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Semaphore (semaphore) setIn a multitasking operating system environment, multiple processes or threads run concurrently, and multiple tasks may work together in order to accomplish the same goal, creating a synchronization relationship between tasks,

SETVAL semaphores? -- Linux general technology-Linux programming and kernel information. The following is a detailed description. Main () { Int flag1, flag2, key, I, init_ OK, tmperrno; Struct semid_ds sem_info; Struct seminfo sem_info2; Union semun

Message Queue can make up for the lack of pipelines and achieve two-way data interaction. it is a method by which a process sends process blocks to another process. Unlike pipelines, pipelines are based on byte streams, message queues are based on

PHP Process Communication Foundation--SHMOP, SEM series function use The principle of process communication is to open up a shared area in the system, whether it is a pipeline or shared memory, this is the principle. If you have this

Shared memoryShared memory is one of the IPC mechanisms that allows two related processes to access the same memory, which is an efficient way to pass data.A.c#include #include#include#include#includestring.h>#defineSIZE

Semaphore function (3)1.semgetPrototype: int semget (key_t key,int nsems,int SEMFLG);Return value: Failed return-1, successfully returns the identity of a signal set (the identity is determined by the first parameter key)Description: Create or

The signal volume is mutually exclusiveSemaphore (AKA: Semaphore) is not the same as other process communication, the main purpose is to protect critical resources (process mutex). The process can determine, based on it, whether certain shared

This article mainly introduces the parsing of file locks, mutex locks, and read/write locks in PHP programs. it focuses on the examples used in the sync module and the pthreads module. For more information, see File lockThe full name is advisory

Ask questions about memory sharing !!! The code is as follows: & lt ;? Php $ sysid & nbsp; $ shmkey & nbsp; ftok (_ FILE __, & nbsp; t); $ flags & nbsp; c; $ mode & nbsp; 0766; $ size & nbsp; 1024; $ shmid & nbsp; s ask questions about memory

1. IPC Defects 1) xsi IPC is kernel-related and exists throughout the system, but does not reference the count, which may result in a waste of resources or data insecurity. Therefore, when the process ends, the content in the structure needs to be

1. Process synchronization: The process in which each process executes in a certain order. Async is not necessarily sequential, but random execution. A set of concurrent processes that cooperate with each other and wait for each other to execute in

Recently, in order to access resources mutex by multiple processes, the System V named semaphore is used. For convenience, C ++ is encapsulated. The Code is as follows. Aoslock. HPP: # Ifndef _ aoslock_hpp # DEFINE _ aoslock_hpp # Include # Include

1) System V shared memoryUse IPCS to debug the shared memory test source program as follows: # Include # Include # Include # Include # Include # Include # Include Void error_out (const char * MSG) { Perror (MSG ); Exit (exit_failure ); } Int

Reference: http://blog.csdn.net/zhsp1029/article/details/2171462   /* Msgserver. c */ # Include # Include String . H># Include # Include # Include # Include # Include # Define Msg_file "/tmp/msg_logs" # Define Protocol 255 # Define Perm

The producer-consumer model is one of the typical problems in the operating system. The model includes the producer process and consumer process. Producer process production information. For example, it can be a process for mathematical calculation.

Linux Message Queue practice (3) and linux Message Queue practiceIntegrated Use of Apis // The parent process sends a message. The child process receives the message struct msgBuf {long mtype;/* message type, must be> 0 */char mtext [104]; /*

Inter-process communication refers to the Process Communication and information exchange between multiple processes. Linux IPC is basically inherited from the UNIX platform. It mainly includes the original Unix IPC, System v ipc, and socket-based

The system calls MMAP () to map a common file to implement shared memory. System V maps files in the SHM of a special file system to implement shared memory communication between processes.That is to say, each shared memory area corresponds to a

Shared storage allows two or more processes to share a given storage area. Because the data does not need to be in the client andReplication between servers, so this is the fastest kind of I P C.The only trick to using shared storage is that

API Integrated UseThe parent process sends a message, and the child process receives the message struct msgbuf{long mtype; /* Message type, must be > 0 */char mtext[104]; /* Message data */};const int msgnumber = 10;int Main () {//Get a key