/*

 * Copyright (c) 1997, 2019, 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

 * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef OS_WINDOWS_OS_WINDOWS_HPP

#define OS_WINDOWS_OS_WINDOWS_HPP

// Win32_OS defines the interface to windows operating systems

// strtok_s is the Windows thread-safe equivalent of POSIX strtok_r

#define strtok_r strtok_s

#define S_ISCHR(mode)   (((mode) & _S_IFCHR) == _S_IFCHR)

#define S_ISFIFO(mode)  (((mode) & _S_IFIFO) == _S_IFIFO)

// Information about the protection of the page at address '0' on this os.

static bool zero_page_read_protected() { return true; }

// File conventions

static const char* file_separator() { return "\\"; }

static const char* line_separator() { return "\r\n"; }

static const char* path_separator() { return ";"; }

class win32 {

  friend class os;

  friend unsigned __stdcall thread_native_entry(class Thread*);

 protected:

  static int    _vm_page_size;

  static int    _vm_allocation_granularity;

  static int    _processor_type;

  static int    _processor_level;

  static julong _physical_memory;

  static size_t _default_stack_size;

  static bool   _is_windows_server;

  static bool   _has_exit_bug;

  static void print_windows_version(outputStream* st);

 public:

  // Windows-specific interface:

  static void   initialize_system_info();

  static void   setmode_streams();

  // Processor info as provided by NT

  static int processor_type()  { return _processor_type;  }

  static int processor_level() {

    return _processor_level;

  }

  static julong available_memory();

  static julong physical_memory() { return _physical_memory; }

  // load dll from Windows system directory or Windows directory

  static HINSTANCE load_Windows_dll(const char* name, char *ebuf, int ebuflen);

 private:

  enum Ept { EPT_THREAD, EPT_PROCESS, EPT_PROCESS_DIE };

  // Wrapper around _endthreadex(), exit() and _exit()

  static int exit_process_or_thread(Ept what, int exit_code);

  static void initialize_performance_counter();

 public:

  // Generic interface:

  // Trace number of created threads

  static          intx  _os_thread_limit;

  static volatile intx  _os_thread_count;

  // Tells whether this is a server version of Windows

  static bool is_windows_server() { return _is_windows_server; }

  // Tells whether there can be the race bug during process exit on this platform

  static bool has_exit_bug() { return _has_exit_bug; }

  // Returns the byte size of a virtual memory page

  static int vm_page_size() { return _vm_page_size; }

  // Returns the size in bytes of memory blocks which can be allocated.

  static int vm_allocation_granularity() { return _vm_allocation_granularity; }

  // Read the headers for the executable that started the current process into

  // the structure passed in (see winnt.h).

  static void read_executable_headers(PIMAGE_NT_HEADERS);

  // Default stack size for the current process.

  static size_t default_stack_size() { return _default_stack_size; }

  static bool get_frame_at_stack_banging_point(JavaThread* thread,

                          struct _EXCEPTION_POINTERS* exceptionInfo,

                          address pc, frame* fr);

#ifndef _WIN64

  // A wrapper to install a structured exception handler for fast JNI accesors.

  static address fast_jni_accessor_wrapper(BasicType);

#endif

  // Fast access to current thread

protected:

  static int _thread_ptr_offset;

private:

  static void initialize_thread_ptr_offset();

public:

  static inline void set_thread_ptr_offset(int offset) {

    _thread_ptr_offset = offset;

  }

  static inline int get_thread_ptr_offset() { return _thread_ptr_offset; }

};

/*

 * Crash protection for the watcher thread. Wrap the callback

 * with a __try { call() }

 * To be able to use this - don't take locks, don't rely on destructors,

 * don't make OS library calls, don't allocate memory, don't print,

 * don't call code that could leave the heap / memory in an inconsistent state,

 * or anything else where we are not in control if we suddenly jump out.

 */

class ThreadCrashProtection : public StackObj {

public:

  static bool is_crash_protected(Thread* thr) {

    return _crash_protection != NULL && _protected_thread == thr;

  }

  ThreadCrashProtection();

  bool call(os::CrashProtectionCallback& cb);

private:

  static Thread* _protected_thread;

  static ThreadCrashProtection* _crash_protection;

  static volatile intptr_t _crash_mux;

};

class PlatformEvent : public CHeapObj<mtSynchronizer> {

  private:

    double CachePad [4] ;   // increase odds that _Event is sole occupant of cache line

    volatile int _Event ;

    HANDLE _ParkHandle ;

  public:       // TODO-FIXME: make dtor private

    ~PlatformEvent() { guarantee (0, "invariant") ; }

  public:

    PlatformEvent() {

      _Event   = 0 ;

      _ParkHandle = CreateEvent (NULL, false, false, NULL) ;

      guarantee (_ParkHandle != NULL, "invariant") ;

    }

    // Exercise caution using reset() and fired() - they may require MEMBARs

    void reset() { _Event = 0 ; }

    int  fired() { return _Event; }

    void park () ;

    void unpark () ;

    int  park (jlong millis) ;

} ;

class PlatformParker : public CHeapObj<mtSynchronizer> {

  protected:

    HANDLE _ParkEvent ;

  public:

    ~PlatformParker () { guarantee (0, "invariant") ; }

    PlatformParker  () {

      _ParkEvent = CreateEvent (NULL, true, false, NULL) ;

      guarantee (_ParkEvent != NULL, "invariant") ;

    }

} ;

// Platform specific implementation that underpins VM Monitor/Mutex class

class PlatformMonitor : public CHeapObj<mtSynchronizer> {

 private:

  CRITICAL_SECTION   _mutex; // Native mutex for locking

  CONDITION_VARIABLE _cond;  // Native condition variable for blocking

 public:

  PlatformMonitor();

  ~PlatformMonitor();

  void lock();

  void unlock();

  bool try_lock();

  int wait(jlong millis);

  void notify();

  void notify_all();

};

#endif // OS_WINDOWS_OS_WINDOWS_HPP