1 /*
2 * Copyright (c) 2003, 2023, 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_PRIMS_JVMTIMANAGECAPABILITIES_HPP
26 #define SHARE_PRIMS_JVMTIMANAGECAPABILITIES_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "memory/allStatic.hpp"
30
31 class JvmtiManageCapabilities : public AllStatic {
32
33 private:
34
35 // these four capabilities sets represent all potentially
36 // available capabilities. They are disjoint, covering
37 // the four cases: (OnLoad vs OnLoad+live phase) X
38 // (one environment vs any environment).
39 static jvmtiCapabilities always_capabilities;
40 static jvmtiCapabilities onload_capabilities;
41 static jvmtiCapabilities always_solo_capabilities;
42 static jvmtiCapabilities onload_solo_capabilities;
43
44 // solo capabilities that have not been grabbed
45 static jvmtiCapabilities always_solo_remaining_capabilities;
46 static jvmtiCapabilities onload_solo_remaining_capabilities;
47
48 // all capabilities ever acquired
49 static jvmtiCapabilities acquired_capabilities;
50
51 // counter for the agents possess can_support_virtual_threads capability
52 static int _can_support_virtual_threads_count;
53
54 // lock to access the class data
55 static Mutex* _capabilities_lock;
56
57 // lock, unless called from a detached thread (e.g. can be a call from Agent_OnLoad)
58 class CapabilitiesMutexLocker: public ConditionalMutexLocker {
59 public:
60 CapabilitiesMutexLocker() :
61 ConditionalMutexLocker(_capabilities_lock,
62 Thread::current_or_null() != nullptr,
63 Mutex::_no_safepoint_check_flag) {}
64 };
65
66 // basic intenal operations
67 static jvmtiCapabilities *either(const jvmtiCapabilities *a, const jvmtiCapabilities *b, jvmtiCapabilities *result);
68 static jvmtiCapabilities *both(const jvmtiCapabilities *a, const jvmtiCapabilities *b, jvmtiCapabilities *result);
69 static jvmtiCapabilities *exclude(const jvmtiCapabilities *a, const jvmtiCapabilities *b, jvmtiCapabilities *result);
70 static bool has_some(const jvmtiCapabilities *a);
71 static void update();
72
73 // init functions
74 static jvmtiCapabilities init_always_capabilities();
75 static jvmtiCapabilities init_onload_capabilities();
76 static jvmtiCapabilities init_always_solo_capabilities();
77 static jvmtiCapabilities init_onload_solo_capabilities();
78
79 // get_potential_capabilities without lock
80 static void get_potential_capabilities_nolock(const jvmtiCapabilities* current,
81 const jvmtiCapabilities* prohibited,
82 jvmtiCapabilities* result);
83
84 public:
85 static void initialize();
86
87 // queries and actions
88 static void get_potential_capabilities(const jvmtiCapabilities *current,
89 const jvmtiCapabilities *prohibited,
90 jvmtiCapabilities *result);
91 static jvmtiError add_capabilities(const jvmtiCapabilities *current,
92 const jvmtiCapabilities *prohibited,
93 const jvmtiCapabilities *desired,
94 jvmtiCapabilities *result);
95 static void relinquish_capabilities(const jvmtiCapabilities *current,
96 const jvmtiCapabilities *unwanted,
97 jvmtiCapabilities *result);
98 static void copy_capabilities(const jvmtiCapabilities *from, jvmtiCapabilities *to);
99
100 #ifndef PRODUCT
101 static void print(const jvmtiCapabilities* caps);
102 #endif
103 };
104
105 #endif // SHARE_PRIMS_JVMTIMANAGECAPABILITIES_HPP