javascript - Single Threaded Event Loop vs Multi Threaded Non Blocking Worker in Node.JS -


node.js biggest advantage it's non blocking nature. it's single threaded, doesn't need spawn new thread each new incoming connection.

behind event-loop (which in fact single threaded), there "non blocking worker". thing not single threaded anymore, (as far understood) can spawn new thread each task.

maybe misunderstood something, advantage. if there many tasks handle, wouldn't non blocking working turn blocking worker?

thanks christian

you need read libuv, "magic" behind node's non-blocking i/o.

the important thing take away libuv book libuv uses host os's asynchronous i/o facilities; it not create new thread every connection.

libuv tells os know changes (connection state, data received, etc) happen on particular set of sockets. os deal managing connections. os may create 1 or more threads accomplish that, that's not our concern. (and won't create thread every connection.)

for other types of operations calls c libraries may computationally expensive (ie crypto), libuv provides thread pool on operations may run. since thread pool, again don't have worry thread count growing without bound. when pool busy, operations queued.

so yes, javascript runs on single thread. yes, node (via libuv) spawns many threads in background work need not block javascript thread. however, thread count controlled, , i/o doesn't own node-allocated thread because that's handled os.


-

Comments

Post a Comment

Popular posts from this blog

html - Sizing a high-res image (~8MB) to display entirely in a small div (circular, diameter 100px) -

first of all, thank being patient know simple question more couple of weeks' experience figure out. i've seen folks persevere , helpful on here , hope you're willing me. here fiddle: http://jsfiddle.net/65uzf/ here 1 of places searched answers on here: ( vertically center image thumbnails fix-sized div ) tried solutions on there , didn't work out me. i've searched ~4 or 5 others, , been unsuccessful those, too. what want take large image (what linked background-image #ysypic , #tabpic divs) , display thumbnail version of image in confines of divs have set it. is, using background properties have laid out in css, portion of image displays inside of circular divs. without these properties, display defaults smaller section of image [presumably pi*(50^2) area in top left] terrible resolution. i not care if entire image doesn't display inside of circles (it won't, given difference in shape), , overflow not being displayed fine. want able see figu
Read more

java - IntelliJ - No such instance method -

using intellij's 12 ultimate, i'm running following code in debugger: java import play.api.libs.json.jsvalue; public class foo { ... public jsvalue tojson() { ... } public class fooexample { ... foo foo = new foo(); system.out.println("...); //<-- breakpoint at breakpoint, right-clicked source code , picked "evaluate expression," typing in: foo.tojson() . but following error showed up: no such instance method: play.api.libs.json.jsvalue$class.com.foo.foo.tojson () am doing wrong? foo#tojson calls scala code, if matters. edit had breakpoint after instantiation of foo. downvoted it, deserved it. edit my answer no longer valid after op modified question (i.e. moved breakpoint actual is).. a breakpoint hit before line executed. in case foo has not yet been declared or instantiated (i.e. foo constructor has not yet been called). you'll need put breakpoint @ next line (or step on current line) if want evaluate foo .
Read more

identifier - Is it possible for an html5 document to have two ids? -

i wondering if html5 element can have 2 ids, this: <button id="thing1" id="thing2" name="button1" onclick="change()">click here</button> or this: <button id="thing1, thing2" name="button1" onclick="change()">click here</button> also, if 1 of ids said 1 thing, , other id said thing, 1 used? tl;dr : no. in versions of html, each element can have 1 id. see the spec : the id attribute specifies element's unique identifier (id). [dom] the value must unique amongst ids in element's home subtree , must contain @ least 1 character. the value must not contain space characters. note: there no other restrictions on form id can take; in particular, ids can consist of digits, start digit, start underscore, consist of punctuation , etc. note: element's unique identifier can used variety of purposes, notably way link specific parts of document usin
Read more