gecko/ipc/glue/SharedMemory.cpp
Nicholas Nethercote c82c609ac3 Bug 936964 (part 7, attempt 2) - Make lots of classes report their own memory consumption, instead of using a separate reporter class. r=mccr8,sr=bz.
* * *
Bug 936964 (part 7b) - Fix a use-after-free found by ASan.

--HG--
extra : rebase_source : d38ab6b63e9d576773baf8e55fa4f7182c33915e
2013-11-07 16:35:30 +11:00

96 lines
2.3 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 ShmemAllocatedReporter MOZ_FINAL : public MemoryUniReporter
{
public:
ShmemAllocatedReporter()
: MemoryUniReporter("shmem-allocated", KIND_OTHER, UNITS_BYTES,
"Memory shared with other processes that is accessible (but not necessarily "
"mapped).")
{}
private:
int64_t Amount() MOZ_OVERRIDE { return gShmemAllocated; }
};
class ShmemMappedReporter MOZ_FINAL : public MemoryUniReporter
{
public:
ShmemMappedReporter()
: MemoryUniReporter("shmem-mapped", KIND_OTHER, UNITS_BYTES,
"Memory shared with other processes that is mapped into the address space.")
{}
private:
int64_t Amount() MOZ_OVERRIDE { return gShmemMapped; }
};
SharedMemory::SharedMemory()
: mAllocSize(0)
, mMappedSize(0)
{
static Atomic<uint32_t> registered;
if (registered.compareExchange(0, 1)) {
RegisterStrongMemoryReporter(new ShmemAllocatedReporter());
RegisterStrongMemoryReporter(new ShmemMappedReporter());
}
}
/*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