hotspot/src/os/linux/vm/jvm_linux.cpp
changeset 1 489c9b5090e2
child 745 47129a5cacd3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/os/linux/vm/jvm_linux.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,202 @@
+/*
+ * Copyright 1999-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_jvm_linux.cpp.incl"
+
+#include <signal.h>
+
+/*
+ * FIXME: This is temporary hack to keep Linux Runtime.exec()
+ * code happy. See $JDK/src/linux/native/java/lang/UnixProcess_md.c
+ */
+int _JVM_native_threads = 1;
+
+// sun.misc.Signal ///////////////////////////////////////////////////////////
+// Signal code is mostly copied from classic vm, signals_md.c   1.4 98/08/23
+/*
+ * This function is included primarily as a debugging aid. If Java is
+ * running in a console window, then pressing <CTRL-\\> will cause
+ * the current state of all active threads and monitors to be written
+ * to the console window.
+ */
+
+JVM_ENTRY_NO_ENV(void*, JVM_RegisterSignal(jint sig, void* handler))
+  // Copied from classic vm
+  // signals_md.c       1.4 98/08/23
+  void* newHandler = handler == (void *)2
+                   ? os::user_handler()
+                   : handler;
+  switch (sig) {
+    /* The following are already used by the VM. */
+    case INTERRUPT_SIGNAL:
+    case SIGFPE:
+    case SIGILL:
+    case SIGSEGV:
+
+    /* The following signal is used by the VM to dump thread stacks unless
+       ReduceSignalUsage is set, in which case the user is allowed to set
+       his own _native_ handler for this signal; thus, in either case,
+       we do not allow JVM_RegisterSignal to change the handler. */
+    case BREAK_SIGNAL:
+      return (void *)-1;
+
+    /* The following signals are used for Shutdown Hooks support. However, if
+       ReduceSignalUsage (-Xrs) is set, Shutdown Hooks must be invoked via
+       System.exit(), Java is not allowed to use these signals, and the the
+       user is allowed to set his own _native_ handler for these signals and
+       invoke System.exit() as needed. Terminator.setup() is avoiding
+       registration of these signals when -Xrs is present.
+       - If the HUP signal is ignored (from the nohup) command, then Java
+         is not allowed to use this signal.
+     */
+
+    case SHUTDOWN1_SIGNAL:
+    case SHUTDOWN2_SIGNAL:
+    case SHUTDOWN3_SIGNAL:
+      if (ReduceSignalUsage) return (void*)-1;
+      if (os::Linux::is_sig_ignored(sig)) return (void*)1;
+  }
+
+  void* oldHandler = os::signal(sig, newHandler);
+  if (oldHandler == os::user_handler()) {
+      return (void *)2;
+  } else {
+      return oldHandler;
+  }
+JVM_END
+
+
+JVM_ENTRY_NO_ENV(jboolean, JVM_RaiseSignal(jint sig))
+  if (ReduceSignalUsage) {
+    // do not allow SHUTDOWN1_SIGNAL,SHUTDOWN2_SIGNAL,SHUTDOWN3_SIGNAL,
+    // BREAK_SIGNAL to be raised when ReduceSignalUsage is set, since
+    // no handler for them is actually registered in JVM or via
+    // JVM_RegisterSignal.
+    if (sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
+        sig == SHUTDOWN3_SIGNAL || sig == BREAK_SIGNAL) {
+      return JNI_FALSE;
+    }
+  }
+  else if ((sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
+            sig == SHUTDOWN3_SIGNAL) && os::Linux::is_sig_ignored(sig)) {
+    // do not allow SHUTDOWN1_SIGNAL to be raised when SHUTDOWN1_SIGNAL
+    // is ignored, since no handler for them is actually registered in JVM
+    // or via JVM_RegisterSignal.
+    // This also applies for SHUTDOWN2_SIGNAL and SHUTDOWN3_SIGNAL
+    return JNI_FALSE;
+  }
+
+  os::signal_raise(sig);
+  return JNI_TRUE;
+JVM_END
+
+/*
+  All the defined signal names for Linux.
+
+  NOTE that not all of these names are accepted by our Java implementation
+
+  Via an existing claim by the VM, sigaction restrictions, or
+  the "rules of Unix" some of these names will be rejected at runtime.
+  For example the VM sets up to handle USR1, sigaction returns EINVAL for
+  STOP, and Linux simply doesn't allow catching of KILL.
+
+  Here are the names currently accepted by a user of sun.misc.Signal with
+  1.4.1 (ignoring potential interaction with use of chaining, etc):
+
+    HUP, INT, TRAP, ABRT, IOT, BUS, USR2, PIPE, ALRM, TERM, STKFLT,
+    CLD, CHLD, CONT, TSTP, TTIN, TTOU, URG, XCPU, XFSZ, VTALRM, PROF,
+    WINCH, POLL, IO, PWR, SYS
+
+*/
+
+struct siglabel {
+  char *name;
+  int   number;
+};
+
+struct siglabel siglabels[] = {
+  /* derived from /usr/include/bits/signum.h on RH7.2 */
+   "HUP",       SIGHUP,         /* Hangup (POSIX).  */
+  "INT",        SIGINT,         /* Interrupt (ANSI).  */
+  "QUIT",       SIGQUIT,        /* Quit (POSIX).  */
+  "ILL",        SIGILL,         /* Illegal instruction (ANSI).  */
+  "TRAP",       SIGTRAP,        /* Trace trap (POSIX).  */
+  "ABRT",       SIGABRT,        /* Abort (ANSI).  */
+  "IOT",        SIGIOT,         /* IOT trap (4.2 BSD).  */
+  "BUS",        SIGBUS,         /* BUS error (4.2 BSD).  */
+  "FPE",        SIGFPE,         /* Floating-point exception (ANSI).  */
+  "KILL",       SIGKILL,        /* Kill, unblockable (POSIX).  */
+  "USR1",       SIGUSR1,        /* User-defined signal 1 (POSIX).  */
+  "SEGV",       SIGSEGV,        /* Segmentation violation (ANSI).  */
+  "USR2",       SIGUSR2,        /* User-defined signal 2 (POSIX).  */
+  "PIPE",       SIGPIPE,        /* Broken pipe (POSIX).  */
+  "ALRM",       SIGALRM,        /* Alarm clock (POSIX).  */
+  "TERM",       SIGTERM,        /* Termination (ANSI).  */
+#ifdef SIGSTKFLT
+  "STKFLT",     SIGSTKFLT,      /* Stack fault.  */
+#endif
+  "CLD",        SIGCLD,         /* Same as SIGCHLD (System V).  */
+  "CHLD",       SIGCHLD,        /* Child status has changed (POSIX).  */
+  "CONT",       SIGCONT,        /* Continue (POSIX).  */
+  "STOP",       SIGSTOP,        /* Stop, unblockable (POSIX).  */
+  "TSTP",       SIGTSTP,        /* Keyboard stop (POSIX).  */
+  "TTIN",       SIGTTIN,        /* Background read from tty (POSIX).  */
+  "TTOU",       SIGTTOU,        /* Background write to tty (POSIX).  */
+  "URG",        SIGURG,         /* Urgent condition on socket (4.2 BSD).  */
+  "XCPU",       SIGXCPU,        /* CPU limit exceeded (4.2 BSD).  */
+  "XFSZ",       SIGXFSZ,        /* File size limit exceeded (4.2 BSD).  */
+  "VTALRM",     SIGVTALRM,      /* Virtual alarm clock (4.2 BSD).  */
+  "PROF",       SIGPROF,        /* Profiling alarm clock (4.2 BSD).  */
+  "WINCH",      SIGWINCH,       /* Window size change (4.3 BSD, Sun).  */
+  "POLL",       SIGPOLL,        /* Pollable event occurred (System V).  */
+  "IO",         SIGIO,          /* I/O now possible (4.2 BSD).  */
+  "PWR",        SIGPWR,         /* Power failure restart (System V).  */
+#ifdef SIGSYS
+  "SYS",        SIGSYS          /* Bad system call. Only on some Linuxen! */
+#endif
+  };
+
+JVM_ENTRY_NO_ENV(jint, JVM_FindSignal(const char *name))
+
+  /* find and return the named signal's number */
+
+  for(uint i=0; i<ARRAY_SIZE(siglabels); i++)
+    if(!strcmp(name, siglabels[i].name))
+      return siglabels[i].number;
+
+  return -1;
+
+JVM_END
+
+// used by os::exception_name()
+extern bool signal_name(int signo, char* buf, size_t len) {
+  for(uint i = 0; i < ARRAY_SIZE(siglabels); i++) {
+    if (signo == siglabels[i].number) {
+      jio_snprintf(buf, len, "SIG%s", siglabels[i].name);
+      return true;
+    }
+  }
+  return false;
+}