Can bogofilter run by multiprocess at the same time

[陈治璋]

在2004年10月14日的06:46，Matthias Andree写道：
> On Wed, 13 Oct 2004, 陈治璋 wrote:
> 
> > > Does it produce an actual deadlock or just make slow progress?
> > It's an actual deadlock. There are many bogofilter processes and they
> > process id remains the same for ever.
> 
> A deadlock is when process A has locked resource R and waits for
> resource S while process B has locked resource S and waits for resource
> R. I managed to trigger a "hang" on Linux, which turned out to be
> processes waiting for input, which is why I don't attribute the hang to
> bogofilter but rather the environment.
> 
> I didn't have the time to retry your code with fork() yet.
> 
> > Yes, I'm using glibc 2.1 in Linux. But in Solaris 2.8, I tested it again
> > by replacing the following function and it blocks:
> > 
> > void* bogo_check(void* p)
> > {
> >                                                                                 
> >    for(int i = 0; i < 10000; i ++){
> >       const char* s_email = "ham.eml";
> >       if (i%2){
> >          s_email= "spam.eml";
> >       }
> >       string email = get_email(s_email);
> >       FILE* file = popen("bogofilter", "w");
> >       signal(SIGPIPE,   SIG_IGN);
> 
> This for instance is bogus, it masks a crashed child.
Maybe it's because that the program needs too file in the current dir:
ham.eml and spam.eml.
> 
> I'm not sure off-hand if the C++ string class is thread-safe.
> 
> > And it blocks at vfork().
> 
> Which vfork()? The original code you posted used POSIX threads.

> BTW, vfork works only if the child process immediately
> calls execve() or _exit(). If it does anything else, you must use fork.

What I mean is that the program hang when calling popen(), which calls
vfork in solaris.

BTW, is there any library that I can call in my C code to check if an
email is a spam instead of calling popen()?