Acquiring mutexes is now wraped in a easy to use MUTEX_SECTION macro.
This scheme will be extended for chained lock propagation soon.
Notes:
* NoBug resourcemanagement is now part of the lower layer,
RESOURCE_ENTER/RESOUCE_LEAVE are maintained automatically
* one must still call RESOURCE_ANNOUNCE/RESOURCE_FORGET, because we want
to maintain high level information about resources.
* MUTEX_SECTIONS must not be left with any kind of jump
lumiera_free() is for now just a static inline wraper around free()
Later this makes it easier to hook in some resource managing functions
or a Garbage Collector in.
Replaced all current uses of free()
* add 'backend' for backend global initialization/destruction
and common functions.
* WIP: 'file' acts as interface to named files, provides posix
filehandles with and acquire/release function pair.
* 'filehandle' manages posix filehandles internally, refcounted.
* WIP: 'filehandlecache' keeps unused filehandles in a MRU cache
* WIP: test for filehandle management
* improved filedescriptor test
* make registry initialization singleton, no parameters.
* remove registry init from all functions, has to be called explicitly.
* some nobug improvements
It is now possible to acquire/release filedescriptors for existing files
and files to be created.
Filedescriptors are managed in a registry by refcounts, they get
automatically destructed when the last user releases them.
We have 'File' which associates a name with a file and will be used to
offer an interface for the application.
Posix 'Filehandles' which are managed in a 'Filehandlecache' to utilize
a limited number of fd's at optimum.
Internally we use 'Filedescriptor's which manage files, mapping and all
kinds of metadata. Filedescriptors weak referenced by a registry and freed
when the last user vanishes.
