[M3devel] __thread?

[Jay]

Mika, please let me know what this does for you, on the old FreeBSD 4.x?

Probably it'll give some compiler errors, but if not, excellent.

Our usess of pthread_get/setspecific should use __thread where it is available.
Below is FreeBSD/i386 7.0. Nice and efficient (even better with -O2).

Actually, "everyone", I'm interested in this.
Probably we should do a little local autoconfery in the m3core m3makefile.
If the below program compiles/links, use __thread, else pthread_get/setspecific.
Another option is determine that it is widely supported and use #if
or find out if there are specific #ifs associated with it. I know Cygwin doesn't support it.
 
 
[jay at jkfbsd1 ~]$ cat 1.c
#include 

__thread int a,b,c,d;

int main()
{
printf("%p%p%p%p\n", &a,&b,&c,&d);
return 0;
}
 
[jay at jkfbsd1 ~]$ gcc -S 1.c
[jay at jkfbsd1 ~]$ cat 1.s
        .file   "1.c"
        .section        .rodata
.LC0:
        .string "%p%p%p%p\n"
        .text
        .p2align 4,,15
.globl main
        .type   main, @function
main:
        leal    4(%esp), %ecx
        andl    $-16, %esp
        pushl   -4(%ecx)
        pushl   %ebp
        movl    %esp, %ebp
        pushl   %ecx
        subl    $20, %esp
        movl    %gs:0, %eax
        leal    d at NTPOFF(%eax), %eax
        movl    %eax, 16(%esp)
        movl    %gs:0, %eax
        leal    c at NTPOFF(%eax), %eax
        movl    %eax, 12(%esp)
        movl    %gs:0, %eax
        leal    b at NTPOFF(%eax), %eax
        movl    %eax, 8(%esp)
        movl    %gs:0, %eax
        leal    a at NTPOFF(%eax), %eax
        movl    %eax, 4(%esp)
        movl    $.LC0, (%esp)
        call    printf
        movl    $0, %eax
        addl    $20, %esp
        popl    %ecx
        popl    %ebp
        leal    -4(%ecx), %esp
        ret
        .size   main, .-main
.globl a
        .section        .tbss,"awT", at nobits


...
 
 
 - Jay