Inter-process communication

？ The shared memory area
1 Remote Procedure Call (Procedure Call,rpc) a way to invoke a function on another system (server host) from a program on one system (customer service host).
And RPC can be used in the same
Between the client and the server on the host, it can be thought that RPC is another form of message delivery.

2 three ways to share information between UNIX processes. See Gallery 5.
3 POSIX Portable Operating System interface
4
We also have to note that, theoretically, all UNIX processes have a pro-spicy relationship with the init process, which is
System Bootstrap initiates the ancestor process of all initialization processes. In practice, however, process affinity
Starting at a login shell is called a session. And all processes that are derived from the shell.
5 UNIX version and portability
Most Unix systems today meet
Because Pasix is updated every time (for example 189,3
Posix. } and POSIX. A version of 2 · We use the qualifier "base" is
Increase in real-time expansion, 199.6: Increase pthreads content), manufacturers have to spend
One or more years (sometimes longer) to implement and add the most recent update content. :
Historically, most Unix systems have either originated from the Kele}, or have been crafted from, system V, but these differences are slow
Slowly disappear, as most manufacturers have started to adopt the POSIX standard. The main difference that still exists is system management, which is
There is no area where pasix standards can be traced.
6 The IPG Example Index table in the book
In order to analyze various characteristics, the book mainly uses three kinds of interactive modes;
File server: Client One server application, the client sends a pathname to the server, the server
The contents of the item are returned to the customer.
Producer One consumer: one or more threads or processes (producers) put the data in a shared buffer, and another
One or more threads or processes (consumers) operate on the data in the shared buffer.
Serial number continues to increase by 1, one or more lines Chengcheng process to a shared serial number continues to increase by 1, the serial number has
When in a shared file, sometimes in a shared memory area.

7 various types of IPC one feature is persistence, and the other is namespace.
8 in the POSIXIPC Semaphore, note sem_open,sem_close,sem_unlink, which is used for the process, and Sem_init,sem_destroy is used for threading.
9

Inter-process communication