【转帖】smartpointer And Extern C Functions
 

smartpointer and extern "c" functions
smartpointer and extern "c" functions
i have this code, which i call from c:
php code:
struct dwgdirect
{
fff">oddbdatabase fff">*fff">pdbfff">;
};
odstaticrxobjectfff"><fff">myservicesfff">> fff">svcfff">;
extern fff">"c" fff">dwgdirect fff">*fff">directopenfff">(const fff">char fff">*fff">sfilenamefff">)
{
fff">dwgdirect fff">*fff">pdirect fff">= new fff">dwgdirectfff">();

fff">odinitializefff">(&fff">svcfff">); fff">//svc is global for now
fff">pdirectfff">->fff">pdb fff">= fff">svcfff">.fff">readfilefff">(fff">sfilenamefff">, fff">truefff">, fff">falsefff">, fff">odafff">::fff">ksharedenynofff">);
if(!fff">pdirectfff">->fff">pdbfff">)
return fff">nullfff">;
return fff">pdirectfff">;
}
extern fff">"c" fff">void directclosefff">(fff">dwgdirect fff">*fff">pdirectfff">)
{
fff">oduninitializefff">();
fff">delete pdirectfff">;
}
extern fff">"c" fff">void getfileextfff">(fff">dwgdirect fff">*fff">pdirectfff">, fff">vgrect fff">*fff">fileextfff">)
{
fff">odgepoint3d upperr fff">= fff">pdirectfff">->fff">pdbfff">->fff">getextmaxfff">();
fff">odgepoint3d lowerl fff">= fff">pdirectfff">->fff">pdbfff">->fff">getextminfff">();
fff">fileextfff">->fff">xmax fff">= fff">upperrfff">.fff">xfff">;
fff">fileextfff">->fff">xmin fff">= fff">lowerlfff">.fff">xfff">;
fff">fileextfff">->fff">ymax fff">= fff">upperrfff">.fff">yfff">;
fff">fileextfff">->fff">ymin fff">= fff">lowerlfff">.fff">yfff">;
}
fff">
the code crashes when i try to call pdirect->pdb->getextmax()
but if i make oddbdatabase *pdb in my struct a smartpointer instead, oddbdatabaseptr pdb, then it works.
...but still the code is not correct, cos when i try to delete my struct it generates a call to the smartpointer's delete, and i get a crash.
can there anyone see what i'm missing?
a little tweak and it seems ok
so it seems this works, when i use smartpointer in my struct:
php code:
extern fff">"c" fff">void directclosefff">(fff">dwgdirect fff">*fff">pdirectfff">)
{
fff">delete pdirectfff">;
fff">oduninitializefff">();
}
fff">
so i guess oduninitialize() do some magic here, which messed up my delete when i had it after it.
feel free to explain why though, cos i don't quite get it.
last edited by oraly; 2nd july 2008 at 04:15 amfff">.
after oduninitialize() any dd object may become invalid. you should free all smart-pointers before calling oduninitialize().
vladimir
i had a similar problem with smart pointers and it would also crash. maybe the smartpointer is freed automatically when you exit the function. i would also like to know how to resolve this.