Re: [Qemu-devel] [PATCH] Make cpu_single_env thread local (Linux only for now)

[Paolo Bonzini]

On 10/05/2011 09:52 AM, Jan Kiszka wrote:
> Yeah, it probably makes sense to build the abstractions around __thread
> so that - one day - we can drop the legacy wrappers.
>
> Just do not prepend "tls__" in the gcc model

Actually I did that on purpose so that people would not forget get_tls. :)

> (there is also some inconsistency with prefixes in patch 3).

Yep, the attached v2 actually builds.  I also needed a small change to 
avoid errors with -Wredundant-decls, and I changed it to support arrays with

DECLARE_TLS(int[10], array);

> And avoid leading "_" unless
> they are dictated by the platform.

Ok, I replaced tls_init_thread with tls_init_main_thread and 
_tls_init_thread with tls_init_thread.

> And patch 3 needs to update darwin-user/main.c as well.

I think the declaration can just be removed.

> What is the default priority of constructors BTW? You picked the
> highest, will others that do not specify one have the same?

Looks like the prioritized constructors always run _before_ the others, 
which is good.

$ cat f.c
int f(void) __attribute__((constructor(101)));
int f(void) { write (1, "101\n", 4); }
int h(void) __attribute__((constructor));
int h(void) { write (1, "default\n", 8); }
int g(void) __attribute__((constructor(102)));
int g(void) { write (1, "102\n", 4); }
int main() { write(1, "main\n", 5); }
$ gcc f.c
$ ./a.out
101
102
default
main

If interested people can test the patches more and submit them more 
formally, I'd be very glad.  I wrote it for RCU, but of course that one 
is not really going to be 1.0 material (even for 9p).

Paolo

tls-cpu-single-env.patch
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