I'm trying to call a function in NodeJS that was returned as a pointer by a function called via ffi. I'm getting segmentation fault. What am I doing wrong?
The ffi imported function gets a pointer to char as argument (that informs to what function the returned pointer should point to) and then return a pointer to void. In ffi.Library declaration, I've tried many return types, I.E.: ref.types.void; ref.reftype(ref.types.void) and now I'm using ref.refType(getDevList), that is the type of my function.
C Function:
void *GetFunctionAddress(const char* fctName)
{
void *address;
...
return address;
}
NodeJS code:
var ffi = require('ffi');
var Gateway;
var DeviceList = StructType({
deviceNumber: ref.types.uint16,
})
DeviceList.defineProperty('device',
ArrayType(ref.refType(DeviceList)))
var deviceListPtr = ref.refType(DeviceList);
var getDevList = ffi.Function(deviceListPtr, []);
Gateway = ffi.Library('./GatewayManager.so', {
'InitializeGateway': ['bool',['void']],
'ReloadConfig' : ['void',['void']],
'ReadPar' : ['uint',['uint','uint','uint', dwordType]],
'WritePar' : ['uint',['uint','uint','uint', dwordType]],
'GetDatablockAddress' : [wordType,['uint','uint','uint']],
'GetFunctionAddress' : [ref.refType(getDevList),['char *']]
});
var retPtr =
Gateway.GetFunctionAddress(ref.allocCString('GetDevList'));
var GetDevList = retPtr.deref();
var DeviceListPtr = GetDevList();
res.send(DeviceListPtr);
console.log(DeviceListPtr);
I'm getting segmentation fault when the following line is in code:
var DeviceListPtr = GetDevList();
You do not need ref.refType() in the following line:
'GetFunctionAddress' : [ref.refType(getDevList),['char *']]
Change it to:
'GetFunctionAddress' : [getDevList,['char *']]
It should work.
Collected from the Internet
Please contact [email protected] to delete if infringement.
Comments