1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/g1/heapRegionSet.hpp Wed Jan 19 19:30:42 2011 -0500
1.3 @@ -0,0 +1,346 @@
1.4 +/*
1.5 + * copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_HPP
1.30 +
1.31 +#include "gc_implementation/g1/heapRegion.hpp"
1.32 +
1.33 +// Large buffer for some cases where the output might be larger than normal.
1.34 +#define HRL_ERR_MSG_BUFSZ 512
1.35 +typedef FormatBuffer<HRL_ERR_MSG_BUFSZ> hrl_err_msg;
1.36 +
1.37 +// Set verification will be forced either if someone defines
1.38 +// HEAP_REGION_SET_FORCE_VERIFY to be 1, or in builds in which
1.39 +// asserts are compiled in.
1.40 +#ifndef HEAP_REGION_SET_FORCE_VERIFY
1.41 +#define HEAP_REGION_SET_FORCE_VERIFY defined(ASSERT)
1.42 +#endif // HEAP_REGION_SET_FORCE_VERIFY
1.43 +
1.44 +//////////////////// HeapRegionSetBase ////////////////////
1.45 +
1.46 +// Base class for all the classes that represent heap region sets. It
1.47 +// contains the basic attributes that each set needs to maintain
1.48 +// (e.g., length, region num, used bytes sum) plus any shared
1.49 +// functionality (e.g., verification).
1.50 +
1.51 +class hrl_ext_msg;
1.52 +
1.53 +class HeapRegionSetBase VALUE_OBJ_CLASS_SPEC {
1.54 + friend class hrl_ext_msg;
1.55 +
1.56 +protected:
1.57 + static size_t calculate_region_num(HeapRegion* hr);
1.58 +
1.59 + static size_t _unrealistically_long_length;
1.60 +
1.61 + // The number of regions added to the set. If the set contains
1.62 + // only humongous regions, this reflects only 'starts humongous'
1.63 + // regions and does not include 'continues humongous' ones.
1.64 + size_t _length;
1.65 +
1.66 + // The total number of regions represented by the set. If the set
1.67 + // does not contain humongous regions, this should be the same as
1.68 + // _length. If the set contains only humongous regions, this will
1.69 + // include the 'continues humongous' regions.
1.70 + size_t _region_num;
1.71 +
1.72 + // We don't keep track of the total capacity explicitly, we instead
1.73 + // recalculate it based on _region_num and the heap region size.
1.74 +
1.75 + // The sum of used bytes in the all the regions in the set.
1.76 + size_t _total_used_bytes;
1.77 +
1.78 + const char* _name;
1.79 +
1.80 + bool _verify_in_progress;
1.81 + size_t _calc_length;
1.82 + size_t _calc_region_num;
1.83 + size_t _calc_total_capacity_bytes;
1.84 + size_t _calc_total_used_bytes;
1.85 +
1.86 + // verify_region() is used to ensure that the contents of a region
1.87 + // added to / removed from a set are consistent. Different sets
1.88 + // make different assumptions about the regions added to them. So
1.89 + // each set can override verify_region_extra(), which is called
1.90 + // from verify_region(), and do any extra verification it needs to
1.91 + // perform in that.
1.92 + virtual const char* verify_region_extra(HeapRegion* hr) { return NULL; }
1.93 + bool verify_region(HeapRegion* hr,
1.94 + HeapRegionSetBase* expected_containing_set);
1.95 +
1.96 + // Indicates whether all regions in the set should be humongous or
1.97 + // not. Only used during verification.
1.98 + virtual bool regions_humongous() = 0;
1.99 +
1.100 + // Indicates whether all regions in the set should be empty or
1.101 + // not. Only used during verification.
1.102 + virtual bool regions_empty() = 0;
1.103 +
1.104 + // Subclasses can optionally override this to do MT safety protocol
1.105 + // checks. It is called in an assert from all methods that perform
1.106 + // updates on the set (and subclasses should also call it too).
1.107 + virtual bool check_mt_safety() { return true; }
1.108 +
1.109 + // fill_in_ext_msg() writes the the values of the set's attributes
1.110 + // in the custom err_msg (hrl_ext_msg). fill_in_ext_msg_extra()
1.111 + // allows subclasses to append further information.
1.112 + virtual void fill_in_ext_msg_extra(hrl_ext_msg* msg) { }
1.113 + void fill_in_ext_msg(hrl_ext_msg* msg, const char* message);
1.114 +
1.115 + // It updates the fields of the set to reflect hr being added to
1.116 + // the set.
1.117 + inline void update_for_addition(HeapRegion* hr);
1.118 +
1.119 + // It updates the fields of the set to reflect hr being added to
1.120 + // the set and tags the region appropriately.
1.121 + inline void add_internal(HeapRegion* hr);
1.122 +
1.123 + // It updates the fields of the set to reflect hr being removed
1.124 + // from the set.
1.125 + inline void update_for_removal(HeapRegion* hr);
1.126 +
1.127 + // It updates the fields of the set to reflect hr being removed
1.128 + // from the set and tags the region appropriately.
1.129 + inline void remove_internal(HeapRegion* hr);
1.130 +
1.131 + // It clears all the fields of the sets. Note: it will not iterate
1.132 + // over the set and remove regions from it. It assumes that the
1.133 + // caller has already done so. It will literally just clear the fields.
1.134 + virtual void clear();
1.135 +
1.136 + HeapRegionSetBase(const char* name);
1.137 +
1.138 +public:
1.139 + static void set_unrealistically_long_length(size_t len);
1.140 +
1.141 + const char* name() { return _name; }
1.142 +
1.143 + size_t length() { return _length; }
1.144 +
1.145 + bool is_empty() { return _length == 0; }
1.146 +
1.147 + size_t region_num() { return _region_num; }
1.148 +
1.149 + size_t total_capacity_bytes() {
1.150 + return region_num() << HeapRegion::LogOfHRGrainBytes;
1.151 + }
1.152 +
1.153 + size_t total_used_bytes() { return _total_used_bytes; }
1.154 +
1.155 + virtual void verify();
1.156 + void verify_start();
1.157 + void verify_next_region(HeapRegion* hr);
1.158 + void verify_end();
1.159 +
1.160 +#if HEAP_REGION_SET_FORCE_VERIFY
1.161 + void verify_optional() {
1.162 + verify();
1.163 + }
1.164 +#else // HEAP_REGION_SET_FORCE_VERIFY
1.165 + void verify_optional() { }
1.166 +#endif // HEAP_REGION_SET_FORCE_VERIFY
1.167 +
1.168 + virtual void print_on(outputStream* out, bool print_contents = false);
1.169 +};
1.170 +
1.171 +// Customized err_msg for heap region sets. Apart from a
1.172 +// assert/guarantee-specific message it also prints out the values of
1.173 +// the fields of the associated set. This can be very helpful in
1.174 +// diagnosing failures.
1.175 +
1.176 +class hrl_ext_msg : public hrl_err_msg {
1.177 +public:
1.178 + hrl_ext_msg(HeapRegionSetBase* set, const char* message) : hrl_err_msg("") {
1.179 + set->fill_in_ext_msg(this, message);
1.180 + }
1.181 +};
1.182 +
1.183 +// These two macros are provided for convenience, to keep the uses of
1.184 +// these two asserts a bit more concise.
1.185 +
1.186 +#define hrl_assert_mt_safety_ok(_set_) \
1.187 + do { \
1.188 + assert((_set_)->check_mt_safety(), hrl_ext_msg((_set_), "MT safety")); \
1.189 + } while (0)
1.190 +
1.191 +#define hrl_assert_region_ok(_set_, _hr_, _expected_) \
1.192 + do { \
1.193 + assert((_set_)->verify_region((_hr_), (_expected_)), \
1.194 + hrl_ext_msg((_set_), "region verification")); \
1.195 + } while (0)
1.196 +
1.197 +//////////////////// HeapRegionSet ////////////////////
1.198 +
1.199 +#define hrl_assert_sets_match(_set1_, _set2_) \
1.200 + do { \
1.201 + assert(((_set1_)->regions_humongous() == \
1.202 + (_set2_)->regions_humongous()) && \
1.203 + ((_set1_)->regions_empty() == (_set2_)->regions_empty()), \
1.204 + hrl_err_msg("the contents of set %s and set %s should match", \
1.205 + (_set1_)->name(), (_set2_)->name())); \
1.206 + } while (0)
1.207 +
1.208 +// This class represents heap region sets whose members are not
1.209 +// explicitly tracked. It's helpful to group regions using such sets
1.210 +// so that we can reason about all the region groups in the heap using
1.211 +// the same interface (namely, the HeapRegionSetBase API).
1.212 +
1.213 +class HeapRegionSet : public HeapRegionSetBase {
1.214 +protected:
1.215 + virtual const char* verify_region_extra(HeapRegion* hr) {
1.216 + if (hr->next() != NULL) {
1.217 + return "next() should always be NULL as we do not link the regions";
1.218 + }
1.219 +
1.220 + return HeapRegionSetBase::verify_region_extra(hr);
1.221 + }
1.222 +
1.223 + HeapRegionSet(const char* name) : HeapRegionSetBase(name) {
1.224 + clear();
1.225 + }
1.226 +
1.227 +public:
1.228 + // It adds hr to the set. The region should not be a member of
1.229 + // another set.
1.230 + inline void add(HeapRegion* hr);
1.231 +
1.232 + // It removes hr from the set. The region should be a member of
1.233 + // this set.
1.234 + inline void remove(HeapRegion* hr);
1.235 +
1.236 + // It removes a region from the set. Instead of updating the fields
1.237 + // of the set to reflect this removal, it accumulates the updates
1.238 + // in proxy_set. The idea is that proxy_set is thread-local to
1.239 + // avoid multiple threads updating the fields of the set
1.240 + // concurrently and having to synchronize. The method
1.241 + // update_from_proxy() will update the fields of the set from the
1.242 + // proxy_set.
1.243 + inline void remove_with_proxy(HeapRegion* hr, HeapRegionSet* proxy_set);
1.244 +
1.245 + // After multiple calls to remove_with_proxy() the updates to the
1.246 + // fields of the set are accumulated in proxy_set. This call
1.247 + // updates the fields of the set from proxy_set.
1.248 + void update_from_proxy(HeapRegionSet* proxy_set);
1.249 +};
1.250 +
1.251 +//////////////////// HeapRegionLinkedList ////////////////////
1.252 +
1.253 +// A set that links all the regions added to it in a singly-linked
1.254 +// list. We should try to avoid doing operations that iterate over
1.255 +// such lists in performance critical paths. Typically we should
1.256 +// add / remove one region at a time or concatenate two lists. All
1.257 +// those operations are done in constant time.
1.258 +
1.259 +class HeapRegionLinkedListIterator;
1.260 +
1.261 +class HeapRegionLinkedList : public HeapRegionSetBase {
1.262 + friend class HeapRegionLinkedListIterator;
1.263 +
1.264 +private:
1.265 + HeapRegion* _head;
1.266 + HeapRegion* _tail;
1.267 +
1.268 + // These are provided for use by the friend classes.
1.269 + HeapRegion* head() { return _head; }
1.270 + HeapRegion* tail() { return _tail; }
1.271 +
1.272 +protected:
1.273 + virtual void fill_in_ext_msg_extra(hrl_ext_msg* msg);
1.274 +
1.275 + // See the comment for HeapRegionSetBase::clear()
1.276 + virtual void clear();
1.277 +
1.278 + HeapRegionLinkedList(const char* name) : HeapRegionSetBase(name) {
1.279 + clear();
1.280 + }
1.281 +
1.282 +public:
1.283 + // It adds hr to the list as the new tail. The region should not be
1.284 + // a member of another set.
1.285 + inline void add_as_tail(HeapRegion* hr);
1.286 +
1.287 + // It removes and returns the head of the list. It assumes that the
1.288 + // list is not empty so it will return a non-NULL value.
1.289 + inline HeapRegion* remove_head();
1.290 +
1.291 + // Convenience method.
1.292 + inline HeapRegion* remove_head_or_null();
1.293 +
1.294 + // It moves the regions from from_list to this list and empties
1.295 + // from_list. The new regions will appear in the same order as they
1.296 + // were in from_list and be linked in the end of this list.
1.297 + void add_as_tail(HeapRegionLinkedList* from_list);
1.298 +
1.299 + // It empties the list by removing all regions from it.
1.300 + void remove_all();
1.301 +
1.302 + // It removes all regions in the list that are pending for removal
1.303 + // (i.e., they have been tagged with "pending_removal"). The list
1.304 + // must not be empty, target_count should reflect the exact number
1.305 + // of regions that are pending for removal in the list, and
1.306 + // target_count should be > 1 (currently, we never need to remove a
1.307 + // single region using this).
1.308 + void remove_all_pending(size_t target_count);
1.309 +
1.310 + virtual void verify();
1.311 +
1.312 + virtual void print_on(outputStream* out, bool print_contents = false);
1.313 +};
1.314 +
1.315 +//////////////////// HeapRegionLinkedList ////////////////////
1.316 +
1.317 +// Iterator class that provides a convenient way to iterator over the
1.318 +// regions in a HeapRegionLinkedList instance.
1.319 +
1.320 +class HeapRegionLinkedListIterator : public StackObj {
1.321 +private:
1.322 + HeapRegionLinkedList* _list;
1.323 + HeapRegion* _curr;
1.324 +
1.325 +public:
1.326 + bool more_available() {
1.327 + return _curr != NULL;
1.328 + }
1.329 +
1.330 + HeapRegion* get_next() {
1.331 + assert(more_available(),
1.332 + "get_next() should be called when more regions are available");
1.333 +
1.334 + // If we are going to introduce a count in the iterator we should
1.335 + // do the "cycle" check.
1.336 +
1.337 + HeapRegion* hr = _curr;
1.338 + assert(_list->verify_region(hr, _list), "region verification");
1.339 + _curr = hr->next();
1.340 + return hr;
1.341 + }
1.342 +
1.343 + HeapRegionLinkedListIterator(HeapRegionLinkedList* list)
1.344 + : _curr(NULL), _list(list) {
1.345 + _curr = list->head();
1.346 + }
1.347 +};
1.348 +
1.349 +#endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSET_HPP
