winsup/cygwin/local_includes/sync.h

   1 /* sync.h: Header file for cygwin synchronization primitives.
   2
   3 This file is part of Cygwin.
   4
   5 This software is a copyrighted work licensed under the terms of the
   6 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   7 details. */
   8
   9 #pragma once
  10
  11 /* FIXME: Note that currently this class cannot be allocated via `new' since
  12    there are issues with malloc and fork. */
  13 class muto
  14 {
  15 public:
  16   char *name;
  17 private:
  18   LONG sync;    /* Used to serialize access to this class. */
  19   LONG waiters; /* Number of threads waiting for lock. */
  20   HANDLE bruteforce; /* event handle used to control waiting for lock. */
  21 public:
  22   LONG visits;  /* Count of number of times a thread has called acquire. */
  23   void *tls;    /* Tls of lock owner. */
  24   // class muto *next;
  25
  26   /* The real constructor. */
  27   muto *init (const char *);
  28
  29 #if 0   /* FIXME: See comment in sync.cc */
  30   ~muto ()
  31 #endif
  32   int acquire (DWORD ms = INFINITE); /* Acquire the lock. */
  33   int release (_cygtls * = &_my_tls); /* Release the lock. */
  34
  35   bool acquired ();
  36   void upforgrabs () {tls = this;}  // just set to an invalid address
  37   void grab ();
  38   operator int () const {return !!name;}
  39 };
  40
  41 class lock_process
  42 {
  43   bool skip_unlock;
  44   static muto locker;
  45 public:
  46   static void init () {locker.init ("lock_process");}
  47   void dont_bother () {skip_unlock = true;}
  48   lock_process (bool exiting = false)
  49   {
  50     locker.acquire ();
  51     skip_unlock = exiting;
  52   }
  53   void release ()
  54   {
  55     locker.release ();
  56     skip_unlock = true;
  57   }
  58   ~lock_process ()
  59   {
  60     if (!skip_unlock)
  61       release ();
  62   }
  63   operator LONG () const {return locker.visits; }
  64   static void force_release (_cygtls *tid) {locker.release (tid);}
  65   friend class dtable;
  66   friend class fhandler_fifo;
  67 };