1 /*
2 * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
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 // A PeriodicTask has the sole purpose of executing its task
26 // function with regular intervals.
27 // Usage:
28 // PeriodicTask pf(10);
29 // pf.enroll();
30 // ...
31 // pf.disenroll();
32
33 class PeriodicTask: public CHeapObj {
34 public:
35 // Useful constants.
36 // The interval constants are used to ensure the declared interval
37 // is appropriate; it must be between min_interval and max_interval,
38 // and have a granularity of interval_gran (all in millis).
39 enum { max_tasks = 10, // Max number of periodic tasks in system
40 interval_gran = 10,
41 min_interval = 10,
42 max_interval = 10000 };
43
44 static int num_tasks() { return _num_tasks; }
96 // Called by the WatcherThread's run method.
97 // This assumes that periodic tasks aren't entering the system
98 // dynamically, except for during startup.
99 static size_t time_to_wait() {
100 if (_num_tasks == 0) {
101 // Don't wait any more; shut down the thread since we don't
102 // currently support dynamic enrollment.
103 return 0;
104 }
105
106 size_t delay = _tasks[0]->time_to_next_interval();
107 for (int index = 1; index < _num_tasks; index++) {
108 delay = MIN2(delay, _tasks[index]->time_to_next_interval());
109 }
110 return delay;
111 }
112
113 // The task to perform at each period
114 virtual void task() = 0;
115 };
|
1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
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_VM_RUNTIME_TASK_HPP
26 #define SHARE_VM_RUNTIME_TASK_HPP
27
28 #include "utilities/top.hpp"
29
30 // A PeriodicTask has the sole purpose of executing its task
31 // function with regular intervals.
32 // Usage:
33 // PeriodicTask pf(10);
34 // pf.enroll();
35 // ...
36 // pf.disenroll();
37
38 class PeriodicTask: public CHeapObj {
39 public:
40 // Useful constants.
41 // The interval constants are used to ensure the declared interval
42 // is appropriate; it must be between min_interval and max_interval,
43 // and have a granularity of interval_gran (all in millis).
44 enum { max_tasks = 10, // Max number of periodic tasks in system
45 interval_gran = 10,
46 min_interval = 10,
47 max_interval = 10000 };
48
49 static int num_tasks() { return _num_tasks; }
101 // Called by the WatcherThread's run method.
102 // This assumes that periodic tasks aren't entering the system
103 // dynamically, except for during startup.
104 static size_t time_to_wait() {
105 if (_num_tasks == 0) {
106 // Don't wait any more; shut down the thread since we don't
107 // currently support dynamic enrollment.
108 return 0;
109 }
110
111 size_t delay = _tasks[0]->time_to_next_interval();
112 for (int index = 1; index < _num_tasks; index++) {
113 delay = MIN2(delay, _tasks[index]->time_to_next_interval());
114 }
115 return delay;
116 }
117
118 // The task to perform at each period
119 virtual void task() = 0;
120 };
121
122 #endif // SHARE_VM_RUNTIME_TASK_HPP
|