windows - How to check in C++ if an application is already running before launching a new instance? -



windows - How to check in C++ if an application is already running before launching a new instance? -

i have found few references implementation 1 clear description in c++ (joseph newcomers article http://www.flounder.com/nomultiples.htm#createmutex), (c)1999 little reluctant utilize without first checking if there "newer/better" ways today.

thanks

any named object do, can file, mutex, event, mailslot, tcp port, etc. error_already_exists tells whether instance existed.

for objects in win32 kernel namespace, there 1 alter since 1999 -- because of terminal services, can utilize prefix of global\ or local\ specify whether it's 1 instance on entire computer vs 1 per user logon session.

if want more portable, binding tcp port, or creating file , exclusively locking it, tend work across variety of oses.

c++ windows

Comments

Post a Comment

Popular posts from this blog

java - How to pass parameters between Request-Scoped Controllers? -

java - How to pass parameters between Request-Scoped Controllers? - i have simple jsf-page , want pass parameter page1 page2. every page has own controller in request scope. the 2 controllers this: controller1: @component("requestcontroller1") @scope("request") public class requestcontroller1 { private list<product> products; private product selectedproduct; @postconstruct public void init() { //load products db } public void setproducts(list<product> products) { this.products = products; } public list<product> getproducts() { homecoming products; } public void setselectedproduct(product selectedproduct) { this.selectedproduct = selectedproduct; } public product getselectedproduct() { homecoming selectedproduct; } controller2: @component("requestcontroller2") @scope("request") public class requestcontroller2 { private long selectedproductid; @postconstruct public void init() ...
Read more

string - what is the difference between "some" == "some\0" and strcmp("some","some\0") in c++? -

string - what is the difference between "some" == "some\0" and strcmp("some","some\0") in c++? - what difference between "some" == "some\0" , strcmp("some","some\0") in c++? why if("some" == "some\0") returns false , if(!strcmp("some","some\0")) returns true ? see next diagram. shows 2 strings in memory, content in box, beside box you'll see address of each one. when you're doing if("some" == "some\0") comparing addresses. translated if (0xdeadbeef == 0x0badcafe) false. when utilize strcmp , compare content of each box until reach \0 in each of them. that's why sec test returns true. if alter first test if("some" == "some") compiler may potentially see same strings , store them once. means test transform if (0x0badcafe == 0x0badcafe) true. c++ string comparison
Read more

actionscript 3 - Flex: moving a point with rotation doesnt change the point XY? -

actionscript 3 - Flex: moving a point with rotation doesnt change the point XY? - i have follow issue : i have point setted @ border on component, changed transform point center of component in order match component rotation. the of import part when seek point xy after rotation - remains same before rotation. how xy, after rotation ( changeing point.rotation property specific degrees of rotaion ) if want point after rotation, cos(r) * x, sin(r) * y easiest way. if want point after transformations, should able utilize displayobject.transform.transformpoint(x, y) . there's displayobject.localtoglobal . in case phone call localtoglobal(x, y) , localtoglobal(0, 0) , calculate difference. see transform livedocs , displayobject livedocs flex actionscript-3
Read more