ems-typed
Version:
Persistent Shared Memory and Parallel Programming Model
164 lines (149 loc) • 7.56 kB
JavaScript
/*-----------------------------------------------------------------------------+
| Extended Memory Semantics (EMS) Version 1.4.5 |
| Synthetic Semantics http://www.synsem.com/ mogill@synsem.com |
+-----------------------------------------------------------------------------+
| Copyright (c) 2011-2014, Synthetic Semantics LLC. All rights reserved. |
| Copyright (c) 2015-2017, Jace A Mogill. All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| * Neither the name of the Synthetic Semantics nor the names of its |
| contributors may be used to endorse or promote products derived |
| from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SYNTHETIC |
| SEMANTICS LLC BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
+-----------------------------------------------------------------------------*/
;
var ems = require('ems')(1, false, 'user');
var http = require('http');
var url_module = require("url");
var cluster = require('cluster');
var port = 8080;
var shared_counters;
var persistent_data;
var myID;
var persistent_data_options = {
dimensions: [100000],
heapSize: [10000000],
useExisting: false,
useMap: true,
filename: '/tmp/persistent_shared_web_data.ems'
};
var shared_counters_options = {
dimensions: [100],
heapSize: [10000],
useExisting: false,
useMap: true,
filename: '/tmp/counters.ems'
};
function handleRequest(request, response) {
var requestN = shared_counters.faa('nRequests', 1); // Increment the count of requests
var parsed_request = url_module.parse(request.url, true);
var key = Object.keys(parsed_request.query)[0];
var value = parsed_request.query[key];
if (value === '') { value = undefined; }
var data;
var opname;
if (!key) {
response.end("ERROR: No key specified in request");
return;
}
if (parsed_request.pathname.indexOf("/readFE") >= 0) {
data = persistent_data.readFE(key);
opname = 'readFE';
} else if (parsed_request.pathname.indexOf("/readFF") >= 0) {
data = persistent_data.readFF(key);
opname = 'readFF';
} else if (parsed_request.pathname.indexOf("/read") >= 0) {
data = persistent_data.read(key);
opname = 'read';
} else if (parsed_request.pathname.indexOf("/writeXE") >= 0) {
data = persistent_data.writeXE(key, value);
opname = 'writeXE';
} else if (parsed_request.pathname.indexOf("/writeXF") >= 0) {
data = persistent_data.writeXF(key, value);
opname = 'writeXF';
} else if (parsed_request.pathname.indexOf("/writeEF") >= 0) {
data = persistent_data.writeEF(key, value);
opname = 'writeEF';
} else if (parsed_request.pathname.indexOf("/write") >= 0) {
data = persistent_data.write(key, value);
opname = 'write';
} else if (parsed_request.pathname.indexOf("/faa") >= 0) {
data = persistent_data.faa(key, value);
opname = 'faa';
} else if (parsed_request.pathname.indexOf("/cas") >= 0) {
opname = 'cas';
var old_new_vals = value.split(',');
if (old_new_vals[0] === '') { old_new_vals[0] = undefined; }
if (old_new_vals[1] === '') { old_new_vals[1] = undefined; }
data = persistent_data.cas(key, old_new_vals[0], old_new_vals[1]);
} else {
data = "ERROR: No EMS command specified.";
}
var datastr = JSON.stringify(data);
console.log("Request #" + requestN + ", slave process " + myID + ": Op(" +
opname + ") key(" + key + ") val(" + value + ") data=" + datastr);
response.end(datastr);
}
if (cluster.isMaster) {
/* The Master Process creates the EMS arrays that the slave processes
* will attach to before creating the slave processes. This prevents
* parallel hazards if all slaves tried creating the EMS arrays.
*/
persistent_data_options.setFEtags = 'empty';
persistent_data_options.doSetFEtags = true;
persistent_data = ems.new(persistent_data_options);
shared_counters_options.dataFill = 0;
shared_counters_options.doDataFill = true;
shared_counters_options.setFEtags = 'full';
shared_counters_options.doSetFEtags = true;
shared_counters = ems.new(shared_counters_options);
// Seed the GUID generator with a unique starting value
shared_counters.writeXF('GUID', Math.floor(Math.random() * 10000000));
// All the one-time initialization is complete, now start slave processes.
// The number of processes is the limit of the number of pending requests
// before deadlock occurs.
var nProcesses = Number(process.argv[2]) || 8; // Number of "cluster" processes to start
for (var procnum = 0; procnum < nProcesses; procnum++) {
cluster.fork();
}
console.log(
"REST API: <EMSCommand>?key[=value]\n" +
" EMSCommand: read, readFE, readFF, writeXE, writeXF, writeEF, faa, cas\n" +
" key: The index into the EMS array, must be a valid JSON element\n" +
" value: For write commands, the value stored in EMS.\n" +
" For CAS, the value is the old and new values separated by a comma:\n" +
" /cas?key=oldval,newval\n");
cluster.on('exit', function (worker, code, signal) {
console.log("worker " + worker.process.pid + "died");
});
} else {
/* Each Slave Cluster processes must connect to the EMS array created
* by the master process.
*/
persistent_data_options.useExisting = true;
persistent_data = ems.new(persistent_data_options);
shared_counters_options.useExisting = true;
shared_counters = ems.new(shared_counters_options);
myID = shared_counters.faa('myID', 1);
http.createServer(handleRequest).listen(port, function () {
console.log("Server " + myID + " listening on: http://localhost:" + port);
});
}