Re: Calling Ada from C (linux/gnat 4.3.2)

[Simon Wright <simon@pushface.org>]

awdorrin <awdorrin@gmail.com> writes:

> I have been trying to search to find what the proper way would be to
> call an Ada procedure from a C pthread, but have had zero luck. I also
> have been unable to determine what the equivalent of the
> 'rts_init_task' would be with Gnat.

The info on-line is sparse; if you google 'gnat foreign threads' you'll
find [1], which tells you to look at the documentation of GNAT.Threads
(g-thread.ads). What it wants you to do is to read the comments in that
file.

In the past I've had success calling Register_Thread from the called Ada
procedure before it does anything at all, but that's not what the
comments seem to be saying. For example, I might have said

procedure P;
pragma export (C, P, "my_ada_proc");
procedure P is
   Id : constant System.Address := GNAT.Threads.Register_Thread;
   ...
begin
   ...

Jeffrey is correct that you need to call adainit() (and you should call
adafinal() before program exit or unloading a shared library).

[1] http://gcc.gnu.org/onlinedocs/gcc-4.6.0/gnat_rm/GNAT_002eThreads-_0028g_002dthread_002eads_0029.html