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,
79 // Handle all interpreter, compiler and jni cases
80 static int wait(Handle obj, jlong millis, TRAPS);
81 static void notify(Handle obj, TRAPS);
82 static void notifyall(Handle obj, TRAPS);
83
84 static bool quick_notify(oopDesc* obj, Thread* self, bool All);
85 static bool quick_enter(oop obj, Thread* self, BasicLock* Lock);
86
87 // Special internal-use-only method for use by JVM infrastructure
88 // that needs to wait() on a java-level object but that can't risk
89 // throwing unexpected InterruptedExecutionExceptions.
90 static void wait_uninterruptibly(Handle obj, jlong Millis, Thread* THREAD);
91
92 // used by classloading to free classloader object lock,
93 // wait on an internal lock, and reclaim original lock
94 // with original recursion count
95 static intptr_t complete_exit(Handle obj, TRAPS);
96 static void reenter (Handle obj, intptr_t recursion, TRAPS);
97
98 // thread-specific and global ObjectMonitor free list accessors
99 static ObjectMonitor* om_alloc(Thread* self);
100 static void om_release(Thread* self, ObjectMonitor* m,
101 bool FromPerThreadAlloc);
102 static void om_flush(Thread* self);
103
104 // Inflate light weight monitor to heavy weight monitor
105 static ObjectMonitor* inflate(Thread* self, oop obj, const InflateCause cause);
106 // This version is only for internal use
107 static void inflate_helper(oop obj);
108 static const char* inflate_cause_name(const InflateCause cause);
109
110 // Returns the identity hash value for an oop
111 // NOTE: It may cause monitor inflation
112 static intptr_t identity_hash_value_for(Handle obj);
113 static intptr_t FastHashCode(Thread* self, oop obj);
114
115 // java.lang.Thread support
116 static bool current_thread_holds_lock(JavaThread* thread, Handle h_obj);
117 static LockOwnership query_lock_ownership(JavaThread* self, Handle h_obj);
118
119 static JavaThread* get_lock_owner(ThreadsList * t_list, Handle h_obj);
120
121 // JNI detach support
122 static void release_monitors_owned_by_thread(TRAPS);
123 static void monitors_iterate(MonitorClosure* m);
124
125 // GC: we current use aggressive monitor deflation policy
126 // Basically we deflate all monitors that are not busy.
127 // An adaptive profile-based deflation policy could be used if needed
128 static void deflate_idle_monitors(DeflateMonitorCounters* counters);
129 static void deflate_thread_local_monitors(Thread* thread, DeflateMonitorCounters* counters);
130 static void prepare_deflate_idle_monitors(DeflateMonitorCounters* counters);
131 static void finish_deflate_idle_monitors(DeflateMonitorCounters* counters);
132
133 // For a given monitor list: global or per-thread, deflate idle monitors
134 static int deflate_monitor_list(ObjectMonitor** list_p,
135 ObjectMonitor** free_head_p,
136 ObjectMonitor** free_tail_p);
137 static bool deflate_monitor(ObjectMonitor* mid, oop obj,
138 ObjectMonitor** free_head_p,
139 ObjectMonitor** free_tail_p);
140 static bool is_cleanup_needed();
141 static void oops_do(OopClosure* f);
142 // Process oops in thread local used monitors
143 static void thread_local_used_oops_do(Thread* thread, OopClosure* f);
144
145 // debugging
146 static void audit_and_print_stats(bool on_exit);
147 static void chk_free_entry(JavaThread* jt, ObjectMonitor* n,
148 outputStream * out, int *error_cnt_p);
149 static void chk_global_free_list_and_count(outputStream * out,
150 int *error_cnt_p);
151 static void chk_global_in_use_list_and_count(outputStream * out,
152 int *error_cnt_p);
153 static void chk_in_use_entry(JavaThread* jt, ObjectMonitor* n,
154 outputStream * out, int *error_cnt_p);
155 static void chk_per_thread_in_use_list_and_count(JavaThread *jt,
156 outputStream * out,
157 int *error_cnt_p);
158 static void chk_per_thread_free_list_and_count(JavaThread *jt,
159 outputStream * out,
160 int *error_cnt_p);
161 static void log_in_use_monitor_details(outputStream * out, bool on_exit);
162 static int log_monitor_list_counts(outputStream * out);
163 static int verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0;
164
165 private:
166 friend class SynchronizerTest;
167
168 enum { _BLOCKSIZE = 128 };
169 // global list of blocks of monitors
170 static PaddedObjectMonitor* volatile g_block_list;
171 // global monitor free list
172 static ObjectMonitor* volatile g_free_list;
173 // global monitor in-use list, for moribund threads,
174 // monitors they inflated need to be scanned for deflation
175 static ObjectMonitor* volatile g_om_in_use_list;
176 // count of entries in g_om_in_use_list
177 static int g_om_in_use_count;
178
179 // Process oops in all global used monitors (i.e. moribund thread's monitors)
180 static void global_used_oops_do(OopClosure* f);
181 // Process oops in monitors on the given list
182 static void list_oops_do(ObjectMonitor* list, OopClosure* f);
183
184 // Support for SynchronizerTest access to GVars fields:
185 static u_char* get_gvars_addr();
186 static u_char* get_gvars_hc_sequence_addr();
187 static size_t get_gvars_size();
188 static u_char* get_gvars_stw_random_addr();
189 };
190
191 // ObjectLocker enforces balanced locking and can never throw an
192 // IllegalMonitorStateException. However, a pending exception may
193 // have to pass through, and we must also be able to deal with
194 // asynchronous exceptions. The caller is responsible for checking
195 // the thread's pending exception if needed.
196 class ObjectLocker : public StackObj {
197 private:
198 Thread* _thread;
199 Handle _obj;
200 BasicLock _lock;
201 bool _dolock; // default true
202 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,
86 // Handle all interpreter, compiler and jni cases
87 static int wait(Handle obj, jlong millis, TRAPS);
88 static void notify(Handle obj, TRAPS);
89 static void notifyall(Handle obj, TRAPS);
90
91 static bool quick_notify(oopDesc* obj, Thread* self, bool All);
92 static bool quick_enter(oop obj, Thread* self, BasicLock* Lock);
93
94 // Special internal-use-only method for use by JVM infrastructure
95 // that needs to wait() on a java-level object but that can't risk
96 // throwing unexpected InterruptedExecutionExceptions.
97 static void wait_uninterruptibly(Handle obj, jlong Millis, Thread* THREAD);
98
99 // used by classloading to free classloader object lock,
100 // wait on an internal lock, and reclaim original lock
101 // with original recursion count
102 static intptr_t complete_exit(Handle obj, TRAPS);
103 static void reenter (Handle obj, intptr_t recursion, TRAPS);
104
105 // thread-specific and global ObjectMonitor free list accessors
106 static ObjectMonitor* om_alloc(Thread* self, const InflateCause cause);
107 static void om_release(Thread* self, ObjectMonitor* m,
108 bool FromPerThreadAlloc);
109 static void om_flush(Thread* self);
110
111 // Inflate light weight monitor to heavy weight monitor
112 static void inflate(ObjectMonitorHandle* omh_p, Thread* self, oop obj,
113 const InflateCause cause);
114 // This version is only for internal use
115 static void inflate_helper(ObjectMonitorHandle* omh_p, oop obj);
116 static const char* inflate_cause_name(const InflateCause cause);
117
118 // Returns the identity hash value for an oop
119 // NOTE: It may cause monitor inflation
120 static intptr_t identity_hash_value_for(Handle obj);
121 static intptr_t FastHashCode(Thread* self, oop obj);
122
123 // java.lang.Thread support
124 static bool current_thread_holds_lock(JavaThread* thread, Handle h_obj);
125 static LockOwnership query_lock_ownership(JavaThread* self, Handle h_obj);
126
127 static JavaThread* get_lock_owner(ThreadsList * t_list, Handle h_obj);
128
129 // JNI detach support
130 static void release_monitors_owned_by_thread(TRAPS);
131 static void monitors_iterate(MonitorClosure* m);
132
133 // GC: we current use aggressive monitor deflation policy
134 // Basically we deflate all monitors that are not busy.
135 // An adaptive profile-based deflation policy could be used if needed
136 static void deflate_idle_monitors(DeflateMonitorCounters* counters);
137 static void deflate_idle_monitors_using_JT();
138 static void deflate_global_idle_monitors_using_JT();
139 static void deflate_per_thread_idle_monitors_using_JT(JavaThread* target);
140 static void deflate_common_idle_monitors_using_JT(bool is_global, JavaThread* target);
141 static void deflate_thread_local_monitors(Thread* thread, DeflateMonitorCounters* counters);
142 static void prepare_deflate_idle_monitors(DeflateMonitorCounters* counters);
143 static void finish_deflate_idle_monitors(DeflateMonitorCounters* counters);
144
145 // For a given monitor list: global or per-thread, deflate idle monitors
146 static int deflate_monitor_list(ObjectMonitor* volatile * list_p,
147 int volatile * count_p,
148 ObjectMonitor** free_head_p,
149 ObjectMonitor** free_tail_p);
150 // For a given in-use monitor list: global or per-thread, deflate idle
151 // monitors using a JavaThread.
152 static int deflate_monitor_list_using_JT(ObjectMonitor* volatile * list_p,
153 int volatile * count_p,
154 ObjectMonitor** free_head_p,
155 ObjectMonitor** free_tail_p,
156 ObjectMonitor** saved_mid_in_use_p);
157 static bool deflate_monitor(ObjectMonitor* mid, oop obj,
158 ObjectMonitor** free_head_p,
159 ObjectMonitor** free_tail_p);
160 static bool deflate_monitor_using_JT(ObjectMonitor* mid,
161 ObjectMonitor** free_head_p,
162 ObjectMonitor** free_tail_p);
163 static bool is_async_deflation_needed();
164 static bool is_safepoint_deflation_needed();
165 static bool is_async_deflation_requested() { return _is_async_deflation_requested; }
166 static bool is_special_deflation_requested() { return _is_special_deflation_requested; }
167 static void set_is_async_deflation_requested(bool new_value) { _is_async_deflation_requested = new_value; }
168 static void set_is_special_deflation_requested(bool new_value) { _is_special_deflation_requested = new_value; }
169 static jlong time_since_last_async_deflation_ms();
170 static void oops_do(OopClosure* f);
171 // Process oops in thread local used monitors
172 static void thread_local_used_oops_do(Thread* thread, OopClosure* f);
173
174 // debugging
175 static void audit_and_print_stats(bool on_exit);
176 static void chk_free_entry(JavaThread* jt, ObjectMonitor* n,
177 outputStream * out, int *error_cnt_p);
178 static void chk_global_free_list_and_count(outputStream * out,
179 int *error_cnt_p);
180 static void chk_global_wait_list_and_count(outputStream * out,
181 int *error_cnt_p);
182 static void chk_global_in_use_list_and_count(outputStream * out,
183 int *error_cnt_p);
184 static void chk_in_use_entry(JavaThread* jt, ObjectMonitor* n,
185 outputStream * out, int *error_cnt_p);
186 static void chk_per_thread_in_use_list_and_count(JavaThread *jt,
187 outputStream * out,
188 int *error_cnt_p);
189 static void chk_per_thread_free_list_and_count(JavaThread *jt,
190 outputStream * out,
191 int *error_cnt_p);
192 static void log_in_use_monitor_details(outputStream * out);
193 static int log_monitor_list_counts(outputStream * out);
194 static int verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0;
195
196 static void do_safepoint_work(DeflateMonitorCounters* counters);
197
198 private:
199 friend class SynchronizerTest;
200
201 enum { _BLOCKSIZE = 128 };
202 // global list of blocks of monitors
203 static PaddedObjectMonitor* volatile g_block_list;
204 static volatile bool _is_async_deflation_requested;
205 static volatile bool _is_special_deflation_requested;
206 static jlong _last_async_deflation_time_ns;
207
208 // Function to prepend new blocks to the appropriate lists:
209 static void prepend_block_to_lists(PaddedObjectMonitor* new_blk);
210
211 // Process oops in all global used monitors (i.e. moribund thread's monitors)
212 static void global_used_oops_do(OopClosure* f);
213 // Process oops in monitors on the given list
214 static void list_oops_do(ObjectMonitor* list, int count, OopClosure* f);
215
216 // Support for SynchronizerTest access to GVars fields:
217 static u_char* get_gvars_addr();
218 static u_char* get_gvars_hc_sequence_addr();
219 static size_t get_gvars_size();
220 static u_char* get_gvars_stw_random_addr();
221 };
222
223 // ObjectLocker enforces balanced locking and can never throw an
224 // IllegalMonitorStateException. However, a pending exception may
225 // have to pass through, and we must also be able to deal with
226 // asynchronous exceptions. The caller is responsible for checking
227 // the thread's pending exception if needed.
228 class ObjectLocker : public StackObj {
229 private:
230 Thread* _thread;
231 Handle _obj;
232 BasicLock _lock;
233 bool _dolock; // default true
234 public:
|