gecko-dev/xpcom/base/nsMemoryImpl.cpp

385 lines
9.9 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* 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 mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 "nsXPCOM.h"
#include "nsMemoryImpl.h"
#include "nsThreadUtils.h"
#include "nsIObserverService.h"
#include "nsIServiceManager.h"
#include "nsISupportsArray.h"
#include "prmem.h"
#include "prcvar.h"
#include "pratom.h"
#include "nsAlgorithm.h"
#include "nsAutoLock.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#if defined(XP_WIN)
#include <windows.h>
#define NS_MEMORY_FLUSHER
#elif defined (NS_OSSO)
#include <osso-mem.h>
#include <fcntl.h>
#include <unistd.h>
const char* kHighMark = "/sys/kernel/high_watermark";
#else
// Need to implement the nsIMemory::IsLowMemory() predicate
#undef NS_MEMORY_FLUSHER
#endif
#ifdef NS_MEMORY_FLUSHER
#include "nsITimer.h"
#endif
////////////////////////////////////////////////////////////////////////////////
// Define NS_OUT_OF_MEMORY_TESTER if you want to force memory failures
#ifdef DEBUG_xwarren
#define NS_OUT_OF_MEMORY_TESTER
#endif
#ifdef NS_OUT_OF_MEMORY_TESTER
// flush memory one in this number of times:
#define NS_FLUSH_FREQUENCY 100000
// fail allocation one in this number of flushes:
#define NS_FAIL_FREQUENCY 10
PRUint32 gFlushFreq = 0;
PRUint32 gFailFreq = 0;
static void*
mallocator(PRSize size, PRUint32& counter, PRUint32 max)
{
if (counter++ >= max) {
counter = 0;
NS_ASSERTION(0, "about to fail allocation... watch out");
return nsnull;
}
return PR_Malloc(size);
}
static void*
reallocator(void* ptr, PRSize size, PRUint32& counter, PRUint32 max)
{
if (counter++ >= max) {
counter = 0;
NS_ASSERTION(0, "about to fail reallocation... watch out");
return nsnull;
}
return PR_Realloc(ptr, size);
}
#define MALLOC1(s) mallocator(s, gFlushFreq, NS_FLUSH_FREQUENCY)
#define REALLOC1(p, s) reallocator(p, s, gFlushFreq, NS_FLUSH_FREQUENCY)
#else
#define MALLOC1(s) PR_Malloc(s)
#define REALLOC1(p, s) PR_Realloc(p, s)
#endif // NS_OUT_OF_MEMORY_TESTER
#if defined(XDEBUG_waterson)
#define NS_TEST_MEMORY_FLUSHER
#endif
#ifdef NS_MEMORY_FLUSHER
/**
* A class that is used to periodically check the status of the system,
* determine if too much memory is in use, and if so, trigger a "memory flush".
*/
class MemoryFlusher : public nsITimerCallback
{
public:
// We don't use the generic macros because we are a special static object
NS_IMETHOD QueryInterface(REFNSIID aIID, void** aResult);
NS_IMETHOD_(nsrefcnt) AddRef(void) { return 2; }
NS_IMETHOD_(nsrefcnt) Release(void) { return 1; }
NS_DECL_NSITIMERCALLBACK
nsresult Init();
void StopAndJoin();
private:
static PRIntervalTime sTimeout;
static PRLock* sLock;
static PRCondVar* sCVar;
enum {
kTimeout = 60000 // milliseconds
};
};
static MemoryFlusher sGlobalMemoryFlusher;
#endif // NS_MEMORY_FLUSHER
static nsMemoryImpl sGlobalMemory;
NS_IMPL_QUERY_INTERFACE1(nsMemoryImpl, nsIMemory)
NS_IMETHODIMP_(void*)
nsMemoryImpl::Alloc(PRSize size)
{
return NS_Alloc(size);
}
NS_IMETHODIMP_(void*)
nsMemoryImpl::Realloc(void* ptr, PRSize size)
{
return NS_Realloc(ptr, size);
}
NS_IMETHODIMP_(void)
nsMemoryImpl::Free(void* ptr)
{
NS_Free(ptr);
}
NS_IMETHODIMP
nsMemoryImpl::HeapMinimize(PRBool aImmediate)
{
return FlushMemory(NS_LITERAL_STRING("heap-minimize").get(), aImmediate);
}
/* this magic number is something greater than 40mb
* and after all, 40mb should be good enough for any web app
* unless it's part of an office suite.
*/
static const int kRequiredMemory = 0x3000000;
NS_IMETHODIMP
nsMemoryImpl::IsLowMemory(PRBool *result)
{
#if defined(WINCE)
*result = PR_FALSE;
// See bug 475595 -- this is incorrect right now, and causes a big
// perf hit since GlobalMemoryStatus has to grab a kernel VM lock
// and do a bunch of munging through VM pages to get the data
// that's requested. We call IsLowMemory in some performance
// critical code (e.g. during painting), so that's bad.
#if 0
MEMORYSTATUS stat;
GlobalMemoryStatus(&stat);
*result = ((float)stat.dwAvailPhys / stat.dwTotalPhys) < 0.1;
#endif
#elif defined(XP_WIN)
MEMORYSTATUSEX stat;
stat.dwLength = sizeof stat;
GlobalMemoryStatusEx(&stat);
*result = (stat.ullAvailPageFile < kRequiredMemory) &&
((float)stat.ullAvailPageFile / stat.ullTotalPageFile) < 0.1;
#elif defined(NS_OSSO)
int fd = open (kHighMark, O_RDONLY);
if (fd == -1) {
*result = PR_FALSE;
return NS_OK;
}
int c = 0;
read (fd, &c, 1);
close(fd);
*result = (c == '1');
#else
*result = PR_FALSE;
#endif
return NS_OK;
}
/*static*/ nsresult
nsMemoryImpl::InitFlusher()
{
#ifdef NS_MEMORY_FLUSHER
return sGlobalMemoryFlusher.Init();
#else
return NS_OK;
#endif
}
/*static*/ nsresult
nsMemoryImpl::Create(nsISupports* outer, const nsIID& aIID, void **aResult)
{
NS_ENSURE_NO_AGGREGATION(outer);
return sGlobalMemory.QueryInterface(aIID, aResult);
}
nsresult
nsMemoryImpl::FlushMemory(const PRUnichar* aReason, PRBool aImmediate)
{
nsresult rv;
if (aImmediate) {
// They've asked us to run the flusher *immediately*. We've
// got to be on the UI main thread for us to be able to do
// that...are we?
if (!NS_IsMainThread()) {
NS_ERROR("can't synchronously flush memory: not on UI thread");
return NS_ERROR_FAILURE;
}
}
PRInt32 lastVal = PR_AtomicSet(&sIsFlushing, 1);
if (lastVal)
return NS_OK;
// Run the flushers immediately if we can; otherwise, proxy to the
// UI thread an run 'em asynchronously.
if (aImmediate) {
rv = RunFlushers(aReason);
}
else {
sFlushEvent.mReason = aReason;
rv = NS_DispatchToMainThread(&sFlushEvent, NS_DISPATCH_NORMAL);
}
return rv;
}
nsresult
nsMemoryImpl::RunFlushers(const PRUnichar* aReason)
{
nsCOMPtr<nsIObserverService> os = do_GetService("@mozilla.org/observer-service;1");
if (os) {
os->NotifyObservers(this, "memory-pressure", aReason);
}
sIsFlushing = 0;
return NS_OK;
}
// XXX need NS_IMPL_STATIC_ADDREF/RELEASE
NS_IMETHODIMP_(nsrefcnt) nsMemoryImpl::FlushEvent::AddRef() { return 2; }
NS_IMETHODIMP_(nsrefcnt) nsMemoryImpl::FlushEvent::Release() { return 1; }
NS_IMPL_QUERY_INTERFACE1(nsMemoryImpl::FlushEvent, nsIRunnable)
NS_IMETHODIMP
nsMemoryImpl::FlushEvent::Run()
{
sGlobalMemory.RunFlushers(mReason);
return NS_OK;
}
PRInt32
nsMemoryImpl::sIsFlushing = 0;
nsMemoryImpl::FlushEvent
nsMemoryImpl::sFlushEvent;
XPCOM_API(void*)
NS_Alloc(PRSize size)
{
if (size > PR_INT32_MAX)
return nsnull;
void* result = MALLOC1(size);
if (! result) {
// Request an asynchronous flush
sGlobalMemory.FlushMemory(NS_LITERAL_STRING("alloc-failure").get(), PR_FALSE);
}
return result;
}
XPCOM_API(void*)
NS_Realloc(void* ptr, PRSize size)
{
if (size > PR_INT32_MAX)
return nsnull;
void* result = REALLOC1(ptr, size);
if (! result && size != 0) {
// Request an asynchronous flush
sGlobalMemory.FlushMemory(NS_LITERAL_STRING("alloc-failure").get(), PR_FALSE);
}
return result;
}
XPCOM_API(void)
NS_Free(void* ptr)
{
PR_Free(ptr);
}
#ifdef NS_MEMORY_FLUSHER
NS_IMPL_QUERY_INTERFACE1(MemoryFlusher, nsITimerCallback)
NS_IMETHODIMP
MemoryFlusher::Notify(nsITimer *timer)
{
PRBool isLowMemory;
sGlobalMemory.IsLowMemory(&isLowMemory);
#ifdef NS_TEST_MEMORY_FLUSHER
// Fire the flusher *every* time
isLowMemory = PR_TRUE;
#endif
if (isLowMemory)
sGlobalMemory.FlushMemory(NS_LITERAL_STRING("low-memory").get(),
PR_FALSE);
return NS_OK;
}
nsresult
MemoryFlusher::Init()
{
nsCOMPtr<nsITimer> timer = do_CreateInstance(NS_TIMER_CONTRACTID);
NS_ENSURE_STATE(timer);
// There is no need to keep a reference to the timer object because we
// don't need to kill the timer. It will be killed automatically when
// XPCOM is shutdown.
return timer->InitWithCallback(this, kTimeout,
nsITimer::TYPE_REPEATING_SLACK);
}
#endif // NS_MEMORY_FLUSHER
nsresult
NS_GetMemoryManager(nsIMemory* *result)
{
return sGlobalMemory.QueryInterface(NS_GET_IID(nsIMemory), (void**) result);
}