1 /*
2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
5  * This code is free software; you can redistribute it and/or modify it
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7  * published by the Free Software Foundation.
8  *
9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20  * or visit www.oracle.com if you need additional information or have any
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23  */
24 
25 #ifndef OS_WINDOWS_OS_WINDOWS_HPP
26 #define OS_WINDOWS_OS_WINDOWS_HPP
27 // Win32_OS defines the interface to windows operating systems
28 
29 // strtok_s is the Windows thread-safe equivalent of POSIX strtok_r
30 #define strtok_r strtok_s
31 
32 #define S_ISCHR(mode)   (((mode) & _S_IFCHR) == _S_IFCHR)
33 #define S_ISFIFO(mode)  (((mode) & _S_IFIFO) == _S_IFIFO)
34 
35 // Information about the protection of the page at address '0' on this os.
zero_page_read_protected()36 static bool zero_page_read_protected() { return true; }
37 
38 // File conventions
file_separator()39 static const char* file_separator() { return "\\"; }
line_separator()40 static const char* line_separator() { return "\r\n"; }
path_separator()41 static const char* path_separator() { return ";"; }
42 
43 class win32 {
44   friend class os;
45   friend unsigned __stdcall thread_native_entry(class Thread*);
46 
47  protected:
48   static int    _vm_page_size;
49   static int    _vm_allocation_granularity;
50   static int    _processor_type;
51   static int    _processor_level;
52   static julong _physical_memory;
53   static size_t _default_stack_size;
54   static bool   _is_windows_server;
55   static bool   _has_exit_bug;
56 
57   static void print_windows_version(outputStream* st);
58   static void print_uptime_info(outputStream* st);
59 
60  public:
61   // Windows-specific interface:
62   static void   initialize_system_info();
63   static void   setmode_streams();
64 
65   // Processor info as provided by NT
processor_type()66   static int processor_type()  { return _processor_type;  }
processor_level()67   static int processor_level() {
68     return _processor_level;
69   }
70   static julong available_memory();
physical_memory()71   static julong physical_memory() { return _physical_memory; }
72 
73   // load dll from Windows system directory or Windows directory
74   static HINSTANCE load_Windows_dll(const char* name, char *ebuf, int ebuflen);
75 
76  private:
77   enum Ept { EPT_THREAD, EPT_PROCESS, EPT_PROCESS_DIE };
78   // Wrapper around _endthreadex(), exit() and _exit()
79   static int exit_process_or_thread(Ept what, int exit_code);
80 
81   static void initialize_performance_counter();
82 
83  public:
84   // Generic interface:
85 
86   // Trace number of created threads
87   static          intx  _os_thread_limit;
88   static volatile intx  _os_thread_count;
89 
90   // Tells whether this is a server version of Windows
is_windows_server()91   static bool is_windows_server() { return _is_windows_server; }
92 
93   // Tells whether there can be the race bug during process exit on this platform
has_exit_bug()94   static bool has_exit_bug() { return _has_exit_bug; }
95 
96   // Returns the byte size of a virtual memory page
vm_page_size()97   static int vm_page_size() { return _vm_page_size; }
98 
99   // Returns the size in bytes of memory blocks which can be allocated.
vm_allocation_granularity()100   static int vm_allocation_granularity() { return _vm_allocation_granularity; }
101 
102   // Read the headers for the executable that started the current process into
103   // the structure passed in (see winnt.h).
104   static void read_executable_headers(PIMAGE_NT_HEADERS);
105 
106   // Default stack size for the current process.
default_stack_size()107   static size_t default_stack_size() { return _default_stack_size; }
108 
109   static bool get_frame_at_stack_banging_point(JavaThread* thread,
110                           struct _EXCEPTION_POINTERS* exceptionInfo,
111                           address pc, frame* fr);
112 
113 #ifndef _WIN64
114   // A wrapper to install a structured exception handler for fast JNI accesors.
115   static address fast_jni_accessor_wrapper(BasicType);
116 #endif
117 
118   // Fast access to current thread
119 protected:
120   static int _thread_ptr_offset;
121 private:
122   static void initialize_thread_ptr_offset();
123 public:
set_thread_ptr_offset(int offset)124   static inline void set_thread_ptr_offset(int offset) {
125     _thread_ptr_offset = offset;
126   }
get_thread_ptr_offset()127   static inline int get_thread_ptr_offset() { return _thread_ptr_offset; }
128 };
129 
130 /*
131  * Crash protection for the watcher thread. Wrap the callback
132  * with a __try { call() }
133  * To be able to use this - don't take locks, don't rely on destructors,
134  * don't make OS library calls, don't allocate memory, don't print,
135  * don't call code that could leave the heap / memory in an inconsistent state,
136  * or anything else where we are not in control if we suddenly jump out.
137  */
138 class ThreadCrashProtection : public StackObj {
139 public:
is_crash_protected(Thread * thr)140   static bool is_crash_protected(Thread* thr) {
141     return _crash_protection != NULL && _protected_thread == thr;
142   }
143 
144   ThreadCrashProtection();
145   bool call(os::CrashProtectionCallback& cb);
146 private:
147   static Thread* _protected_thread;
148   static ThreadCrashProtection* _crash_protection;
149   static volatile intptr_t _crash_mux;
150 };
151 
152 class PlatformEvent : public CHeapObj<mtSynchronizer> {
153   private:
154     double CachePad [4] ;   // increase odds that _Event is sole occupant of cache line
155     volatile int _Event ;
156     HANDLE _ParkHandle ;
157 
158   public:       // TODO-FIXME: make dtor private
~PlatformEvent()159     ~PlatformEvent() { guarantee (0, "invariant") ; }
160 
161   public:
PlatformEvent()162     PlatformEvent() {
163       _Event   = 0 ;
164       _ParkHandle = CreateEvent (NULL, false, false, NULL) ;
165       guarantee (_ParkHandle != NULL, "invariant") ;
166     }
167 
168     // Exercise caution using reset() and fired() - they may require MEMBARs
reset()169     void reset() { _Event = 0 ; }
fired()170     int  fired() { return _Event; }
171     void park () ;
172     void unpark () ;
173     int  park (jlong millis) ;
174 } ;
175 
176 
177 
178 class PlatformParker : public CHeapObj<mtSynchronizer> {
179   protected:
180     HANDLE _ParkEvent ;
181 
182   public:
~PlatformParker()183     ~PlatformParker () { guarantee (0, "invariant") ; }
PlatformParker()184     PlatformParker  () {
185       _ParkEvent = CreateEvent (NULL, true, false, NULL) ;
186       guarantee (_ParkEvent != NULL, "invariant") ;
187     }
188 
189 } ;
190 
191 // Platform specific implementation that underpins VM Monitor/Mutex class
192 class PlatformMonitor : public CHeapObj<mtSynchronizer> {
193  private:
194   CRITICAL_SECTION   _mutex; // Native mutex for locking
195   CONDITION_VARIABLE _cond;  // Native condition variable for blocking
196 
197  public:
198   PlatformMonitor();
199   ~PlatformMonitor();
200   void lock();
201   void unlock();
202   bool try_lock();
203   int wait(jlong millis);
204   void notify();
205   void notify_all();
206 };
207 
208 #endif // OS_WINDOWS_OS_WINDOWS_HPP
209