callCIF: Dynamically invoke a compiled routine

In omegahat/Rffi: Interface to libffi to dynamically invoke arbitrary compiled routines at run-time without compiled bindings

Dynamically invoke a compiled routine

Description

This function takes a CIF to invoke a compiled routine with a given signature and applies it to invoke a specific routine with that signature. The R inputs are converted to the appropriate types and the result returned as an R object.

Usage

callCIF(cif, sym, ...,
        returnInputs = is(cif, "CIFWithMutableInputs") || any(cif@pointerParameters),
        .args = list(...))

Arguments

cif	the previously prepared template CIF for the given signature
sym	an identifier for the compiled routine to be called. This can be a string giving the name or, preferably, an object returned from a call to getNativeSymbolInfo which allows us to specify the routine by name and containing loaded library/shared object (dll/so). One can also specify the address of the routine as an external pointer, again typically obtained via getNativeSymbolInfo.
...	zero or more R objects that are passed as the inputs to the compiled routine, having been converted to the appropriate native types.
returnInputs	a logical value that indicates whether the function should return just the value returned by the compiled routine or also any inputs that may have been modified by the routine, i.e. parameters that are pointers.
.args	the list of the individual arguments in the call to the routine. This can be a convenient way to pass them when they are already grouped into a single object rather than being specificied individually in the call via the ....

Details

The invocation checks that the number of arguments matches the number expected by the CIF. It also performs the conversion as necessary.

Value

The function returns the value from the compiled routine, having converted to an appropriate R type.

Author(s)

Duncan Temple Lang

References

http://sourceware.org/libffi/

See Also

CIF

Examples

 void = CIF(voidType)
 callCIF(void, "voidCall")

 cif = CIF(doubleType, list(sint32Type, doubleType))
 callCIF(cif, "foo", -1L, pi)

   # use this CIF in another call.
 callCIF(cif, "foo", 10L, pi)

   # and call a different routine with the same signature
 callCIF(cif, "otherFoo", 10L, pi)

   # getting a string
 cif = CIF(stringType)
 ans = callCIF(cif, "retString")
 print(ans)

omegahat/Rffi documentation built on Nov. 29, 2023, 12:48 a.m.