/* -*-C-*-

$Id: ntproc.c,v 1.8 1999/01/02 06:11:34 cph Exp $

Copyright (c) 1997-1999 Massachusetts Institute of Technology

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

This program 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 for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "nt.h"
#include "ntproc.h"
#include "ntio.h"
#include "ntscreen.h"
#include "ntgui.h"

extern const char * OS_working_dir_pathname (void);

typedef struct
{
  PROCESS_INFORMATION handles;
  unsigned long tick;
  unsigned long sync_tick;
  DWORD raw_reason;
  DWORD reason;
  enum process_status raw_status;
  enum process_status status;
} process_t;
#define _PROCESS(process) (process_table [(process)])
#define PROCESS_HANDLES(process) ((_PROCESS(process)) . handles)
#define PROCESS_TICK(process) ((_PROCESS(process)) . tick)
#define PROCESS_SYNC_TICK(process) ((_PROCESS(process)) . sync_tick)
#define PROCESS_RAW_REASON(process) ((_PROCESS(process)) . raw_reason)
#define PROCESS_REASON(process) ((_PROCESS(process)) . reason)
#define PROCESS_RAW_STATUS(process) ((_PROCESS(process)) . raw_status)
#define PROCESS_STATUS(process) ((_PROCESS(process)) . status)

#define PROCESS_HANDLE(process) ((PROCESS_HANDLES (process)) . hProcess)
#define PROCESS_ID(process) ((PROCESS_HANDLES (process)) . dwProcessId)

#ifndef NT_DEFAULT_PROCESS_TABLE_SIZE
#define NT_DEFAULT_PROCESS_TABLE_SIZE 4096
#endif
size_t OS_process_table_size;
enum process_jc_status scheme_jc_status;

static process_t * process_table;
static unsigned long process_tick;
static unsigned long sync_tick;

#undef USE_PROCESS_TABLE_LOCK
#ifdef USE_PROCESS_TABLE_LOCK
static CRITICAL_SECTION process_table_lock;
#define GRAB_PROCESS_TABLE() EnterCriticalSection (&process_table_lock)
#define RELEASE_PROCESS_TABLE() LeaveCriticalSection (&process_table_lock)
#else
#define GRAB_PROCESS_TABLE()
#define RELEASE_PROCESS_TABLE()
#endif

#define PROCESS_STATUS_SYNC(process)					\
{									\
  (PROCESS_STATUS (process)) = (PROCESS_RAW_STATUS (process));		\
  (PROCESS_REASON (process)) = (PROCESS_RAW_REASON (process));		\
  (PROCESS_SYNC_TICK (process)) = (PROCESS_TICK (process));		\
}

/* I have no idea what a good value for this might be, so I've picked
   a random non-zero value.  */
#define TERMINATE_PROCESS_EXIT_CODE 0xFF

#undef TRACE_NTPROC
#ifdef TRACE_NTPROC
FILE * trace_file;
#ifndef TRACE_NTPROC_FILENAME
#define TRACE_NTPROC_FILENAME "nttrace.out"
#endif
#endif

static void lock_process_table (void);
static void lock_process_table_1 (void *);
static HANDLE stdio_handle (DWORD, Tchannel, enum process_channel_type);
static HANDLE copy_handle (HANDLE);
static Tprocess allocate_process (void);
static void allocate_process_abort (void *);
static HWND find_child_console (DWORD);
static BOOL CALLBACK find_child_console_1 (HWND, LPARAM);
static void process_wait_1 (Tprocess, DWORD);
static void process_death (Tprocess);

void
NT_initialize_processes (void)
{
#ifdef TRACE_NTPROC
  trace_file = (fopen (TRACE_NTPROC_FILENAME, "w"));
#endif
  OS_process_table_size = NT_DEFAULT_PROCESS_TABLE_SIZE;
  process_table = (OS_malloc (OS_process_table_size * (sizeof (process_t))));
  {
    Tprocess process;
    for (process = 0; (process < OS_process_table_size); process += 1)
      OS_process_deallocate (process);
  }
#ifdef USE_PROCESS_TABLE_LOCK
  InitializeCriticalSection (&process_table_lock);
#endif
  scheme_jc_status = process_jc_status_no_ctty;
  process_tick = 0;
  sync_tick = 0;
}

static void
lock_process_table (void)
{
  GRAB_PROCESS_TABLE ();
  transaction_record_action (tat_always, lock_process_table_1, 0);
}

static void
lock_process_table_1 (void * ignore)
{
  RELEASE_PROCESS_TABLE ();
}

Tprocess
NT_make_subprocess (const char * filename,
		    const char * command_line,
		    const char * environment,
		    const char * working_directory,
		    enum process_channel_type channel_in_type,
		    Tchannel channel_in,
		    enum process_channel_type channel_out_type,
		    Tchannel channel_out,
		    enum process_channel_type channel_err_type,
		    Tchannel channel_err,
		    int hide_windows_p)
{
  Tprocess child;
  SECURITY_ATTRIBUTES sap;
  SECURITY_DESCRIPTOR sdp;
  STARTUPINFO si;

  transaction_begin ();

  /* Explicitly specify no security */
  STD_BOOL_API_CALL
    (InitializeSecurityDescriptor, ((&sdp), SECURITY_DESCRIPTOR_REVISION));
  STD_BOOL_API_CALL (SetSecurityDescriptorDacl, ((&sdp), TRUE, 0, FALSE));
  (sap . nLength) = (sizeof (sap));
  (sap . lpSecurityDescriptor) = (&sdp);
  (sap . bInheritHandle) = FALSE;

  memset ((&si), 0, (sizeof (si)));
  (si . cb) = (sizeof (si));
  /* Specify the handles to be used by the child process.  */
  (si . dwFlags) = STARTF_USESTDHANDLES;
  (si . hStdInput)
    = (stdio_handle (STD_INPUT_HANDLE, channel_in, channel_in_type));
  (si . hStdOutput)
    = (stdio_handle (STD_OUTPUT_HANDLE, channel_out, channel_out_type));
  (si . hStdError)
    = (stdio_handle (STD_ERROR_HANDLE, channel_err, channel_err_type));
  /* If requested, hide the top-level window of the child process.  */
  if (hide_windows_p)
    {
      (si . dwFlags) |= STARTF_USESHOWWINDOW;
      (si . wShowWindow) |= SW_HIDE;
    }

  lock_process_table ();
  child = (allocate_process ());
  STD_BOOL_API_CALL
    (CreateProcess,
     (((LPCTSTR) filename),
      ((LPSTR) command_line),
      (&sap),
      0,
      TRUE,
      (CREATE_DEFAULT_ERROR_MODE | CREATE_NEW_CONSOLE),
      ((LPVOID) environment),
      ((LPCTSTR) working_directory),
      (&si),
      (& (PROCESS_HANDLES (child)))));
  (PROCESS_RAW_STATUS (child)) = process_status_running;
  (PROCESS_RAW_REASON (child)) = STILL_ACTIVE;
  (PROCESS_TICK (child)) = process_tick;
  PROCESS_STATUS_SYNC (child);
  STD_BOOL_API_CALL (CloseHandle, (si . hStdInput));
  STD_BOOL_API_CALL (CloseHandle, (si . hStdOutput));
  STD_BOOL_API_CALL (CloseHandle, (si . hStdError));
  transaction_commit ();
  STD_BOOL_API_CALL (CloseHandle, ((PROCESS_HANDLES (child)) . hThread));
  ((PROCESS_HANDLES (child)) . hThread) = INVALID_HANDLE_VALUE;
#ifdef TRACE_NTPROC
  fprintf (trace_file, "Subprocess created: id=0x%x\n", (PROCESS_ID (child)));
  fflush (trace_file);
#endif
  return (child);
}

static HANDLE
stdio_handle (DWORD target, Tchannel channel, enum process_channel_type type)
{
  return
    (copy_handle ((type == process_channel_type_explicit)
		  ? (CHANNEL_HANDLE (channel))
		  : (GetStdHandle (target))));
}

static HANDLE
copy_handle (HANDLE handle)
{
  HANDLE parent = (GetCurrentProcess ());
  HANDLE copy;
  STD_BOOL_API_CALL
    (DuplicateHandle,
     (parent, handle, parent, (&copy), 0, TRUE, DUPLICATE_SAME_ACCESS));
  NT_handle_close_on_abort (copy);
  return (copy);
}

static Tprocess
allocate_process (void)
{
  unsigned int process;
  for (process = 0; (process < OS_process_table_size); process += 1)
    if ((PROCESS_RAW_STATUS (process)) == process_status_free)
      {
	Tprocess * pp = (dstack_alloc (sizeof (Tprocess)));
	(*pp) = process;
	transaction_record_action (tat_abort, allocate_process_abort, pp);
	(PROCESS_RAW_STATUS (process)) = process_status_allocated;
	return (process);
      }
  error_out_of_processes ();
  return (NO_PROCESS);
}

static void
allocate_process_abort (void * environment)
{
  Tprocess process = (* ((Tprocess *) environment));
  OS_process_deallocate (process);
}

struct fcc_info
{
  DWORD pid;
  HWND hwnd;
};

static HWND
find_child_console (DWORD pid)
{
  struct fcc_info fi;
  (fi . pid) = pid;
  (fi . hwnd) = INVALID_HANDLE_VALUE;
  EnumWindows (find_child_console_1, ((LPARAM) (&fi)));
  return (fi . hwnd);
}

static BOOL CALLBACK
find_child_console_1 (HWND hwnd, LPARAM lfi)
{
  struct fcc_info * fi = ((struct fcc_info *) lfi);
  DWORD pid;

  (void) GetWindowThreadProcessId (hwnd, (&pid));
  if (pid == (fi -> pid))
    {
      char window_class [32];
      unsigned int n
	= (GetClassName (hwnd, window_class, (sizeof (window_class))));
      const char * console_class
	= ((NT_windows_type == wintype_95) ? "tty" : "ConsoleWindowClass");
      if ((n == (strlen (console_class)))
	  && ((strcmp (window_class, console_class)) == 0))
	{
	  (fi -> hwnd) = hwnd;
	  return (FALSE);
	}
    }
  /* keep looking */
  return (TRUE);
}

void
OS_process_deallocate (Tprocess process)
{
  (PROCESS_RAW_STATUS (process)) = process_status_free;
}

int
OS_process_valid_p (Tprocess process)
{
  switch (PROCESS_RAW_STATUS (process))
    {
    case process_status_exited:
    case process_status_signalled:
    case process_status_running:
      return (1);
    default:
      return (0);
    }
}

int
OS_process_continuable_p (Tprocess process)
{
  return ((PROCESS_RAW_STATUS (process)) == process_status_running);
}

int
OS_process_foregroundable_p (Tprocess process)
{
  return (0);
}

pid_t
OS_process_id (Tprocess process)
{
  return (PROCESS_ID (process));
}

enum process_jc_status
OS_process_jc_status (Tprocess process)
{
  return (process_jc_status_no_ctty);
}

int
OS_process_status_sync (Tprocess process)
{
#ifdef TRACE_NTPROC
  fprintf (trace_file, "OS_process_status_sync: id=0x%x\n",
	   (PROCESS_ID (process)));
  fflush (trace_file);
#endif
  transaction_begin ();
  lock_process_table ();
  {
    int result = ((PROCESS_TICK (process)) != (PROCESS_SYNC_TICK (process)));
    if (result)
      {
#ifdef TRACE_NTPROC
	fprintf (trace_file, "(status=0x%x raw_status=0x%x)\n",
		 (PROCESS_STATUS (process)),
		 (PROCESS_RAW_STATUS (process)));
	fflush (trace_file);
#endif
	PROCESS_STATUS_SYNC (process);
      }
    transaction_commit ();
    return (result);
  }
}

int
OS_process_status_sync_all (void)
{
#ifdef TRACE_NTPROC
  fprintf (trace_file, "OS_process_status_sync_all\n");
  fflush (trace_file);
#endif
  transaction_begin ();
  lock_process_table ();
  {
    int result = (process_tick != sync_tick);
    if (result)
      {
#ifdef TRACE_NTPROC
	fprintf (trace_file, "(status change)\n");
	fflush (trace_file);
#endif
	sync_tick = process_tick;
      }
    transaction_commit ();
    return (result);
  }
}

enum process_status
OS_process_status (Tprocess process)
{
#ifdef TRACE_NTPROC
  fprintf (trace_file, "OS_process_status: id=0x%x status=0x%x\n",
	   (PROCESS_ID (process)),
	   (PROCESS_STATUS (process)));
  fflush (trace_file);
#endif
  return (PROCESS_STATUS (process));
}

unsigned short
OS_process_reason (Tprocess process)
{
  return ((unsigned short) (PROCESS_REASON (process)));
}

void
OS_process_send_signal (Tprocess process, int sig)
{
  error_unimplemented_primitive ();
}

void
OS_process_kill (Tprocess process)
{
#ifdef TRACE_NTPROC
  fprintf (trace_file, "OS_process_kill: id=0x%x\n", (PROCESS_ID (process)));
  fflush (trace_file);
#endif
  if (NT_windows_type == wintype_nt)
    {
      HWND hwnd = (find_child_console (PROCESS_ID (process)));
      if (hwnd != INVALID_HANDLE_VALUE)
	{
	  PostMessage (hwnd, WM_CLOSE, 0, 0);
	  return;
	}
    }
#ifdef TRACE_NTPROC
  fprintf (trace_file, "(using TerminateProcess)\n");
  fflush (trace_file);
#endif
  if (!TerminateProcess ((PROCESS_HANDLE (process)),
			 TERMINATE_PROCESS_EXIT_CODE))
    {
      DWORD code = (GetLastError ());
      if (code != ERROR_ACCESS_DENIED)
	NT_error_api_call ((GetLastError ()), apicall_TerminateProcess);
#ifdef TRACE_NTPROC
      fprintf (trace_file, "(ERROR_ACCESS_DENIED)\n");
      fflush (trace_file);
#endif
    }
}

void
OS_process_stop (Tprocess process)
{
  error_unimplemented_primitive ();
}

void
OS_process_interrupt (Tprocess process)
{
  HWND hwnd;
  BYTE control_scan_code;
  BYTE vk_break_code;
  BYTE break_scan_code;
  /* BYTE keyboard_state [256]; */
  HWND foreground_window;

#ifdef TRACE_NTPROC
  fprintf (trace_file, "OS_process_interrupt: id=0x%x\n",
	   (PROCESS_ID (process)));
  fflush (trace_file);
#endif
  hwnd = (find_child_console (PROCESS_ID (process)));
  if (hwnd == INVALID_HANDLE_VALUE)
    return;
  control_scan_code = ((BYTE) (MapVirtualKey (VK_CONTROL, 0)));
  vk_break_code = VK_CANCEL;
  break_scan_code = ((BYTE) (MapVirtualKey (vk_break_code, 0)));
  if (break_scan_code == 0)
    {
      /* Fake Ctrl-C if we can't manage Ctrl-Break. */
      vk_break_code = 'C';
      break_scan_code = ((BYTE) (MapVirtualKey (vk_break_code, 0)));
    }
  /* STD_BOOL_API_CALL (GetKeyboardState, (keyboard_state)); */
  foreground_window = (GetForegroundWindow ());
  if (SetForegroundWindow (hwnd))
    {
      /* Generate keystrokes as if user had typed Ctrl-Break or Ctrl-C.  */
      keybd_event (VK_CONTROL, control_scan_code, 0, 0);
      keybd_event (vk_break_code, break_scan_code, 0, 0);
      keybd_event (vk_break_code, break_scan_code, KEYEVENTF_KEYUP, 0);
      keybd_event (VK_CONTROL, control_scan_code, KEYEVENTF_KEYUP, 0);
      if (foreground_window)
	(void) SetForegroundWindow (foreground_window);
    }
  /* STD_BOOL_API_CALL (SetKeyboardState, (keyboard_state)); */
}

void
OS_process_quit (Tprocess process)
{
  error_unimplemented_primitive ();
}

void
OS_process_hangup (Tprocess process)
{
  /* Edwin assumes that this primitive works.  Under unix, the default
     behavior of SIGHUP is to kill the process, so we will emulate
     SIGHUP by killing the process.  */
  OS_process_kill (process);
}

void
OS_process_continue_background (Tprocess process)
{
  /* A no-op, this should only be called when OS_process_continuable_p
     is true, i.e. when the process is already running.  */
}

void
OS_process_continue_foreground (Tprocess process)
{
  error_unimplemented_primitive ();
}

#ifndef WIN32_WAIT_INTERVAL
#define WIN32_WAIT_INTERVAL 50
#endif

void
OS_process_wait (Tprocess process)
{
  process_wait_1 (process, 0);
  while (1)
    {
      if (((PROCESS_RAW_STATUS (process)) != process_status_running)
	  || (pending_interrupts_p ()))
	break;
      process_wait_1 (process, WIN32_WAIT_INTERVAL);
    }
}

static void
process_wait_1 (Tprocess process, DWORD interval)
{
#ifdef TRACE_NTPROC
  fprintf (trace_file, "process_wait_1: id=0x%x raw_status=0x%x\n",
	   (PROCESS_ID (process)),
	   (PROCESS_RAW_STATUS (process)));
  fflush (trace_file);
#endif
  if ((PROCESS_RAW_STATUS (process)) == process_status_running)
    {
      DWORD code
	= (MsgWaitForMultipleObjects (1,
				      (& (PROCESS_HANDLE (process))),
				      FALSE,
				      interval,
				      QS_ALLINPUT));
#ifdef TRACE_NTPROC
      fprintf (trace_file, "(wait result = 0x%x)\n", code);
      fflush (trace_file);
#endif
      switch (code)
	{
	case WAIT_OBJECT_0:
	  process_death (process);
	  break;
	case WAIT_FAILED:
	  NT_error_api_call ((GetLastError ()),
			     apicall_MsgWaitForMultipleObjects);
	  break;
	}
    }
}

int
OS_process_any_status_change (void)
{
  Tprocess process;
#ifdef TRACE_NTPROC
  fprintf (trace_file, "OS_process_any_status_change\n");
  fflush (trace_file);
#endif
  for (process = 0; (process < OS_process_table_size); process += 1)
    if ((PROCESS_RAW_STATUS (process)) == process_status_running)
      switch (WaitForSingleObject ((PROCESS_HANDLE (process)), 0))
	{
	case WAIT_OBJECT_0:
	  process_death (process);
	  break;
	case WAIT_FAILED:
	  NT_error_api_call ((GetLastError ()),
			     apicall_MsgWaitForMultipleObjects);
	  break;
	}
#ifdef TRACE_NTPROC
  if (process_tick != sync_tick)
    {
      fprintf (trace_file, "(status change)\n");
      fflush (trace_file);
    }
#endif
  return (process_tick != sync_tick);
}

static void
process_death (Tprocess process)
{
  DWORD exit_code;
#ifdef TRACE_NTPROC
  fprintf (trace_file, "process_death: id=0x%x\n", (PROCESS_ID (process)));
  fflush (trace_file);
#endif
  STD_BOOL_API_CALL
    (GetExitCodeProcess, ((PROCESS_HANDLE (process)), (&exit_code)));
#ifdef TRACE_NTPROC
  fprintf (trace_file, "(exit_code = 0x%x)\n", exit_code);
  fflush (trace_file);
#endif
  GRAB_PROCESS_TABLE ();
  (PROCESS_RAW_STATUS (process))
    = ((exit_code == STATUS_CONTROL_C_EXIT)
       ? process_status_signalled
       : process_status_exited);
  (PROCESS_RAW_REASON (process)) = exit_code;
  (PROCESS_TICK (process)) = (++process_tick);
  STD_BOOL_API_CALL (CloseHandle, (PROCESS_HANDLE (process)));
  (PROCESS_HANDLE (process)) = INVALID_HANDLE_VALUE;
  RELEASE_PROCESS_TABLE ();
}

Tprocess
OS_make_subprocess (const char * filename,
		    const char ** argv,
		    const char ** envp,
		    const char * working_directory,
		    enum process_ctty_type ctty_type,
		    char * ctty_name,
		    enum process_channel_type channel_in_type,
		    Tchannel channel_in,
		    enum process_channel_type channel_out_type,
		    Tchannel channel_out,
		    enum process_channel_type channel_err_type,
		    Tchannel channel_err)
{
  error_unimplemented_primitive ();
  return (NO_PROCESS);
}