xaliphostes/README.md

## README.md

      
    Raw
  

              README.md
            
          
    A small multi-threaded C++ library (so, does not include any main) compiled with emscripten and pthread running under the main thread in the browser, a web worker or using node.js.
Note: Emscripten will produce lib.js.
Using a web browser

Running this lib in the main thread is fine but, obviously, block the main thread.
Running it using a web worker leads no error with modification of the worker script (see below)
Using node.js

Run fine except that it prevents Node app from ever exiting.

  
## compile.sh
#!/bin/bash

emcc -std=c++17 \
  -O3 --bind \
  -s SINGLE_FILE=1 \
  -s PTHREAD_POOL_SIZE=4 \
  -s USE_PTHREADS=1 \
  -s ASSERTIONS=1 \
  -s EXPORT_NAME=LibModule \
  -s WASM=1 \
  -s MODULARIZE=1 \
  -s ALLOW_MEMORY_GROWTH=1 \
  -o lib.js \
  main.cxx

## index.html
<!DOCTYPE html>
<html>
    <title>pthread test</title>
    <head>
        <style>
            .styled:hover {
                background-color: rgb(140, 139, 139);
            }

        </style>
    </head>
    <body>
        <button class="favorite styled" type="button" onclick="runMain('thread')">Main thread</button>
        <button class="favorite styled" type="button" onclick="runMain('serial')">Main serial</button><br><br>
        <button class="favorite styled" type="button" onclick="runWorker('thread')">Worker thread</button>
        <button class="favorite styled" type="button" onclick="runWorker('serial')">Worker Serial</button>
        <script src="lib.js"></script>
        <script>
            function runWorker(method) {
                const worker = new Worker('./worker.js')
                worker.onmessage = e => console.log(e)
                worker.postMessage(method)
            }

            function runMain(method) {
                LibModule().then( lib => {
                    const a = performance.now()
                    method === 'thread' ? lib.thread() : lib.serial() ;
                    console.log( `${method} done in ${(performance.now()-a)}ms` )
                })
            }
        </script>
    </body>
</html>

## main.cxx
#include <string>
#include <thread>
#include <future>
#include <iostream>
#include <vector>

#include <emscripten/bind.h>
using namespace emscripten ;


std::vector<int> s = {40000, 40000, 40000, 40000} ;

void longCompute(int id, int iterations) {
    double val = 0 ;
    for (int i=0; i<10000; ++i) {
        for (int j=0; j<iterations; ++j) {
            val += 3.1415 ;
        }
    }
    std::cout << "thread " << (id) << ": " << val << std::endl ;
}

void testThread() {
    std::cout << "Using std::thread" << std::endl ;
    std::vector<std::thread> threads ;
    for (int i = 0; i < s.size(); i++) {
        threads.push_back( std::thread(longCompute, i, s[i]) ) ;
    }
    std::cerr << "start threads"<< std::endl ;
    for (auto &th : threads) {
        th.join() ;
    }
    std::cerr << "end threads"<< std::endl ;
}

void testSerial() {
    std::cout << "Using serial" << std::endl ;
    for (int i = 0; i < s.size(); i++) {
        longCompute(i, s[i]) ;
    }
    std::cerr << "end serial"<< std::endl ;
}

// ------------------------------
// Only expose 2 functions in js
// ------------------------------
EMSCRIPTEN_BINDINGS(test) {
    function("thread", &testThread) ;
    function("serial", &testSerial) ;
}

## run-node.sh
#!/bin/bash

# Make sure node version is greater than 15.1.0
ver="$(node --version)"
ver=${ver:1} # remove the prefix 'v'
major="$(cut -d '.' -f 1 <<< "$ver")"
minor="$(cut -d '.' -f 2 <<< "$ver")"

if [ $major -ge 15 ] && [ $minor -ge 1 ]; then
    node --experimental-wasm-threads script.js
else
    echo "Cannot run node. Require version 15.1.0 or greater"
fi

## script.js
// ----------------------------------------
// To be used with node.js
// ----------------------------------------

const LibModule = require('./lib')

function runMain(method) {
    LibModule().then( lib => {
        const a = performance.now()
        method === 'thread' ? lib.thread() : lib.serial() ;
        console.log( `${method} done in ${(performance.now()-a)}ms` )
    })
}

runMain('thread')
runMain('serial')

## worker.js
// ----------------------------------------
// Used with index.html
// ----------------------------------------

importScripts("lib.js")

onmessage = e => {
    const Lib = {
        locateFile: (file) => file,
        onRuntimeInitialized: () => {
            const a = performance.now()
            e.data === 'thread' ? Lib.thread() : Lib.serial() ;
            console.log( `${e.data} done in ${(performance.now()-a)}ms` )
        },
        mainScriptUrlOrBlob: "lib.js",
    };

    // LibModule is the name of the exported library with emscripten
    LibModule(Lib)
}


// Was previously (loading of the worker not working)
/*
importScripts("lib.js")

onmessage = e => {
    LibModule().then( lib => {
        const a = performance.now()
        e.data === 'thread' ? lib.thread() : lib.serial() ;
        console.log( `${e.data} done in ${(performance.now()-a)}ms` )
    })
}
*/
	#!/bin/bash

	emcc -std=c++17 \
	-O3 --bind \
	-s SINGLE_FILE=1 \
	-s PTHREAD_POOL_SIZE=4 \
	-s USE_PTHREADS=1 \
	-s ASSERTIONS=1 \
	-s EXPORT_NAME=LibModule \
	-s WASM=1 \
	-s MODULARIZE=1 \
	-s ALLOW_MEMORY_GROWTH=1 \
	-o lib.js \
	main.cxx
	<!DOCTYPE html>
	<html>
	<title>pthread test</title>
	<head>
	<style>
	.styled:hover {
	background-color: rgb(140, 139, 139);
	}

	</style>
	</head>
	<body>
	<button class="favorite styled" type="button" onclick="runMain('thread')">Main thread</button>
	<button class="favorite styled" type="button" onclick="runMain('serial')">Main serial</button><br><br>
	<button class="favorite styled" type="button" onclick="runWorker('thread')">Worker thread</button>
	<button class="favorite styled" type="button" onclick="runWorker('serial')">Worker Serial</button>
	<script src="lib.js"></script>
	<script>
	function runWorker(method) {
	const worker = new Worker('./worker.js')
	worker.onmessage = e => console.log(e)
	worker.postMessage(method)
	}

	function runMain(method) {
	LibModule().then( lib => {
	const a = performance.now()
	method === 'thread' ? lib.thread() : lib.serial() ;
	console.log( `${method} done in ${(performance.now()-a)}ms` )
	})
	}
	</script>
	</body>
	</html>
	#include <string>
	#include <thread>
	#include <future>
	#include <iostream>
	#include <vector>

	#include <emscripten/bind.h>
	using namespace emscripten ;


	std::vector<int> s = {40000, 40000, 40000, 40000} ;

	void longCompute(int id, int iterations) {
	double val = 0 ;
	for (int i=0; i<10000; ++i) {
	for (int j=0; j<iterations; ++j) {
	val += 3.1415 ;
	}
	}
	std::cout << "thread " << (id) << ": " << val << std::endl ;
	}

	void testThread() {
	std::cout << "Using std::thread" << std::endl ;
	std::vector<std::thread> threads ;
	for (int i = 0; i < s.size(); i++) {
	threads.push_back( std::thread(longCompute, i, s[i]) ) ;
	}
	std::cerr << "start threads"<< std::endl ;
	for (auto &th : threads) {
	th.join() ;
	}
	std::cerr << "end threads"<< std::endl ;
	}

	void testSerial() {
	std::cout << "Using serial" << std::endl ;
	for (int i = 0; i < s.size(); i++) {
	longCompute(i, s[i]) ;
	}
	std::cerr << "end serial"<< std::endl ;
	}

	// ------------------------------
	// Only expose 2 functions in js
	// ------------------------------
	EMSCRIPTEN_BINDINGS(test) {
	function("thread", &testThread) ;
	function("serial", &testSerial) ;
	}
	#!/bin/bash

	# Make sure node version is greater than 15.1.0
	ver="$(node --version)"
	ver=${ver:1} # remove the prefix 'v'
	major="$(cut -d '.' -f 1 <<< "$ver")"
	minor="$(cut -d '.' -f 2 <<< "$ver")"

	if [ $major -ge 15 ] && [ $minor -ge 1 ]; then
	node --experimental-wasm-threads script.js
	else
	echo "Cannot run node. Require version 15.1.0 or greater"
	fi
	// ----------------------------------------
	// To be used with node.js
	// ----------------------------------------

	const LibModule = require('./lib')

	function runMain(method) {
	LibModule().then( lib => {
	const a = performance.now()
	method === 'thread' ? lib.thread() : lib.serial() ;
	console.log( `${method} done in ${(performance.now()-a)}ms` )
	})
	}

	runMain('thread')
	runMain('serial')
	// ----------------------------------------
	// Used with index.html
	// ----------------------------------------

	importScripts("lib.js")

	onmessage = e => {
	const Lib = {
	locateFile: (file) => file,
	onRuntimeInitialized: () => {
	const a = performance.now()
	e.data === 'thread' ? Lib.thread() : Lib.serial() ;
	console.log( `${e.data} done in ${(performance.now()-a)}ms` )
	},
	mainScriptUrlOrBlob: "lib.js",
	};

	// LibModule is the name of the exported library with emscripten
	LibModule(Lib)
	}


	// Was previously (loading of the worker not working)
	/*
	importScripts("lib.js")

	onmessage = e => {
	LibModule().then( lib => {
	const a = performance.now()
	e.data === 'thread' ? lib.thread() : lib.serial() ;
	console.log( `${e.data} done in ${(performance.now()-a)}ms` )
	})
	}
	*/