47
48 /**
49 * java.lang.Process subclass in the UNIX environment.
50 *
51 * @author Mario Wolczko and Ross Knippel.
52 * @author Konstantin Kladko (ported to Linux)
53 * @author Martin Buchholz
54 */
55 final class UNIXProcess extends Process {
56 private static final sun.misc.JavaIOFileDescriptorAccess fdAccess
57 = sun.misc.SharedSecrets.getJavaIOFileDescriptorAccess();
58
59 private final int pid;
60 private int exitcode;
61 private boolean hasExited;
62
63 private /* final */ OutputStream stdin;
64 private /* final */ InputStream stdout;
65 private /* final */ InputStream stderr;
66
67 /* this is for the reaping thread */
68 private native int waitForProcessExit(int pid);
69
70 /**
71 * Create a process using fork(2) and exec(2).
72 *
73 * @param fds an array of three file descriptors.
74 * Indexes 0, 1, and 2 correspond to standard input,
75 * standard output and standard error, respectively. On
76 * input, a value of -1 means to create a pipe to connect
77 * child and parent processes. On output, a value which
78 * is not -1 is the parent pipe fd corresponding to the
79 * pipe which has been created. An element of this array
80 * is -1 on input if and only if it is <em>not</em> -1 on
81 * output.
82 * @return the pid of the subprocess
83 */
84 private native int forkAndExec(byte[] prog,
85 byte[] argBlock, int argc,
86 byte[] envBlock, int envc,
87 byte[] dir,
88 int[] fds,
89 boolean redirectErrorStream)
90 throws IOException;
91
92 /**
93 * The thread factory used to create "process reaper" daemon threads.
94 */
95 private static class ProcessReaperThreadFactory implements ThreadFactory {
96 private final static ThreadGroup group = getRootThreadGroup();
97
98 private static ThreadGroup getRootThreadGroup() {
99 return doPrivileged(new PrivilegedAction<ThreadGroup> () {
100 public ThreadGroup run() {
101 ThreadGroup root = Thread.currentThread().getThreadGroup();
102 while (root.getParent() != null)
103 root = root.getParent();
104 return root;
116 }
117
118 /**
119 * The thread pool of "process reaper" daemon threads.
120 */
121 private static final Executor processReaperExecutor =
122 doPrivileged(new PrivilegedAction<Executor>() {
123 public Executor run() {
124 return Executors.newCachedThreadPool
125 (new ProcessReaperThreadFactory());
126 }});
127
128 UNIXProcess(final byte[] prog,
129 final byte[] argBlock, final int argc,
130 final byte[] envBlock, final int envc,
131 final byte[] dir,
132 final int[] fds,
133 final boolean redirectErrorStream)
134 throws IOException {
135
136 pid = forkAndExec(prog,
137 argBlock, argc,
138 envBlock, envc,
139 dir,
140 fds,
141 redirectErrorStream);
142
143 try {
144 doPrivileged(new PrivilegedExceptionAction<Void>() {
145 public Void run() throws IOException {
146 initStreams(fds);
147 return null;
148 }});
149 } catch (PrivilegedActionException ex) {
150 throw (IOException) ex.getException();
151 }
152 }
153
154 static FileDescriptor newFileDescriptor(int fd) {
155 FileDescriptor fileDescriptor = new FileDescriptor();
156 fdAccess.set(fileDescriptor, fd);
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47
48 /**
49 * java.lang.Process subclass in the UNIX environment.
50 *
51 * @author Mario Wolczko and Ross Knippel.
52 * @author Konstantin Kladko (ported to Linux)
53 * @author Martin Buchholz
54 */
55 final class UNIXProcess extends Process {
56 private static final sun.misc.JavaIOFileDescriptorAccess fdAccess
57 = sun.misc.SharedSecrets.getJavaIOFileDescriptorAccess();
58
59 private final int pid;
60 private int exitcode;
61 private boolean hasExited;
62
63 private /* final */ OutputStream stdin;
64 private /* final */ InputStream stdout;
65 private /* final */ InputStream stderr;
66
67 private static String javahome;
68 private static String helperpath;
69
70 enum LaunchMechanism {
71 CLONE(1), FORK(2),
72 VFORK(3), SPAWN(4);
73
74 private int value;
75 LaunchMechanism(int x) {value = x;}
76 };
77
78 /* default is VFORK on Linux */
79 private static LaunchMechanism launchMechanism = LaunchMechanism.VFORK;
80
81 static {
82 AccessController.doPrivileged(new PrivilegedAction<Void>() {
83 public Void run() {
84 String javahome = System.getProperty("java.home");
85 String osarch = System.getProperty("os.arch");
86
87 helperpath = javahome + "/lib/" + osarch + "/jspawnhelper";
88 String s = System.getProperty("java.lang.useFork");
89 if (s != null) {
90 launchMechanism = LaunchMechanism.FORK;
91 }
92 return null;
93 }
94 });
95 }
96
97 /* this is for the reaping thread */
98 private native int waitForProcessExit(int pid);
99
100 /**
101 * Create a process. Depending on the mode flag, this is done by
102 * one of the following mechanisms.
103 * - fork(2) and exec(2)
104 * - clone(2) and exec(2)
105 * - vfork(2) and exec(2)
106 *
107 * @param fds an array of three file descriptors.
108 * Indexes 0, 1, and 2 correspond to standard input,
109 * standard output and standard error, respectively. On
110 * input, a value of -1 means to create a pipe to connect
111 * child and parent processes. On output, a value which
112 * is not -1 is the parent pipe fd corresponding to the
113 * pipe which has been created. An element of this array
114 * is -1 on input if and only if it is <em>not</em> -1 on
115 * output.
116 * @return the pid of the subprocess
117 */
118 private native int forkAndExec(int mode, byte[] prog,
119 byte[] argBlock, int argc,
120 byte[] envBlock, int envc,
121 byte[] dir,
122 int[] fds,
123 boolean redirectErrorStream)
124 throws IOException;
125
126 /**
127 * The thread factory used to create "process reaper" daemon threads.
128 */
129 private static class ProcessReaperThreadFactory implements ThreadFactory {
130 private final static ThreadGroup group = getRootThreadGroup();
131
132 private static ThreadGroup getRootThreadGroup() {
133 return doPrivileged(new PrivilegedAction<ThreadGroup> () {
134 public ThreadGroup run() {
135 ThreadGroup root = Thread.currentThread().getThreadGroup();
136 while (root.getParent() != null)
137 root = root.getParent();
138 return root;
150 }
151
152 /**
153 * The thread pool of "process reaper" daemon threads.
154 */
155 private static final Executor processReaperExecutor =
156 doPrivileged(new PrivilegedAction<Executor>() {
157 public Executor run() {
158 return Executors.newCachedThreadPool
159 (new ProcessReaperThreadFactory());
160 }});
161
162 UNIXProcess(final byte[] prog,
163 final byte[] argBlock, final int argc,
164 final byte[] envBlock, final int envc,
165 final byte[] dir,
166 final int[] fds,
167 final boolean redirectErrorStream)
168 throws IOException {
169
170 pid = forkAndExec(launchMechanism.value,
171 prog,
172 argBlock, argc,
173 envBlock, envc,
174 dir,
175 fds,
176 redirectErrorStream);
177
178 try {
179 doPrivileged(new PrivilegedExceptionAction<Void>() {
180 public Void run() throws IOException {
181 initStreams(fds);
182 return null;
183 }});
184 } catch (PrivilegedActionException ex) {
185 throw (IOException) ex.getException();
186 }
187 }
188
189 static FileDescriptor newFileDescriptor(int fd) {
190 FileDescriptor fileDescriptor = new FileDescriptor();
191 fdAccess.set(fileDescriptor, fd);
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