8372272: Hotspot shared lib loading - add load attempts to Events::log

Reviewed-by: lucy, azeller

src/hotspot/os/aix/os_aix.cpp

@@ -1038,6 +1038,8 @@ static void* dll_load_library(const char *filename, int *eno, char *ebuf, int eb
     dflags |= RTLD_MEMBER;
   }
 
+  Events::log_dll_message(nullptr, "Attempting to load shared library %s", filename);
+
   void* result;
   const char* error_report = nullptr;
   JFR_ONLY(NativeLibraryLoadEvent load_event(filename, &result);)

src/hotspot/os/bsd/os_bsd.cpp

@@ -1035,6 +1035,8 @@ void *os::Bsd::dlopen_helper(const char *filename, int mode, char *ebuf, int ebu
   int rtn = fegetenv(&default_fenv);
   assert(rtn == 0, "fegetenv must succeed");
 
+  Events::log_dll_message(nullptr, "Attempting to load shared library %s", filename);
+
   void* result;
   JFR_ONLY(NativeLibraryLoadEvent load_event(filename, &result);)
   result = ::dlopen(filename, RTLD_LAZY);

src/hotspot/os/linux/os_linux.cpp

@@ -1875,6 +1875,8 @@ void * os::Linux::dlopen_helper(const char *filename, char *ebuf, int ebuflen) {
   assert(rtn == 0, "fegetenv must succeed");
 #endif // IA32
 
+  Events::log_dll_message(nullptr, "Attempting to load shared library %s", filename);
+
   void* result;
   JFR_ONLY(NativeLibraryLoadEvent load_event(filename, &result);)
   result = ::dlopen(filename, RTLD_LAZY);

src/hotspot/os/windows/os_windows.cpp

@@ -1715,6 +1715,8 @@ static int _print_module(const char* fname, address base_address,
 // same architecture as Hotspot is running on
 void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
   log_info(os)("attempting shared library load of %s", name);
+  Events::log_dll_message(nullptr, "Attempting to load shared library %s", name);
+
   void* result;
   JFR_ONLY(NativeLibraryLoadEvent load_event(name, &result);)
   result = LoadLibrary(name);