Native Image C API
Native Image provides a GraalVM-specific API to manage Java objects from the C/C++ languages, initialize isolates and attach threads. The C API is available when Native Image is built as a shared library and its declarations are included in the header file that is generated during the native image build.
/* * Structure representing an isolate. A pointer to such a structure can be * passed to an entry point as the execution context. */ struct __graal_isolate_t; typedef struct _graal_isolate_t graal_isolate_t; /* * Structure representing a thread that is attached to an isolate. A pointer to * such a structure can be passed to an entry point as the execution context, * requiring that the calling thread has been attached to that isolate. */ struct __graal_isolatethread_t; typedef struct __graal_isolatethread_t graal_isolatethread_t; /* Parameters for the creation of a new isolate. */ struct __graal_create_isolate_params_t { /* for future use */ }; typedef struct __graal_create_isolate_params_t graal_create_isolate_params_t; /* * Create a new isolate, considering the passed parameters (which may be NULL). * Returns 0 on success, or a non-zero value on failure. * On success, the current thread is attached to the created isolate, and the * address of the isolate and the isolate thread structures is written to the * passed pointers if they are not NULL. */ int graal_create_isolate(graal_create_isolate_params_t* params, graal_isolate_t** isolate, graal_isolatethread_t** thread); /* * Attaches the current thread to the passed isolate. * On failure, returns a non-zero value. On success, writes the address of the * created isolate thread structure to the passed pointer and returns 0. * If the thread has already been attached, the call succeeds and also provides * the thread's isolate thread structure. */ int graal_attach_thread(graal_isolate_t* isolate, graal_isolatethread_t** thread); /* * Given an isolate to which the current thread is attached, returns the address of * the thread's associated isolate thread structure. If the current thread is not * attached to the passed isolate or if another error occurs, returns NULL. */ graal_isolatethread_t* graal_get_current_thread(graal_isolate_t* isolate); /* * Given an isolate thread structure, determines to which isolate it belongs and * returns the address of its isolate structure. If an error occurs, returns NULL * instead. */ graal_isolate_t* graal_get_isolate(graal_isolatethread_t* thread); /* * Detaches the passed isolate thread from its isolate and discards any state or * context that is associated with it. At the time of the call, no code may still * be executing in the isolate thread's context. * Returns 0 on success, or a non-zero value on failure. */ int graal_detach_thread(graal_isolatethread_t* thread); /* * Tears down the isolate of the passed (and still attached) isolate thread * waiting for any attached threads to detach from it, then discards its objects, * threads, and any other state or context that is associated with it. * Returns 0 on success, or a non-zero value on failure. */ int graal_tear_down_isolate(graal_isolatethread_t* thread); In addition to the C level API, you can use the JNI Invocation API to create an isolate from Java, expose and call Java methods embedded in a native shared library.