modula-2: Fix stack size request in initPreemptive [PR108405]

As noted in the PR, the problem is that we make a request for additional
stack that violates the constraints on some systems.

This patch chooses a value that is divisible by common OS page sizes.

TODO: the user value should be checked and then an exception thrown if it
is not suitable.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
	PR modula2/108405

gcc/m2/ChangeLog:

	* gm2-libs-iso/Preemptive.mod (initPreemptive): Use a value for
	extra space that is divisible by common OS pagesizes.

diff --git a/gcc/m2/gm2-libs-iso/Preemptive.mod b/gcc/m2/gm2-libs-iso/Preemptive.mod
index 53952e1..44aa62b 100644 (file)
--- a/gcc/m2/gm2-libs-iso/Preemptive.mod
+++ b/gcc/m2/gm2-libs-iso/Preemptive.mod
@@ -33,6 +33,9 @@ FROM libc IMPORT printf ;
 
 CONST
    debugging = FALSE ;
+   (* The space we request becomes part of a stack request, which generally
+      has constraints on size and alignment.  *)
+   extraWorkSpace = 10 * 1024 * 1024 ;
 
 (*
    timer - the timer process which runs at maximum scheduling priority with
@@ -107,7 +110,7 @@ BEGIN
    IF NOT init
    THEN
       init := TRUE ;
-      Create (timer, 10000000, MAX (Urgency), NIL, timerId) ;
+      Create (timer, extraWorkSpace, MAX (Urgency), NIL, timerId) ;
       Activate (timerId)
    END
 END initPreemptive ;