mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-08 20:47:44 +00:00
138 lines
4.2 KiB
C++
138 lines
4.2 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* vim: sw=2 ts=8 et :
|
|
*/
|
|
/* ***** 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 IPC.
|
|
*
|
|
* The Initial Developer of the Original Code is
|
|
* The Mozilla Foundation
|
|
* Portions created by the Initial Developer are Copyright (C) 2009-2010
|
|
* the Initial Developer. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
*
|
|
* Alternatively, the contents of this file may be used under the terms of
|
|
* either 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 ***** */
|
|
|
|
#ifndef mozilla_ipc_SharedMemory_h
|
|
#define mozilla_ipc_SharedMemory_h
|
|
|
|
#include "nsDebug.h"
|
|
#include "nsISupportsImpl.h" // NS_INLINE_DECL_REFCOUNTING
|
|
|
|
//
|
|
// This is a low-level wrapper around platform shared memory. Don't
|
|
// use it directly; use Shmem allocated through IPDL interfaces.
|
|
//
|
|
namespace {
|
|
enum Rights {
|
|
RightsNone = 0,
|
|
RightsRead = 1 << 0,
|
|
RightsWrite = 1 << 1
|
|
};
|
|
}
|
|
|
|
namespace mozilla {
|
|
namespace ipc {
|
|
|
|
class SharedMemory
|
|
{
|
|
public:
|
|
enum SharedMemoryType {
|
|
TYPE_BASIC,
|
|
TYPE_SYSV,
|
|
TYPE_UNKNOWN
|
|
};
|
|
|
|
virtual ~SharedMemory() { Unmapped(); Destroyed(); }
|
|
|
|
size_t Size() const { return mMappedSize; }
|
|
|
|
virtual void* memory() const = 0;
|
|
|
|
virtual bool Create(size_t size) = 0;
|
|
virtual bool Map(size_t nBytes) = 0;
|
|
|
|
virtual SharedMemoryType Type() const = 0;
|
|
|
|
void
|
|
Protect(char* aAddr, size_t aSize, int aRights)
|
|
{
|
|
char* memStart = reinterpret_cast<char*>(memory());
|
|
if (!memStart)
|
|
NS_RUNTIMEABORT("SharedMemory region points at NULL!");
|
|
char* memEnd = memStart + Size();
|
|
|
|
char* protStart = aAddr;
|
|
if (!protStart)
|
|
NS_RUNTIMEABORT("trying to Protect() a NULL region!");
|
|
char* protEnd = protStart + aSize;
|
|
|
|
if (!(memStart <= protStart
|
|
&& protEnd <= memEnd))
|
|
NS_RUNTIMEABORT("attempt to Protect() a region outside this SharedMemory");
|
|
|
|
// checks alignment etc.
|
|
SystemProtect(aAddr, aSize, aRights);
|
|
}
|
|
|
|
NS_INLINE_DECL_REFCOUNTING(SharedMemory)
|
|
|
|
static void SystemProtect(char* aAddr, size_t aSize, int aRights);
|
|
static size_t SystemPageSize();
|
|
static size_t PageAlignedSize(size_t aSize);
|
|
|
|
protected:
|
|
SharedMemory();
|
|
|
|
// Implementations should call these methods on shmem usage changes,
|
|
// but *only if* the OS-specific calls are known to have succeeded.
|
|
// The methods are expected to be called in the pattern
|
|
//
|
|
// Created (Mapped Unmapped)* Destroy
|
|
//
|
|
// but this isn't checked.
|
|
void Created(size_t aNBytes);
|
|
void Mapped(size_t aNBytes);
|
|
void Unmapped();
|
|
void Destroyed();
|
|
|
|
// The size of the shmem region requested in Create(), if
|
|
// successful. SharedMemory instances that are opened from a
|
|
// foreign handle have an alloc size of 0, even though they have
|
|
// access to the alloc-size information.
|
|
size_t mAllocSize;
|
|
// The size of the region mapped in Map(), if successful. All
|
|
// SharedMemorys that are mapped have a non-zero mapped size.
|
|
size_t mMappedSize;
|
|
};
|
|
|
|
} // namespace ipc
|
|
} // namespace mozilla
|
|
|
|
|
|
#endif // ifndef mozilla_ipc_SharedMemory_h
|