#include "rJava.h"

#ifdef ENABLE_JRICB

#include <R_ext/eventloop.h>

#include <unistd.h>

#include "callback.h"

int RJava_has_control = 0;

/* ipcin -> receives requests on R thread

ipcout <- write to place requests to main R thread

resout <- written by main thread to respond

resin -> read to get info from main thread */

static int ipcin, ipcout, resin, resout;

static struct rJavaInfoBlock_s {

int ipcin, ipcout, resin, resout;

int *has_control;

} rJavaInfoBlock;

struct rJavaInfoBlock_s *RJava_get_info_block() {

return &rJavaInfoBlock;

}

typedef void(callbackfn)(void*);

static void RJava_ProcessEvents(void *data) {

long buf[4];

int n = read(ipcin, buf, sizeof(long));

if (buf[0] == IPCC_LOCK_REQUEST) {

RJava_has_control = 1;

buf[0] = IPCC_LOCK_GRANTED;

write(resout, buf, sizeof(long));

n = read(ipcin, buf, sizeof(long));

}

if (buf[0] == IPCC_CLEAR_LOCK) {

RJava_has_control = 0;

}

if (buf[0] == IPCC_CONTROL_ADDR) {

buf[1] = (long) (void*) &RJava_has_control;

write(resout, buf, sizeof(long)*2);

}

if (buf[0] == IPCC_CALL_REQUEST) {

callbackfn *fn;

read(ipcin, buf+1, sizeof(long)*2);

fn = (callbackfn*) buf[1];

RJava_has_control = 1;

fn((void*) buf[2]);

RJava_has_control = 0;

}

}

int RJava_init_loop() {

int pfd[2];

pipe(pfd);

ipcin = pfd[0];

ipcout = pfd[1];

pipe(pfd);

resin = pfd[0];

resout = pfd[1];

rJavaInfoBlock.ipcin = ipcin;

rJavaInfoBlock.ipcout = ipcout;

rJavaInfoBlock.resin = resin;

rJavaInfoBlock.resout = resout;

rJavaInfoBlock.has_control = &RJava_has_control;

addInputHandler(R_InputHandlers, ipcin, RJava_ProcessEvents, RJavaActivity);

return 0;

}

#endif