gecko/ipc/glue/SharedMemory.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=8 et :
*/
2012-05-21 04:12:37 -07:00
/* 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"
namespace mozilla {
namespace ipc {
static int64_t gShmemAllocated;
static int64_t gShmemMapped;
static int64_t GetShmemAllocated() { return gShmemAllocated; }
static int64_t GetShmemMapped() { return gShmemMapped; }
NS_MEMORY_REPORTER_IMPLEMENT(ShmemAllocated,
"shmem-allocated",
KIND_OTHER,
UNITS_BYTES,
GetShmemAllocated,
"Memory shared with other processes that is accessible (but not "
"necessarily mapped).")
NS_MEMORY_REPORTER_IMPLEMENT(ShmemMapped,
"shmem-mapped",
KIND_OTHER,
UNITS_BYTES,
GetShmemMapped,
"Memory shared with other processes that is mapped into the address space.")
SharedMemory::SharedMemory()
: mAllocSize(0)
, mMappedSize(0)
{
// NB: SharedMemory is main-thread-only at the moment, but that may
// change soon
static bool registered;
if (!registered) {
NS_RegisterMemoryReporter(new NS_MEMORY_REPORTER_NAME(ShmemAllocated));
NS_RegisterMemoryReporter(new NS_MEMORY_REPORTER_NAME(ShmemMapped));
registered = true;
}
}
/*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 >= int64_t(mMappedSize),
"Can't unmap more than mapped");
gShmemMapped -= mMappedSize;
mMappedSize = 0;
}
/*static*/ void
SharedMemory::Destroyed()
{
NS_ABORT_IF_FALSE(gShmemAllocated >= int64_t(mAllocSize),
"Can't destroy more than allocated");
gShmemAllocated -= mAllocSize;
mAllocSize = 0;
}
} // namespace ipc
} // namespace mozilla