2006-10-13 Andrew Haley <aph@redhat.com>gcj/gcj-tls-experimental-branch

        * java-gimplify.c: Revert last changes.
        * java-tree.h: Likewise.
        * jcf-parse.c: Likewise.
        * parse.y: Likewise.
        * class.c: Likewise.

2006-10-12  Andrew Haley  <aph@redhat.com>

        * java/lang/natThreadLocal.cc: New file.
        * java/lang/ThreadLocal.java: Rewrite to use native TLS.
        * Makefile.am: Add java/lang/natThreadLocal.cc.
        * sources.am: Move classpath/java/lang/ThreadLocal.java to
        java/lang/ThreadLocal.java.



git-svn-id: https://gcc.gnu.org/svn/gcc/branches/gcj/gcj-tls-experimental-branch@117693 138bc75d-0d04-0410-961f-82ee72b054a4

9 files changed, 104 insertions, 268 deletions

diff --git a/gcc/java/ChangeLog b/gcc/java/ChangeLog
index 51043db398e..dccb08e6ae5 100644
--- a/gcc/java/ChangeLog
+++ b/gcc/java/ChangeLog
@@ -1,3 +1,11 @@
+2006-10-13  Andrew Haley  <aph@redhat.com>
+
+	* java-gimplify.c: Revert last changes.
+	* java-tree.h: Likewise.
+	* jcf-parse.c: Likewise.
+	* parse.y: Likewise.
+	* class.c: Likewise.
+
 2006-09-01  Andrew Haley  <aph@redhat.com>
 
 	* class.c (find_tls_thunk): New function.
diff --git a/gcc/java/class.c b/gcc/java/class.c
index ea9bf719822..cdb298e77a1 100644
--- a/gcc/java/class.c
+++ b/gcc/java/class.c
@@ -65,7 +65,6 @@ static int assume_compiled (const char *);
 static tree build_symbol_entry (tree, tree);
 static tree emit_assertion_table (tree);
 static void register_class (void);
-static void build_tls_thunk (tree decl);
 
 struct obstack temporary_obstack;
 
@@ -1617,96 +1616,6 @@ supers_all_compiled (tree type)
   return 1;
 }
 
-tree 
-find_tls_thunk (tree decl)
-{
-  char *buf = alloca (4096);
-  tree id;
-  
-  sprintf (buf, "_Jv_thread_local_thunk_%s_%s", 
-	   IDENTIFIER_POINTER (DECL_NAME (decl)), 
-	   IDENTIFIER_POINTER (mangled_classname ("", DECL_CONTEXT (decl))));
-  id = get_identifier (buf);
-  return id ? IDENTIFIER_GLOBAL_VALUE (id) : NULL_TREE;
-}
-
-void
-build_tls_thunks (tree class)
-{
-  tree field;
-
-  if (targetm.have_tls)
-    for (field = TYPE_FIELDS (class); field != NULL_TREE; field = TREE_CHAIN (field))
-      {
-	if (TREE_CODE (field) == VAR_DECL
-	    && TREE_CODE (TREE_TYPE (field)) == POINTER_TYPE
-	    && FIELD_STATIC (field)
-	    && ((DECL_NAME (TYPE_NAME (TREE_TYPE (TREE_TYPE (field)))))
-		== get_identifier ("java.lang.ThreadLocal")))
-	  build_tls_thunk (field);
-      }      
-}
-
-static void
-build_tls_thunk (tree decl)
-{
-  tree fdecl, vdecl;
-  char *buf = alloca (4096);
-  tree stmts;
-  tree_stmt_iterator it;
-  tree ret_stmt;
-  tree result_decl;
-  tree function_identifier;
-  tree buf_type = make_node (RECORD_TYPE);
-
-  {
-    tree id_field = build_decl (FIELD_DECL, NULL_TREE, long_type_node);
-    tree ptr_field = build_decl (FIELD_DECL, NULL_TREE, ptr_type_node);
-    TYPE_FIELDS (buf_type) = id_field;
-    TREE_CHAIN (id_field) = ptr_field;
-    layout_type (buf_type);
-  }
-
-  sprintf (buf, "_Jv_thread_local_%s_%s", 
-	   IDENTIFIER_POINTER (DECL_NAME (decl)), 
-	   IDENTIFIER_POINTER (mangled_classname ("", DECL_CONTEXT (decl))));
-  vdecl = build_decl (VAR_DECL, get_identifier (buf), buf_type);
-  DECL_TLS_MODEL (vdecl) = decl_default_tls_model (vdecl);
-  TREE_STATIC (vdecl) = 1;
-  DECL_IGNORED_P (vdecl) = 1;
-  DECL_ARTIFICIAL (vdecl) = 1;
-  rest_of_decl_compilation (vdecl, 1, 0);
-
-  sprintf (buf, "_Jv_thread_local_thunk_%s_%s", 
-	   IDENTIFIER_POINTER (DECL_NAME (decl)), 
-	   IDENTIFIER_POINTER (mangled_classname ("", DECL_CONTEXT (decl))));
-  function_identifier = get_identifier (buf);
-  fdecl = build_decl (FUNCTION_DECL, function_identifier,
-		      build_function_type_list (ptr_type_node, 
-						void_type_node, 
-						NULL_TREE));
-  IDENTIFIER_GLOBAL_VALUE (function_identifier) = fdecl;
-  result_decl = build_result_decl (fdecl);
-
-  ret_stmt
-    = build1 (RETURN_EXPR, ptr_type_node, 
-	      (build2 (MODIFY_EXPR, ptr_type_node,
-		       result_decl,
-		       fold_convert (ptr_type_node, 
-				     build_address_of (vdecl)))));
-
-  stmts = make_node (STATEMENT_LIST);
-  it = tsi_last (stmts);
-  tsi_link_after (&it, ret_stmt, TSI_CONTINUE_LINKING);
-  TREE_TYPE (stmts) = void_type_node;
-
-  DECL_SAVED_TREE (fdecl) = stmts;
-  DECL_INITIAL (fdecl) = make_node (BLOCK);
-  
-  java_genericize (fdecl);
-  cgraph_finalize_function (fdecl, false);
-}
-
 void
 make_class_data (tree type)
 {
@@ -1737,7 +1646,6 @@ make_class_data (tree type)
       to where objects actually point at, following new g++ ABI. */
   tree dtable_start_offset = build_int_cst (NULL_TREE,
 					    2 * POINTER_SIZE / BITS_PER_UNIT);
-  tree first_field;
 
   this_class_addr = build_static_class_ref (type);
   decl = TREE_OPERAND (this_class_addr, 0);
@@ -1759,16 +1667,13 @@ make_class_data (tree type)
 	class_dtable_decl = dtable_decl;
     }
 
-  /* Find the first real field.  */
-  first_field = TYPE_FIELDS (type);
-  while (first_field && DECL_ARTIFICIAL (first_field))
-    first_field = TREE_CHAIN (first_field);  /* Skip dummy fields.  */
-  if (first_field && DECL_NAME (first_field) == NULL_TREE)
-    first_field = TREE_CHAIN (first_field);  /* Skip dummy field 
-						for inherited data. */
-
   /* Build Field array. */
-  for (field = first_field; field != NULL_TREE; field = TREE_CHAIN (field))
+  field = TYPE_FIELDS (type);
+  while (field && DECL_ARTIFICIAL (field))
+    field = TREE_CHAIN (field);  /* Skip dummy fields.  */
+  if (field && DECL_NAME (field) == NULL_TREE)
+    field = TREE_CHAIN (field);  /* Skip dummy field for inherited data. */
+  for ( ;  field != NULL_TREE;  field = TREE_CHAIN (field))
     {
       if (! DECL_ARTIFICIAL (field))
 	{
diff --git a/gcc/java/java-gimplify.c b/gcc/java/java-gimplify.c
index 3d3171653ff..54900d3f9ab 100644
--- a/gcc/java/java-gimplify.c
+++ b/gcc/java/java-gimplify.c
@@ -26,14 +26,11 @@ The Free Software Foundation is independent of Sun Microsystems, Inc.  */
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
-#include "target.h"
 #include "tree.h"
 #include "java-tree.h"
 #include "tree-dump.h"
 #include "tree-gimple.h"
 #include "toplev.h"
-#include "rtl.h" /* For decl_default_tls_model.  */
-#include "jcf.h"
 
 static tree java_gimplify_labeled_block_expr (tree);
 static tree java_gimplify_exit_block_expr (tree);
@@ -269,77 +266,14 @@ java_gimplify_component_ref (tree *expr_p, tree *pre_p, tree *post_p)
   return GS_UNHANDLED;
 }
   
-static enum gimplify_status
-java_maybe_replace_init_expr (tree *modify_expr_p,
-			      tree *pre_p ATTRIBUTE_UNUSED, 
-			      tree *post_p ATTRIBUTE_UNUSED)
-{
-  tree modify_expr = *modify_expr_p;
-  tree lhs = TREE_OPERAND (modify_expr, 0);
-  tree lhs_type = TREE_TYPE (lhs);
-  tree name = NULL_TREE;
-  tree fdecl, arg_list;
-
-  if (targetm.have_tls
-      && TREE_CODE (lhs) == VAR_DECL
-      && TREE_CODE (lhs_type) == POINTER_TYPE
-      && FIELD_STATIC (lhs)
-      && ((name = DECL_NAME (TYPE_NAME (TREE_TYPE (lhs_type)))) 
-	  == get_identifier ("java.lang.ThreadLocal"))
-      && (fdecl = find_tls_thunk (lhs)) != NULL_TREE)
-    {
-      tree call_expr;
-      tree rhs = TREE_OPERAND (modify_expr, 1);
-      enum gimplify_status stat;
-      tree maybe_method
-	= lookup_java_method (TREE_TYPE (lhs_type), 
-			      get_identifier ("setTLS"),
-			      get_identifier ("(Lgnu/gcj/RawData;)V"));
-      if (! maybe_method /* && ! flag_verify_invocations */)
-	{
-	  maybe_method
-	    = add_method (TREE_TYPE (lhs_type), ACC_FINAL|ACC_PRIVATE, 
-			  get_identifier ("setTLS"), 
-			  get_identifier ("(Lgnu/gcj/RawData;)V"));
-	  DECL_EXTERNAL (maybe_method) = 1;
-	}
-/*       IDENTIFIER_GLOBAL_VALUE (name) = NULL_TREE; */
-      stat = gimplify_expr (&rhs, pre_p, post_p,
-			    is_gimple_formal_tmp_var, fb_rvalue);
-      if (stat == GS_ERROR)
-	return stat;
-
-      arg_list = tree_cons (NULL_TREE, rhs, build_tree_list (NULL_TREE, 
-							     build_address_of (fdecl)));
-
-      call_expr = build3 (CALL_EXPR, void_type_node,
-			  build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (maybe_method)), 
-/* 				  build_invokevirtual (invoke_build_dtable (0, arg_list), */
-/* 						       maybe_method, */
-/* 						       integer_one_node) */
-				  build_known_method_ref (maybe_method, TREE_TYPE (maybe_method),
-							  DECL_CONTEXT (maybe_method),
-							  get_identifier ("(Lgnu/gcj/RawData;)V"),
-							  arg_list, integer_one_node)),
-			  arg_list,
-			  NULL_TREE);
-      TREE_OPERAND (modify_expr, 1) = build2 (COMPOUND_EXPR, TREE_TYPE (rhs), call_expr, rhs);
-    }
-
-  return GS_UNHANDLED;
-}
 
 static enum gimplify_status
 java_gimplify_modify_expr (tree *modify_expr_p, tree *pre_p, tree *post_p)
 {
   tree modify_expr = *modify_expr_p;
-  tree lhs, lhs_type, rhs;
-
-  java_maybe_replace_init_expr (&modify_expr, pre_p, post_p);
-
-  lhs = TREE_OPERAND (modify_expr, 0);
-  rhs = TREE_OPERAND (modify_expr, 1);
-  lhs_type = TREE_TYPE (lhs);
+  tree lhs = TREE_OPERAND (modify_expr, 0);
+  tree rhs = TREE_OPERAND (modify_expr, 1);
+  tree lhs_type = TREE_TYPE (lhs);
 
   if (CLASS_FROM_SOURCE_P (output_class)
       && TREE_CODE (lhs) == COMPONENT_REF
diff --git a/gcc/java/java-tree.h b/gcc/java/java-tree.h
index 452eaa23f2e..f3478692d70 100644
--- a/gcc/java/java-tree.h
+++ b/gcc/java/java-tree.h
@@ -1405,9 +1405,6 @@ extern int in_same_package (tree, tree);
 extern tree builtin_function (const char *, tree, int, enum built_in_class,
 			      const char *, tree);
 
-tree find_tls_thunk (tree decl);
-void build_tls_thunks (tree class);
-
 #define DECL_FINAL(DECL) DECL_LANG_FLAG_3 (DECL)
 
 /* Access flags etc for a method (a FUNCTION_DECL): */
diff --git a/gcc/java/jcf-parse.c b/gcc/java/jcf-parse.c
index 8d576b2526b..b9d52b61f8c 100644
--- a/gcc/java/jcf-parse.c
+++ b/gcc/java/jcf-parse.c
@@ -856,7 +856,6 @@ parse_class_file (void)
   (*debug_hooks->start_source_file) (input_line, input_filename);
 
   gen_indirect_dispatch_tables (current_class);
-  build_tls_thunks (current_class);
 
   java_mark_class_local (current_class);
 
diff --git a/gcc/java/parse.y b/gcc/java/parse.y
index b7c3de119b1..39a5ac94997 100644
--- a/gcc/java/parse.y
+++ b/gcc/java/parse.y
@@ -8272,8 +8272,6 @@ java_expand_method_bodies (tree class)
 {
   tree decl;
 
-  build_tls_thunks (class);
-
   for (decl = TYPE_METHODS (class); decl; decl = TREE_CHAIN (decl))
     {
       tree block;
diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index 3b98a204d65..0dccbe7e806 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,11 @@
+2006-10-12  Andrew Haley  <aph@redhat.com>
+
+	* java/lang/natThreadLocal.cc: New file.
+	* java/lang/ThreadLocal.java: Rewrite to use native TLS.
+	* Makefile.am: Add java/lang/natThreadLocal.cc.
+	* sources.am: Move classpath/java/lang/ThreadLocal.java to
+	java/lang/ThreadLocal.java.
+
 2006-09-01  Andrew Haley  <aph@redhat.com>
 
 	* Makefile.in: Rebuild.
diff --git a/libjava/java/lang/ThreadLocal.java b/libjava/java/lang/ThreadLocal.java
index cd6276f5d7d..644c93b67e4 100644
--- a/libjava/java/lang/ThreadLocal.java
+++ b/libjava/java/lang/ThreadLocal.java
@@ -100,6 +100,7 @@ public class ThreadLocal
    */
   public ThreadLocal()
   {
+    constructNative();
   }
 
   /**
@@ -125,7 +126,7 @@ public class ThreadLocal
    */
   public native Object get();
 
-  private final Object slowGet()
+  private final Object internalGet()
   {
     Map map = Thread.getThreadLocals();
     // Note that we don't have to synchronize, as only this thread will
@@ -149,7 +150,7 @@ public class ThreadLocal
    */
   public native void set(Object value);
 
-  private final void slowSet(Object value)
+  private final void internalSet(Object value)
   {
     Map map = Thread.getThreadLocals();
     // Note that we don't have to synchronize, as only this thread will
@@ -164,27 +165,15 @@ public class ThreadLocal
    */
   public native void remove();
 
-  private final void slowRemove()
+  private final void internalRemove()
   {
     Map map = Thread.getThreadLocals();
     map.remove(this);
   }
 
-  private final void setTLS(gnu.gcj.RawData p)
-  {
-    synchronized (sentinel)
-      {
-	if (counter == 0)
-	  // We've run out of unique TLS IDs.  Fall back to using slow
-	  // TLS.
-	  return;
-	id = counter++;
-	TLSPointer = p;
-      }	
-  }
+  protected native void finalize () throws Throwable;
 
-  static private long counter = 1;
+  private native void constructNative();
 
   private gnu.gcj.RawData TLSPointer;
-  private long id;
 }
diff --git a/libjava/java/lang/natThreadLocal.cc b/libjava/java/lang/natThreadLocal.cc
index 3bced24541a..1b81aab63f0 100644
--- a/libjava/java/lang/natThreadLocal.cc
+++ b/libjava/java/lang/natThreadLocal.cc
@@ -52,55 +52,10 @@ details.  */
    So, we can't simply replace get() and set() with accesses of a
    __thread variable.
 
-   This is how our soloution works:
-     
-   Whenever we create a static field of Class ThreadLocal, we also
-   create a variable with __thread attribute, but it is only used as a
-   cache of a ThreadLocal entry.  Whenever we set() a static
-   ThreadLocal, we must update a map of ThreadLocals and the __thread
-   variable we're using to cache the entry.  However, when we get() a
-   static ThreadLocal, we only need to read the cache.
-
-   
-   In detail:
-
-   When gcj allocates a static field that is an instance of
-   ThreadLocal, it also allocates a thread-local cache variable.  This
-   is is a static structure of type tls_t:
-
-      typedef struct
-      {
-	jlong id;
-	void *val;
-      } tls_t;
-
-   When gcj generates a store that sets a ThreadLocal static field, it
-   also generates a call to setTLS(ptr).  ptr is a pointer to a
-   function that returns the address of the cache variable in thread
-   local memory.  ThreadLocal.setTLS(ptr) saves that function pointer
-   and also generates a unique ID that will be used to identify this
-   instance of ThreadLocal.  So, the ThreadLocal instance is now
-   "tied" to that cache variable.
-
-   The first time that ThreadLocal.set() is called in a particular
-   thread, we check the ID in the cache variable to see if it is the
-   same as the ID of this ThreadLocal instance.  We see that it is
-   not, because all __thread variables are initialized to zero, so we
-   write the ID of this ThreadLocal and the value into the cache
-   variable.  We also update the map of ThreadLocals on the heap; we
-   must do this for the benefit of the garbage collector.
-
-   When get() is called, we look in the cache variable, check the ID,
-   see that it is the same as the ID of this ThreadLocal instance, and
-   return the value immediately.
-
-   Whenever we need to invalidate the cache, we can do so by setting
-   ID to 0.
-
-   This is safe even in degenerate cases such as assigning the same
-   ThreadLocal instance to multiple static fields or repeatedly
-   re-assigning a static field in multiple threads.  If the cached
-   value doesn't belong to this ThreadLocal, we simply ignore it.
+   So, we create a pthread_key in each ThreadLocal object and use that
+   as a kind of "look-aside cache".  When a ThreadLocal is set, we
+   also set the corresponding thread-specific value.  When the
+   ThreadLocal is collected, we delete the key.
 
    This scheme is biased towards efficiency when get() is called much
    more frequently than set().  It is slightly slower than the
@@ -110,19 +65,22 @@ details.  */
 */
 
 
-typedef struct
-{
-  jlong id;
-  void *val;
-} tls_t;
+#ifdef _POSIX_PTHREAD_SEMANTICS
 
-static inline tls_t*
-get_tls_addr (void *p)
+class tls_t
 {
-  typedef tls_t* func (void);
-  func *fptr = (func*)p;
+public:
+  pthread_key_t key;
+};
 
-  return fptr ();
+void
+java::lang::ThreadLocal::constructNative (void)
+{
+  tls_t *tls = (tls_t *)_Jv_Malloc (sizeof (tls_t));
+  if (pthread_key_create (&tls->key, NULL) == 0)
+    TLSPointer = (::gnu::gcj::RawData *)tls;
+  else
+    _Jv_Free (tls);
 }
 
 void 
@@ -130,28 +88,27 @@ java::lang::ThreadLocal::set (::java::lang::Object *value)
 {
   if (TLSPointer != NULL)
     {
-      tls_t* tls_var_p = get_tls_addr (TLSPointer);
-      tls_var_p->val = value;
-      tls_var_p->id = id;
-    }
+      tls_t* tls = (tls_t*)TLSPointer;
+      pthread_setspecific (tls->key, value);
+    } 
 
-  slowSet (value);
+  internalSet (value);
 }
 
 ::java::lang::Object *
 java::lang::ThreadLocal::get (void)
 {
   if (TLSPointer == NULL)
-    return slowGet ();
+    return internalGet ();
 
-  tls_t* tls_var_p = get_tls_addr (TLSPointer);
+  tls_t* tls = (tls_t*)TLSPointer;
+  void *obj = pthread_getspecific(tls->key);
 
-  if (tls_var_p->id == this->id)
-    return (::java::lang::Object *)tls_var_p->val;
+  if (obj)
+    return (::java::lang::Object *)obj;
 
-  ::java::lang::Object *value = slowGet ();
-  tls_var_p->val = value;
-  tls_var_p->id = this->id;
+  ::java::lang::Object *value = internalGet ();
+  pthread_setspecific (tls->key, value);
 
   return value;
 }
@@ -161,11 +118,52 @@ java::lang::ThreadLocal::remove (void)
 {
   if (TLSPointer != NULL)
     {
-      tls_t* tls_var_p = get_tls_addr (TLSPointer);
-      tls_var_p->val = NULL;
-      tls_var_p->id = 0;
+      tls_t* tls = (tls_t*)TLSPointer;
+      pthread_setspecific (tls->key, NULL);
+    }
+
+  internalRemove ();
+}
+
+void 
+java::lang::ThreadLocal::finalize (void)
+{
+  if (TLSPointer != NULL)
+    {
+      tls_t* tls = (tls_t*)TLSPointer;
+      pthread_key_delete (tls->key);
+      _Jv_Free (tls);
     }
+}
+
+#else
+
+void
+java::lang::ThreadLocal::constructNative (void)
+{
+}
 
-  slowRemove ();
+void 
+java::lang::ThreadLocal::set (::java::lang::Object *value)
+{
+  internalSet (value);
+}
+
+::java::lang::Object *
+java::lang::ThreadLocal::get (void)
+{
+  return internalGet ();
+}
+
+void 
+java::lang::ThreadLocal::remove (void)
+{
+  internalRemove ();
+}
+
+void 
+java::lang::ThreadLocal::finalize (void)
+{
 }
 
+#endif