Re: [Tinycc-devel] make tcc reentrant

[Michael Matz]

Hi,

On Sun, 8 Dec 2019, uso ewin wrote:

> I've made a version that should support multi thread on my github
> https://github.com/cosmo-ray/tcc/commit/46d0e73edc7e448f0f514936fdb4f62e2c8800a4
> I didn't tests it, it's just here to show the
> possibility using _Thread_local.

Ulrich doesn't care for multiple threads in and off itself, he cares for 
multiple TCCState objects, i.e. multiple compiler instances.  And for that 
all global data (that necessarily are currently singletons) either needs 
to move to that state or its updating needs to be harmless when faced 
with multiple states.  Having multiple copies of global data (one per 
thread) _still_ doesn't allow multiple such states within one thread.


Ciao,
Michael.

> 
> This approach even if it doesn't enable reentrancy,
> allow multy-thread, can be disable
> and doesn't modify a lot of code.
> 
> Do you think you could use that Ulrich ?
> 
> Thanks,
> Matthias
> 
> On Sat, Dec 7, 2019 at 12:51 PM Daniel Glöckner <address@hidden> wrote:
> >
> > Hi,
> >
> > On Sat, Dec 07, 2019 at 11:34:11AM +0100, Ulrich Schmidt wrote:
> > > - The in scenario1 unloved 1 function parameter can be ignored and the
> > > values stored locally:
> > >   #define LIBPARAM1
> > >   #define VALUE(v) v
> > >   ..
> > >
> > >   somereturn somefunc(LIBPARAM1 ...) {
> > >     VALUE(count) = 0;
> > >     ...
> > >
> > > - in scenario 2 we define the 2 macros different:
> > >   #define LIBPARAM1 TCCState *s1,
> > >   #define VALUE(v) s1->v
> >
> > We need a macro
> >
> > #if scenario == 1
> > #define PASSPARAM1
> > #else
> > #define PASSPARAM1 s1,
> > #endif
> >
> > Grouping all globals in the TCCState structure might be beneficial
> > even if we don't switch to those macros, because of the cache locality
> > Christian wrote about. The VALUE macro in scenario 1 would then be
> > #define VALUE(v) global_state.v
> >
> > Btw, has anyone thought about handling TCCState like the context is
> > handled in the OpenGL API? It has one function to select the context
> > to use for following operations and the operations themselves don't
> > have a parameter for the context. If the pointer to the TCCState is
> > stored in a normal or in a TLS variable is up to us and might even
> > be a compile time option (that is set to "normal" for compilation
> > with tcc as long as tcc doesn't know how to generate TLS variables).
> >
> > Best regards,
> >
> >   Daniel
> >
> > _______________________________________________
> > Tinycc-devel mailing list
> > address@hidden
> > https://lists.nongnu.org/mailman/listinfo/tinycc-devel
> 
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