8075805: Crash while trying to release CompiledICHolder

Removed nmethod transition to zombie outside of sweeper. Added cleaning of ICs of unloaded nmethods.

Reviewed-by: kvn, iveresov

hotspot/src/share/vm/code/codeCache.cpp

@@ -746,14 +746,17 @@ void CodeCache::gc_prologue() {
 void CodeCache::gc_epilogue() {
   assert_locked_or_safepoint(CodeCache_lock);
   NMethodIterator iter;
-  while(iter.next_alive()) {
+  while(iter.next()) {
     nmethod* nm = iter.method();
-    assert(!nm->is_unloaded(), "Tautology");
-    if (needs_cache_clean()) {
-      nm->cleanup_inline_caches();
+    if (!nm->is_zombie()) {
+      if (needs_cache_clean()) {
+        // Clean ICs of unloaded nmethods as well because they may reference other
+        // unloaded nmethods that may be flushed earlier in the sweeper cycle.
+        nm->cleanup_inline_caches();
+      }
+      DEBUG_ONLY(nm->verify());
+      DEBUG_ONLY(nm->verify_oop_relocations());
     }
-    DEBUG_ONLY(nm->verify());
-    DEBUG_ONLY(nm->verify_oop_relocations());
   }
   set_needs_cache_clean(false);
   prune_scavenge_root_nmethods();
@@ -993,29 +996,6 @@ int CodeCache::mark_for_deoptimization(Method* dependee) {
   return number_of_marked_CodeBlobs;
 }
 
-void CodeCache::make_marked_nmethods_zombies() {
-  assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
-  NMethodIterator iter;
-  while(iter.next_alive()) {
-    nmethod* nm = iter.method();
-    if (nm->is_marked_for_deoptimization()) {
-
-      // If the nmethod has already been made non-entrant and it can be converted
-      // then zombie it now. Otherwise make it non-entrant and it will eventually
-      // be zombied when it is no longer seen on the stack. Note that the nmethod
-      // might be "entrant" and not on the stack and so could be zombied immediately
-      // but we can't tell because we don't track it on stack until it becomes
-      // non-entrant.
-
-      if (nm->is_not_entrant() && nm->can_not_entrant_be_converted()) {
-        nm->make_zombie();
-      } else {
-        nm->make_not_entrant();
-      }
-    }
-  }
-}
-
 void CodeCache::make_marked_nmethods_not_entrant() {
   assert_locked_or_safepoint(CodeCache_lock);
   NMethodIterator iter;
@@ -1072,7 +1052,7 @@ void CodeCache::flush_evol_dependents_on(instanceKlassHandle ev_k_h) {
     // Deoptimize all activations depending on marked nmethods
     Deoptimization::deoptimize_dependents();
 
-    // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
+    // Make the dependent methods not entrant
     make_marked_nmethods_not_entrant();
   }
 }
@@ -1102,7 +1082,7 @@ void CodeCache::flush_dependents_on_method(methodHandle m_h) {
     // Deoptimize all activations depending on marked nmethods
     Deoptimization::deoptimize_dependents();
 
-    // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
+    // Make the dependent methods not entrant
     make_marked_nmethods_not_entrant();
   }
 }

hotspot/src/share/vm/code/codeCache.hpp

@@ -225,7 +225,6 @@ class CodeCache : AllStatic {
  public:
   static void mark_all_nmethods_for_deoptimization();
   static int  mark_for_deoptimization(Method* dependee);
-  static void make_marked_nmethods_zombies();
   static void make_marked_nmethods_not_entrant();
 
   // Flushing and deoptimization

hotspot/src/share/vm/code/compiledIC.cpp

@@ -343,8 +343,8 @@ void CompiledIC::set_to_clean() {
     // Kill any leftover stub we might have too
     clear_ic_stub();
     if (is_optimized()) {
-    set_ic_destination(entry);
-  } else {
+      set_ic_destination(entry);
+    } else {
       set_ic_destination_and_value(entry, (void*)NULL);
     }
   } else {

hotspot/src/share/vm/code/compiledIC.hpp

@@ -214,7 +214,7 @@ class CompiledIC: public ResourceObj {
   //
   // They all takes a TRAP argument, since they can cause a GC if the inline-cache buffer is full.
   //
-  void set_to_clean();  // Can only be called during a safepoint operation
+  void set_to_clean();
   void set_to_monomorphic(CompiledICInfo& info);
   void clear_ic_stub();
 

hotspot/src/share/vm/code/nmethod.cpp

@@ -1021,7 +1021,6 @@ void nmethod::clear_ic_stubs() {
 
 
 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
@@ -1037,7 +1036,8 @@ 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()) {
@@ -1049,7 +1049,7 @@ 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
+          // Clean inline caches pointing to zombie, non-entrant and unloaded methods
           if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
         }
         break;
@@ -1059,7 +1059,7 @@ 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;
@@ -2529,7 +2529,7 @@ 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.

hotspot/src/share/vm/prims/jvmtiRedefineClasses.cpp

@@ -3771,7 +3771,7 @@ void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) {
     // Deoptimize all activations depending on marked nmethods
     Deoptimization::deoptimize_dependents();
 
-    // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
+    // Make the dependent methods not entrant
     CodeCache::make_marked_nmethods_not_entrant();
 
     // From now on we know that the dependency information is complete

hotspot/src/share/vm/runtime/sweeper.cpp

@@ -618,19 +618,14 @@ NMethodSweeper::MethodStateChange NMethodSweeper::process_nmethod(nmethod* nm) {
         MutexLocker cl(CompiledIC_lock);
         nm->clear_ic_stubs();
       }
-      // Acquiring the CompiledIC_lock may block for a safepoint and set the
-      // nmethod to zombie (see 'CodeCache::make_marked_nmethods_zombies').
-      // Check if nmethod is still non-entrant at this point.
-      if (nm->is_not_entrant()) {
-        if (PrintMethodFlushing && Verbose) {
-          tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm);
-        }
-        // Code cache state change is tracked in make_zombie()
-        nm->make_zombie();
-        SWEEP(nm);
-        assert(result == None, "sanity");
-        result = MadeZombie;
+      if (PrintMethodFlushing && Verbose) {
+        tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm);
       }
+      // Code cache state change is tracked in make_zombie()
+      nm->make_zombie();
+      SWEEP(nm);
+      assert(result == None, "sanity");
+      result = MadeZombie;
       assert(nm->is_zombie(), "nmethod must be zombie");
     } else {
       // Still alive, clean up its inline caches

hotspot/src/share/vm/runtime/vm_operations.cpp

@@ -109,8 +109,8 @@ void VM_Deoptimize::doit() {
   // Deoptimize all activations depending on marked nmethods
   Deoptimization::deoptimize_dependents();
 
-  // Make the dependent methods zombies
-  CodeCache::make_marked_nmethods_zombies();
+  // Make the dependent methods not entrant
+  CodeCache::make_marked_nmethods_not_entrant();
 }
 
 void VM_MarkActiveNMethods::doit() {