Using more than one SICStus run-time in a process is only supported when
the dynamic library version of the SICStus run-time is used (e.g,
sprt311.dll
, libsprt311.so
).
An application that wants to use more than one SICStus run-time needs to
be built using the --multi-sp-aware
option to spld
. C-code
compiled by spld --multi-sp-aware
will have the C preprocessor macro
MULTI_SP_AWARE
defined and non-zero.
Unlike the single run-time case described above, an application built
with --multi-sp-aware
will not have a global variable that holds the
dispatch vector. Instead, your code will have to take steps to ensure that
the appropriate dispatch vector is used when switching between SICStus
run-times.
There are several steps needed to access a SICStus run-time from an
application built with --multi-sp-aware
.
SP_get_dispatch()
. Note that this function is special in
that it is not accessed through the dispatch vector; instead, it is
exported in the ordinary manner from the SICStus run-time dynamic
library (libsprt311.so
under Windows and, typically,
sprt311.dll
under UNIX).
SICStusDISPATCHVAR
expands to something that references the dispatch vector obtained in
step 1.
The C pre-processor macro SICStusDISPATCHVAR
should expand to a
SICSTUS_API_STRUCT_TYPE *
, that is, a pointer to the dispatch
vector that should be used. When --multi-sp-aware
is not used
SICStusDISPATCHVAR
expands to sp_GlobalSICStus
as
described above. When using --multi-sp-aware
it is
probably best to let SICStusDISPATCHVAR
expand to a local
variable.
SP_load_sicstus_run_time()
to
load additional run-times.
SICSTUS_API_STRUCT_TYPE *SP_get_dispatch(void *reserved);
SP_get_dispatch()
returns the dispatch vector of the SICStus
run-time. The argument reserved
should be NULL
. This
function can be called from any thread.
typedef SICSTUS_API_STRUCT_TYPE *SP_get_dispatch_type(void *); int SP_load_sicstus_run_time(SP_get_dispatch_type **ppfunc, void **phandle);
SP_load_sicstus_run_time()
loads a new SICStus
run-time. SP_load_sicstus_run_time()
returns zero if a new
run-time could not be loaded. If a new run-time could be loaded a
non-zero value is returned and the address of the
SP_get_dispatch()
function of the newly loaded SICStus run-time
is stored at the address ppfunc
. The second argument,
phandle
, is reserved and should be NULL
.
As a special case, if SP_load_sicstus_run_time()
is called from a
SICStus run-time that has not been initialized (with
SP_initialize()
) and that has not previously been loaded as the
result of calling SP_load_sicstus_run_time()
, then no new run-time
is loaded. Instead, the SP_get_dispatch()
of the run-time itself is
returned. In particular, the first time SP_load_sicstus_run_time()
is called on the initial SICStus run-time, and if this happens before
the initial SICStus run-time is initialized, then no new run-time is
loaded.
Calling SP_load_sicstus_run_time()
from a particular run-time can
be done from any thread.
An application that links statically with the SICStus run-time should
not call SP_load_sicstus_run_time()
.
You should not use pre-linked foreign resources when using multiple SICStus run-times in the same process.
For an example of loading and using multiple SICStus run-times, see
library/jasper/spnative.c
that implements this functionality for
the Java interface Jasper.