8151322: Implement os::set_native_thread_name() on Solaris

Reviewed-by: sla, kbarrett, gziemski

src/os/solaris/vm/os_solaris.cpp

@@ -160,6 +160,7 @@ address os::Solaris::handler_end;    // end pc of thr_sighndlrinfo
 
 address os::Solaris::_main_stack_base = NULL;  // 4352906 workaround
 
+os::Solaris::pthread_setname_np_func_t os::Solaris::_pthread_setname_np = NULL;
 
 // "default" initializers for missing libc APIs
 extern "C" {
@@ -519,8 +520,15 @@ static bool assign_distribution(processorid_t* id_array,
 }
 
 void os::set_native_thread_name(const char *name) {
-  // Not yet implemented.
-  return;
+  if (Solaris::_pthread_setname_np != NULL) {
+    // Only the first 31 bytes of 'name' are processed by pthread_setname_np
+    // but we explicitly copy into a size-limited buffer to avoid any
+    // possible overflow.
+    char buf[32];
+    snprintf(buf, sizeof(buf), "%s", name);
+    buf[sizeof(buf) - 1] = '\0';
+    Solaris::_pthread_setname_np(pthread_self(), buf);
+  }
 }
 
 bool os::distribute_processes(uint length, uint* distribution) {
@@ -4921,6 +4929,13 @@ void os::init(void) {
   // the minimum of what the OS supports (thr_min_stack()), and
   // enough to allow the thread to get to user bytecode execution.
   Solaris::min_stack_allowed = MAX2(thr_min_stack(), Solaris::min_stack_allowed);
+
+  // retrieve entry point for pthread_setname_np
+  void * handle = dlopen("libc.so.1", RTLD_LAZY);
+  if (handle != NULL) {
+    Solaris::_pthread_setname_np =
+        (Solaris::pthread_setname_np_func_t)dlsym(handle, "pthread_setname_np");
+  }
   // If the pagesize of the VM is greater than 8K determine the appropriate
   // number of initial guard pages.  The user can change this with the
   // command line arguments, if needed.

src/os/solaris/vm/os_solaris.hpp

 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, 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
@@ -132,6 +132,9 @@ class Solaris {
   static void set_SIGinterrupt(int newsig) { _SIGinterrupt = newsig; }
   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;
+
  public:
   // Large Page Support--ISM.
   static bool largepage_range(char* addr, size_t size);

src/share/vm/utilities/globalDefinitions.hpp

@@ -332,7 +332,7 @@ inline size_t pointer_delta(const MetaWord* left, const MetaWord* right) {
 // so far from the middle of the road that it is likely to be problematic in
 // many C++ compilers.
 //
-#define CAST_TO_FN_PTR(func_type, value) ((func_type)(castable_address(value)))
+#define CAST_TO_FN_PTR(func_type, value) (reinterpret_cast<func_type>(value))
 #define CAST_FROM_FN_PTR(new_type, func_ptr) ((new_type)((address_word)(func_ptr)))
 
 // Unsigned byte types for os and stream.hpp