`volatile` effectively prevents instruction reordering by the compiler
and fixes an issue with -O3 compiled components.
Note, this commit does not address further arguments regarding memory
barriers and volatile voiced in issue #693.
Issue #693
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 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
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
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
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
