/* * Copyright (c) 1997, 2015, 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 "code/nmethod.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 OopClosure; class DepChange; class CodeCache : AllStatic { friend class VMStructs; friend class JVMCIVMStructs; friend class NMethodIterator; friend class WhiteBox; friend class CodeCacheLoader; private: // CodeHeaps of the cache static GrowableArray* _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 bool _needs_cache_clean; // True if inline caches of the nmethods needs to be flushed static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link() static void mark_scavenge_root_nmethods() PRODUCT_RETURN; static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN; // 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(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 size_t heap_alignment(); // Returns the alignment of the CodeHeaps in bytes 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 first alive CodeBlob on the given CodeHeap static CodeBlob* next_blob(CodeBlob* cb); // Returns the next CodeBlob of the given type succeeding the given CodeBlob static size_t bytes_allocated_in_freelists(); static int allocated_segments(); static size_t freelists_length(); public: // Initialization static void initialize(); // Allocation/administration static CodeBlob* allocate(int size, int code_blob_type, bool strict = 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 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); // 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 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 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; // Apply f to every live code blob in scavengable nmethods. Remove nmethods from // the list if f->fix_relocations and the nmethod no longer has scavengable oops. static void scavenge_root_nmethods_do(CodeBlobToOopClosure* 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, nmethod* prev = NULL); static void prune_scavenge_root_nmethods(); // 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); // 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 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 // 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 nmethod static int get_code_blob_type(nmethod* nm) { return get_code_heap(nm)->code_blob_type(); } // 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(DepChange& changes); #ifdef HOTSWAP static int mark_for_evol_deoptimization(instanceKlassHandle dependee); #endif // HOTSWAP 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(instanceKlassHandle dependee); #ifdef HOTSWAP // Flushing and deoptimization in case of evolution static void flush_evol_dependents_on(instanceKlassHandle dependee); #endif // HOTSWAP // Support for fullspeed debugging static void flush_dependents_on_method(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; } }; // Iterator to iterate over nmethods in the CodeCache. class NMethodIterator : public StackObj { private: CodeBlob* _code_blob; // Current CodeBlob int _code_blob_type; // Refers to current CodeHeap public: NMethodIterator() { initialize(NULL); // Set to NULL, initialized by first call to next() } NMethodIterator(nmethod* nm) { initialize(nm); } // Advance iterator to next nmethod bool next() { assert_locked_or_safepoint(CodeCache_lock); assert(_code_blob_type < CodeBlobType::NumTypes, "end reached"); bool result = next_nmethod(); while (!result && (_code_blob_type < CodeBlobType::MethodProfiled)) { // Advance to next code heap if segmented code cache _code_blob_type++; result = next_nmethod(); } return result; } // Advance iterator to next alive nmethod bool next_alive() { bool result = next(); while(result && !_code_blob->is_alive()) { result = next(); } return result; } bool end() const { return _code_blob == NULL; } nmethod* method() const { return (nmethod*)_code_blob; } private: // Initialize iterator to given nmethod void initialize(nmethod* nm) { _code_blob = (CodeBlob*)nm; if (!SegmentedCodeCache) { // Iterate over all CodeBlobs _code_blob_type = CodeBlobType::All; } else if (nm != NULL) { _code_blob_type = CodeCache::get_code_blob_type(nm); } else { // Only iterate over method code heaps, starting with non-profiled _code_blob_type = CodeBlobType::MethodNonProfiled; } } // Advance iterator to the next nmethod in the current code heap bool next_nmethod() { // Get first method CodeBlob if (_code_blob == NULL) { _code_blob = CodeCache::first_blob(_code_blob_type); if (_code_blob == NULL) { return false; } else if (_code_blob->is_nmethod()) { return true; } } // Search for next method CodeBlob _code_blob = CodeCache::next_blob(_code_blob); while (_code_blob != NULL && !_code_blob->is_nmethod()) { _code_blob = CodeCache::next_blob(_code_blob); } return _code_blob != NULL; } }; #endif // SHARE_VM_CODE_CODECACHE_HPP