gecko-dev/xpcom/base/nsMemoryImpl.cpp

211 lines
5.0 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsMemoryImpl.h"
#include "nsThreadUtils.h"
#include "nsIObserver.h"
#include "nsIObserverService.h"
#include "nsISimpleEnumerator.h"
#include "nsCOMPtr.h"
#include "mozilla/Services.h"
#ifdef ANDROID
#include <stdio.h>
#define LOW_MEMORY_THRESHOLD_KB (384 * 1024)
#endif
static nsMemoryImpl sGlobalMemory;
NS_IMPL_QUERY_INTERFACE1(nsMemoryImpl, nsIMemory)
NS_IMETHODIMP_(void*)
nsMemoryImpl::Alloc(size_t size)
{
return NS_Alloc(size);
}
NS_IMETHODIMP_(void*)
nsMemoryImpl::Realloc(void* ptr, size_t size)
{
return NS_Realloc(ptr, size);
}
NS_IMETHODIMP_(void)
nsMemoryImpl::Free(void* ptr)
{
NS_Free(ptr);
}
NS_IMETHODIMP
nsMemoryImpl::HeapMinimize(bool aImmediate)
{
return FlushMemory(NS_LITERAL_STRING("heap-minimize").get(), aImmediate);
}
NS_IMETHODIMP
nsMemoryImpl::IsLowMemory(bool *result)
{
NS_ERROR("IsLowMemory is deprecated. See bug 592308.");
*result = false;
return NS_OK;
}
NS_IMETHODIMP
nsMemoryImpl::IsLowMemoryPlatform(bool *result)
{
#ifdef ANDROID
static int sLowMemory = -1; // initialize to unknown, lazily evaluate to 0 or 1
if (sLowMemory == -1) {
sLowMemory = 0; // assume "not low memory" in case file operations fail
*result = false;
// check if MemTotal from /proc/meminfo is less than LOW_MEMORY_THRESHOLD_KB
FILE* fd = fopen("/proc/meminfo", "r");
if (!fd) {
return NS_OK;
}
uint64_t mem = 0;
int rv = fscanf(fd, "MemTotal: %lu kB", &mem);
if (fclose(fd)) {
return NS_OK;
}
if (rv != 1) {
return NS_OK;
}
sLowMemory = (mem < LOW_MEMORY_THRESHOLD_KB) ? 1 : 0;
}
*result = (sLowMemory == 1);
#else
*result = false;
#endif
return NS_OK;
}
/*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, bool aImmediate)
{
nsresult rv = NS_OK;
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;
}
}
int32_t lastVal = sIsFlushing.exchange(1);
if (lastVal)
return NS_OK;
PRIntervalTime now = PR_IntervalNow();
// Run the flushers immediately if we can; otherwise, proxy to the
// UI thread an run 'em asynchronously.
if (aImmediate) {
rv = RunFlushers(aReason);
}
else {
// Don't broadcast more than once every 1000ms to avoid being noisy
if (PR_IntervalToMicroseconds(now - sLastFlushTime) > 1000) {
sFlushEvent.mReason = aReason;
rv = NS_DispatchToMainThread(&sFlushEvent, NS_DISPATCH_NORMAL);
}
}
sLastFlushTime = now;
return rv;
}
nsresult
nsMemoryImpl::RunFlushers(const PRUnichar* aReason)
{
nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
if (os) {
// Instead of:
// os->NotifyObservers(this, "memory-pressure", aReason);
// we are going to do this manually to see who/what is
// deallocating.
nsCOMPtr<nsISimpleEnumerator> e;
os->EnumerateObservers("memory-pressure", getter_AddRefs(e));
if ( e ) {
nsCOMPtr<nsIObserver> observer;
bool loop = true;
while (NS_SUCCEEDED(e->HasMoreElements(&loop)) && loop)
{
e->GetNext(getter_AddRefs(observer));
if (!observer)
continue;
observer->Observe(observer, "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;
}
mozilla::Atomic<int32_t>
nsMemoryImpl::sIsFlushing;
PRIntervalTime
nsMemoryImpl::sLastFlushTime = 0;
nsMemoryImpl::FlushEvent
nsMemoryImpl::sFlushEvent;
XPCOM_API(void*)
NS_Alloc(size_t size)
{
return moz_xmalloc(size);
}
XPCOM_API(void*)
NS_Realloc(void* ptr, size_t size)
{
return moz_xrealloc(ptr, size);
}
XPCOM_API(void)
NS_Free(void* ptr)
{
moz_free(ptr);
}
nsresult
NS_GetMemoryManager(nsIMemory* *result)
{
return sGlobalMemory.QueryInterface(NS_GET_IID(nsIMemory), (void**) result);
}