On May 3 08:44, Oh, Choong-Hyun (HPSS-BSM) wrote: > Dear all, > > I found strange behavior of cywin application under windows 2003 x64 R2 > version. > When I run bash, it creates parent bash process and also child bash process > as like followings; > > > cmd.exe > +- bash.exe > +- bash.exe > > services.exe > +- cygrunsvr.exe > +- cygrunsvr.exe > > > But on Windows 2008 x64 R2 system, it create only one process as like > followings;
I assume you mean non-64 bit here. > cmd.exe > +- bash.exe > > services.exe > +- cygrunsvr.exe > > So I am wondering whether it is normal behavior of cygwin on Windows 2003 x64 > R2 system or not. > And also if so, what's a cause of this happening. This happens if a Cygwin process (which is 32 bit and thus running in the WOW64 environment) is called from a 64 bit Windows process. On the older XP and 2003 64 bit systems, the first WOW64 processes main thread started from a 64 bit process gets a stack address in the range where usually the application itself resides. This in turn breaks Cygwin's fork. Therefore a Cygwin process checks at process startup if it has been started by a 64 bit parent process and if the stack address is in the dangerous region. If so, it re-spawns itself. Since this second process is started from another 32 bit process, its stack address is useful again. The intermediate process keeps in memory as long as the re-spawned process runs. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Project Co-Leader cygwin AT cygwin DOT com Red Hat -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
