Index: src/OFFile.m
==================================================================
--- src/OFFile.m
+++ src/OFFile.m
@@ -76,11 +76,11 @@
 #endif
 
 #ifndef OF_AMIGAOS
 # define closeHandle(h) close(h)
 #else
-struct of_file_handle {
+static struct of_file_handle {
 	of_file_handle_t previous, next;
 	BPTR handle;
 	bool append;
 } *firstHandle = NULL;
 

Index: src/once.m
==================================================================
--- src/once.m
+++ src/once.m
@@ -15,10 +15,12 @@
  * file.
  */
 
 #include "config.h"
 
+#include <stdbool.h>
+
 #import "once.h"
 
 #ifdef OF_AMIGAOS
 # include <proto/exec.h>
 #endif
@@ -31,16 +33,20 @@
 void
 of_once(of_once_t *control, void (*func)(void))
 {
 #if !defined(OF_HAVE_THREADS)
 	if (*control == 0) {
-		*control = 1;
 		func();
+		*control = 1;
 	}
 #elif defined(OF_HAVE_PTHREADS)
 	pthread_once(control, func);
 #elif defined(OF_HAVE_ATOMIC_OPS)
+	/* Avoid atomic operations in case it's already done. */
+	if (*control == 2)
+		return;
+
 	if (of_atomic_int_cmpswap(control, 0, 1)) {
 		func();
 
 		of_memory_barrier();
 
@@ -47,18 +53,35 @@
 		of_atomic_int_inc(control);
 	} else
 		while (*control == 1)
 			of_thread_yield();
 #elif defined(OF_AMIGAOS)
+	bool run = false;
+
+	/* Avoid Forbid() in case it's already done. */
+	if (*control == 2)
+		return;
+
 	Forbid();
-	@try {
-		if (*control == 0) {
-			*control = 1;
-			func();
+
+	switch (*control) {
+	case 0:
+		*control = 1;
+		run = true;
+		break;
+	case 1:
+		while (*control == 1) {
+			Permit();
+			Forbid();
 		}
-	} @finally {
-		Permit();
+	}
+
+	Permit();
+
+	if (run) {
+		func();
+		*control = 2;
 	}
 #else
 # error No of_once available
 #endif
 }