 'Avl_node'. In order
to enable the 'List' and 'Avl_tree' to access the meta data, the
'List' must become a friend.
* Instead of adding a virtual destructor to abstract base classes,
we inherit the new 'Interface' class, which contains a virtual
destructor. This way, single-line abstract base classes can stay
as compact as they are now. The 'Interface' utility resides in
base/include/util/interface.h.
* With the new warnings enabled, all member variables must be explicitly
initialized. Basic types may be initialized with '='. All other types
are initialized with braces '{ ... }' or as class initializers. If
basic types and non-basic types appear in a row, it is nice to only
use the brace syntax (also for basic types) and align the braces.
* If a class contains pointers as members, it must now also provide a
copy constructor and assignment operator. In the most cases, one
would make them private, effectively disallowing the objects to be
copied. Unfortunately, this warning cannot be fixed be inheriting
our existing 'Noncopyable' class (the compiler fails to detect that
the inheriting class cannot be copied and still gives the error).
For now, we have to manually add declarations for both the copy
constructor and assignment operator as private class members. Those
declarations should be prepended with a comment like this:
/*
* Noncopyable
*/
Thread(Thread const &);
Thread &operator = (Thread const &);
In the future, we should revisit these places and try to replace
the pointers with references. In the presence of at least one
reference member, the compiler would no longer implicitly generate
a copy constructor. So we could remove the manual declaration.
Issue #465
