1 /*
2 * Copyright (c) 2019, 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 CGROUP_SUBSYSTEM_LINUX_HPP
26 #define CGROUP_SUBSYSTEM_LINUX_HPP
27
28 #include "memory/allocation.hpp"
29 #include "runtime/os.hpp"
30 #include "logging/log.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/macros.hpp"
33 #include "osContainer_linux.hpp"
34
35 // Shared cgroups code (used by cgroup version 1 and version 2)
36
37 /*
38 * PER_CPU_SHARES has been set to 1024 because CPU shares' quota
39 * is commonly used in cloud frameworks like Kubernetes[1],
40 * AWS[2] and Mesos[3] in a similar way. They spawn containers with
41 * --cpu-shares option values scaled by PER_CPU_SHARES. Thus, we do
42 * the inverse for determining the number of possible available
43 * CPUs to the JVM inside a container. See JDK-8216366.
44 *
45 * [1] https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/#meaning-of-cpu
46 * In particular:
47 * When using Docker:
48 * The spec.containers[].resources.requests.cpu is converted to its core value, which is potentially
49 * fractional, and multiplied by 1024. The greater of this number or 2 is used as the value of the
50 * --cpu-shares flag in the docker run command.
51 * [2] https://docs.aws.amazon.com/AmazonECS/latest/APIReference/API_ContainerDefinition.html
52 * [3] https://github.com/apache/mesos/blob/3478e344fb77d931f6122980c6e94cd3913c441d/src/docker/docker.cpp#L648
53 * https://github.com/apache/mesos/blob/3478e344fb77d931f6122980c6e94cd3913c441d/src/slave/containerizer/mesos/isolators/cgroups/constants.hpp#L30
54 */
55 #define PER_CPU_SHARES 1024
56
57 typedef char * cptr;
58
59 class CgroupController: CHeapObj<mtInternal> {
60 friend class CgroupSubsystemFactory;
61 public:
62 virtual char *subsystem_path();
63 };
64
65 PRAGMA_DIAG_PUSH
66 PRAGMA_FORMAT_NONLITERAL_IGNORED
67 template <typename T> int subsystem_file_line_contents(CgroupController* c,
68 const char *filename,
69 const char *matchline,
70 const char *scan_fmt,
71 T returnval) {
72 FILE *fp = NULL;
73 char *p;
74 char file[MAXPATHLEN+1];
75 char buf[MAXPATHLEN+1];
76 char discard[MAXPATHLEN+1];
77 bool found_match = false;
78
79 if (c == NULL) {
80 log_debug(os, container)("subsystem_file_line_contents: CgroupController* is NULL");
81 return OSCONTAINER_ERROR;
82 }
83 if (c->subsystem_path() == NULL) {
84 log_debug(os, container)("subsystem_file_line_contents: subsystem path is NULL");
85 return OSCONTAINER_ERROR;
86 }
87
88 strncpy(file, c->subsystem_path(), MAXPATHLEN);
89 file[MAXPATHLEN-1] = '\0';
90 int filelen = strlen(file);
91 if ((filelen + strlen(filename)) > (MAXPATHLEN-1)) {
92 log_debug(os, container)("File path too long %s, %s", file, filename);
93 return OSCONTAINER_ERROR;
94 }
95 strncat(file, filename, MAXPATHLEN-filelen);
96 log_trace(os, container)("Path to %s is %s", filename, file);
97 fp = fopen(file, "r");
98 if (fp != NULL) {
99 int err = 0;
100 while ((p = fgets(buf, MAXPATHLEN, fp)) != NULL) {
101 found_match = false;
102 if (matchline == NULL) {
103 // single-line file case
104 int matched = sscanf(p, scan_fmt, returnval);
105 found_match = (matched == 1);
106 } else {
107 // multi-line file case
108 if (strstr(p, matchline) != NULL) {
109 // discard matchline string prefix
110 int matched = sscanf(p, scan_fmt, discard, returnval);
111 found_match = (matched == 2);
112 } else {
113 continue; // substring not found
114 }
115 }
116 if (found_match) {
117 fclose(fp);
118 return 0;
119 } else {
120 err = 1;
121 log_debug(os, container)("Type %s not found in file %s", scan_fmt, file);
122 }
123 }
124 if (err == 0) {
125 log_debug(os, container)("Empty file %s", file);
126 }
127 } else {
128 log_debug(os, container)("Open of file %s failed, %s", file, os::strerror(errno));
129 }
130 if (fp != NULL)
131 fclose(fp);
132 return OSCONTAINER_ERROR;
133 }
134 PRAGMA_DIAG_POP
135
136 #define GET_CONTAINER_INFO(return_type, subsystem, filename, \
137 logstring, scan_fmt, variable) \
138 return_type variable; \
139 { \
140 int err; \
141 err = subsystem_file_line_contents(subsystem, \
142 filename, \
143 NULL, \
144 scan_fmt, \
145 &variable); \
146 if (err != 0) \
147 return (return_type) OSCONTAINER_ERROR; \
148 \
149 log_trace(os, container)(logstring, variable); \
150 }
151
152 #define GET_CONTAINER_INFO_CPTR(return_type, subsystem, filename, \
153 logstring, scan_fmt, variable, bufsize) \
154 char variable[bufsize]; \
155 { \
156 int err; \
157 err = subsystem_file_line_contents(subsystem, \
158 filename, \
159 NULL, \
160 scan_fmt, \
161 variable); \
162 if (err != 0) \
163 return (return_type) NULL; \
164 \
165 log_trace(os, container)(logstring, variable); \
166 }
167
168 #define GET_CONTAINER_INFO_LINE(return_type, controller, filename, \
169 matchline, logstring, scan_fmt, variable) \
170 return_type variable; \
171 { \
172 int err; \
173 err = subsystem_file_line_contents(controller, \
174 filename, \
175 matchline, \
176 scan_fmt, \
177 &variable); \
178 if (err != 0) \
179 return (return_type) OSCONTAINER_ERROR; \
180 \
181 log_trace(os, container)(logstring, variable); \
182 }
183
184 class CgroupSubsystem: CHeapObj<mtInternal> {
185 friend class CgroupSubsystemFactory;
186 public:
187 int active_processor_count(int physical_proc_count);
188
189 virtual int cpu_quota();
190 virtual int cpu_period();
191 virtual int cpu_shares();
192 virtual jlong memory_usage_in_bytes();
193 virtual jlong memory_and_swap_limit_in_bytes();
194 virtual jlong memory_soft_limit_in_bytes();
195 virtual jlong memory_max_usage_in_bytes();
196 virtual char * cpu_cpuset_cpus();
197 virtual char * cpu_cpuset_memory_nodes();
198 virtual jlong memory_limit_in_bytes();
199 virtual const char * container_type();
200 };
201
202 class CgroupSubsystemFactory: AllStatic {
203 public:
204 static CgroupSubsystem* create();
205 };
206
207 #endif // CGROUP_SUBSYSTEM_LINUX_HPP