c++ - expected duration between kill and the ability to reap with waitpid -

-

i have linux app must spawn child process on request 1 of exec() functions.

if child process has not finished before it's time spawn again, app must kill previous instance before starting new one. with

kill(pid, sigterm);

i'm keeping pid of previous instance , using 

waitpid(pid, &status, wnohang)

to reap process.

it seems there's extremely long time window (possibly hundreds of milliseconds) between issuing kill call , being able reap process waitpid.

what cause this? thought unless child process set signal hander (this 1 doesn't) killed virtually immediately. on 200mhz arm9 still ... seems odd me.

the process may catch sigterm in order perform own cleanup before shutting down.

even if doesn't, don't know how long it'll take os shut down process.

trying rely on things fool's errand.


Comments

Post a Comment

Popular posts from this blog

c# - How to set Z index when using WPF DrawingContext? -

-
how set z-index drawing object when using drawingcontext.drawxxx() methods? the object drawn last have higher z index. can't change index of drawn objects. way draw in order. if using wpf (as placed tag), can use, example, canvas control. create shapes need like polyline obj = new polyline(); //... // ... set properties of obj and add them canvas uielementcollection: yourcanvasname.children.add(obj); //or yourcanvasname.children.insert(i, obj); first items of collection have higher z index. advantages in way: no need redraw on window changes, can anytime move objects , change order.
Read more

razor - Is this a bug in WebMatrix PageData? -

-
i think may have found bug in webmatrix's pagedata, not sure. concerns how pass data partial page calling page. in webmatrix documentation (tutorials, e.g. " 3 - creating consistent look ", , example code), pagedata recommended mechanism pass data between pages (e.g. content page layout page, or partial page). however have found not work other way, pass data partial page calling page. modifying or adding entries in pagedata in partial page, not seem calling page. cutting right down simplest possible example, in test page may have this: @{ pagedata["test"] = "initial entry"; } <p>before calling partial page, test value @pagedata["test"]</p> @renderpage("_testpartial.cshtml") <p>after returning calling page, test value @pagedata["test"]</p> and in _testpartial.cshtml page might have this: @{ pagedata["test"] = "modified entry"; } <p>in partial page...
Read more

visual c++ - Using relative values in array sorting ( asm ) -

-
i need sort through array , sort each individual row in array in ascending order. doesn't seem going (surprise!) keep getting hit 2 errors: a2101: cannot add 2 relocatable labels , a2026: constant expected here's sort, makes sense me, think i'm still trying implement high-lvl language techniqes assembly. there way around not being able use relative values? (the array 7 rows 9 columns, btw). mov cx, 7; cx = number of rows outer: ; outer loop walk through rows push cx mov cx, 9 mov row, cx ;rows middle: ; middle-loop walk through columns push cx sub cx, 1 ;cx = cx-1 mov column, cx ;columns inner: ;inner loop - compare , exchange column values cmp marray[row*9 + column], marray[row*9 + column+1] xchg marray[row*9 + column+1], marray[row*9 + column] ; compare , exchange values marray table inc column loop inner pop cx loop mid...
Read more