view Python/thread.c @ 12584:cde4da18c4fa legacy-trunk

Fast NonRecursiveMutex support by Yakov Markovitch, markovitch@iso.ru, who wrote: Here's the new version of thread_nt.h. More particular, there is a new version of thread lock that uses kernel object (e.g. semaphore) only in case of contention; in other case it simply uses interlocked functions, which are faster by the order of magnitude. It doesn't make much difference without threads present, but as soon as thread machinery initialised and (mostly) the interpreter global lock is on, difference becomes tremendous. I've included a small script, which initialises threads and launches pystone. With original thread_nt.h, Pystone results with initialised threads are twofold worse then w/o threads. With the new version, only 10% worse. I have used this patch for about 6 months (with threaded and non-threaded applications). It works remarkably well (though I'd desperately prefer Python was free-threaded; I hope, it will soon).
author Guido van Rossum <guido@python.org>
date Thu, 04 May 2000 18:47:15 +0000
parents c27f484aefff
children b320cf3a98b9
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/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI or Corporation for National Research Initiatives or
CNRI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.

While CWI is the initial source for this software, a modified version
is made available by the Corporation for National Research Initiatives
(CNRI) at the Internet address ftp://ftp.python.org.

STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* Thread package.
   This is intended to be usable independently from Python.
   The implementation for system foobar is in a file thread_foobar.h
   which is included by this file dependent on config settings.
   Stuff shared by all thread_*.h files is collected here. */

#include "config.h"

/* config.h may or may not define DL_IMPORT */
#ifndef DL_IMPORT	/* declarations for DLL import/export */
#define DL_IMPORT(RTYPE) RTYPE
#endif

#ifndef DONT_HAVE_STDIO_H
#include <stdio.h>
#endif

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#else
#ifdef Py_DEBUG
extern char *getenv();
#endif
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef __DGUX
#define _USING_POSIX4A_DRAFT6
#endif

#ifdef __sgi
#ifndef HAVE_PTHREAD_H /* XXX Need to check in configure.in */
#undef _POSIX_THREADS
#endif
#endif

#include "pythread.h"

#ifdef __ksr__
#define _POSIX_THREADS
#endif

#ifndef _POSIX_THREADS

#ifdef __sgi
#define SGI_THREADS
#endif

#ifdef HAVE_THREAD_H
#define SOLARIS_THREADS
#endif

#if defined(sun) && !defined(SOLARIS_THREADS)
#define SUN_LWP
#endif

#ifdef __MWERKS__
#define _POSIX_THREADS
#endif

#endif /* _POSIX_THREADS */

#ifdef __STDC__
#define _P(args)		args
#define _P0()			(void)
#define _P1(v,t)		(t)
#define _P2(v1,t1,v2,t2)	(t1,t2)
#else
#define _P(args)		()
#define _P0()			()
#define _P1(v,t)		(v) t;
#define _P2(v1,t1,v2,t2)	(v1,v2) t1; t2;
#endif /* __STDC__ */

#ifdef Py_DEBUG
static int thread_debug = 0;
#define dprintf(args)	((thread_debug & 1) && printf args)
#define d2printf(args)	((thread_debug & 8) && printf args)
#else
#define dprintf(args)
#define d2printf(args)
#endif

static int initialized;

static void PyThread__init_thread(); /* Forward */

void PyThread_init_thread _P0()
{
#ifdef Py_DEBUG
	char *p = getenv("THREADDEBUG");

	if (p) {
		if (*p)
			thread_debug = atoi(p);
		else
			thread_debug = 1;
	}
#endif /* Py_DEBUG */
	if (initialized)
		return;
	initialized = 1;
	dprintf(("PyThread_init_thread called\n"));
	PyThread__init_thread();
}

#ifdef SGI_THREADS
#include "thread_sgi.h"
#endif

#ifdef SOLARIS_THREADS
#include "thread_solaris.h"
#endif

#ifdef SUN_LWP
#include "thread_lwp.h"
#endif

#ifdef _POSIX_THREADS
#include "thread_pthread.h"
#endif

#ifdef C_THREADS
#include "thread_cthread.h"
#endif

#ifdef NT_THREADS
#include "thread_nt.h"
#endif

#ifdef OS2_THREADS
#include "thread_os2.h"
#endif

#ifdef BEOS_THREADS
#include "thread_beos.h"
#endif

#ifdef WINCE_THREADS
#include "thread_wince.h"
#endif

/*
#ifdef FOOBAR_THREADS
#include "thread_foobar.h"
#endif
*/