Warn about using an unsafe +initialize

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@32455 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,13 @@
+2011-03-05  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSUserDefaults.m: Small optimisation suggested by Fred.
+	* config/config.initialize.m: Test for working +initialize
+	* configure.ac: Use test for +initialize thread safety
+	* Headers/Additions/GNUstepBase/config.h.in: regenerate
+	* configure: regenerate
+	* Source/NSThread.m: Log warning when going multithreaded without
+	a reliable runtime.
+
 2011-03-05  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/NSNumberFormatter.m: Make error text compatible with OSX

Headers/Additions/GNUstepBase/config.h.in

@@ -1,5 +1,8 @@
 /* Headers/Additions/GNUstepBase/config.h.in.  Generated from configure.ac by autoheader.  */
 
+/* Define if building universal (internal helper macro) */
+#undef AC_APPLE_UNIVERSAL_BUILD
+
 /* The normal alignment of `pthread_cond_t', in bytes. */
 #undef ALIGNOF_PTHREAD_COND_T
 
@@ -283,6 +286,9 @@
 /* Define to 1 if you have the `inet_pton' function. */
 #undef HAVE_INET_PTON
 
+/* Define if libobjc has thread-safe +initialize support */
+#undef HAVE_INITIALIZE
+
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 
@@ -723,26 +729,44 @@
 /* Define if using the libffi library for invocations */
 #undef USE_LIBFFI
 
+/* Enable extensions on AIX 3, Interix.  */
+#ifndef _ALL_SOURCE
+# undef _ALL_SOURCE
+#endif
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
+/* Enable threading extensions on Solaris.  */
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# undef _POSIX_PTHREAD_SEMANTICS
+#endif
+/* Enable extensions on HP NonStop.  */
+#ifndef _TANDEM_SOURCE
+# undef _TANDEM_SOURCE
+#endif
+/* Enable general extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# undef __EXTENSIONS__
+#endif
+
+
 /* Define if vasprintf returns the length printed */
 #undef VASPRINTF_RETURNS_LENGTH
 
 /* Define if vsprintf returns the length printed */
 #undef VSPRINTF_RETURNS_LENGTH
 
-/* Define to 1 if your processor stores words with the most significant byte
+/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
-   first (like Motorola and SPARC, unlike Intel and VAX). */
+   significant byte first (like Motorola and SPARC, unlike Intel). */
-#undef WORDS_BIGENDIAN
+#if defined AC_APPLE_UNIVERSAL_BUILD
-
+# if defined __BIG_ENDIAN__
-/* Define to 1 if on AIX 3.
+#  define WORDS_BIGENDIAN 1
-   System headers sometimes define this.
+# endif
-   We just want to avoid a redefinition error message.  */
+#else
-#ifndef _ALL_SOURCE
+# ifndef WORDS_BIGENDIAN
-# undef _ALL_SOURCE
+#  undef WORDS_BIGENDIAN
-#endif
+# endif
-
-/* Enable GNU extensions on systems that have them.  */
-#ifndef _GNU_SOURCE
-# undef _GNU_SOURCE
 #endif
 
 /* Define to 1 if on MINIX. */
@@ -755,17 +779,6 @@
 /* Define to 1 if you need to in order for `stat' and other things to work. */
 #undef _POSIX_SOURCE
 
-/* Enable extensions on Solaris.  */
-#ifndef __EXTENSIONS__
-# undef __EXTENSIONS__
-#endif
-#ifndef _POSIX_PTHREAD_SEMANTICS
-# undef _POSIX_PTHREAD_SEMANTICS
-#endif
-#ifndef _TANDEM_SOURCE
-# undef _TANDEM_SOURCE
-#endif
-
 /* Define to `__inline__' or `__inline' if that's what the C compiler
    calls it, or to nothing if 'inline' is not supported under any name.  */
 #ifndef __cplusplus

Source/NSThread.m

@@ -380,15 +380,13 @@ gnustep_base_thread_callback(void)
 	       * Won't work properly if threads are not all created
 	       * by this class, but it's better than nothing.
 	       */
-	      // FIXME: This code is complete nonsense; this can be called from
-	      // any thread (and is when adding new foreign threads), so this
-	      // will often be called from the wrong thread, delivering
-	      // notifications to the wrong thread, and generally doing the
-	      // wrong thing..
 	      if (nc == nil)
 		{
 		  nc = RETAIN([NSNotificationCenter defaultCenter]);
 		}
+#if	!defined(HAVE_INITIALIZE)
+	      NSLog(@"WARNING your program is becoming multi-threaded, but you are using an ObjectiveC runtime library which does not have a thread-safe implementation of the +initialize method.  This means that any classes not already used may be incorrectly initialised, potentially causing strange behaviors and crashes.  Please build/run GNUstep-base with a runtime which supports the +initialize method.");
+#endif
 	      [nc postNotificationName: NSWillBecomeMultiThreadedNotification
 				object: nil
 			      userInfo: nil];
@@ -536,11 +534,7 @@ unregisterActiveThread(NSThread *thread)
        * if we have become multi-threaded due to a call to the runtime directly
        * rather than via the NSThread class.
        */
-#if defined(__GNUSTEP_RUNTIME__) || defined(NeXT_RUNTIME)
-      gnustep_base_thread_callback();
-#else
       objc_set_thread_callback(gnustep_base_thread_callback);
-#endif
     }
 }
 

Source/NSUserDefaults.m

@@ -783,15 +783,15 @@ newLanguages(NSArray *oldNames)
 
 + (NSArray*) userLanguages
 {
-  return [[NSUserDefaults standardUserDefaults]
+  return [[self standardUserDefaults] stringArrayForKey: @"NSLanguages"];
-    stringArrayForKey: @"NSLanguages"];
 }
 
 + (void) setUserLanguages: (NSArray*)languages
 {
-  NSUserDefaults	*defs = [NSUserDefaults standardUserDefaults];
+  NSUserDefaults	*defs;
   NSMutableDictionary	*dict;
 
+  defs = [self standardUserDefaults];
   dict = [[defs volatileDomainForName: GSPrimaryDomain] mutableCopy];
   if (languages == nil)          // Remove the entry
     {

config/config.initialize.m

@@ -0,0 +1,82 @@
+/* Test whether Objective-C runtime +initialize support is thread-safe
+ */
+
+#include "objc-common.g"
+#include <pthread.h>
+
+static unsigned	initialize_entered = 0;
+static unsigned	initialize_exited = 0;
+static unsigned	class_entered = 0;
+static BOOL	may_proceed = NO;
+
+@interface	MyClass : NSObject
+@end
+@implementation	MyClass
++ (void) initialize
+{
+  initialize_entered++;
+  while (NO == may_proceed)
+    sleep(1);
+  initialize_exited++;
+}
++ (Class) class
+{
+  class_entered++;
+  return self;
+}
+@end
+
+static void test(void *arg)
+{
+  [MyClass class];
+}
+
+int
+main()
+{
+  pthread_t     t1;
+  pthread_t     t2;
+
+  if (0 == pthread_create(&t1, 0, test, 0))
+    {
+      unsigned	counter = 0;
+
+      while (0 == initialize_entered && counter++ < 3)
+	{
+	  sleep(1);
+	}
+      if (0 == initialize_entered)
+	{
+	  fprintf(stderr, "Failed to initialize\n");
+	  return 1;
+	}
+      if (0 == pthread_create(&t1, 0, test, 0))
+        {
+	  sleep(1);
+	  if (class_entered > 0)
+	    {
+	      fprintf(stderr, "class entered prematurely\n");
+	      return 1;
+	    }
+	  may_proceed = YES;
+	  sleep(1);
+	  if (2 == class_entered)
+	    {
+	      return 0;	// OK
+	    }
+	  fprintf(stderr, "problem with initialize\n");
+	  return 1;
+	}
+      else
+	{
+	  fprintf(stderr, "failed to create t2\n");
+	  return 1;
+	}
+    }
+  else
+    {
+      fprintf(stderr, "failed to create t1\n");
+      return 1;
+    }
+}
+

configure.ac

@@ -1457,6 +1457,66 @@ OBJC_SYS_DYNAMIC_LINKER()
 # NOTE: libdl should be in LIBS now if it's available.
 AC_CHECK_FUNCS(dladdr)
 
+#--------------------------------------------------------------------
+# Check for pthread.h 
+#--------------------------------------------------------------------
+AC_CHECK_HEADERS(pthread.h)
+if test $ac_cv_header_pthread_h = yes ; then
+  AC_CHECK_SIZEOF(pthread_mutex_t,,[AC_INCLUDES_DEFAULT
+#include <pthread.h>])
+  GS_SIZEOF_MUTEX_T=$ac_cv_sizeof_pthread_mutex_t
+  if test $ac_cv_sizeof_pthread_mutex_t = 0 ; then
+    AC_MSG_ERROR([Unable to find size of pthread_mutex_t (required).])
+  fi
+  AC_SUBST(GS_SIZEOF_MUTEX_T)
+  AC_CHECK_SIZEOF(pthread_cond_t,,[AC_INCLUDES_DEFAULT
+#include <pthread.h>])
+  if test $ac_cv_sizeof_pthread_cond_t = 0 ; then
+    AC_MSG_ERROR([Unable to find size of pthread_cond_t (required).])
+  fi
+  GS_SIZEOF_COND_T=$ac_cv_sizeof_pthread_cond_t
+  AC_SUBST(GS_SIZEOF_COND_T)
+  AC_CHECK_ALIGNOF(pthread_mutex_t,[AC_INCLUDES_DEFAULT
+#include <pthread.h>])
+  GS_ALIGNOF_MUTEX_T=$ac_cv_alignof_pthread_mutex_t
+  if test $ac_cv_alignof_pthread_mutex_t = 0 ; then
+    AC_MSG_ERROR([Unable to find align of pthread_mutex_t (required).])
+  fi
+  AC_SUBST(GS_ALIGNOF_MUTEX_T)
+  AC_CHECK_ALIGNOF(pthread_cond_t,[AC_INCLUDES_DEFAULT
+#include <pthread.h>])
+  if test $ac_cv_alignof_pthread_cond_t = 0 ; then
+    AC_MSG_ERROR([Unable to find align of pthread_cond_t (required).])
+  fi
+  GS_ALIGNOF_COND_T=$ac_cv_alignof_pthread_cond_t
+  AC_SUBST(GS_ALIGNOF_COND_T)
+else
+  AC_MSG_ERROR([Unable to find pthread.h (needed for thread support).])
+fi
+AC_CHECK_LIB(pthread, pthread_join, pthread_ok=yes, pthread_ok=no)
+ismingw=no
+case "$target_os" in
+  mingw*)	ismingw=yes;;
+esac
+if test $pthread_ok = yes ; then
+  LIBS="$LIBS -lpthread"
+else
+  if test $ismingw = yes ; then
+    AC_CHECK_LIB(pthreadGC2, pthread_join, pthread_ok=yes, pthread_ok=no)
+    if test $pthread_ok = yes ; then
+      LIBS="$LIBS -lpthreadGC2"
+    fi
+  fi
+fi
+if test $pthread_ok = no ; then
+  AC_MSG_ERROR([Unable to find pthread library (needed for thread support).])
+fi
+
+
+# Typically need librt on Solaris for sched_yield
+AC_CHECK_LIB(rt, sched_yield)
+
+
 #--------------------------------------------------------------------
 # Check whether Objective-C /really/ works
 #--------------------------------------------------------------------
@@ -1570,6 +1630,8 @@ else
 fi
 AC_SUBST(OBJCSYNC)
 
+# Don't revert any Objective-C flags as they are used in the next test
+
 #--------------------------------------------------------------------
 # Check for ObjC2 support in runtime
 #--------------------------------------------------------------------
@@ -1581,6 +1643,8 @@ else
 fi
 AC_SUBST(OBJC2RUNTIME)
 
+# Don't revert any Objective-C flags as they are used in the next test
+
 GS_NONFRAGILE=0
 GS_MIXEDABI=0
 if test "$nonfragile" = "yes"; then
@@ -1632,6 +1696,8 @@ if test $have_set_uncaught_exception_handler = yes; then
 fi
 AC_MSG_RESULT($have_set_uncaught_exception_handler)
 
+# Don't revert any Objective-C flags as they are used in the next test
+
 AC_MSG_CHECKING(for objc_set_unexpected() in runtime)
 AC_LINK_IFELSE([#include "$srcdir/config/config.set_unexpected.m"],
 	have_set_unexpected=yes, have_set_unexpected=no)
@@ -1641,6 +1707,8 @@ if test $have_set_unexpected = yes; then
 fi
 AC_MSG_RESULT($have_set_unexpected)
 
+# Don't revert any Objective-C flags as they are used in the next test
+
 AC_MSG_CHECKING(for _objc_unexpected_exception in runtime)
 AC_RUN_IFELSE([#include "$srcdir/config/config.unexpected.m"],
 	have_unexpected=yes, have_unexpected=no)
@@ -1671,6 +1739,19 @@ if test $ac_cv_func_objc_sync_enter = yes ; then
 fi
 AC_SUBST(HAVE_OBJC_SYNC_ENTER)
 
+# Don't revert any Objective-C flags as they are used in the next test
+
+AC_MSG_CHECKING(for thread-safe +initialize in runtime)
+AC_RUN_IFELSE([#include "$srcdir/config/config.initialize.m"],
+	safe_initialize=yes, safe_initialize=no)
+if test $safe_initialize = yes; then
+  AC_DEFINE(HAVE_INITIALIZE,1,
+	    [Define if libobjc has thread-safe +initialize support])
+else
+  AC_MSG_WARN([Your ObjectiveC runtime does not support thread-safe class initialisation.  Please use a different runtime if you intend to use threads.])
+fi
+AC_MSG_RESULT($safe_initialize)
+
 LIBS="$saved_LIBS"
 CPPFLAGS="$saved_CPPFLAGS"
 
@@ -1805,64 +1886,6 @@ if test $ac_cv_header_poll_h = yes; then
   fi
 fi
 
-#--------------------------------------------------------------------
-# Check for pthread.h 
-#--------------------------------------------------------------------
-AC_CHECK_HEADERS(pthread.h)
-if test $ac_cv_header_pthread_h = yes ; then
-  AC_CHECK_SIZEOF(pthread_mutex_t,,[AC_INCLUDES_DEFAULT
-#include <pthread.h>])
-  GS_SIZEOF_MUTEX_T=$ac_cv_sizeof_pthread_mutex_t
-  if test $ac_cv_sizeof_pthread_mutex_t = 0 ; then
-    AC_MSG_ERROR([Unable to find size of pthread_mutex_t (required).])
-  fi
-  AC_SUBST(GS_SIZEOF_MUTEX_T)
-  AC_CHECK_SIZEOF(pthread_cond_t,,[AC_INCLUDES_DEFAULT
-#include <pthread.h>])
-  if test $ac_cv_sizeof_pthread_cond_t = 0 ; then
-    AC_MSG_ERROR([Unable to find size of pthread_cond_t (required).])
-  fi
-  GS_SIZEOF_COND_T=$ac_cv_sizeof_pthread_cond_t
-  AC_SUBST(GS_SIZEOF_COND_T)
-  AC_CHECK_ALIGNOF(pthread_mutex_t,[AC_INCLUDES_DEFAULT
-#include <pthread.h>])
-  GS_ALIGNOF_MUTEX_T=$ac_cv_alignof_pthread_mutex_t
-  if test $ac_cv_alignof_pthread_mutex_t = 0 ; then
-    AC_MSG_ERROR([Unable to find align of pthread_mutex_t (required).])
-  fi
-  AC_SUBST(GS_ALIGNOF_MUTEX_T)
-  AC_CHECK_ALIGNOF(pthread_cond_t,[AC_INCLUDES_DEFAULT
-#include <pthread.h>])
-  if test $ac_cv_alignof_pthread_cond_t = 0 ; then
-    AC_MSG_ERROR([Unable to find align of pthread_cond_t (required).])
-  fi
-  GS_ALIGNOF_COND_T=$ac_cv_alignof_pthread_cond_t
-  AC_SUBST(GS_ALIGNOF_COND_T)
-else
-  AC_MSG_ERROR([Unable to find pthread.h (needed for thread support).])
-fi
-AC_CHECK_LIB(pthread, pthread_join, pthread_ok=yes, pthread_ok=no)
-ismingw=no
-case "$target_os" in
-  mingw*)	ismingw=yes;;
-esac
-if test $pthread_ok = yes ; then
-  LIBS="$LIBS -lpthread"
-else
-  if test $ismingw = yes ; then
-    AC_CHECK_LIB(pthreadGC2, pthread_join, pthread_ok=yes, pthread_ok=no)
-    if test $pthread_ok = yes ; then
-      LIBS="$LIBS -lpthreadGC2"
-    fi
-  fi
-fi
-if test $pthread_ok = no ; then
-  AC_MSG_ERROR([Unable to find pthread library (needed for thread support).])
-fi
-
-# Typically need librt on Solaris for sched_yield
-AC_CHECK_LIB(rt, sched_yield)
-
 #--------------------------------------------------------------------
 # This function needed by StdioStream.m
 #--------------------------------------------------------------------
@@ -2212,8 +2235,7 @@ elif test "$enable_pass_arguments" = "no"; then
   if test "$objc_load_method_worked" = yes -a \( "$ac_cv_sys_procfs" = yes -o "$have_kvm_env" = 1 -o "$ac_cv_sys_procfs_psinfo" = yes \); then
     GS_FAKE_MAIN=0
     if test "$have_kvm_env" = "1"; then
-      echo "WARNING ... using libkvm which is known to be buggy on some systems"
+      AC_MSG_WARN([Using libkvm which is known to be buggy on some systems consider configuring with --enable-fake-main instead.])
-      echo "consider configuring with --enable-fake-main instead."
     fi
   else
     GS_FAKE_MAIN=1