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/*
* Copyright (c) 1997, 2022, 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_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"
#include "utilities/numberSeq.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 compilation mode 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 tiered mode 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 NativePostCallNop;
class CodeCache : AllStatic {
friend class VMStructs;
friend class JVMCIVMStructs;
template <class T, class Filter, bool is_compiled_method> 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 uint64_t _gc_epoch; // Global state for tracking when nmethods were found to be on-stack
static uint64_t _cold_gc_count; // Global state for determining how many GCs are needed before an nmethod is cold
static size_t _last_unloading_used;
static double _last_unloading_time;
static TruncatedSeq _unloading_gc_intervals;
static TruncatedSeq _unloading_allocation_rates;
static volatile bool _unloading_threshold_gc_requested;
static nmethod* volatile _unlinked_head;
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, CodeBlobType 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(CodeBlobType 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(CodeBlobType 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(CodeBlobType 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
private:
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, CodeBlobType code_blob_type, bool handle_alloc_failure = true, CodeBlobType 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
static void metadata_do(MetadataClosure* f); // iterates over metadata in alive nmethods
// Lookup
static CodeBlob* find_blob(void* start); // Returns the CodeBlob containing the given address
static CodeBlob* find_blob_fast(void* start); // Returns the CodeBlob containing the given address
static CodeBlob* find_blob_and_oopmap(void* start, int& slot); // Returns the CodeBlob containing the given address
static int find_oopmap_slot_fast(void* start); // Returns a fast oopmap slot if there is any; -1 otherwise
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(CodeBlobType code_blob_type);
static int adapter_count(); // Returns the total number of Adapters in the cache
static int adapter_count(CodeBlobType code_blob_type);
static int nmethod_count(); // Returns the total number of nmethods in the cache
static int nmethod_count(CodeBlobType 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;
IsUnloadingBehaviour* _saved_behaviour;
public:
UnloadingScope(BoolObjectClosure* is_alive);
~UnloadingScope();
};
// Code cache unloading heuristics
static uint64_t cold_gc_count();
static void update_cold_gc_count();
static void gc_on_allocation();
// The GC epoch and marking_cycle code below is there to support sweeping
// nmethods in loom stack chunks.
static uint64_t gc_epoch();
static bool is_gc_marking_cycle_active();
static uint64_t previous_completed_gc_marking_cycle();
static void on_gc_marking_cycle_start();
static void on_gc_marking_cycle_finish();
static void arm_all_nmethods();
static void flush_unlinked_nmethods();
static void register_unlinked(nmethod* nm);
static void do_unloading(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);
LINUX_ONLY(static void write_perf_map();)
static const char* get_code_heap_name(CodeBlobType code_blob_type) { return (heap_available(code_blob_type) ? get_code_heap(code_blob_type)->name() : "Unused"); }
static void report_codemem_full(CodeBlobType 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(CodeBlobType code_blob_type);
static address high_bound() { return _high_bound; }
static address high_bound(CodeBlobType code_blob_type);
// Profiling
static size_t capacity();
static size_t unallocated_capacity(CodeBlobType code_blob_type);
static size_t unallocated_capacity();
static size_t max_capacity();
static double reverse_free_ratio();
static size_t max_distance_to_non_nmethod();
static bool is_non_nmethod(address addr);
static void clear_inline_caches(); // clear all inline caches
static void cleanup_inline_caches_whitebox(); // clean bad nmethods from inline caches
// Returns true if an own CodeHeap for the given CodeBlobType is available
static bool heap_available(CodeBlobType code_blob_type);
// Returns the CodeBlobType for the given CompiledMethod
static CodeBlobType get_code_blob_type(CompiledMethod* cm) {
return get_code_heap(cm)->code_blob_type();
}
static bool code_blob_type_accepts_compiled(CodeBlobType code_blob_type) {
bool result = code_blob_type == CodeBlobType::All || code_blob_type <= CodeBlobType::MethodProfiled;
return result;
}
static bool code_blob_type_accepts_nmethod(CodeBlobType type) {
return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled;
}
static bool code_blob_type_accepts_allocable(CodeBlobType type) {
return type <= CodeBlobType::All;
}
// Returns the CodeBlobType for the given compilation level
static CodeBlobType 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 static_cast<CodeBlobType>(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_deoptimized();
static void make_nmethod_deoptimized(CompiledMethod* nm);
// Flushing and deoptimization
static void flush_dependents_on(InstanceKlass* dependee);
// RedefineClasses support
// Flushing and deoptimization in case of evolution
static int mark_dependents_for_evol_deoptimization();
static void mark_all_nmethods_for_evol_deoptimization();
static void flush_evol_dependents();
static void old_nmethods_do(MetadataClosure* f) NOT_JVMTI_RETURN;
static void unregister_old_nmethod(CompiledMethod* c) NOT_JVMTI_RETURN;
// 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(CodeBlobType 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, size_t 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 code blobs in the CodeCache.
// The relaxed iterators only hold the CodeCache_lock across next calls
template <class T, class Filter, bool is_relaxed> class CodeBlobIterator : public StackObj {
public:
enum LivenessFilter { all_blobs, only_not_unloading };
private:
CodeBlob* _code_blob; // Current CodeBlob
GrowableArrayIterator<CodeHeap*> _heap;
GrowableArrayIterator<CodeHeap*> _end;
bool _only_not_unloading;
void initialize_iteration(T* nm) {
}
bool next_impl() {
for (;;) {
// Walk through heaps as required
if (!next_blob()) {
if (_heap == _end) {
return false;
}
++_heap;
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;
}
}
public:
CodeBlobIterator(LivenessFilter filter, T* nm = NULL)
: _only_not_unloading(filter == only_not_unloading)
{
if (Filter::heaps() == NULL) {
// The iterator is supposed to shortcut since we have
// _heap == _end, but make sure we do not have garbage
// in other fields as well.
_code_blob = nullptr;
return;
}
_heap = Filter::heaps()->begin();
_end = Filter::heaps()->end();
// If set to NULL, initialized by first call to next()
_code_blob = 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() {
if (is_relaxed) {
MutexLocker ml(CodeCache_lock, Mutex::_no_safepoint_check_flag);
return next_impl();
} else {
assert_locked_or_safepoint(CodeCache_lock);
return next_impl();
}
}
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(); }
};
struct AllCodeBlobsFilter {
static bool apply(CodeBlob* cb) { return true; }
static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::heaps(); }
};
typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter, false /* is_relaxed */> CompiledMethodIterator;
typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter, true /* is_relaxed */> RelaxedCompiledMethodIterator;
typedef CodeBlobIterator<nmethod, NMethodFilter, false /* is_relaxed */> NMethodIterator;
typedef CodeBlobIterator<CodeBlob, AllCodeBlobsFilter, false /* is_relaxed */> AllCodeBlobsIterator;
#endif // SHARE_CODE_CODECACHE_HPP
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