coffi.ffi

Functions for creating handles to native functions and loading native libraries.

cfn

(cfn symbol args ret)

Constructs a Clojure function to call the native function referenced by symbol.

The function returned will serialize any passed arguments into the args types, and deserialize the return to the ret type.

If your args and ret are constants, then it is more efficient to call make-downcall followed by make-serde-wrapper because the latter has an inline definition which will result in less overhead from serdes.

const

(const symbol-or-addr type)

Gets the value of a constant stored in symbol-or-addr.

defcfn

macro

(defcfn name docstring? attr-map? symbol arg-types ret-type)(defcfn name docstring? attr-map? symbol arg-types ret-type native-fn & fn-tail)

Defines a Clojure function which maps to a native function.

name is the symbol naming the resulting var. symbol is a symbol or string naming the library symbol to link against. arg-types is a vector of qualified keywords representing the argument types. ret-type is a single qualified keyword representing the return type. fn-tail is the body of the function (potentially with multiple arities) which wraps the native one. Inside the function, native-fn is bound to a function that will serialize its arguments, call the native function, and deserialize its return type. If any body is present, you must call this function in order to call the native code.

If no fn-tail is provided, then the resulting function will simply serialize the arguments according to arg-types, call the native function, and deserialize the return value.

The number of args in the fn-tail need not match the number of arg-types for the native function. It need only call the native wrapper function with the correct arguments.

See serialize, deserialize, make-downcall.

defconst

macro

(defconst symbol docstring? symbol-or-addr type)

Defines a var named by symbol to be the value of the given type from symbol-or-addr.

defvar

macro

(defvar symbol docstring? symbol-or-addr type)

Defines a var named by symbol to be a reference to the native memory from symbol-or-addr.

ensure-symbol

(ensure-symbol symbol-or-addr)

Returns the argument if it is a MemorySegment, otherwise calls find-symbol on it.

find-symbol

(find-symbol sym)

Gets the MemorySegment of a symbol from the loaded libraries.

freset!

(freset! static-var newval)

Sets the value of static-var to newval, running it through serialize.

fswap!

(fswap! static-var f & args)

Non-atomically runs the function f over the value stored in static-var.

The value is deserialized before passing it to f, and serialized before putting the value into static-var.

load-library

(load-library path)

Loads the library at path.

load-system-library

(load-system-library libname)

Loads the library named libname from the system’s load path.

make-downcall

(make-downcall symbol-or-addr args ret)

Constructs a downcall function reference to symbol-or-addr with the given args and ret types.

The function returned takes only arguments whose types match exactly the java-layout for that type, and returns an argument with exactly the java-layout of the ret type. This function will perform no serialization or deserialization of arguments or the return type.

If the ret type is non-primitive, then the returned function will take a first argument of a SegmentAllocator.

make-serde-varargs-wrapper

(make-serde-varargs-wrapper varargs-factory required-args ret-type)

Constructs a wrapper function for the varargs-factory which produces functions that serialize the arguments and deserialize the return value.

make-serde-wrapper

(make-serde-wrapper downcall arg-types ret-type)

Constructs a wrapper function for the downcall which serializes the arguments and deserializes the return value.

make-varargs-factory

(make-varargs-factory symbol required-args ret)

Returns a function for constructing downcalls with additional types for arguments.

The required-args are the types of the first arguments passed to the downcall handle, and the values passed to the returned function are only the varargs types.

The returned function is memoized, so that only one downcall function will be generated per combination of argument types.

See make-downcall.

reify-libspec

(reify-libspec libspec)

Loads all the symbols specified in the libspec.

The value of each key of the passed map is transformed as by reify-symbolspec.

reify-symbolspec

multimethod

Takes a spec for a symbol reference and returns a live value for that type.

static-variable

(static-variable symbol-or-addr type)

Constructs a reference to a mutable value stored in symbol-or-addr.

The returned value can be dereferenced, and has metadata.

See freset!, fswap!.

static-variable-segment

(static-variable-segment static-var)

Gets the backing MemorySegment from static-var.

This is primarily useful when you need to pass the static variable’s address to a native function which takes an Addressable.

vacfn-factory

(vacfn-factory symbol required-args ret)

Constructs a varargs factory to call the native function referenced by symbol.

The function returned takes any number of type arguments and returns a specialized Clojure function for calling the native function with those arguments.