gecko-dev/ipc/glue/SharedMemory.cpp

102 lines
2.4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 <math.h>
#include "nsString.h"
#include "nsIMemoryReporter.h"
#include "mozilla/ipc/SharedMemory.h"
#include "mozilla/Atomics.h"
namespace mozilla {
namespace ipc {
static Atomic<size_t> gShmemAllocated;
static Atomic<size_t> gShmemMapped;
class ShmemReporter MOZ_FINAL : public nsIMemoryReporter
{
~ShmemReporter() {}
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_IMETHOD
CollectReports(nsIHandleReportCallback* aHandleReport, nsISupports* aData,
bool aAnonymize)
{
nsresult rv;
rv = MOZ_COLLECT_REPORT(
"shmem-allocated", KIND_OTHER, UNITS_BYTES, gShmemAllocated,
"Memory shared with other processes that is accessible (but not "
"necessarily mapped).");
NS_ENSURE_SUCCESS(rv, rv);
rv = MOZ_COLLECT_REPORT(
"shmem-mapped", KIND_OTHER, UNITS_BYTES, gShmemMapped,
"Memory shared with other processes that is mapped into the address "
"space.");
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
};
NS_IMPL_ISUPPORTS(ShmemReporter, nsIMemoryReporter)
SharedMemory::SharedMemory()
: mAllocSize(0)
, mMappedSize(0)
{
static Atomic<bool> registered;
if (registered.compareExchange(false, true)) {
RegisterStrongMemoryReporter(new ShmemReporter());
}
}
/*static*/ size_t
SharedMemory::PageAlignedSize(size_t aSize)
{
size_t pageSize = SystemPageSize();
size_t nPagesNeeded = size_t(ceil(double(aSize) / double(pageSize)));
return pageSize * nPagesNeeded;
}
void
SharedMemory::Created(size_t aNBytes)
{
mAllocSize = aNBytes;
gShmemAllocated += mAllocSize;
}
void
SharedMemory::Mapped(size_t aNBytes)
{
mMappedSize = aNBytes;
gShmemMapped += mMappedSize;
}
void
SharedMemory::Unmapped()
{
NS_ABORT_IF_FALSE(gShmemMapped >= mMappedSize,
"Can't unmap more than mapped");
gShmemMapped -= mMappedSize;
mMappedSize = 0;
}
/*static*/ void
SharedMemory::Destroyed()
{
NS_ABORT_IF_FALSE(gShmemAllocated >= mAllocSize,
"Can't destroy more than allocated");
gShmemAllocated -= mAllocSize;
mAllocSize = 0;
}
} // namespace ipc
} // namespace mozilla