unixgc.c revision 677833bc953b6cb418c701facbdcf4aa18d6c44e
0N/A/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
0N/A/* ***** BEGIN LICENSE BLOCK *****
0N/A * Version: MPL 1.1/GPL 2.0/LGPL 2.1
0N/A *
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Netscape Portable Runtime (NSPR).
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998-2000
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "prlock.h"
#include "prlog.h"
#include "prmem.h"
#include "gcint.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
#define _PR_GC_VMBASE 0x40000000
#if defined(SOLARIS)
#define _MD_MMAP_FLAGS MAP_SHARED
#elif defined(RELIANTUNIX)
#define _MD_MMAP_FLAGS MAP_PRIVATE|MAP_FIXED
#else
#define _MD_MMAP_FLAGS MAP_PRIVATE
#endif
static PRInt32 zero_fd = -1;
static PRLock *zero_fd_lock = NULL;
void _MD_InitGC(void)
{
#ifdef DEBUG
/*
* Disable using mmap(2) if NSPR_NO_MMAP is set
*/
if (getenv("NSPR_NO_MMAP")) {
zero_fd = -2;
return;
}
#endif
zero_fd = open("/dev/zero",O_RDWR , 0);
zero_fd_lock = PR_NewLock();
}
/* This static variable is used by _MD_GrowGCHeap and _MD_ExtendGCHeap */
static void *lastaddr = (void*) _PR_GC_VMBASE;
void *_MD_GrowGCHeap(PRUint32 *sizep)
{
void *addr;
PRUint32 size;
size = *sizep;
PR_Lock(zero_fd_lock);
if (zero_fd < 0) {
goto mmap_loses;
}
/* Extend the mapping */
addr = mmap(lastaddr, size, PROT_READ|PROT_WRITE|PROT_EXEC,
_MD_MMAP_FLAGS,
zero_fd, 0);
if (addr == (void*)-1) {
zero_fd = -1;
goto mmap_loses;
}
lastaddr = ((char*)addr + size);
#ifdef DEBUG
PR_LOG(_pr_msgc_lm, PR_LOG_WARNING,
("GC: heap extends from %08x to %08x\n",
_PR_GC_VMBASE,
_PR_GC_VMBASE + (char*)lastaddr - (char*)_PR_GC_VMBASE));
#endif
PR_Unlock(zero_fd_lock);
return addr;
mmap_loses:
PR_Unlock(zero_fd_lock);
return PR_MALLOC(size);
}
/* XXX - This is disabled. MAP_FIXED just does not work. */
#if 0
PRBool _MD_ExtendGCHeap(char *base, PRInt32 oldSize, PRInt32 newSize) {
PRBool rv = PR_FALSE;
void* addr;
PRInt32 allocSize = newSize - oldSize;
PR_Lock(zero_fd_lock);
addr = mmap(base + oldSize, allocSize, PROT_READ|PROT_WRITE|PROT_EXEC,
_MD_MMAP_FLAGS | MAP_FIXED, zero_fd, 0);
if (addr == (void*)-1) {
goto loser;
}
if (addr != (void*) (base + oldSize)) {
munmap(base + oldSize, allocSize);
goto loser;
}
lastaddr = ((char*)base + newSize);
PR_LOG(_pr_msgc_lm, PR_LOG_ALWAYS,
("GC: heap now extends from %p to %p",
base, base + newSize));
rv = PR_TRUE;
loser:
PR_Unlock(zero_fd_lock);
return rv;
}
#else
PRBool _MD_ExtendGCHeap(char *base, PRInt32 oldSize, PRInt32 newSize) {
return PR_FALSE;
}
#endif
void _MD_FreeGCSegment(void *base, PRInt32 len)
{
if (zero_fd < 0) {
PR_DELETE(base);
} else {
(void) munmap(base, len);
}
}