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pjs/xpcom/base/nsMemoryImpl.cpp

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/* -*- 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 "nsIEventQueueService.h"
#include "nsIObserverService.h"
#include "nsIRunnable.h"
#include "nsIServiceManager.h"
#include "nsISupportsArray.h"
#include "nsIThread.h"
#include "prmem.h"
#include "plevent.h"
#include "nsAlgorithm.h"
#include "nsAutoLock.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#if defined(XP_WIN)
#include <windows.h>
#define NS_MEMORY_FLUSHER_THREAD
#elif defined(XP_MAC)
#include <MacMemory.h>
#define NS_MEMORY_FLUSHER_THREAD
#else
// Need to implement the nsIMemory::IsLowMemory() predicate
#undef NS_MEMORY_FLUSHER_THREAD
#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_THREAD
/**
* A runnable 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 nsIRunnable
{
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 1; }
NS_IMETHOD_(nsrefcnt) Release(void) { return 1; }
NS_DECL_NSIRUNNABLE
nsresult Init();
void StopAndJoin();
private:
static PRBool sRunning;
static PRIntervalTime sTimeout;
static PRLock* sLock;
static PRCondVar* sCVar;
static nsIThread* sThread;
enum {
kInitialTimeout = 60 /*seconds*/
};
};
static MemoryFlusher sGlobalMemoryFlusher;
#endif // NS_MEMORY_FLUSHER_THREAD
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);
}
NS_IMETHODIMP
nsMemoryImpl::IsLowMemory(PRBool *result)
{
#if defined(XP_WIN)
MEMORYSTATUS stat;
GlobalMemoryStatus(&stat);
*result = ((float)stat.dwAvailPageFile / stat.dwTotalPageFile) < 0.1;
#elif defined(XP_MAC)
const long kReserveHeapFreeSpace = (256 * 1024);
const long kReserveHeapContigSpace = (128 * 1024);
long totalSpace, contiguousSpace;
// this call measures how much memory would be available if the OS
// purged. Despite the name, it does not purge (that happens
// automatically when heap space is low).
::PurgeSpace(&totalSpace, &contiguousSpace);
if (totalSpace < kReserveHeapFreeSpace || contiguousSpace < kReserveHeapContigSpace)
{
NS_WARNING("Found that heap mem is low");
*result = PR_TRUE;
return NS_OK;
}
// see how much temp mem is available (since our allocators allocate 1Mb chunks
// in temp mem. We don't use TempMaxMem() (to get contig space) here, because it
// compacts the application heap, so can be slow.
const long kReserveTempFreeSpace = (2 * 1024 * 1024); // 2Mb
long totalTempSpace = ::TempFreeMem();
if (totalTempSpace < kReserveTempFreeSpace)
{
NS_WARNING("Found that temp mem is low");
*result = PR_TRUE;
return NS_OK;
}
*result = PR_FALSE;
#else
*result = PR_FALSE;
#endif
return NS_OK;
}
nsresult
nsMemoryImpl::Startup()
{
sFlushLock = PR_NewLock();
if (!sFlushLock) return NS_ERROR_FAILURE;
#ifdef NS_MEMORY_FLUSHER_THREAD
return sGlobalMemoryFlusher.Init();
#else
return NS_OK;
#endif
}
void
nsMemoryImpl::Shutdown()
{
#ifdef NS_MEMORY_FLUSHER_THREAD
sGlobalMemoryFlusher.StopAndJoin();
#endif
if (sFlushLock) PR_DestroyLock(sFlushLock);
sFlushLock = nsnull;
}
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?
PRBool isOnUIThread = PR_FALSE;
nsCOMPtr<nsIThread> main;
rv = nsIThread::GetMainThread(getter_AddRefs(main));
if (NS_SUCCEEDED(rv)) {
nsCOMPtr<nsIThread> current;
rv = nsIThread::GetCurrent(getter_AddRefs(current));
if (NS_SUCCEEDED(rv)) {
if (current == main)
isOnUIThread = PR_TRUE;
}
}
if (! isOnUIThread) {
NS_ERROR("can't synchronously flush memory: not on UI thread");
return NS_ERROR_FAILURE;
}
}
{
// Are we already flushing?
nsAutoLock l(sFlushLock);
if (sIsFlushing)
return NS_OK;
// Well, we are now!
sIsFlushing = PR_TRUE;
}
// Run the flushers immediately if we can; otherwise, proxy to the
// UI thread an run 'em asynchronously.
if (aImmediate) {
rv = RunFlushers(aReason);
}
else {
nsCOMPtr<nsIEventQueueService> eqs = do_GetService(NS_EVENTQUEUESERVICE_CONTRACTID, &rv);
if (eqs) {
nsCOMPtr<nsIEventQueue> eq;
rv = eqs->GetThreadEventQueue(NS_UI_THREAD, getter_AddRefs(eq));
if (NS_SUCCEEDED(rv)) {
PL_InitEvent(&sFlushEvent.mEvent, this, HandleFlushEvent, DestroyFlushEvent);
sFlushEvent.mReason = aReason;
rv = eq->PostEvent(NS_REINTERPRET_CAST(PLEvent*, &sFlushEvent));
}
}
}
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);
}
{
// Done flushing
nsAutoLock l(sFlushLock);
sIsFlushing = PR_FALSE;
}
return NS_OK;
}
void*
nsMemoryImpl::HandleFlushEvent(PLEvent* aEvent)
{
FlushEvent* event = NS_REINTERPRET_CAST(FlushEvent*, aEvent);
sGlobalMemory.RunFlushers(event->mReason);
return 0;
}
void
nsMemoryImpl::DestroyFlushEvent(PLEvent* aEvent)
{
// no-op, since mEvent is a member of nsMemoryImpl
}
PRLock*
nsMemoryImpl::sFlushLock;
PRBool
nsMemoryImpl::sIsFlushing = PR_FALSE;
nsMemoryImpl::FlushEvent
nsMemoryImpl::sFlushEvent;
extern "C" NS_EXPORT void*
NS_Alloc(PRSize size)
{
NS_ASSERTION(size, "NS_Alloc of size 0");
void* result = MALLOC1(size);
if (! result) {
// Request an asynchronous flush
sGlobalMemory.FlushMemory(NS_LITERAL_STRING("alloc-failure").get(), PR_FALSE);
}
return result;
}
extern "C" NS_EXPORT void*
NS_Realloc(void* ptr, PRSize size)
{
NS_ASSERTION(size, "NS_Realloc of size 0");
void* result = REALLOC1(ptr, size);
if (! result) {
// Request an asynchronous flush
sGlobalMemory.FlushMemory(NS_LITERAL_STRING("alloc-failure").get(), PR_FALSE);
}
return result;
}
extern "C" NS_EXPORT void
NS_Free(void* ptr)
{
PR_Free(ptr);
}
#ifdef NS_MEMORY_FLUSHER_THREAD
NS_IMPL_QUERY_INTERFACE1(MemoryFlusher, nsIRunnable)
NS_IMETHODIMP
MemoryFlusher::Run()
{
nsresult rv;
sRunning = PR_TRUE;
while (1) {
PRStatus status;
{
nsAutoLock l(sLock);
if (! sRunning) {
rv = NS_OK;
break;
}
status = PR_WaitCondVar(sCVar, sTimeout);
}
if (status != PR_SUCCESS) {
rv = NS_ERROR_FAILURE;
break;
}
if (! sRunning) {
rv = NS_OK;
break;
}
PRBool isLowMemory;
rv = sGlobalMemory.IsLowMemory(&isLowMemory);
if (NS_FAILED(rv))
break;
#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);
}
}
sRunning = PR_FALSE;
return rv;
}
nsresult
MemoryFlusher::Init()
{
sTimeout = PR_SecondsToInterval(kInitialTimeout);
sLock = PR_NewLock();
if (!sLock) return NS_ERROR_FAILURE;
sCVar = PR_NewCondVar(sLock);
if (!sCVar) return NS_ERROR_FAILURE;
return NS_NewThread(&sThread,
this,
0, /* XXX use default stack size? */
PR_JOINABLE_THREAD);
}
void
MemoryFlusher::StopAndJoin()
{
if (sRunning) {
{
nsAutoLock l(sLock);
sRunning = PR_FALSE;
PR_NotifyCondVar(sCVar);
}
if (sThread)
sThread->Join();
}
NS_IF_RELEASE(sThread);
if (sLock)
PR_DestroyLock(sLock);
if (sCVar)
PR_DestroyCondVar(sCVar);
}
PRBool
MemoryFlusher::sRunning;
PRIntervalTime
MemoryFlusher::sTimeout;
PRLock*
MemoryFlusher::sLock;
PRCondVar*
MemoryFlusher::sCVar;
nsIThread*
MemoryFlusher::sThread;
#endif // NS_MEMORY_FLUSHER_THREAD
nsresult
NS_GetMemoryManager(nsIMemory* *result)
{
return sGlobalMemory.QueryInterface(NS_GET_IID(nsIMemory), (void**) result);
}
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