Category Archives: 操作系统

IPC(Inter-process communication)进程间通讯

进程间通讯方式

Method Short Description Provided by (operating systems or other environments)
File A record stored on disk, or a record synthesized on demand by a file server, which can be accessed by multiple processes. Most operating systems
Signal; also Asynchronous System Trap A system message sent from one process to another, not usually used to transfer data but instead used to remotely command the partnered process. Most operating systems
Socket A data stream sent over a network interface, either to a different process on the same computer or to another computer on the network. Typically byte-oriented, sockets rarely preserve message boundaries. Data written through a socket requires formatting to preserve message boundaries. Most operating systems
Message queue A data stream similar to a socket, but which usually preserves message boundaries. Typically implemented by the operating system, they allow multiple processes to read and write to the message queue without being directly connected to each other. Most operating systems
Pipe A unidirectional data channel. Data written to the write end of the pipe is buffered by the operating system until it is read from the read end of the pipe. Two-way data streams between processes can be achieved by creating two pipes utilizing standard input and output. All POSIX systems, Windows
Named pipe A pipe implemented through a file on the file system instead of standard input and output. Multiple processes can read and write to the file as a buffer for IPC data. All POSIX systems, Windows, AmigaOS 2.0+
Semaphore A simple structure that synchronizes multiple processes acting on shared resources. All POSIX systems, Windows, AmigaOS
Shared memory Multiple processes are given access to the same block of memory which creates a shared buffer for the processes to communicate with each other. All POSIX systems, Windows
Message passing Allows multiple programs to communicate using message queues and/or non-OS managed channels, commonly used in concurrency models. Used in RPC, RMI, and MPI paradigms, Java RMI, CORBA, DDS, MSMQ, MailSlots, QNX, others
Memory-mapped file A file mapped to RAM and can be modified by changing memory addresses directly instead of outputting to a stream. This shares the same benefits as a standard file. All POSIX systems, Windows

The following are messaging and information systems that utilize IPC mechanisms, but don’t implement IPC themselves:

Interprocess communication for Windows in C#

refer:Inter-process communication

 

IO Streams

理解inode句柄 是对资源地址的引用,相对固定。

四、引喻:
牧童遥指杏花村
牧童的手为指针,杏花村的牌子为句柄,杏花村酒店为对象的实例.

同步IO和异步IO的区别就在于:数据拷贝的时候进程是否阻塞!

阻塞IO和非阻塞IO的区别就在于:应用程序的调用是否立即返回!

理解inode

理解inode

Standard streams https://en.wikipedia.org/wiki/Standard_streams

Pipeline (Unix) https://en.wikipedia.org/wiki/Pipeline_(Unix)

Redirection (computing)https://en.wikipedia.org/wiki/Redirection_(computing)

File descriptor https://en.wikipedia.org/wiki/File_descriptor

Handle (computing) https://en.wikipedia.org/wiki/Handle_(computing)

Common resource handles are file descriptors, network sockets, database connections, process identifiers (PIDs), and job IDs.

Process IDs and job IDs are explicitly visible integers, while file descriptors and sockets (which are often implemented as a form of file descriptor) are represented as integers, but are typically considered opaque. In traditional implementations, file descriptors are indices into a (per-process) file descriptor table, thence a (system-wide) file table.

Java输入输出流

也谈IO模型

Linux五种IO模型性能分析

linux系统编程之基础必备(四):C 标准库IO缓冲区和内核缓冲区的区别