8175817: Clean up Solaris signal code: SIGUSR2, SIGasync, SIGJVM1/2

Reviewed-by: rehn, stuefe, dsamersoff

hotspot/src/os/solaris/vm/jvm_solaris.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2017, Oracle and/or its affiliates. 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
@@ -85,7 +85,7 @@
 /* Signal definitions */
 
 #define BREAK_SIGNAL     SIGQUIT           /* Thread dumping support.    */
-#define ASYNC_SIGNAL     SIGUSR2           /* Watcher & async err support. */
+#define ASYNC_SIGNAL     SIGJVM2           /* Event-based suspend/resume support */
 #define SHUTDOWN1_SIGNAL SIGHUP            /* Shutdown Hooks support.    */
 #define SHUTDOWN2_SIGNAL SIGINT
 #define SHUTDOWN3_SIGNAL SIGTERM

hotspot/src/os/solaris/vm/os_solaris.cpp

@@ -1013,21 +1013,9 @@ bool os::create_thread(Thread* thread, ThreadType thr_type,
   return true;
 }
 
-// defined for >= Solaris 10. This allows builds on earlier versions
-// of Solaris to take advantage of the newly reserved Solaris JVM signals.
-// With SIGJVM1, SIGJVM2, ASYNC_SIGNAL is SIGJVM2. Previously INTERRUPT_SIGNAL
-// was SIGJVM1.
-//
-#if !defined(SIGJVM1)
-  #define SIGJVM1 39
-  #define SIGJVM2 40
-#endif
-
 debug_only(static bool signal_sets_initialized = false);
 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 
-int os::Solaris::_SIGasync = ASYNC_SIGNAL;
-
 bool os::Solaris::is_sig_ignored(int sig) {
   struct sigaction oact;
   sigaction(sig, (struct sigaction*)NULL, &oact);
@@ -1040,12 +1028,6 @@ bool os::Solaris::is_sig_ignored(int sig) {
   }
 }
 
-// Note: SIGRTMIN is a macro that calls sysconf() so it will
-// dynamically detect SIGRTMIN value for the system at runtime, not buildtime
-static bool isJVM1available() {
-  return SIGJVM1 < SIGRTMIN;
-}
-
 void os::Solaris::signal_sets_init() {
   // Should also have an assertion stating we are still single-threaded.
   assert(!signal_sets_initialized, "Already initialized");
@@ -1068,12 +1050,7 @@ void os::Solaris::signal_sets_init() {
   sigaddset(&unblocked_sigs, SIGSEGV);
   sigaddset(&unblocked_sigs, SIGBUS);
   sigaddset(&unblocked_sigs, SIGFPE);
-
+  sigaddset(&unblocked_sigs, ASYNC_SIGNAL);
-  // Always true on Solaris 10+
-  guarantee(isJVM1available(), "SIGJVM1/2 missing!");
-  os::Solaris::set_SIGasync(SIGJVM2);
-
-  sigaddset(&unblocked_sigs, os::Solaris::SIGasync());
 
   if (!ReduceSignalUsage) {
     if (!os::Solaris::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
@@ -1918,7 +1895,6 @@ void os::print_memory_info(outputStream* st) {
 
 // Moved from whole group, because we need them here for diagnostic
 // prints.
-#define OLDMAXSIGNUM 32
 static int Maxsignum = 0;
 static int *ourSigFlags = NULL;
 
@@ -2011,7 +1987,6 @@ void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
   print_signal_handler(st, SHUTDOWN1_SIGNAL , buf, buflen);
   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
   print_signal_handler(st, SHUTDOWN3_SIGNAL, buf, buflen);
-  print_signal_handler(st, os::Solaris::SIGasync(), buf, buflen);
 }
 
 static char saved_jvm_path[MAXPATHLEN] = { 0 };
@@ -2179,14 +2154,12 @@ void os::signal_raise(int signal_number) {
 
 // a counter for each possible signal value
 static int Sigexit = 0;
-static int Maxlibjsigsigs;
 static jint *pending_signals = NULL;
 static int *preinstalled_sigs = NULL;
 static struct sigaction *chainedsigactions = NULL;
 static sema_t sig_sem;
 typedef int (*version_getting_t)();
 version_getting_t os::Solaris::get_libjsig_version = NULL;
-static int libjsigversion = NULL;
 
 int os::sigexitnum_pd() {
   assert(Sigexit > 0, "signal memory not yet initialized");
@@ -2199,8 +2172,6 @@ void os::Solaris::init_signal_mem() {
   Sigexit = Maxsignum+1;
   assert(Maxsignum >0, "Unable to obtain max signal number");
 
-  Maxlibjsigsigs = Maxsignum;
-
   // pending_signals has one int per signal
   // The additional signal is for SIGEXIT - exit signal to signal_thread
   pending_signals = (jint *)os::malloc(sizeof(jint) * (Sigexit+1), mtInternal);
@@ -3564,7 +3535,7 @@ void os::Solaris::SR_handler(Thread* thread, ucontext_t* uc) {
 
       // get current set of blocked signals and unblock resume signal
       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
-      sigdelset(&suspend_set, os::Solaris::SIGasync());
+      sigdelset(&suspend_set, ASYNC_SIGNAL);
 
       sr_semaphore.signal();
       // wait here until we are resumed
@@ -3619,7 +3590,7 @@ bool os::message_box(const char* title, const char* message) {
 }
 
 static int sr_notify(OSThread* osthread) {
-  int status = thr_kill(osthread->thread_id(), os::Solaris::SIGasync());
+  int status = thr_kill(osthread->thread_id(), ASYNC_SIGNAL);
   assert_status(status == 0, status, "thr_kill");
   return status;
 }
@@ -3764,7 +3735,7 @@ void os::os_exception_wrapper(java_call_t f, JavaValue* value,
 //
 // This routine may recognize any of the following kinds of signals:
 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, BREAK_SIGNAL, SIGPIPE, SIGXFSZ,
-// os::Solaris::SIGasync
+// ASYNC_SIGNAL.
 // It should be consulted by handlers for any of those signals.
 //
 // The caller of this routine must pass in the three arguments supplied
@@ -3799,7 +3770,7 @@ get_signal_t os::Solaris::get_signal_action = NULL;
 struct sigaction* os::Solaris::get_chained_signal_action(int sig) {
   struct sigaction *actp = NULL;
 
-  if ((libjsig_is_loaded)  && (sig <= Maxlibjsigsigs)) {
+  if ((libjsig_is_loaded)  && (sig <= Maxsignum)) {
     // Retrieve the old signal handler from libjsig
     actp = (*get_signal_action)(sig);
   }
@@ -3964,6 +3935,7 @@ void os::run_periodic_checks() {
   DO_SIGNAL_CHECK(SIGBUS);
   DO_SIGNAL_CHECK(SIGPIPE);
   DO_SIGNAL_CHECK(SIGXFSZ);
+  DO_SIGNAL_CHECK(ASYNC_SIGNAL);
 
   // ReduceSignalUsage allows the user to override these handlers
   // see comments at the very top and jvm_solaris.h
@@ -3973,10 +3945,6 @@ void os::run_periodic_checks() {
     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
     DO_SIGNAL_CHECK(BREAK_SIGNAL);
   }
-
-  // See comments above for using JVM1/JVM2
-  DO_SIGNAL_CHECK(os::Solaris::SIGasync());
-
 }
 
 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
@@ -4008,6 +3976,7 @@ void os::Solaris::check_signal_handler(int sig) {
   case SIGPIPE:
   case SIGXFSZ:
   case SIGILL:
+  case ASYNC_SIGNAL:
     jvmHandler = CAST_FROM_FN_PTR(address, signalHandler);
     break;
 
@@ -4019,17 +3988,9 @@ void os::Solaris::check_signal_handler(int sig) {
     break;
 
   default:
-    int asynsig = os::Solaris::SIGasync();
-
-    if (sig == asynsig) {
-      jvmHandler = CAST_FROM_FN_PTR(address, signalHandler);
-    } else {
       return;
-    }
-    break;
   }
 
-
   if (thisHandler != jvmHandler) {
     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
@@ -4061,7 +4022,6 @@ void os::Solaris::check_signal_handler(int sig) {
 }
 
 void os::Solaris::install_signal_handlers() {
-  bool libjsigdone = false;
   signal_handlers_are_installed = true;
 
   // signal-chaining
@@ -4079,7 +4039,8 @@ void os::Solaris::install_signal_handlers() {
                                          dlsym(RTLD_DEFAULT, "JVM_get_libjsig_version"));
     libjsig_is_loaded = true;
     if (os::Solaris::get_libjsig_version != NULL) {
-      libjsigversion =  (*os::Solaris::get_libjsig_version)();
+      int libjsigversion =  (*os::Solaris::get_libjsig_version)();
+      assert(libjsigversion == JSIG_VERSION_1_4_1, "libjsig version mismatch");
     }
     assert(UseSignalChaining, "should enable signal-chaining");
   }
@@ -4094,21 +4055,9 @@ void os::Solaris::install_signal_handlers() {
   set_signal_handler(SIGBUS, true, true);
   set_signal_handler(SIGILL, true, true);
   set_signal_handler(SIGFPE, true, true);
+  set_signal_handler(ASYNC_SIGNAL, true, true);
 
-
+  if (libjsig_is_loaded) {
-  if (os::Solaris::SIGasync() > OLDMAXSIGNUM) {
-    // Pre-1.4.1 Libjsig limited to signal chaining signals <= 32 so
-    // can not register overridable signals which might be > 32
-    if (libjsig_is_loaded && libjsigversion <= JSIG_VERSION_1_4_1) {
-      // Tell libjsig jvm has finished setting signal handlers
-      (*end_signal_setting)();
-      libjsigdone = true;
-    }
-  }
-
-  set_signal_handler(os::Solaris::SIGasync(), true, true);
-
-  if (libjsig_is_loaded && !libjsigdone) {
     // Tell libjsig jvm finishes setting signal handlers
     (*end_signal_setting)();
   }
@@ -4408,10 +4357,6 @@ jint os::init_2(void) {
   Solaris::init_signal_mem();
   Solaris::install_signal_handlers();
 
-  if (libjsigversion < JSIG_VERSION_1_4_1) {
-    Maxlibjsigsigs = OLDMAXSIGNUM;
-  }
-
   // initialize synchronization primitives to use either thread or
   // lwp synchronization (controlled by UseLWPSynchronization)
   Solaris::synchronization_init();

hotspot/src/os/solaris/vm/os_solaris.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. 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
@@ -109,9 +109,6 @@ class Solaris {
   static int (*get_libjsig_version)();
   static void save_preinstalled_handler(int, struct sigaction&);
   static void check_signal_handler(int sig);
-  // For overridable signals
-  static int _SIGasync;                      // user-overridable ASYNC_SIGNAL
-  static void set_SIGasync(int newsig) { _SIGasync = newsig; }
 
   typedef int (*pthread_setname_np_func_t)(pthread_t, const char*);
   static pthread_setname_np_func_t _pthread_setname_np;
@@ -120,7 +117,6 @@ class Solaris {
   // Large Page Support--ISM.
   static bool largepage_range(char* addr, size_t size);
 
-  static int SIGasync() { return _SIGasync; }
   static address handler_start, handler_end; // start and end pc of thr_sighndlrinfo
 
   static bool valid_stack_address(Thread* thread, address sp);

hotspot/src/os_cpu/solaris_sparc/vm/os_solaris_sparc.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2017, Oracle and/or its affiliates. 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
@@ -362,14 +362,14 @@ JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
     }
   }
 
-  if (sig == os::Solaris::SIGasync()) {
+  if (sig == ASYNC_SIGNAL) {
     if (thread || vmthread) {
       OSThread::SR_handler(t, uc);
       return true;
     } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
       return true;
     } else {
-      // If os::Solaris::SIGasync not chained, and this is a non-vm and
+      // If ASYNC_SIGNAL not chained, and this is a non-vm and
       // non-java thread
       return true;
     }

hotspot/src/os_cpu/solaris_x86/vm/os_solaris_x86.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2017, Oracle and/or its affiliates. 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
@@ -437,14 +437,14 @@ JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
     }
   }
 
-  if (sig == os::Solaris::SIGasync()) {
+  if (sig == ASYNC_SIGNAL) {
     if(thread || vmthread){
       OSThread::SR_handler(t, uc);
       return true;
     } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
       return true;
     } else {
-      // If os::Solaris::SIGasync not chained, and this is a non-vm and
+      // If ASYNC_SIGNAL not chained, and this is a non-vm and
       // non-java thread
       return true;
     }