David Xu wrote:If you worry about that GCC should generate thread safe code, then they should have another
I definitly agree with Dan, -pthread is too ugly, it really really is
nothing to do with compiler and should be removed.
Really? What if invoking the threading library required the compiler to
compile code differently? Surely it might require that on some platforms,
say certain optimizations weren't thread safe. You're looking at this from
the FreeBSD perspective rather than the GCC perspective.
switch not -pthread, think about we want GCC to generate thread safe code for our kernel,
then what switch is needed ? if you think -pthread forces GCC to generate thread safe code,
then for our kernel, we need -freebsd-kernel switch ?
Break what ? I don't think we are forcing GCC to add another switch for our special threading library.
If someone
thinks -pthread
should be kept, then think about Microsoft, you are doing
Microsoft way and
cause lots of trouble when I am programmming on Windows,
Microsoft has two
version of c library, threaded library and non-threaded library,
it need a
compiler flag -MT to link a thread library, then lots of library conflict
with this flag at linking time because some were compiled with
-MT some were
not, this is rather annoying. This is a bit OT, but I hope we can
avoid such decision bug.
You can't avoid this. Suppose that some optimizations have to be disabled to make code thread safe and say these optimizations are significant. Then what would you do? Compile all code with the optimizations disabled and lose performance for all the apps that aren't threaded? You can't change the fact that threaded code and non-threaded code are incompatible on some platforms.
Many software use autoconf, autconf prefers -lpthread than
-pthread, it even prefers -lc_r then -pthread (if I remembered it right ).
And then autconf breaks when what you need to do to make pthreads works changes. What happens if the next threading library requires compiler flags? Or generates incompatible object code?
All we want to do is resolving conflict between several thread libraries. We now have libc_r, libkse 1:1,
libkse M:N, libthr, what library should be default for -pthread switch ?
pthread is not a language, -ansi is a language switch.
if system has a libpthread there, it will generate Makefile to
use -lpthread
not -pthread, obviously -pthread is not suggested to use.
Not suggested by whom? The whole point of '-pthread' was to have a way to
say, "I want to use this standard". If '-pthread' is wrong, so is '-ansi'.
So is '-std=<whatever>'.
If you are really programming according POSIX standard, then you should use
One word, just let -pthread die.
Only if you thing standards are a bad thing.
I'm sorry, I told myself I'd stay out of this now. I really appreciate the
concern being shown and the direction that things are going. However, I
think '-pthread' is a good thing. It's nice to have a portable way to say
that I want to compile POSIX code. What good is a standard if there's no
standard way to get to it?
_POSIX_SOURCE_XXX etc macros in your source code, not a magic compiler switch,
it is not portable.
Regards, David Xu
DS
_______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[EMAIL PROTECTED]"
_______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[EMAIL PROTECTED]"
