操作系统内核-GNU Mach
2015-11-02 10:08:45 
阿炯
Mach是一个由卡内基梅隆大学开发的用于支持操作系统研究的操作系统内核。该项目在1985年启动，并且在1994年因为mach3.0的显著失败而告终，但是mach却是一个真正的微核。mach被开发成了UNIX中BSD的替代内核，所以没必要再开发设计他的衍生系统。
GNU Mach is the microkernel upon which a GNU Hurd system is based. It provides an Inter Process Communication (IPC) mechanism that the Hurd uses to define interfaces for implementing in a distributed multi-server fashion the services a traditional operating system kernel provides.
其他还有许多人继续Mach的研究包括犹他大学的Mach 4。Mach的开发是为了取代BSD的UNIX核心，所以是许多新的操作系统的设计基础。Mach的研究到至今似乎是退出，虽然有许多商业化操作系统，如 NEXTSTEP与OPENSTEP，特别是Mac OS X（使用XNU核心）都是使用Mach或其派生系统。Mach的虚拟内存（VM）系统也被BSD的开发者用于CSRG，并出现在BSD派生的系统中，如 FreeBSD。Mac OS X与FreeBSD并未保留Mach首倡的微核心结构，除了Mac OS X继续提供微核心于内部处理通信以及应用程序直接控制。
Mach继承卡内基梅隆大学的Accent kernel，Mach项目主导人理查德·拉希德曾于微软的研究部门担任高级人员，后成为微软副总裁。另一Mach开发者阿瓦德斯·特凡尼安(Avie Tevanian)曾是NeXT首席程序员，之后担任苹果电脑软件技术部门主管直到2006年。
现在，一个名为GNU Mach的计划与GNU HURD联系紧密。Debian GNU/Hurd就是基于GNU Mach的。今天虽然mach及其衍生品在许多商业操作系统被广泛使用，但是对mach的进一步实验研究已经结束。例如,OPENSTEP NeXTSTEP,最明显的是Mac OS X操作系统内核，他使用XNU其中包括一个早期(非微核)mach作为主要组件。
Features
GNU Mach is not the most advanced microkernel known to the planet, nor is it the fastest or smallest, but it has a rich set of interfaces and some features which make it useful as the base of the Hurd system.
it's free software
Anybody can use, modify, and redistribute it under the terms of the ?GNU General Public License (GPL).
it's built to survive
As a microkernel, GNU Mach doesn't implement a lot of the features commonly found in an operating system, but only the bare minimum that is required to implement a full operating system on top of it. This means that a lot of the operating system code is maintained outside of GNU Mach, and while this code may go through a complete redesign, the code of the microkernel can remain comparatively stable.
it's scalable
Mach is particularly well suited for SMP and network cluster techniques. Thread support is provided at the kernel level, and the kernel itself takes advantage of that. Network transparency at the IPC level makes resources of the system available across machine boundaries (with NORMA IPC, currently not available in GNU Mach).
it exists
The Mach microkernel is real software that works Right Now. It is not a research or a proposal. You don't have to wait at all before you can start using and developing it. Mach has been used in many operating systems in the past, usually as the base for a single UNIX server. In the GNU system, Mach is the base of a functional multi-server operating system, the Hurd.
最新版本：1.6
项目主页：https://www.gnu.org/software/hurd/microkernel/mach/gnumach.html
GNU Mach is the microkernel upon which a GNU Hurd system is based. It provides an Inter Process Communication (IPC) mechanism that the Hurd uses to define interfaces for implementing in a distributed multi-server fashion the services a traditional operating system kernel provides.
其他还有许多人继续Mach的研究包括犹他大学的Mach 4。Mach的开发是为了取代BSD的UNIX核心，所以是许多新的操作系统的设计基础。Mach的研究到至今似乎是退出，虽然有许多商业化操作系统，如 NEXTSTEP与OPENSTEP，特别是Mac OS X（使用XNU核心）都是使用Mach或其派生系统。Mach的虚拟内存（VM）系统也被BSD的开发者用于CSRG，并出现在BSD派生的系统中，如 FreeBSD。Mac OS X与FreeBSD并未保留Mach首倡的微核心结构，除了Mac OS X继续提供微核心于内部处理通信以及应用程序直接控制。
Mach继承卡内基梅隆大学的Accent kernel，Mach项目主导人理查德·拉希德曾于微软的研究部门担任高级人员，后成为微软副总裁。另一Mach开发者阿瓦德斯·特凡尼安(Avie Tevanian)曾是NeXT首席程序员，之后担任苹果电脑软件技术部门主管直到2006年。
现在，一个名为GNU Mach的计划与GNU HURD联系紧密。Debian GNU/Hurd就是基于GNU Mach的。今天虽然mach及其衍生品在许多商业操作系统被广泛使用，但是对mach的进一步实验研究已经结束。例如,OPENSTEP NeXTSTEP,最明显的是Mac OS X操作系统内核，他使用XNU其中包括一个早期(非微核)mach作为主要组件。
Features
GNU Mach is not the most advanced microkernel known to the planet, nor is it the fastest or smallest, but it has a rich set of interfaces and some features which make it useful as the base of the Hurd system.
it's free software
Anybody can use, modify, and redistribute it under the terms of the ?GNU General Public License (GPL).
it's built to survive
As a microkernel, GNU Mach doesn't implement a lot of the features commonly found in an operating system, but only the bare minimum that is required to implement a full operating system on top of it. This means that a lot of the operating system code is maintained outside of GNU Mach, and while this code may go through a complete redesign, the code of the microkernel can remain comparatively stable.
it's scalable
Mach is particularly well suited for SMP and network cluster techniques. Thread support is provided at the kernel level, and the kernel itself takes advantage of that. Network transparency at the IPC level makes resources of the system available across machine boundaries (with NORMA IPC, currently not available in GNU Mach).
it exists
The Mach microkernel is real software that works Right Now. It is not a research or a proposal. You don't have to wait at all before you can start using and developing it. Mach has been used in many operating systems in the past, usually as the base for a single UNIX server. In the GNU system, Mach is the base of a functional multi-server operating system, the Hurd.
最新版本：1.6
项目主页：https://www.gnu.org/software/hurd/microkernel/mach/gnumach.html