gen-thread/index.js

103 lines
2.4 KiB
JavaScript

module.exports.run = runThread;
module.exports.runParallel = runParallel;
var q = [];
var pending = [];
function finishq()
{
for (var i = 0; i < q.length; i++)
{
if (q[i]._done)
{
q.splice(i, 1);
i--;
}
}
while (pending.length > 0 && q.length < pending[0][2])
{
var t = pending.shift();
q.push(t[0]);
process.nextTick(t[1]);
}
}
var tid = 0;
function runThread(main, arg, done)
{
var thread = function()
{
// pass parameters as yield result
var pass = Array.prototype.slice.call(arguments, 0);
var v;
try
{
v = thread.gen.next(pass);
}
catch (e)
{
v = { done: 1, error: e };
}
if (v.done)
{
thread._done = true;
process.nextTick(finishq);
}
if (v.error)
throw v.error;
if (v.done && done)
done(v.value);
};
thread.id = tid++;
thread.gen = main(thread, arg);
thread.throttle = function(count)
{
finishq();
if (q.length < count)
{
q.push(thread);
process.nextTick(thread.cb());
}
else
{
pending.push([ thread, thread.cb(), count ]);
}
};
thread.cb = function()
{
var fn = function()
{
if (thread._current != fn)
{
throw new Error('Broken control flow! Callback'+
thread._current._stack.replace(/^\s*Error\s*at Function\.thread\.cb\s*\([^)]*\)/, '')+
'\nmust be called to resume thread, but this one is called instead:'+
fn._stack.replace(/^\s*Error\s*at Function\.thread\.cb\s*\([^)]*\)/, '')+'\n--'
);
}
return thread.apply(thread, arguments);
};
fn._stack = new Error().stack;
thread._current = fn;
return fn;
};
thread();
}
function runParallel(threads, done)
{
var results = [];
var resultCount = 0;
var allDone = function(i, result)
{
if (!results[i])
{
results[i] = result;
resultCount++;
if (resultCount == threads.length)
done(results);
}
};
threads.map((t, i) => runThread(t, null, function(result) { allDone(i, result); }));
}