/*

 * Copyright (c) 1997, 2019, 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.

 *

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#ifndef SHARE_CODE_CODECACHE_HPP

#define SHARE_CODE_CODECACHE_HPP

#include "code/codeBlob.hpp"

#include "code/nmethod.hpp"

#include "gc/shared/gcBehaviours.hpp"

#include "memory/allocation.hpp"

#include "memory/heap.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/oopsHierarchy.hpp"

#include "runtime/mutexLocker.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 --

// The CodeCache consists of one or more CodeHeaps, each of which contains

// CodeBlobs of a specific CodeBlobType. Currently heaps for the following

// types are available:

//  - Non-nmethods: Non-nmethods like Buffers, Adapters and Runtime Stubs

//  - Profiled nmethods: nmethods that are profiled, i.e., those

//    executed at level 2 or 3

//  - Non-Profiled nmethods: nmethods that are not profiled, i.e., those

//    executed at level 1 or 4 and native methods

//  - All: Used for code of all types if code cache segmentation is disabled.

//

// In the rare case of the non-nmethod code heap getting full, non-nmethod code

// will be stored in the non-profiled code heap as a fallback solution.

//

// Depending on the availability of compilers and TieredCompilation there

// may be fewer heaps. The size of the code heaps depends on the values of

// ReservedCodeCacheSize, NonProfiledCodeHeapSize and ProfiledCodeHeapSize

// (see CodeCache::heap_available(..) and CodeCache::initialize_heaps(..)

// for details).

//

// Code cache segmentation is controlled by the flag SegmentedCodeCache.

// If turned off, all code types are stored in a single code heap. By default

// code cache segmentation is turned on if TieredCompilation is enabled and

// ReservedCodeCacheSize >= 240 MB.

//

// All methods of the CodeCache accepting a CodeBlobType only apply to

// CodeBlobs of the given type. For example, iteration over the

// CodeBlobs of a specific type can be done by using CodeCache::first_blob(..)

// and CodeCache::next_blob(..) and providing the corresponding CodeBlobType.

//

// IMPORTANT: If you add new CodeHeaps to the code cache or change the

// existing ones, make sure to adapt the dtrace scripts (jhelper.d) for

// Solaris and BSD.

class ExceptionCache;

class KlassDepChange;

class OopClosure;

class ShenandoahParallelCodeHeapIterator;

class CodeCache : AllStatic {

  friend class VMStructs;

  friend class JVMCIVMStructs;

  template <class T, class Filter> friend class CodeBlobIterator;

  friend class WhiteBox;

  friend class CodeCacheLoader;

  friend class ShenandoahParallelCodeHeapIterator;

 private:

  // CodeHeaps of the cache

  static GrowableArray<CodeHeap*>* _heaps;

  static GrowableArray<CodeHeap*>* _compiled_heaps;

  static GrowableArray<CodeHeap*>* _nmethod_heaps;

  static GrowableArray<CodeHeap*>* _allocable_heaps;

  static address _low_bound;                            // Lower bound of CodeHeap addresses

  static address _high_bound;                           // Upper bound of CodeHeap addresses

  static int _number_of_nmethods_with_dependencies;     // Total number of nmethods with dependencies

  static uint8_t _unloading_cycle;                      // Global state for recognizing old nmethods that need to be unloaded

  static ExceptionCache* volatile _exception_cache_purge_list;

  // CodeHeap management

  static void initialize_heaps();                             // Initializes the CodeHeaps

  // Check the code heap sizes set by the user via command line

  static void check_heap_sizes(size_t non_nmethod_size, size_t profiled_size, size_t non_profiled_size, size_t cache_size, bool all_set);

  // Creates a new heap with the given name and size, containing CodeBlobs of the given type

  static void add_heap(ReservedSpace rs, const char* name, int code_blob_type);

  static CodeHeap* get_code_heap_containing(void* p);         // Returns the CodeHeap containing the given pointer, or NULL

  static CodeHeap* get_code_heap(const CodeBlob* cb);         // Returns the CodeHeap for the given CodeBlob

  static CodeHeap* get_code_heap(int code_blob_type);         // Returns the CodeHeap for the given CodeBlobType

  // Returns the name of the VM option to set the size of the corresponding CodeHeap

  static const char* get_code_heap_flag_name(int code_blob_type);

  static ReservedCodeSpace reserve_heap_memory(size_t size);  // Reserves one continuous chunk of memory for the CodeHeaps

  // Iteration

  static CodeBlob* first_blob(CodeHeap* heap);                // Returns the first CodeBlob on the given CodeHeap

  static CodeBlob* first_blob(int code_blob_type);            // Returns the first CodeBlob of the given type

  static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb);   // Returns the next CodeBlob on the given CodeHeap

  static size_t bytes_allocated_in_freelists();

  static int    allocated_segments();

  static size_t freelists_length();

  // Make private to prevent unsafe calls.  Not all CodeBlob*'s are embedded in a CodeHeap.

  static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; }

 public:

  // Initialization

  static void initialize();

  static size_t page_size(bool aligned = true, size_t min_pages = 1); // Returns the page size used by the CodeCache

  static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs);

  static void add_heap(CodeHeap* heap);

  static const GrowableArray<CodeHeap*>* heaps() { return _heaps; }

  static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; }

  static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; }

  // Allocation/administration

  static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // 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 free_unused_tail(CodeBlob* cb, size_t used); // frees the unused tail of a CodeBlob (only used by TemplateInterpreter::initialize())

  static bool contains(void *p);                           // returns whether p is included

  static bool contains(nmethod* nm);                       // returns whether nm 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

  // Lookup

  static CodeBlob* find_blob(void* start);              // Returns the CodeBlob containing the given address

  static CodeBlob* find_blob_unsafe(void* start);       // Same as find_blob but does not fail if looking up a zombie method

  static nmethod*  find_nmethod(void* start);           // Returns the nmethod containing the given address

  static CompiledMethod* find_compiled(void* start);

  static int       blob_count();                        // Returns the total number of CodeBlobs in the cache

  static int       blob_count(int code_blob_type);

  static int       adapter_count();                     // Returns the total number of Adapters in the cache

  static int       adapter_count(int code_blob_type);

  static int       nmethod_count();                     // Returns the total number of nmethods in the cache

  static int       nmethod_count(int code_blob_type);

  // GC support

  static void verify_oops();

  // If any oops are not marked this method unloads (i.e., breaks root links

  // to) any unmarked codeBlobs in the cache.  Sets "marked_for_unloading"

  // to "true" iff some code got unloaded.

  // "unloading_occurred" controls whether metadata should be cleaned because of class unloading.

  class UnloadingScope: StackObj {

    ClosureIsUnloadingBehaviour _is_unloading_behaviour;

  public:

    UnloadingScope(BoolObjectClosure* is_alive);

    ~UnloadingScope();

  };

  static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);

  static uint8_t unloading_cycle() { return _unloading_cycle; }

  static void increment_unloading_cycle();

  static void release_exception_cache(ExceptionCache* entry);

  static void purge_exception_caches();

  // Printing/debugging

  static void print();                           // prints summary

  static void print_internals();

  static void print_memory_overhead();

  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);

  static const char* get_code_heap_name(int code_blob_type)  { return (heap_available(code_blob_type) ? get_code_heap(code_blob_type)->name() : "Unused"); }

  static void report_codemem_full(int code_blob_type, bool print);

  // Dcmd (Diagnostic commands)

  static void print_codelist(outputStream* st);

  static void print_layout(outputStream* st);

  // The full limits of the codeCache

  static address low_bound()                          { return _low_bound; }

  static address low_bound(int code_blob_type);

  static address high_bound()                         { return _high_bound; }

  static address high_bound(int code_blob_type);

  // Have to use far call instructions to call this pc.

  static bool is_far_target(address pc);

  // Profiling

  static size_t capacity();

  static size_t unallocated_capacity(int code_blob_type);

  static size_t unallocated_capacity();

  static size_t max_capacity();

  static double reverse_free_ratio(int code_blob_type);

  static void clear_inline_caches();                  // clear all inline caches

  static void cleanup_inline_caches();                // clean unloaded/zombie nmethods from inline caches

  // Returns true if an own CodeHeap for the given CodeBlobType is available

  static bool heap_available(int code_blob_type);

  // Returns the CodeBlobType for the given CompiledMethod

  static int get_code_blob_type(CompiledMethod* cm) {

    return get_code_heap(cm)->code_blob_type();

  }

  static bool code_blob_type_accepts_compiled(int type) {

    bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;

    AOT_ONLY( result = result || type == CodeBlobType::AOT; )

    return result;

  }

  static bool code_blob_type_accepts_nmethod(int type) {

    return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;

  }

  static bool code_blob_type_accepts_allocable(int type) {

    return type <= CodeBlobType::All;

  }

  // Returns the CodeBlobType for the given compilation level

  static int get_code_blob_type(int comp_level) {

    if (comp_level == CompLevel_none ||

        comp_level == CompLevel_simple ||

        comp_level == CompLevel_full_optimization) {

      // Non profiled methods

      return CodeBlobType::MethodNonProfiled;

    } else if (comp_level == CompLevel_limited_profile ||

               comp_level == CompLevel_full_profile) {

      // Profiled methods

      return CodeBlobType::MethodProfiled;

    }

    ShouldNotReachHere();

    return 0;

  }

  static void verify_clean_inline_caches();

  static void verify_icholder_relocations();

  // Deoptimization

 private:

  static int  mark_for_deoptimization(KlassDepChange& changes);

 public:

  static void mark_all_nmethods_for_deoptimization();

  static int  mark_for_deoptimization(Method* dependee);

  static void make_marked_nmethods_not_entrant();

  // Flushing and deoptimization

  static void flush_dependents_on(InstanceKlass* dependee);

  // Flushing and deoptimization in case of evolution

  static void mark_for_evol_deoptimization(InstanceKlass* dependee);

  static int  mark_dependents_for_evol_deoptimization();

  static void flush_evol_dependents();

  // Support for fullspeed debugging

  static void flush_dependents_on_method(const methodHandle& dependee);

  // tells how many nmethods have dependencies

  static int number_of_nmethods_with_dependencies();

  static int get_codemem_full_count(int code_blob_type) {

    CodeHeap* heap = get_code_heap(code_blob_type);

    return (heap != NULL) ? heap->full_count() : 0;

  }

  // CodeHeap State Analytics.

  // interface methods for CodeHeap printing, called by CompileBroker

  static void aggregate(outputStream *out, const char* granularity);

  static void discard(outputStream *out);

  static void print_usedSpace(outputStream *out);

  static void print_freeSpace(outputStream *out);

  static void print_count(outputStream *out);

  static void print_space(outputStream *out);

  static void print_age(outputStream *out);

  static void print_names(outputStream *out);

};

// Iterator to iterate over nmethods in the CodeCache.

template <class T, class Filter> class CodeBlobIterator : public StackObj {

 public:

  enum LivenessFilter { all_blobs, only_alive, only_alive_and_not_unloading };

 private:

  CodeBlob* _code_blob;   // Current CodeBlob

  GrowableArrayIterator<CodeHeap*> _heap;

  GrowableArrayIterator<CodeHeap*> _end;

  bool _only_alive;

  bool _only_not_unloading;

 public:

  CodeBlobIterator(LivenessFilter filter, T* nm = NULL)

    : _only_alive(filter == only_alive || filter == only_alive_and_not_unloading),

      _only_not_unloading(filter == only_alive_and_not_unloading)

  {

    if (Filter::heaps() == NULL) {

      return;

    }

    _heap = Filter::heaps()->begin();

    _end = Filter::heaps()->end();

    // If set to NULL, initialized by first call to next()

    _code_blob = (CodeBlob*)nm;

    if (nm != NULL) {

      while(!(*_heap)->contains_blob(_code_blob)) {

        ++_heap;

      }

      assert((*_heap)->contains_blob(_code_blob), "match not found");

    }

  }

  // Advance iterator to next blob

  bool next() {

    assert_locked_or_safepoint(CodeCache_lock);

    for (;;) {

      // Walk through heaps as required

      if (!next_blob()) {

        if (_heap == _end) {

          return false;

        }

        ++_heap;

        continue;

      }

      // Filter is_alive as required

      if (_only_alive && !_code_blob->is_alive()) {

        continue;

      }

      // Filter is_unloading as required

      if (_only_not_unloading) {

        CompiledMethod* cm = _code_blob->as_compiled_method_or_null();

        if (cm != NULL && cm->is_unloading()) {

          continue;

        }

      }

      return true;

    }

  }

  bool end()  const { return _code_blob == NULL; }

  T* method() const { return (T*)_code_blob; }

private:

  // Advance iterator to the next blob in the current code heap

  bool next_blob() {

    if (_heap == _end) {

      return false;

    }

    CodeHeap *heap = *_heap;

    // Get first method CodeBlob

    if (_code_blob == NULL) {

      _code_blob = CodeCache::first_blob(heap);

      if (_code_blob == NULL) {

        return false;

      } else if (Filter::apply(_code_blob)) {

        return true;

      }

    }

    // Search for next method CodeBlob

    _code_blob = CodeCache::next_blob(heap, _code_blob);

    while (_code_blob != NULL && !Filter::apply(_code_blob)) {

      _code_blob = CodeCache::next_blob(heap, _code_blob);

    }

    return _code_blob != NULL;

  }

};

struct CompiledMethodFilter {

  static bool apply(CodeBlob* cb) { return cb->is_compiled(); }

  static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); }

};

struct NMethodFilter {

  static bool apply(CodeBlob* cb) { return cb->is_nmethod(); }

  static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); }

};

typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator;

typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator;

#endif // SHARE_CODE_CODECACHE_HPP