newlib/winsup/cygwin/sync.h

72 lines
1.9 KiB
C++

/* sync.h: Header file for cygwin synchronization primitives.
Copyright 1999, 2000, 2001, 2002, 2003, 2004 Red Hat, Inc.
Written by Christopher Faylor <cgf@cygnus.com>
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#ifndef _SYNC_H
#define _SYNC_H
/* FIXME: Note that currently this class cannot be allocated via `new' since
there are issues with malloc and fork. */
class muto
{
public:
const char *name;
private:
static DWORD exiting_thread;
LONG sync; /* Used to serialize access to this class. */
LONG waiters; /* Number of threads waiting for lock. */
HANDLE bruteforce; /* event handle used to control waiting for lock. */
public:
LONG visits; /* Count of number of times a thread has called acquire. */
void *tls; /* Tls of lock owner. */
// class muto *next;
/* The real constructor. */
muto *init (const char *) __attribute__ ((regparm (2)));
#if 0 /* FIXME: See comment in sync.cc */
~muto ()
#endif
int acquire (DWORD ms = INFINITE) __attribute__ ((regparm (2))); /* Acquire the lock. */
int release () __attribute__ ((regparm (1))); /* Release the lock. */
bool acquired () __attribute__ ((regparm (1)));
void upforgrabs () {tls = this;} // just set to an invalid address
void grab () __attribute__ ((regparm (1)));
operator int () const {return !!name;}
static void set_exiting_thread () {exiting_thread = GetCurrentThreadId ();}
};
class lock_process
{
bool skip_unlock;
static muto locker;
public:
static void init () {locker.init ("lock_process");}
lock_process (bool exiting = false)
{
locker.acquire ();
skip_unlock = exiting;
if (exiting && exit_state < ES_SET_MUTO)
{
exit_state = ES_SET_MUTO;
muto::set_exiting_thread ();
}
}
~lock_process ()
{
if (!skip_unlock)
locker.release ();
}
friend class dtable;
};
#endif /*_SYNC_H*/