newlib/winsup/cygwin/sync.h
Christopher Faylor 9aa07a8f60 Fix final round of gcc warnings relating to unused parameters.
* debug.cc (iscygthread): New function.
* debug.h: Declare it.
* exceptions.cc (set_process_mask): Flush pending signals.
(handle_sigsuspend): No need to flush pending signals.
(call_handler): Refine previous tests of muto ownership.  Only clear wait()'s
when we have definitely responded to a signal.
* fhandler_console.cc (fhandler_console::read): Don't set EINTR if executing in
a "cygwin" thread.
* sigproc.cc (proc_subproc): Use second argument to control whether CLEARWAIT
actually sets "signalled" flag.
* sync.h (muto): Add 'unstable' method.
2000-02-24 06:45:32 +00:00

51 lines
1.7 KiB
C++

/* sync.h: Header file for cygwin synchronization primitives.
Copyright 1999, 2000 Cygnus Solutions.
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. */
/* FIXME: Note that currently this class cannot be allocated via `new' since
there are issues with malloc and fork. */
class muto
{
LONG sync; /* Used to serialize access to this class. */
LONG visits; /* Count of number of times a thread has called acquire. */
LONG waiters; /* Number of threads waiting for lock. */
HANDLE bruteforce; /* event handle used to control waiting for lock. */
DWORD tid; /* Thread Id of lock owner. */
public:
void *operator new (size_t, void *p) {return p;}
void *operator new (size_t) {return ::new muto; }
void operator delete (void *) {;} /* can't handle allocated mutos
currently */
/* This simple constructor is used for cases where no bruteforce
event handling is required. */
muto(): sync(0), visits(0), waiters(-1), bruteforce(0), tid(0) {;}
/* A more complicated constructor. */
muto(int inh, const char *name);
~muto ();
int acquire (DWORD ms = INFINITE); /* Acquire the lock. */
int release (); /* Release the lock. */
/* Return true if caller thread owns the lock. */
int ismine () {return tid == GetCurrentThreadId ();}
DWORD owner () {return tid;}
int unstable () {return !tid && (sync || waiters >= 0);}
};
/* Use a statically allocated buffer as the storage for a muto */
#define new_muto(__inh, __name) \
({ \
static NO_COPY char __mbuf[sizeof(class muto) + 100] = {0}; \
muto *m; \
m = new (__mbuf) muto ((__inh), (__name)); \
m; \
})