--- old/src/share/vm/code/codeCache.hpp 2014-09-03 12:15:30.179797423 +0200 +++ new/src/share/vm/code/codeCache.hpp 2014-09-03 12:15:29.907797414 +0200 @@ -26,105 +26,117 @@ #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: -// - 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. +// -- 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-methods: Non-methods 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-method code heap getting full, non-method 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 NMethodIterator; 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() + // 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_blobs; // Total number of CodeBlobs in the cache + static int _number_of_adapters; // Total number of Adapters in the cache + static int _number_of_nmethods; // Total number of nmethods in the cache + 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 int _codemem_full_count; // Number of times a CodeHeap in the cache was full static void mark_scavenge_root_nmethods() PRODUCT_RETURN; static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN; - static int _codemem_full_count; - static size_t bytes_allocated_in_freelist() { return _heap->allocated_in_freelist(); } - static int allocated_segments() { return _heap->allocated_segments(); } - static size_t freelist_length() { return _heap->freelist_length(); } + // CodeHeap management + static void initialize_heaps(); // Initializes the CodeHeaps + // 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, size_t size_initial, int code_blob_type); + static CodeHeap* get_code_heap(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 + static bool heap_available(int code_blob_type); // Returns true if a CodeHeap for the given CodeBlobType is available + static ReservedCodeSpace reserve_heap_memory(size_t size); // Reserves one continuous chunk of memory for the CodeHeaps - public: + // 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(); - 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 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 + static CodeBlob* allocate(int size, int code_blob_type, 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 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; } + 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 nof_blobs() { return _number_of_blobs; } // Returns the total number of CodeBlobs in the cache + static int nof_adapters() { return _number_of_adapters; } // Returns the total number of Adapters in the cache + static int nof_nmethods() { return _number_of_nmethods; } // Returns the total number of nmethods in the cache // GC support static void gc_epilogue(); @@ -137,7 +149,7 @@ 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 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); @@ -151,23 +163,43 @@ 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); // 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(); } + static address low_bound() { return _low_bound; } + static address high_bound() { return _high_bound; } // 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 size_t capacity(int code_blob_type) { return heap_available(code_blob_type) ? get_code_heap(code_blob_type)->capacity() : 0; } + static size_t capacity(); + static size_t unallocated_capacity(int code_blob_type) { return heap_available(code_blob_type) ? get_code_heap(code_blob_type)->unallocated_capacity() : 0; } + static size_t unallocated_capacity(); + static size_t max_capacity(int code_blob_type) { return heap_available(code_blob_type) ? get_code_heap(code_blob_type)->max_capacity() : 0; } + static size_t max_capacity(); + + static bool is_full(int* code_blob_type); + 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 the CodeBlobType for nmethods of 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(); @@ -183,10 +215,87 @@ static void make_marked_nmethods_zombies(); static void make_marked_nmethods_not_entrant(); - // tells how many nmethods have dependencies + // tells how many nmethods have dependencies static int number_of_nmethods_with_dependencies(); static int get_codemem_full_count() { return _codemem_full_count; } }; + +// 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->comp_level()); + } 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