another threads reliability fix: serialize writes to thr->threadsv

avoid most uses of PL_na (which is much more inefficient than a
simple local); update docs to suit; PL_na now being thr->Tna may
be a minor compatibility issue for extensions--will require dTHR
outside of XSUBs (those get automatic dTHR)

p4raw-id: //depot/perl@2387

1 files changed, 2 insertions, 1 deletions

diff --git a/malloc.c b/malloc.c
index add79bb218..d99b059d05 100644
--- a/malloc.c
+++ b/malloc.c
@@ -726,6 +726,7 @@ emergency_sbrk(MEM_SIZE size)
 	SV *sv;
 	char *pv;
 	int have = 0;
+	STRLEN n_a;
 
 	if (emergency_buffer_size) {
 	    add_to_chain(emergency_buffer, emergency_buffer_size, 0);
@@ -741,7 +742,7 @@ emergency_sbrk(MEM_SIZE size)
 	    return (char *)-1;		/* Now die die die... */
 	}
 	/* Got it, now detach SvPV: */
-	pv = SvPV(sv, PL_na);
+	pv = SvPV(sv, n_a);
 	/* Check alignment: */
 	if (((UV)(pv - sizeof(union overhead))) & ((1<<LOG_OF_MIN_ARENA) - 1)) {
 	    PerlIO_puts(PerlIO_stderr(),"Bad alignment of $^M!\n");