- The thread-safe system() call now blocks all standard I/O operations

until the function has returned. Which is harsh, but there is no
  elegant solution to the issue of keeping the same dos.library
  file handles from concurrent use which SystemTagList() might just
  end up using.


git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@14898 87f5fb63-7c3d-0410-a384-fd976d0f7a62

library/stdlib_system.c

@@ -1,5 +1,5 @@
 /*
- * $Id: stdlib_system.c,v 1.5 2005-03-18 12:38:25 obarthel Exp $
+ * $Id: stdlib_system.c,v 1.6 2005-03-24 15:31:16 obarthel Exp $
  *
  * :ts=4
  *
@@ -35,6 +35,10 @@
 #include "stdlib_headers.h"
 #endif /* _STDLIB_HEADERS_H */
 
+#ifndef _STIO_HEADERS_H
+#include "stdio_headers.h"
+#endif /* _STDIO_HEADERS_H */
+
 /****************************************************************************/
 
 #ifndef _STDLIB_MEMORY_H
@@ -172,7 +176,18 @@ system(const char * command)
 		SHOWSTRING(command);
 
 		PROFILE_OFF();
+
+		/* In thread-safe mode, system() operation can interfere with
+		   regular file I/O if the same dos.library file handles are
+		   involved. Because we really cannot predict which file handles
+		   will be associated with the current Output() and Input()
+		   streams, we play it safe and just block everything. */
+		__stdio_lock();
+
 		result = SystemTagList((STRPTR)command, (struct TagItem *)system_tags);
+
+		__stdio_unlock();
+
 		PROFILE_ON();
 	}