From: Ilya Zakharevich <ilya@math.berkeley.edu>
Date: Mon, 20 Jul 1998 21:40:00 +0000 (-0400)
Subject: tweaked version of suggested patch
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=8b73bbec3102cdf25a35c954eb1aab85acc07808;p=p5sagit%2Fp5-mst-13.2.git

tweaked version of suggested patch
	Message-Id: <199807210140.VAA17186@monk.mps.ohio-state.edu>
	Subject: [PATCH 5.004_75] Enable -DS

p4raw-id: //depot/maint-5.005/perl@1701
---

diff --git a/README.threads b/README.threads
index e9f6966..8357056 100644
--- a/README.threads
+++ b/README.threads
@@ -150,13 +150,13 @@ haven't tracked down yet) and there are very probably others too.
 
 Debugging
 
-Use the -DL command-line option to turn on debugging of the
+Use the -DS command-line option to turn on debugging of the
 multi-threading code. Under Linux, that also turns on a quick
 hack I did to grab a bit of extra information from segfaults.
 If you have a fancier gdb/threads setup than I do then you'll
 have to delete the lines in perl.c which say
     #if defined(DEBUGGING) && defined(USE_THREADS) && defined(__linux__)
-        DEBUG_L(signal(SIGSEGV, (void(*)(int))catch_sigsegv););
+        DEBUG_S(signal(SIGSEGV, (void(*)(int))catch_sigsegv););
     #endif
 
 
diff --git a/ext/Thread/Thread.xs b/ext/Thread/Thread.xs
index 6659565..48f8aa0 100644
--- a/ext/Thread/Thread.xs
+++ b/ext/Thread/Thread.xs
@@ -23,7 +23,7 @@ static void
 remove_thread(struct perl_thread *t)
 {
 #ifdef USE_THREADS
-    DEBUG_L(WITH_THR(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(WITH_THR(PerlIO_printf(PerlIO_stderr(),
 				   "%p: remove_thread %p\n", thr, t)));
     MUTEX_LOCK(&PL_threads_mutex);
     MUTEX_DESTROY(&t->mutex);
@@ -48,7 +48,7 @@ threadstart(void *arg)
     AV *av;
     int i;
 
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "new thread %p starting at %s\n",
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "new thread %p starting at %s\n",
 			  thr, SvPEEK(TOPs)));
     thr = (Thread) arg;
     savemark = TOPMARK;
@@ -67,7 +67,7 @@ threadstart(void *arg)
     myop.op_flags |= OPf_KNOW;
     myop.op_flags |= OPf_WANT_LIST;
     PL_op = pp_entersub(ARGS);
-    DEBUG_L(if (!PL_op)
+    DEBUG_S(if (!PL_op)
 	    PerlIO_printf(PerlIO_stderr(), "thread starts at Nullop\n"));
     /*
      * When this thread is next scheduled, we start in the right
@@ -88,7 +88,7 @@ threadstart(void *arg)
     AV *av = newAV();
     int i, ret;
     dJMPENV;
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "new thread %p waiting to start\n",
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "new thread %p waiting to start\n",
 			  thr));
 
     /* Don't call *anything* requiring dTHR until after SET_THR() */
@@ -110,7 +110,7 @@ threadstart(void *arg)
     SET_THR(thr);
 
     /* Only now can we use SvPEEK (which calls sv_newmortal which does dTHR) */
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "new thread %p starting at %s\n",
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "new thread %p starting at %s\n",
 			  thr, SvPEEK(TOPs)));
 
     sv = POPs;
@@ -125,10 +125,10 @@ threadstart(void *arg)
 	MUTEX_UNLOCK(&thr->mutex);
 	av_store(av, 0, &PL_sv_no);
 	av_store(av, 1, newSVsv(thr->errsv));
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(), "%p died: %s\n",
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(), "%p died: %s\n",
 			      thr, SvPV(thr->errsv, PL_na)));
     } else {
-	DEBUG_L(STMT_START {
+	DEBUG_S(STMT_START {
 	    for (i = 1; i <= retval; i++) {
 		PerlIO_printf(PerlIO_stderr(), "%p return[%d] = %s\n",
 				thr, i, SvPEEK(SP[i - 1]));
@@ -177,28 +177,28 @@ threadstart(void *arg)
     /*SvREFCNT_dec(PL_defoutgv);*/
 
     MUTEX_LOCK(&thr->mutex);
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			  "%p: threadstart finishing: state is %u\n",
 			  thr, ThrSTATE(thr)));
     switch (ThrSTATE(thr)) {
     case THRf_R_JOINABLE:
 	ThrSETSTATE(thr, THRf_ZOMBIE);
 	MUTEX_UNLOCK(&thr->mutex);
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "%p: R_JOINABLE thread finished\n", thr));
 	break;
     case THRf_R_JOINED:
 	ThrSETSTATE(thr, THRf_DEAD);
 	MUTEX_UNLOCK(&thr->mutex);
 	remove_thread(thr);
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "%p: R_JOINED thread finished\n", thr));
 	break;
     case THRf_R_DETACHED:
 	ThrSETSTATE(thr, THRf_DEAD);
 	MUTEX_UNLOCK(&thr->mutex);
 	SvREFCNT_dec(av);
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "%p: DETACHED thread finished\n", thr));
 	remove_thread(thr);	/* This might trigger main thread to finish */
 	break;
@@ -234,7 +234,7 @@ newthread (SV *startsv, AV *initargs, char *classname)
     savethread = thr;
     thr = new_struct_thread(thr);
     SPAGAIN;
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			  "%p: newthread (%p), tid is %u, preparing stack\n",
 			  savethread, thr, thr->tid));
     /* The following pushes the arg list and startsv onto the *new* stack */
@@ -283,7 +283,7 @@ newthread (SV *startsv, AV *initargs, char *classname)
     MUTEX_UNLOCK(&thr->mutex);
 #endif
     if (err) {
-        DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+        DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "%p: create of %p failed %d\n",
 			      savethread, thr, err));
 	/* Thread creation failed--clean up */
@@ -322,7 +322,7 @@ handle_thread_signal(int sig)
      * so don't be surprised if this isn't robust while debugging
      * with -DL.
      */
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 	    "handle_thread_signal: got signal %d\n", sig););
     write(sig_pipe[1], &c, 1);
 }
@@ -345,7 +345,7 @@ join(t)
 	int	i = NO_INIT
     PPCODE:
 #ifdef USE_THREADS
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(), "%p: joining %p (state %u)\n",
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(), "%p: joining %p (state %u)\n",
 			      thr, t, ThrSTATE(t)););
     	MUTEX_LOCK(&t->mutex);
 	switch (ThrSTATE(t)) {
@@ -372,7 +372,7 @@ join(t)
 		XPUSHs(sv_2mortal(*av_fetch(av, i, FALSE)));
 	} else {
 	    char *mess = SvPV(*av_fetch(av, 1, FALSE), PL_na);
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  "%p: join propagating die message: %s\n",
 				  thr, mess));
 	    croak(mess);
@@ -384,7 +384,7 @@ detach(t)
 	Thread	t
     CODE:
 #ifdef USE_THREADS
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(), "%p: detaching %p (state %u)\n",
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(), "%p: detaching %p (state %u)\n",
 			      thr, t, ThrSTATE(t)););
     	MUTEX_LOCK(&t->mutex);
 	switch (ThrSTATE(t)) {
@@ -476,7 +476,7 @@ CODE:
 	    sv = SvRV(sv);
 
 	mg = condpair_magic(sv);
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(), "%p: cond_wait %p\n", thr, sv));
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(), "%p: cond_wait %p\n", thr, sv));
 	MUTEX_LOCK(MgMUTEXP(mg));
 	if (MgOWNER(mg) != thr) {
 	    MUTEX_UNLOCK(MgMUTEXP(mg));
@@ -500,7 +500,7 @@ CODE:
 	    sv = SvRV(sv);
 
 	mg = condpair_magic(sv);
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(), "%p: cond_signal %p\n",thr,sv));
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(), "%p: cond_signal %p\n",thr,sv));
 	MUTEX_LOCK(MgMUTEXP(mg));
 	if (MgOWNER(mg) != thr) {
 	    MUTEX_UNLOCK(MgMUTEXP(mg));
@@ -520,7 +520,7 @@ CODE:
 	    sv = SvRV(sv);
 
 	mg = condpair_magic(sv);
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(), "%p: cond_broadcast %p\n",
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(), "%p: cond_broadcast %p\n",
 			      thr, sv));
 	MUTEX_LOCK(MgMUTEXP(mg));
 	if (MgOWNER(mg) != thr) {
@@ -623,7 +623,7 @@ await_signal()
 	ST(0) = sv_newmortal();
 	if (ret)
 	    sv_setsv(ST(0), c ? psig_ptr[c] : &PL_sv_no);
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "await_signal returning %s\n", SvPEEK(ST(0))););
 
 MODULE = Thread		PACKAGE = Thread::Specific
diff --git a/ext/Thread/typemap b/ext/Thread/typemap
index fd6e99d..21eb6c3 100644
--- a/ext/Thread/typemap
+++ b/ext/Thread/typemap
@@ -13,7 +13,7 @@ T_XSCPTR
 		|| mg->mg_private != ${ntype}_MAGIC_SIGNATURE)
 		croak(\"XSUB ${func_name}: $var is a forged ${ntype} object\");
 	    $var = ($type) SvPVX(mg->mg_obj);
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  \"XSUB ${func_name}: %p\\n\", $var);)
 	} STMT_END
 T_IVREF
diff --git a/mg.c b/mg.c
index 1d78f13..9dfbd4f 100644
--- a/mg.c
+++ b/mg.c
@@ -1845,7 +1845,7 @@ int
 magic_mutexfree(SV *sv, MAGIC *mg)
 {
     dTHR;
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "0x%lx: magic_mutexfree 0x%lx\n",
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "0x%lx: magic_mutexfree 0x%lx\n",
 			  (unsigned long)thr, (unsigned long)sv);)
     if (MgOWNER(mg))
 	croak("panic: magic_mutexfree");
diff --git a/op.c b/op.c
index 16f528d..f285193 100644
--- a/op.c
+++ b/op.c
@@ -548,7 +548,7 @@ find_threadsv(char *name)
 	default:
 	    sv_magic(sv, 0, 0, name, 1); 
 	}
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "find_threadsv: new SV %p for $%s%c\n",
 			      sv, (*name < 32) ? "^" : "",
 			      (*name < 32) ? toCTRL(*name) : *name));
diff --git a/perl.c b/perl.c
index 0e39dbe..7217536 100644
--- a/perl.c
+++ b/perl.c
@@ -256,7 +256,7 @@ perl_destruct(register PerlInterpreter *sv_interp)
     /* Pass 1 on any remaining threads: detach joinables, join zombies */
   retry_cleanup:
     MUTEX_LOCK(&PL_threads_mutex);
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			  "perl_destruct: waiting for %d threads...\n",
 			  PL_nthreads - 1));
     for (t = thr->next; t != thr; t = t->next) {
@@ -264,7 +264,7 @@ perl_destruct(register PerlInterpreter *sv_interp)
 	switch (ThrSTATE(t)) {
 	    AV *av;
 	case THRf_ZOMBIE:
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  "perl_destruct: joining zombie %p\n", t));
 	    ThrSETSTATE(t, THRf_DEAD);
 	    MUTEX_UNLOCK(&t->mutex);
@@ -278,11 +278,11 @@ perl_destruct(register PerlInterpreter *sv_interp)
 	    MUTEX_UNLOCK(&PL_threads_mutex);
 	    JOIN(t, &av);
 	    SvREFCNT_dec((SV*)av);
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  "perl_destruct: joined zombie %p OK\n", t));
 	    goto retry_cleanup;
 	case THRf_R_JOINABLE:
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  "perl_destruct: detaching thread %p\n", t));
 	    ThrSETSTATE(t, THRf_R_DETACHED);
 	    /* 
@@ -296,7 +296,7 @@ perl_destruct(register PerlInterpreter *sv_interp)
 	    MUTEX_UNLOCK(&t->mutex);
 	    goto retry_cleanup;
 	default:
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  "perl_destruct: ignoring %p (state %u)\n",
 				  t, ThrSTATE(t)));
 	    MUTEX_UNLOCK(&t->mutex);
@@ -308,14 +308,14 @@ perl_destruct(register PerlInterpreter *sv_interp)
     /* Pass 2 on remaining threads: wait for the thread count to drop to one */
     while (PL_nthreads > 1)
     {
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "perl_destruct: final wait for %d threads\n",
 			      PL_nthreads - 1));
 	COND_WAIT(&PL_nthreads_cond, &PL_threads_mutex);
     }
     /* At this point, we're the last thread */
     MUTEX_UNLOCK(&PL_threads_mutex);
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "perl_destruct: armageddon has arrived\n"));
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "perl_destruct: armageddon has arrived\n"));
     MUTEX_DESTROY(&PL_threads_mutex);
     COND_DESTROY(&PL_nthreads_cond);
 #endif /* !defined(FAKE_THREADS) */
@@ -1064,10 +1064,8 @@ perl_run(PerlInterpreter *sv_interp)
     if (!PL_restartop) {
 	DEBUG_x(dump_all());
 	DEBUG(PerlIO_printf(Perl_debug_log, "\nEXECUTING...\n\n"));
-#ifdef USE_THREADS
-	DEBUG_L(PerlIO_printf(Perl_debug_log, "main thread is 0x%lx\n",
+	DEBUG_S(PerlIO_printf(Perl_debug_log, "main thread is 0x%lx\n",
 			      (unsigned long) thr));
-#endif /* USE_THREADS */	
 
 	if (PL_minus_c) {
 	    PerlIO_printf(PerlIO_stderr(), "%s syntax OK\n", PL_origfilename);
@@ -1571,7 +1569,7 @@ moreswitches(char *s)
 #ifdef DEBUGGING
 	forbid_setid("-D");
 	if (isALPHA(s[1])) {
-	    static char debopts[] = "psltocPmfrxuLHXD";
+	    static char debopts[] = "psltocPmfrxuLHXDS";
 	    char *d;
 
 	    for (s++; *s && (d = strchr(debopts,*s)); s++)
@@ -2889,10 +2887,8 @@ my_exit(U32 status)
 {
     dTHR;
 
-#ifdef USE_THREADS
-    DEBUG_L(PerlIO_printf(Perl_debug_log, "my_exit: thread %p, status %lu\n",
+    DEBUG_S(PerlIO_printf(Perl_debug_log, "my_exit: thread %p, status %lu\n",
 			  thr, (unsigned long) status));
-#endif /* USE_THREADS */
     switch (status) {
     case 0:
 	STATUS_ALL_SUCCESS;
diff --git a/perl.h b/perl.h
index c6cc872..6a063b8 100644
--- a/perl.h
+++ b/perl.h
@@ -1443,6 +1443,11 @@ Gid_t getegid _((void));
 #define DEBUG_H(a) if (PL_debug & 8192)	a
 #define DEBUG_X(a) if (PL_debug & 16384)	a
 #define DEBUG_D(a) if (PL_debug & 32768)	a
+#  ifdef USE_THREADS
+#    define DEBUG_S(a) if (PL_debug & (1<<16))	a
+#  else
+#    define DEBUG_S(a)
+#  endif
 #else
 #define DEB(a)
 #define DEBUG(a)
@@ -1458,10 +1463,11 @@ Gid_t getegid _((void));
 #define DEBUG_r(a)
 #define DEBUG_x(a)
 #define DEBUG_u(a)
-#define DEBUG_L(a)
+#define DEBUG_S(a)
 #define DEBUG_H(a)
 #define DEBUG_X(a)
 #define DEBUG_D(a)
+#define DEBUG_S(a)
 #endif
 #define YYMAXDEPTH 300
 
diff --git a/pod/perlrun.pod b/pod/perlrun.pod
index da96acd..a0c85b9 100644
--- a/pod/perlrun.pod
+++ b/pod/perlrun.pod
@@ -272,6 +272,7 @@ equivalent to B<-Dtls>):
      8192  H  Hash dump -- usurps values()
     16384  X  Scratchpad allocation
     32768  D  Cleaning up
+    65536  S  Thread synchronization
 
 All these flags require C<-DDEBUGGING> when you compile the Perl
 executable.  This flag is automatically set if you include C<-g>
diff --git a/pp.c b/pp.c
index 35c76bc..8068f41 100644
--- a/pp.c
+++ b/pp.c
@@ -4486,7 +4486,7 @@ unlock_condpair(void *svv)
 	croak("panic: unlock_condpair unlocking mutex that we don't own");
     MgOWNER(mg) = 0;
     COND_SIGNAL(MgOWNERCONDP(mg));
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "0x%lx: unlock 0x%lx\n",
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "0x%lx: unlock 0x%lx\n",
 			  (unsigned long)thr, (unsigned long)svv);)
     MUTEX_UNLOCK(MgMUTEXP(mg));
 }
@@ -4511,7 +4511,7 @@ PP(pp_lock)
 	while (MgOWNER(mg))
 	    COND_WAIT(MgOWNERCONDP(mg), MgMUTEXP(mg));
 	MgOWNER(mg) = thr;
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(), "0x%lx: pp_lock lock 0x%lx\n",
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(), "0x%lx: pp_lock lock 0x%lx\n",
 			      (unsigned long)thr, (unsigned long)sv);)
 	MUTEX_UNLOCK(MgMUTEXP(mg));
 	SvREFCNT_inc(sv);	/* keep alive until magic_mutexfree */
diff --git a/pp_hot.c b/pp_hot.c
index 9b68c1c..e82c095 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -39,10 +39,10 @@ unset_cvowner(void *cvarg)
     dTHR;
 #endif /* DEBUGGING */
 
-    DEBUG_L((PerlIO_printf(PerlIO_stderr(), "%p unsetting CvOWNER of %p:%s\n",
+    DEBUG_S((PerlIO_printf(PerlIO_stderr(), "%p unsetting CvOWNER of %p:%s\n",
 			   thr, cv, SvPEEK((SV*)cv))));
     MUTEX_LOCK(CvMUTEXP(cv));
-    DEBUG_L(if (CvDEPTH(cv) != 0)
+    DEBUG_S(if (CvDEPTH(cv) != 0)
 		PerlIO_printf(PerlIO_stderr(), "depth %ld != 0\n",
 			      CvDEPTH(cv)););
     assert(thr == CvOWNER(cv));
@@ -2091,7 +2091,7 @@ PP(pp_entersub)
 	    while (MgOWNER(mg))
 		COND_WAIT(MgOWNERCONDP(mg), MgMUTEXP(mg));
 	    MgOWNER(mg) = thr;
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "%p: pp_entersub lock %p\n",
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "%p: pp_entersub lock %p\n",
 				  thr, sv);)
 	    MUTEX_UNLOCK(MgMUTEXP(mg));
 	    SvREFCNT_inc(sv);	/* Keep alive until magic_mutexfree */
@@ -2135,7 +2135,7 @@ PP(pp_entersub)
 	    /* We already have a clone to use */
 	    MUTEX_UNLOCK(CvMUTEXP(cv));
 	    cv = *(CV**)svp;
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  "entersub: %p already has clone %p:%s\n",
 				  thr, cv, SvPEEK((SV*)cv)));
 	    CvOWNER(cv) = thr;
@@ -2149,7 +2149,7 @@ PP(pp_entersub)
 		CvOWNER(cv) = thr;
 		SvREFCNT_inc(cv);
 		MUTEX_UNLOCK(CvMUTEXP(cv));
-		DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+		DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			    "entersub: %p grabbing %p:%s in stash %s\n",
 			    thr, cv, SvPEEK((SV*)cv), CvSTASH(cv) ?
 	    			HvNAME(CvSTASH(cv)) : "(none)"));
@@ -2158,7 +2158,7 @@ PP(pp_entersub)
 		CV *clonecv;
 		SvREFCNT_inc(cv); /* don't let it vanish from under us */
 		MUTEX_UNLOCK(CvMUTEXP(cv));
-		DEBUG_L((PerlIO_printf(PerlIO_stderr(),
+		DEBUG_S((PerlIO_printf(PerlIO_stderr(),
 				       "entersub: %p cloning %p:%s\n",
 				       thr, cv, SvPEEK((SV*)cv))));
 		/*
@@ -2175,7 +2175,7 @@ PP(pp_entersub)
 		cv = clonecv;
 		SvREFCNT_inc(cv);
 	    }
-	    DEBUG_L(if (CvDEPTH(cv) != 0)
+	    DEBUG_S(if (CvDEPTH(cv) != 0)
 			PerlIO_printf(PerlIO_stderr(), "depth %ld != 0\n",
 				      CvDEPTH(cv)););
 	    SAVEDESTRUCTOR(unset_cvowner, (void*) cv);
@@ -2325,7 +2325,7 @@ PP(pp_entersub)
 	    SV** ary;
 
 #if 0
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 	    			  "%p entersub preparing @_\n", thr));
 #endif
 	    av = (AV*)PL_curpad[0];
@@ -2363,7 +2363,7 @@ PP(pp_entersub)
 	    }
 	}
 #if 0
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			      "%p entersub returning %p\n", thr, CvSTART(cv)));
 #endif
 	RETURNOP(CvSTART(cv));
diff --git a/scope.c b/scope.c
index 1008ab1..067e29e 100644
--- a/scope.c
+++ b/scope.c
@@ -382,7 +382,7 @@ save_threadsv(PADOFFSET i)
 #ifdef USE_THREADS
     dTHR;
     SV **svp = &THREADSV(i);	/* XXX Change to save by offset */
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "save_threadsv %u: %p %p:%s\n",
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "save_threadsv %u: %p %p:%s\n",
 			  i, svp, *svp, SvPEEK(*svp)));
     save_svref(svp);
     return svp;
@@ -567,7 +567,7 @@ leave_scope(I32 base)
 	    ptr = SSPOPPTR;
 	restore_sv:
 	    sv = *(SV**)ptr;
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 				  "restore svref: %p %p:%s -> %p:%s\n",
 			  	  ptr, sv, SvPEEK(sv), value, SvPEEK(value)));
 	    if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv) &&
diff --git a/thread.h b/thread.h
index 0f350ed..3eb061a 100644
--- a/thread.h
+++ b/thread.h
@@ -194,7 +194,7 @@ struct perl_thread *getTHR _((void));
 #define ThrSETSTATE(t, s) STMT_START {		\
 	(t)->flags &= ~THRf_STATE_MASK;		\
 	(t)->flags |= (s);			\
-	DEBUG_L(PerlIO_printf(PerlIO_stderr(),	\
+	DEBUG_S(PerlIO_printf(PerlIO_stderr(),	\
 			      "thread %p set to state %d\n", (t), (s))); \
     } STMT_END
 
diff --git a/util.c b/util.c
index b91601d..431c5fa 100644
--- a/util.c
+++ b/util.c
@@ -1253,21 +1253,17 @@ die(const char* pat, ...)
     GV *gv;
     CV *cv;
 
-#ifdef USE_THREADS
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			  "%p: die: curstack = %p, mainstack = %p\n",
 			  thr, PL_curstack, PL_mainstack));
-#endif /* USE_THREADS */
 
     va_start(args, pat);
     message = pat ? mess(pat, &args) : Nullch;
     va_end(args);
 
-#ifdef USE_THREADS
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			  "%p: die: message = %s\ndiehook = %p\n",
 			  thr, message, PL_diehook));
-#endif /* USE_THREADS */
     if (PL_diehook) {
 	/* sv_2cv might call croak() */
 	SV *olddiehook = PL_diehook;
@@ -1301,11 +1297,9 @@ die(const char* pat, ...)
     }
 
     PL_restartop = die_where(message);
-#ifdef USE_THREADS
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 	  "%p: die: restartop = %p, was_in_eval = %d, top_env = %p\n",
 	  thr, PL_restartop, was_in_eval, PL_top_env));
-#endif /* USE_THREADS */
     if ((!PL_restartop && was_in_eval) || PL_top_env->je_prev)
 	JMPENV_JUMP(3);
     return PL_restartop;
@@ -1324,9 +1318,7 @@ croak(const char* pat, ...)
     va_start(args, pat);
     message = mess(pat, &args);
     va_end(args);
-#ifdef USE_THREADS
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(), "croak: 0x%lx %s", (unsigned long) thr, message));
-#endif /* USE_THREADS */
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(), "croak: 0x%lx %s", (unsigned long) thr, message));
     if (PL_diehook) {
 	/* sv_2cv might call croak() */
 	SV *olddiehook = PL_diehook;
@@ -2711,7 +2703,7 @@ condpair_magic(SV *sv)
 	    mg->mg_ptr = (char *)cp;
 	    mg->mg_len = sizeof(cp);
 	    UNLOCK_SV_MUTEX;
-	    DEBUG_L(WITH_THR(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(WITH_THR(PerlIO_printf(PerlIO_stderr(),
 					   "%p: condpair_magic %p\n", thr, sv));)
 	}
     }
@@ -2812,7 +2804,7 @@ new_struct_thread(struct perl_thread *t)
 	    SV *sv = newSVsv(*svp);
 	    av_store(thr->threadsv, i, sv);
 	    sv_magic(sv, 0, 0, &PL_threadsv_names[i], 1);
-	    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+	    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 		"new_struct_thread: copied threadsv %d %p->%p\n",i, t, thr));
 	}
     } 
diff --git a/win32/win32thread.c b/win32/win32thread.c
index 14ac5d7..1eb0e87 100644
--- a/win32/win32thread.c
+++ b/win32/win32thread.c
@@ -93,7 +93,7 @@ Perl_thread_create(struct perl_thread *thr, thread_func_t *fn)
     unsigned long th;
 
     MUTEX_LOCK(&thr->mutex);
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			  "%p: create OS thread\n", thr));
 #ifdef USE_RTL_THREAD_API
     /* See comment about USE_RTL_THREAD_API in win32thread.h */
@@ -124,7 +124,7 @@ Perl_thread_create(struct perl_thread *thr, thread_func_t *fn)
 #else	/* !USE_RTL_THREAD_API */
     thr->self = CreateThread(NULL, 0, fn, (void*)thr, 0, &junk);
 #endif	/* !USE_RTL_THREAD_API */
-    DEBUG_L(PerlIO_printf(PerlIO_stderr(),
+    DEBUG_S(PerlIO_printf(PerlIO_stderr(),
 			  "%p: OS thread = %p, id=%ld\n", thr, thr->self, junk));
     MUTEX_UNLOCK(&thr->mutex);
     return thr->self ? 0 : -1;