PERF: Discourage DomainThreader from spawning superfluous threads
PERF: Discourage DomainThreader from spawning superfluous threads

Change-Id: I459e632ddcf6e1190d4bba1244e19b0001883bf8

zachary-williamson/ITK,LucHermitte/ITK,jmerkow/ITK,LucasGandel/ITK,spinicist/ITK,vfonov/ITK,fbudin69500/ITK,richardbeare/ITK,fedral/ITK,atsnyder/ITK,stnava/ITK,msmolens/ITK,jcfr/ITK,jmerkow/ITK,stnava/ITK,LucasGandel/ITK,InsightSoftwareConsortium/ITK,LucHermitte/ITK,malaterre/ITK,biotrump/ITK,malaterre/ITK,vfonov/ITK,spinicist/ITK,hendradarwin/ITK,BRAINSia/ITK,fbudin69500/ITK,jcfr/ITK,jcfr/ITK,heimdali/ITK,jcfr/ITK,malaterre/ITK,jmerkow/ITK,Kitware/ITK,biotrump/ITK,zachary-williamson/ITK,richardbeare/ITK,vfonov/ITK,GEHC-Surgery/ITK,ajjl/ITK,thewtex/ITK,stnava/ITK,LucasGandel/ITK,GEHC-Surgery/ITK,BRAINSia/ITK,Kitware/ITK,Kitware/ITK,jcfr/ITK,atsnyder/ITK,stnava/ITK,PlutoniumHeart/ITK,richardbeare/ITK,atsnyder/ITK,fbudin69500/ITK,thewtex/ITK,vfonov/ITK,InsightSoftwareConsortium/ITK,eile/ITK,PlutoniumHeart/ITK,Kitware/ITK,eile/ITK,jmerkow/ITK,heimdali/ITK,GEHC-Surgery/ITK,hjmjohnson/ITK,ajjl/ITK,msmolens/ITK,blowekamp/ITK,BRAINSia/ITK,fbudin69500/ITK,BlueBrain/ITK,stnava/ITK,heimdali/ITK,GEHC-Surgery/ITK,blowekamp/ITK,ajjl/ITK,BRAINSia/ITK,LucHermitte/ITK,thewtex/ITK,eile/ITK,spinicist/ITK,eile/ITK,LucHermitte/ITK,zachary-williamson/ITK,vfonov/ITK,PlutoniumHeart/ITK,atsnyder/ITK,malaterre/ITK,hjmjohnson/ITK,vfonov/ITK,spinicist/ITK,spinicist/ITK,hendradarwin/ITK,GEHC-Surgery/ITK,thewtex/ITK,ajjl/ITK,jmerkow/ITK,fbudin69500/ITK,zachary-williamson/ITK,malaterre/ITK,vfonov/ITK,hjmjohnson/ITK,blowekamp/ITK,stnava/ITK,PlutoniumHeart/ITK,ajjl/ITK,msmolens/ITK,LucasGandel/ITK,hjmjohnson/ITK,heimdali/ITK,biotrump/ITK,spinicist/ITK,BlueBrain/ITK,stnava/ITK,Kitware/ITK,InsightSoftwareConsortium/ITK,vfonov/ITK,eile/ITK,zachary-williamson/ITK,blowekamp/ITK,malaterre/ITK,msmolens/ITK,BRAINSia/ITK,PlutoniumHeart/ITK,BlueBrain/ITK,LucasGandel/ITK,msmolens/ITK,jmerkow/ITK,jmerkow/ITK,LucHermitte/ITK,spinicist/ITK,jcfr/ITK,msmolens/ITK,stnava/ITK,spinicist/ITK,thewtex/ITK,fedral/ITK,biotrump/ITK,biotrump/ITK,BlueBrain/ITK,GEHC-Surgery/ITK,BRAINSia/ITK,malaterre/ITK,BlueBrain/ITK,richardbeare/ITK,fbudin69500/ITK,thewtex/ITK,PlutoniumHeart/ITK,jmerkow/ITK,blowekamp/ITK,PlutoniumHeart/ITK,atsnyder/ITK,PlutoniumHeart/ITK,atsnyder/ITK,fedral/ITK,jcfr/ITK,vfonov/ITK,blowekamp/ITK,ajjl/ITK,heimdali/ITK,spinicist/ITK,LucasGandel/ITK,heimdali/ITK,Kitware/ITK,InsightSoftwareConsortium/ITK,fedral/ITK,heimdali/ITK,hendradarwin/ITK,InsightSoftwareConsortium/ITK,jcfr/ITK,eile/ITK,zachary-williamson/ITK,biotrump/ITK,hendradarwin/ITK,InsightSoftwareConsortium/ITK,ajjl/ITK,fbudin69500/ITK,fbudin69500/ITK,fedral/ITK,richardbeare/ITK,LucasGandel/ITK,Kitware/ITK,hendradarwin/ITK,LucHermitte/ITK,richardbeare/ITK,zachary-williamson/ITK,fedral/ITK,eile/ITK,GEHC-Surgery/ITK,BlueBrain/ITK,atsnyder/ITK,BlueBrain/ITK,biotrump/ITK,hjmjohnson/ITK,heimdali/ITK,biotrump/ITK,msmolens/ITK,hendradarwin/ITK,malaterre/ITK,LucHermitte/ITK,blowekamp/ITK,hendradarwin/ITK,eile/ITK,thewtex/ITK,richardbeare/ITK,InsightSoftwareConsortium/ITK,blowekamp/ITK,GEHC-Surgery/ITK,atsnyder/ITK,zachary-williamson/ITK,hjmjohnson/ITK,fedral/ITK,hendradarwin/ITK,LucasGandel/ITK,LucHermitte/ITK,zachary-williamson/ITK,hjmjohnson/ITK,fedral/ITK,stnava/ITK,msmolens/ITK,atsnyder/ITK,BRAINSia/ITK,ajjl/ITK,BlueBrain/ITK,malaterre/ITK,eile/ITK