hotspot/src/share/vm/code/codeCache.hpp - edge/openjdk - Git at Google

 /*
  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 #ifndef SHARE_VM_CODE_CODECACHE_HPP
 #define SHARE_VM_CODE_CODECACHE_HPP

 #include "code/codeBlob.hpp"
 #include "memory/allocation.hpp"
 #include "memory/heap.hpp"
 #include "oops/instanceKlass.hpp"
 #include "oops/oopsHierarchy.hpp"

 // The CodeCache implements the code cache for various pieces of generated
 // code, e.g., compiled java methods, runtime stubs, transition frames, etc.
 // The entries in the CodeCache are all CodeBlob's.

 // Implementation:
 //   - Each CodeBlob occupies one chunk of memory.
 //   - Like the offset table in oldspace the zone has at table for
 //     locating a method given a addess of an instruction.

 class OopClosure;
 class DepChange;

 class CodeCache : AllStatic {
   friend class VMStructs;
  private:
   // CodeHeap is malloc()'ed at startup and never deleted during shutdown,
   // so that the generated assembly code is always there when it's needed.
   // This may cause memory leak, but is necessary, for now. See 4423824,
   // 4422213 or 4436291 for details.
   static CodeHeap * _heap;
   static int _number_of_blobs;
   static int _number_of_adapters;
   static int _number_of_nmethods;
   static int _number_of_nmethods_with_dependencies;
   static bool _needs_cache_clean;
   static nmethod* _scavenge_root_nmethods;  // linked via nm->scavenge_root_link()

   static void verify_if_often() PRODUCT_RETURN;

   static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
   static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;

   static int _codemem_full_count;

  public:

   // Initialization
   static void initialize();

   static void report_codemem_full();

   // Allocation/administration
   static CodeBlob* allocate(int size, bool is_critical = false); // allocates a new CodeBlob
   static void commit(CodeBlob* cb);                 // called when the allocated CodeBlob has been filled
   static int alignment_unit();                      // guaranteed alignment of all CodeBlobs
   static int alignment_offset();                    // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
   static void free(CodeBlob* cb);                   // frees a CodeBlob
   static void flush();                              // flushes all CodeBlobs
   static bool contains(void *p);                    // returns whether p is included
   static void blobs_do(void f(CodeBlob* cb));       // iterates over all CodeBlobs
   static void blobs_do(CodeBlobClosure* f);         // iterates over all CodeBlobs
   static void nmethods_do(void f(nmethod* nm));     // iterates over all nmethods
   static void alive_nmethods_do(void f(nmethod* nm)); // iterates over all alive nmethods

   // Lookup
   static CodeBlob* find_blob(void* start);
   static nmethod*  find_nmethod(void* start);

   // Lookup that does not fail if you lookup a zombie method (if you call this, be sure to know
   // what you are doing)
   static CodeBlob* find_blob_unsafe(void* start) {
     // NMT can walk the stack before code cache is created
     if (_heap == NULL) return NULL;

     CodeBlob* result = (CodeBlob*)_heap->find_start(start);
     // this assert is too strong because the heap code will return the
     // heapblock containing start. That block can often be larger than
     // the codeBlob itself. If you look up an address that is within
     // the heapblock but not in the codeBlob you will assert.
     //
     // Most things will not lookup such bad addresses. However
     // AsyncGetCallTrace can see intermediate frames and get that kind
     // of invalid address and so can a developer using hsfind.
     //
     // The more correct answer is to return NULL if blob_contains() returns
     // false.
     // assert(result == NULL || result->blob_contains((address)start), "found wrong CodeBlob");

     if (result != NULL && !result->blob_contains((address)start)) {
       result = NULL;
     }
     return result;
   }

   // Iteration
   static CodeBlob* first();
   static CodeBlob* next (CodeBlob* cb);
   static CodeBlob* alive(CodeBlob *cb);
   static nmethod* alive_nmethod(CodeBlob *cb);
   static nmethod* first_nmethod();
   static nmethod* next_nmethod (CodeBlob* cb);
   static int       nof_blobs()                 { return _number_of_blobs; }
   static int       nof_adapters()              { return _number_of_adapters; }
   static int       nof_nmethods()              { return _number_of_nmethods; }

   // GC support
   static void gc_epilogue();
   static void gc_prologue();
   static void verify_oops();
   // If "unloading_occurred" is true, then unloads (i.e., breaks root links
   // to) any unmarked codeBlobs in the cache.  Sets "marked_for_unloading"
   // to "true" iff some code got unloaded.
   static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
   static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
   static void scavenge_root_nmethods_do(CodeBlobClosure* f);

   static nmethod* scavenge_root_nmethods()          { return _scavenge_root_nmethods; }
   static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
   static void add_scavenge_root_nmethod(nmethod* nm);
   static void drop_scavenge_root_nmethod(nmethod* nm);
   static void prune_scavenge_root_nmethods();

   // Printing/debugging
   static void print();                           // prints summary
   static void print_internals();
   static void verify();                          // verifies the code cache
   static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
   static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
   static void log_state(outputStream* st);

   // The full limits of the codeCache
   static address  low_bound()                    { return (address) _heap->low_boundary(); }
   static address  high_bound()                   { return (address) _heap->high_boundary(); }
   static address  high()                         { return (address) _heap->high(); }

   // Profiling
   static address first_address();                // first address used for CodeBlobs
   static address last_address();                 // last  address used for CodeBlobs
   static size_t  capacity()                      { return _heap->capacity(); }
   static size_t  max_capacity()                  { return _heap->max_capacity(); }
   static size_t  unallocated_capacity()          { return _heap->unallocated_capacity(); }
   static double  reverse_free_ratio();

   static bool needs_cache_clean()                { return _needs_cache_clean; }
   static void set_needs_cache_clean(bool v)      { _needs_cache_clean = v;    }
   static void clear_inline_caches();             // clear all inline caches

   static void verify_clean_inline_caches();
   static void verify_icholder_relocations();

   // Deoptimization
   static int  mark_for_deoptimization(DepChange& changes);
 #ifdef HOTSWAP
   static int  mark_for_evol_deoptimization(instanceKlassHandle dependee);
 #endif // HOTSWAP

   static void mark_all_nmethods_for_deoptimization();
   static int  mark_for_deoptimization(Method* dependee);
   static void make_marked_nmethods_not_entrant();

     // tells how many nmethods have dependencies
   static int number_of_nmethods_with_dependencies();

   static int get_codemem_full_count() { return _codemem_full_count; }
 };

 #endif // SHARE_VM_CODE_CODECACHE_HPP
	/*
	* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	#ifndef SHARE_VM_CODE_CODECACHE_HPP
	#define SHARE_VM_CODE_CODECACHE_HPP

	#include "code/codeBlob.hpp"
	#include "memory/allocation.hpp"
	#include "memory/heap.hpp"
	#include "oops/instanceKlass.hpp"
	#include "oops/oopsHierarchy.hpp"

	// The CodeCache implements the code cache for various pieces of generated
	// code, e.g., compiled java methods, runtime stubs, transition frames, etc.
	// The entries in the CodeCache are all CodeBlob's.

	// Implementation:
	// - Each CodeBlob occupies one chunk of memory.
	// - Like the offset table in oldspace the zone has at table for
	// locating a method given a addess of an instruction.

	class OopClosure;
	class DepChange;

	class CodeCache : AllStatic {
	friend class VMStructs;
	private:
	// CodeHeap is malloc()'ed at startup and never deleted during shutdown,
	// so that the generated assembly code is always there when it's needed.
	// This may cause memory leak, but is necessary, for now. See 4423824,
	// 4422213 or 4436291 for details.
	static CodeHeap * _heap;
	static int _number_of_blobs;
	static int _number_of_adapters;
	static int _number_of_nmethods;
	static int _number_of_nmethods_with_dependencies;
	static bool _needs_cache_clean;
	static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link()

	static void verify_if_often() PRODUCT_RETURN;

	static void mark_scavenge_root_nmethods() PRODUCT_RETURN;
	static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN;

	static int _codemem_full_count;

	public:

	// Initialization
	static void initialize();

	static void report_codemem_full();

	// Allocation/administration
	static CodeBlob* allocate(int size, bool is_critical = false); // allocates a new CodeBlob
	static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled
	static int alignment_unit(); // guaranteed alignment of all CodeBlobs
	static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header)
	static void free(CodeBlob* cb); // frees a CodeBlob
	static void flush(); // flushes all CodeBlobs
	static bool contains(void *p); // returns whether p is included
	static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs
	static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs
	static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods
	static void alive_nmethods_do(void f(nmethod* nm)); // iterates over all alive nmethods

	// Lookup
	static CodeBlob* find_blob(void* start);
	static nmethod* find_nmethod(void* start);

	// Lookup that does not fail if you lookup a zombie method (if you call this, be sure to know
	// what you are doing)
	static CodeBlob* find_blob_unsafe(void* start) {
	// NMT can walk the stack before code cache is created
	if (_heap == NULL) return NULL;

	CodeBlob* result = (CodeBlob*)_heap->find_start(start);
	// this assert is too strong because the heap code will return the
	// heapblock containing start. That block can often be larger than
	// the codeBlob itself. If you look up an address that is within
	// the heapblock but not in the codeBlob you will assert.
	//
	// Most things will not lookup such bad addresses. However
	// AsyncGetCallTrace can see intermediate frames and get that kind
	// of invalid address and so can a developer using hsfind.
	//
	// The more correct answer is to return NULL if blob_contains() returns
	// false.
	// assert(result == NULL \|\| result->blob_contains((address)start), "found wrong CodeBlob");

	if (result != NULL && !result->blob_contains((address)start)) {
	result = NULL;
	}
	return result;
	}

	// Iteration
	static CodeBlob* first();
	static CodeBlob* next (CodeBlob* cb);
	static CodeBlob* alive(CodeBlob *cb);
	static nmethod* alive_nmethod(CodeBlob *cb);
	static nmethod* first_nmethod();
	static nmethod* next_nmethod (CodeBlob* cb);
	static int nof_blobs() { return _number_of_blobs; }
	static int nof_adapters() { return _number_of_adapters; }
	static int nof_nmethods() { return _number_of_nmethods; }

	// GC support
	static void gc_epilogue();
	static void gc_prologue();
	static void verify_oops();
	// If "unloading_occurred" is true, then unloads (i.e., breaks root links
	// to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading"
	// to "true" iff some code got unloaded.
	static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
	static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN;
	static void scavenge_root_nmethods_do(CodeBlobClosure* f);

	static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; }
	static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; }
	static void add_scavenge_root_nmethod(nmethod* nm);
	static void drop_scavenge_root_nmethod(nmethod* nm);
	static void prune_scavenge_root_nmethods();

	// Printing/debugging
	static void print(); // prints summary
	static void print_internals();
	static void verify(); // verifies the code cache
	static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN;
	static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage
	static void log_state(outputStream* st);

	// The full limits of the codeCache
	static address low_bound() { return (address) _heap->low_boundary(); }
	static address high_bound() { return (address) _heap->high_boundary(); }
	static address high() { return (address) _heap->high(); }

	// Profiling
	static address first_address(); // first address used for CodeBlobs
	static address last_address(); // last address used for CodeBlobs
	static size_t capacity() { return _heap->capacity(); }
	static size_t max_capacity() { return _heap->max_capacity(); }
	static size_t unallocated_capacity() { return _heap->unallocated_capacity(); }
	static double reverse_free_ratio();

	static bool needs_cache_clean() { return _needs_cache_clean; }
	static void set_needs_cache_clean(bool v) { _needs_cache_clean = v; }
	static void clear_inline_caches(); // clear all inline caches

	static void verify_clean_inline_caches();
	static void verify_icholder_relocations();

	// Deoptimization
	static int mark_for_deoptimization(DepChange& changes);
	#ifdef HOTSWAP
	static int mark_for_evol_deoptimization(instanceKlassHandle dependee);
	#endif // HOTSWAP

	static void mark_all_nmethods_for_deoptimization();
	static int mark_for_deoptimization(Method* dependee);
	static void make_marked_nmethods_not_entrant();

	// tells how many nmethods have dependencies
	static int number_of_nmethods_with_dependencies();

	static int get_codemem_full_count() { return _codemem_full_count; }
	};

	#endif // SHARE_VM_CODE_CODECACHE_HPP