15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_SYNCHRONIZER_HPP
26 #define SHARE_RUNTIME_SYNCHRONIZER_HPP
27
28 #include "memory/padded.hpp"
29 #include "oops/markWord.hpp"
30 #include "runtime/basicLock.hpp"
31 #include "runtime/handles.hpp"
32 #include "runtime/perfData.hpp"
33
34 class ObjectMonitor;
35 class ThreadsList;
36
37 typedef PaddedEnd<ObjectMonitor, DEFAULT_CACHE_LINE_SIZE> PaddedObjectMonitor;
38
39 struct DeflateMonitorCounters {
40 int n_in_use; // currently associated with objects
41 int n_in_circulation; // extant
42 int n_scavenged; // reclaimed (global and per-thread)
43 int per_thread_scavenged; // per-thread scavenge total
44 double per_thread_times; // per-thread scavenge times
45 };
46
47 class ObjectSynchronizer : AllStatic {
48 friend class VMStructs;
49 public:
50 typedef enum {
51 owner_self,
52 owner_none,
53 owner_other
54 } LockOwnership;
55
56 typedef enum {
57 inflate_cause_vm_internal = 0,
58 inflate_cause_monitor_enter = 1,
59 inflate_cause_wait = 2,
60 inflate_cause_notify = 3,
61 inflate_cause_hash_code = 4,
62 inflate_cause_jni_enter = 5,
63 inflate_cause_jni_exit = 6,
92 // Handle all interpreter, compiler and jni cases
93 static int wait(Handle obj, jlong millis, TRAPS);
94 static void notify(Handle obj, TRAPS);
95 static void notifyall(Handle obj, TRAPS);
96
97 static bool quick_notify(oopDesc* obj, Thread* self, bool All);
98 static bool quick_enter(oop obj, Thread* self, BasicLock* Lock);
99
100 // Special internal-use-only method for use by JVM infrastructure
101 // that needs to wait() on a java-level object but that can't risk
102 // throwing unexpected InterruptedExecutionExceptions.
103 static void wait_uninterruptibly(Handle obj, jlong Millis, Thread* THREAD);
104
105 // used by classloading to free classloader object lock,
106 // wait on an internal lock, and reclaim original lock
107 // with original recursion count
108 static intptr_t complete_exit(Handle obj, TRAPS);
109 static void reenter (Handle obj, intptr_t recursion, TRAPS);
110
111 // thread-specific and global ObjectMonitor free list accessors
112 static ObjectMonitor* om_alloc(Thread* self);
113 static void om_release(Thread* self, ObjectMonitor* m,
114 bool FromPerThreadAlloc);
115 static void om_flush(Thread* self);
116
117 // Inflate light weight monitor to heavy weight monitor
118 static ObjectMonitor* inflate(Thread* self, oop obj, const InflateCause cause);
119 // This version is only for internal use
120 static void inflate_helper(oop obj);
121 static const char* inflate_cause_name(const InflateCause cause);
122
123 // Returns the identity hash value for an oop
124 // NOTE: It may cause monitor inflation
125 static intptr_t identity_hash_value_for(Handle obj);
126 static intptr_t FastHashCode(Thread* self, oop obj);
127
128 // java.lang.Thread support
129 static bool current_thread_holds_lock(JavaThread* thread, Handle h_obj);
130 static LockOwnership query_lock_ownership(JavaThread* self, Handle h_obj);
131
132 static JavaThread* get_lock_owner(ThreadsList * t_list, Handle h_obj);
133
134 // JNI detach support
135 static void release_monitors_owned_by_thread(TRAPS);
136 static void monitors_iterate(MonitorClosure* m);
137
138 // GC: we current use aggressive monitor deflation policy
139 // Basically we deflate all monitors that are not busy.
140 // An adaptive profile-based deflation policy could be used if needed
141 static void deflate_idle_monitors(DeflateMonitorCounters* counters);
142 static void deflate_thread_local_monitors(Thread* thread, DeflateMonitorCounters* counters);
143 static void prepare_deflate_idle_monitors(DeflateMonitorCounters* counters);
144 static void finish_deflate_idle_monitors(DeflateMonitorCounters* counters);
145
146 // For a given monitor list: global or per-thread, deflate idle monitors
147 static int deflate_monitor_list(ObjectMonitor** list_p,
148 ObjectMonitor** free_head_p,
149 ObjectMonitor** free_tail_p);
150 static bool deflate_monitor(ObjectMonitor* mid, oop obj,
151 ObjectMonitor** free_head_p,
152 ObjectMonitor** free_tail_p);
153 static bool is_cleanup_needed();
154 static void oops_do(OopClosure* f);
155 // Process oops in thread local used monitors
156 static void thread_local_used_oops_do(Thread* thread, OopClosure* f);
157
158 // debugging
159 static void audit_and_print_stats(bool on_exit);
160 static void chk_free_entry(JavaThread* jt, ObjectMonitor* n,
161 outputStream * out, int *error_cnt_p);
162 static void chk_global_free_list_and_count(outputStream * out,
163 int *error_cnt_p);
164 static void chk_global_in_use_list_and_count(outputStream * out,
165 int *error_cnt_p);
166 static void chk_in_use_entry(JavaThread* jt, ObjectMonitor* n,
167 outputStream * out, int *error_cnt_p);
168 static void chk_per_thread_in_use_list_and_count(JavaThread *jt,
169 outputStream * out,
170 int *error_cnt_p);
171 static void chk_per_thread_free_list_and_count(JavaThread *jt,
172 outputStream * out,
173 int *error_cnt_p);
174 static void log_in_use_monitor_details(outputStream * out, bool on_exit);
175 static int log_monitor_list_counts(outputStream * out);
176 static int verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0;
177
178 private:
179 friend class SynchronizerTest;
180
181 enum { _BLOCKSIZE = 128 };
182 // global list of blocks of monitors
183 static PaddedObjectMonitor* volatile g_block_list;
184 // global monitor free list
185 static ObjectMonitor* volatile g_free_list;
186 // global monitor in-use list, for moribund threads,
187 // monitors they inflated need to be scanned for deflation
188 static ObjectMonitor* volatile g_om_in_use_list;
189 // count of entries in g_om_in_use_list
190 static int g_om_in_use_count;
191
192 // Process oops in all global used monitors (i.e. moribund thread's monitors)
193 static void global_used_oops_do(OopClosure* f);
194 // Process oops in monitors on the given list
195 static void list_oops_do(ObjectMonitor* list, OopClosure* f);
196
197 // Support for SynchronizerTest access to GVars fields:
198 static u_char* get_gvars_addr();
199 static u_char* get_gvars_hc_sequence_addr();
200 static size_t get_gvars_size();
201 static u_char* get_gvars_stw_random_addr();
202 };
203
204 // ObjectLocker enforces balanced locking and can never throw an
205 // IllegalMonitorStateException. However, a pending exception may
206 // have to pass through, and we must also be able to deal with
207 // asynchronous exceptions. The caller is responsible for checking
208 // the thread's pending exception if needed.
209 class ObjectLocker : public StackObj {
210 private:
211 Thread* _thread;
212 Handle _obj;
213 BasicLock _lock;
214 bool _dolock; // default true
215 public:
|
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_SYNCHRONIZER_HPP
26 #define SHARE_RUNTIME_SYNCHRONIZER_HPP
27
28 #include "memory/padded.hpp"
29 #include "oops/markWord.hpp"
30 #include "runtime/basicLock.hpp"
31 #include "runtime/handles.hpp"
32 #include "runtime/perfData.hpp"
33
34 class ObjectMonitor;
35 class ObjectMonitorHandle;
36 class ThreadsList;
37
38 #ifndef OM_CACHE_LINE_SIZE
39 // Use DEFAULT_CACHE_LINE_SIZE if not already specified for
40 // the current build platform.
41 #define OM_CACHE_LINE_SIZE DEFAULT_CACHE_LINE_SIZE
42 #endif
43
44 typedef PaddedEnd<ObjectMonitor, OM_CACHE_LINE_SIZE> PaddedObjectMonitor;
45
46 struct DeflateMonitorCounters {
47 volatile int n_in_use; // currently associated with objects
48 volatile int n_in_circulation; // extant
49 volatile int n_scavenged; // reclaimed (global and per-thread)
50 volatile int per_thread_scavenged; // per-thread scavenge total
51 double per_thread_times; // per-thread scavenge times
52 };
53
54 class ObjectSynchronizer : AllStatic {
55 friend class VMStructs;
56 public:
57 typedef enum {
58 owner_self,
59 owner_none,
60 owner_other
61 } LockOwnership;
62
63 typedef enum {
64 inflate_cause_vm_internal = 0,
65 inflate_cause_monitor_enter = 1,
66 inflate_cause_wait = 2,
67 inflate_cause_notify = 3,
68 inflate_cause_hash_code = 4,
69 inflate_cause_jni_enter = 5,
70 inflate_cause_jni_exit = 6,
99 // Handle all interpreter, compiler and jni cases
100 static int wait(Handle obj, jlong millis, TRAPS);
101 static void notify(Handle obj, TRAPS);
102 static void notifyall(Handle obj, TRAPS);
103
104 static bool quick_notify(oopDesc* obj, Thread* self, bool All);
105 static bool quick_enter(oop obj, Thread* self, BasicLock* Lock);
106
107 // Special internal-use-only method for use by JVM infrastructure
108 // that needs to wait() on a java-level object but that can't risk
109 // throwing unexpected InterruptedExecutionExceptions.
110 static void wait_uninterruptibly(Handle obj, jlong Millis, Thread* THREAD);
111
112 // used by classloading to free classloader object lock,
113 // wait on an internal lock, and reclaim original lock
114 // with original recursion count
115 static intptr_t complete_exit(Handle obj, TRAPS);
116 static void reenter (Handle obj, intptr_t recursion, TRAPS);
117
118 // thread-specific and global ObjectMonitor free list accessors
119 static ObjectMonitor* om_alloc(Thread* self, const InflateCause cause);
120 static void om_release(Thread* self, ObjectMonitor* m,
121 bool FromPerThreadAlloc);
122 static void om_flush(Thread* self);
123
124 // Inflate light weight monitor to heavy weight monitor
125 static void inflate(ObjectMonitorHandle* omh_p, Thread* self, oop obj,
126 const InflateCause cause);
127 // This version is only for internal use
128 static void inflate_helper(ObjectMonitorHandle* omh_p, oop obj);
129 static const char* inflate_cause_name(const InflateCause cause);
130
131 // Returns the identity hash value for an oop
132 // NOTE: It may cause monitor inflation
133 static intptr_t identity_hash_value_for(Handle obj);
134 static intptr_t FastHashCode(Thread* self, oop obj);
135
136 // java.lang.Thread support
137 static bool current_thread_holds_lock(JavaThread* thread, Handle h_obj);
138 static LockOwnership query_lock_ownership(JavaThread* self, Handle h_obj);
139
140 static JavaThread* get_lock_owner(ThreadsList * t_list, Handle h_obj);
141
142 // JNI detach support
143 static void release_monitors_owned_by_thread(TRAPS);
144 static void monitors_iterate(MonitorClosure* m);
145
146 // GC: we current use aggressive monitor deflation policy
147 // Basically we deflate all monitors that are not busy.
148 // An adaptive profile-based deflation policy could be used if needed
149 static void deflate_idle_monitors(DeflateMonitorCounters* counters);
150 static void deflate_global_idle_monitors_using_JT();
151 static void deflate_per_thread_idle_monitors_using_JT(JavaThread* target);
152 static void deflate_common_idle_monitors_using_JT(bool is_global, JavaThread* target);
153 static void deflate_thread_local_monitors(Thread* thread, DeflateMonitorCounters* counters);
154 static void prepare_deflate_idle_monitors(DeflateMonitorCounters* counters);
155 static void finish_deflate_idle_monitors(DeflateMonitorCounters* counters);
156
157 // For a given monitor list: global or per-thread, deflate idle monitors
158 static int deflate_monitor_list(ObjectMonitor* volatile * list_p,
159 int volatile * count_p,
160 ObjectMonitor** free_head_p,
161 ObjectMonitor** free_tail_p);
162 // For a given in-use monitor list: global or per-thread, deflate idle
163 // monitors using a JavaThread.
164 static int deflate_monitor_list_using_JT(ObjectMonitor* volatile * list_p,
165 int volatile * count_p,
166 ObjectMonitor** free_head_p,
167 ObjectMonitor** free_tail_p,
168 ObjectMonitor** saved_mid_in_use_p);
169 static bool deflate_monitor(ObjectMonitor* mid, oop obj,
170 ObjectMonitor** free_head_p,
171 ObjectMonitor** free_tail_p);
172 static bool deflate_monitor_using_JT(ObjectMonitor* mid,
173 ObjectMonitor** free_head_p,
174 ObjectMonitor** free_tail_p);
175 static bool is_async_deflation_needed();
176 static bool is_safepoint_deflation_needed();
177 static bool is_async_deflation_requested() { return _is_async_deflation_requested; }
178 static bool is_special_deflation_requested() { return _is_special_deflation_requested; }
179 static void set_is_async_deflation_requested(bool new_value) { _is_async_deflation_requested = new_value; }
180 static void set_is_special_deflation_requested(bool new_value) { _is_special_deflation_requested = new_value; }
181 static jlong time_since_last_async_deflation_ms();
182 static void oops_do(OopClosure* f);
183 // Process oops in thread local used monitors
184 static void thread_local_used_oops_do(Thread* thread, OopClosure* f);
185
186 // debugging
187 static void audit_and_print_stats(bool on_exit);
188 static void chk_free_entry(JavaThread* jt, ObjectMonitor* n,
189 outputStream * out, int *error_cnt_p);
190 static void chk_global_free_list_and_count(outputStream * out,
191 int *error_cnt_p);
192 static void chk_global_in_use_list_and_count(outputStream * out,
193 int *error_cnt_p);
194 static void chk_in_use_entry(JavaThread* jt, ObjectMonitor* n,
195 outputStream * out, int *error_cnt_p);
196 static void chk_per_thread_in_use_list_and_count(JavaThread *jt,
197 outputStream * out,
198 int *error_cnt_p);
199 static void chk_per_thread_free_list_and_count(JavaThread *jt,
200 outputStream * out,
201 int *error_cnt_p);
202 static void log_in_use_monitor_details(outputStream * out);
203 static int log_monitor_list_counts(outputStream * out);
204 static int verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0;
205
206 static void do_safepoint_work(DeflateMonitorCounters* counters);
207
208 private:
209 friend class SynchronizerTest;
210
211 enum { _BLOCKSIZE = 128 };
212 // global list of blocks of monitors
213 static PaddedObjectMonitor* volatile g_block_list;
214 static volatile bool _is_async_deflation_requested;
215 static volatile bool _is_special_deflation_requested;
216 static jlong _last_async_deflation_time_ns;
217
218 // Function to prepend new blocks to the appropriate lists:
219 static void prepend_block_to_lists(PaddedObjectMonitor* new_blk);
220
221 // Process oops in all global used monitors (i.e. moribund thread's monitors)
222 static void global_used_oops_do(OopClosure* f);
223 // Process oops in monitors on the given list
224 static void list_oops_do(ObjectMonitor* list, int count, OopClosure* f);
225
226 // Support for SynchronizerTest access to GVars fields:
227 static u_char* get_gvars_addr();
228 static u_char* get_gvars_hc_sequence_addr();
229 static size_t get_gvars_size();
230 static u_char* get_gvars_stw_random_addr();
231 };
232
233 // ObjectLocker enforces balanced locking and can never throw an
234 // IllegalMonitorStateException. However, a pending exception may
235 // have to pass through, and we must also be able to deal with
236 // asynchronous exceptions. The caller is responsible for checking
237 // the thread's pending exception if needed.
238 class ObjectLocker : public StackObj {
239 private:
240 Thread* _thread;
241 Handle _obj;
242 BasicLock _lock;
243 bool _dolock; // default true
244 public:
|