This patch alleviates the need for any non-core process to create Unix
domain sockets locally. All sockets used for RPC communication are
created by core and subsequently passed to the other processes via RPC
or the parent interface. The immediate benefit is that no process other
than core needs to access the 'rpath' directory in order to communicate.
However, access to 'rpath' is still needed for accessing dataspaces.
Core creates one socket pair per thread on demand on the first call of
the 'Linux_cpu_session::server_sd()' or 'Linux_cpu_session::client_sd()'
functions. 'Linux_cpu_session' is a Linux-specific extension to the CPU
session interface. In addition to the socket accessors, the extension
provides a mechanism to register the PID/TID of a thread. Those
information were formerly propagated into core along with the thread
name as argument to 'create_thread()'.
Because core creates socket pairs for entrypoints, it needs to know all
threads that are potential entrypoints. For lx_hybrid programs, we
hadn't had propagated any thread information into core, yet. Hence, this
patch also contains the code for registering threads of hybrid
applications at core.
Setting the handler for SIGCHLD to SIG_IGN (ignore) informs the kernel
not to enter the zombie state: (man 2 wait)
POSIX.1-2001 specifies that if the disposition of SIGCHLD is set to
SIG_IGN or the SA_NOCLDWAIT flag is set for SIGCHLD (see
sigaction(2)), then children that terminate do not become zombies
[...]
Fixes#271.
This patch reads program arguments from the config file and makes them
available to the application via the 'argc' and 'argv' arguments of the
'main()' function. The configuration syntax looks like this:
<config>
<arg value="...">
<arg value="...">
...
</config>
The 'value' attribute of the first <arg> node becomes 'argv[0]' and so on.
Fixes#184.
- Let hybrid Linux/Genode programs use POSIX threads for the
implementation of the Thread API.
- Prevent linkage of cxx library to hybrid Linux/Genode programs because
the cxx functionality is covered by glibc.
