dll could not be initialized in module.js

[RichardFoss]

Hi,

I am using node v6.11.0 together with nw.js. I have installed cap successfully, and am now wanting to use it to send AVDECC ethernet packets. When I try to initialize with c = new Cap(); I get an error message indicating that a dll cannot be initialized in module.js.

I have used cap successfully on the Mac and am now porting the same code to Windows. I have Visual Studio 2015 enterprise edition installed.

Any idea what might be causing this run time message?

Thanks!

[RichardFoss]

To be more explicit with the error message, it is:
Uncaught error: A dynamic link library (DLL) initialization routine failed module.js :640

[RichardFoss]

Sorry, didn't mean to close this!!

[mscdex]

Sorry, I don't really have any experience with compiling addons for use with nw.js.

[RichardFoss]

Thanks for the quick reply - I will see if I can initialize cap under Windows just from node.js. I didn't think that nw.js would be the problem. I used nw.js with cap on the Mac and it worked fine.

[mscdex]

IIRC nw.js has its own special method of compiling addons (using nw-gyp) in order to properly integrate with its bundled chrome/chromium (V8 really).

Using cap directly with node on Windows should definitely work fine though.

[RichardFoss]

This all makes sense. I will try node and cap tomorrow. Thanks for the help!

[RichardFoss]

Using cap directly with node on Windows does indeed take me beyond the 'require' statement where my error occurred. I do need the nw capabilities, and have posted the following on the nw.js site:

I have been successfully using the module cap in an osx node/nw program to receive and transmit Ethernet packets. I am porting the program to Windows, and have an issue with the cap module.

I am using node.js v6.11.0 and nw.js v0.23.5. Windows 8.1.

A problem arises at the statement:
var Cap = require('cap').Cap;
Where I get the following output:

module.js:640 Uncaught Error: A dynamic link library (DLL) initialization routine failed.
\?\D:\AVBFlexSDK\node_modules\cap\build\Release\cap.node
at Object.Module._extensions..node (module.js:640:18)
at Module.load (module.js:527:32)
at tryModuleLoad (module.js:490:12)
at Function.Module._load (module.js:482:3)
at Module.require (module.js:537:17)
at require (internal/module.js:11:18)
at Object. (D:\AVBFlexSDK\node_modules\cap\lib\Cap.js:3:13)
at Module._compile (module.js:593:30)
at Object.Module._extensions..js (module.js:610:10)
at Module.load (module.js:527:32)

The statement is not a problem within a node.js program, and the cap module installs fine (Python 2.7 and Visual C++ installed). I have done the following to resolve the issue:

1. Given that I am using an LTS release, I first replaced the win_delay_load_hook.cc file with the one given on the nw.js documentation page. The require statement resulted in the same error message.
2. I then followed the procedure for the non-LTS releases:
   set PYTHON=C:\Python27\python.exe
   set npm_config_target=0.23.5
   set npm_config_arch=x64
   set npm_config_runtime=node-webkit
   set npm_config_build_from_source=true
   set npm_config_node_gyp=C:\Users<my info>\AppData\Roaming\npm\node_modules
   Still the same result - an error at the require statement.

Possibly someone in this group has had a similar experience and resolved it - which would be wonderful!

[robsontenorio]

@RichardFoss Its just about "prebuild" the target package "cap" (https://www.npmjs.com/package/prebuild).
I use Electron, so "prebuild" provide a way to compile the package to the target OS/arch. You need to find some similar tool on NW.JS.

So, that issue has nothing to do with "cap", but the way packages are compiled to the target OS.

[RichardFoss]

Thanks robsontenorio! I managed to resolve my issue and have meant to post my solution to the group in case anyone else has a similar dilemma. The steps I took are given below. Step d is the "similar tool" that you are referring to.

For native node modules (for example cap), you will:
a. First need to install all the required tools and configurations. To do this, you could use Microsoft's windows-build-tools using:
npm install --global --production windows-build-tools
from an elevated PowerShell or CMD.exe (run as Administrator). This will install Visual Studio and also Python 2.7.
b. On Windows, you need to replace the file
\node_modules\node-gyp\src\win_delay_load_hook.cc
with the one at
https://github.com/nwjs/nw.js/blob/nw18/tools/win_delay_load_hook.cc
before installing modules with node-gyp or npm.
c. Run the following command in your terminal to install nw-gyp globally:
npm install -g nw-gyp
d. If for example, cap is the native module, then in the node_modules/cap folder, run
nw-gyp rebuild --target=0.23.5(or whatever your version of nw.js is)
e. In your native module documentation, look for any programming guidelines that are unique to Windows. For example in cap:
setMinBytes(< integer >nBytes) - (void) - (Windows ONLY) This sets the minimum number of packet bytes that must be captured before the full packet data is made available.

[mscdex]

Thanks for the information @robsontenorio and @RichardFoss