1 files changed, 24 insertions, 8 deletions

diff --git a/src/share/vm/code/nmethod.cpp b/src/share/vm/code/nmethod.cpp
index b31ede05e..6ea39aea9 100644
--- a/src/share/vm/code/nmethod.cpp
+++ b/src/share/vm/code/nmethod.cpp
@@ -1148,9 +1148,20 @@ void nmethod::clear_inline_caches() {
   }
 }
 
+// Clear ICStubs of all compiled ICs
+void nmethod::clear_ic_stubs() {
+  assert_locked_or_safepoint(CompiledIC_lock);
+  RelocIterator iter(this);
+  while(iter.next()) {
+    if (iter.type() == relocInfo::virtual_call_type) {
+      CompiledIC* ic = CompiledIC_at(&iter);
+      ic->clear_ic_stub();
+    }
+  }
+}
 
-void nmethod::cleanup_inline_caches() {
 
+void nmethod::cleanup_inline_caches() {
   assert_locked_or_safepoint(CompiledIC_lock);
 
   // If the method is not entrant or zombie then a JMP is plastered over the
@@ -1166,7 +1177,8 @@ void nmethod::cleanup_inline_caches() {
     // In fact, why are we bothering to look at oops in a non-entrant method??
   }
 
-  // Find all calls in an nmethod, and clear the ones that points to zombie methods
+  // Find all calls in an nmethod and clear the ones that point to non-entrant,
+  // zombie and unloaded nmethods.
   ResourceMark rm;
   RelocIterator iter(this, low_boundary);
   while(iter.next()) {
@@ -1178,8 +1190,8 @@ void nmethod::cleanup_inline_caches() {
         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
         if( cb != NULL && cb->is_nmethod() ) {
           nmethod* nm = (nmethod*)cb;
-          // Clean inline caches pointing to both zombie and not_entrant methods
-          if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
+          // Clean inline caches pointing to zombie, non-entrant and unloaded methods
+          if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean(is_alive());
         }
         break;
       }
@@ -1188,7 +1200,7 @@ void nmethod::cleanup_inline_caches() {
         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
         if( cb != NULL && cb->is_nmethod() ) {
           nmethod* nm = (nmethod*)cb;
-          // Clean inline caches pointing to both zombie and not_entrant methods
+          // Clean inline caches pointing to zombie, non-entrant and unloaded methods
           if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
         }
         break;
@@ -1279,7 +1291,7 @@ void nmethod::mark_as_seen_on_stack() {
 // Tell if a non-entrant method can be converted to a zombie (i.e.,
 // there are no activations on the stack, not in use by the VM,
 // and not in use by the ServiceThread)
-bool nmethod::can_not_entrant_be_converted() {
+bool nmethod::can_convert_to_zombie() {
   assert(is_not_entrant(), "must be a non-entrant method");
 
   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
@@ -1607,7 +1619,11 @@ void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
       // During GC the is_alive closure is non-NULL, and is used to
       // determine liveness of dependees that need to be updated.
       if (is_alive == NULL || klass->is_loader_alive(is_alive)) {
-        InstanceKlass::cast(klass)->remove_dependent_nmethod(this);
+        // The GC defers deletion of this entry, since there might be multiple threads
+        // iterating over the _dependencies graph. Other call paths are single-threaded
+        // and may delete it immediately.
+        bool delete_immediately = is_alive == NULL;
+        InstanceKlass::cast(klass)->remove_dependent_nmethod(this, delete_immediately);
       }
     }
   }
@@ -2695,7 +2711,7 @@ void nmethod::verify() {
   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
   // seems odd.
 
-  if( is_zombie() || is_not_entrant() )
+  if (is_zombie() || is_not_entrant() || is_unloaded())
     return;
 
   // Make sure all the entry points are correctly aligned for patching.