Programmer Group

Timer module overview    sylar implements the timer function based on epoll. Because the accuracy of epoll is milliseconds, the accuracy of its timer is also milliseconds. The timer has the design based on time wheel and time heap. In sylar, it adopts the design of minimum heap. For the specific explanation of timer, please refer ...

IDO-EVB6Y09 is a multi interface internet of things gateway device equipped with NXP imx6uliec processor, with a maximum dominant frequency of 800MHz. It has three functions: 4G industrial router, 4GDTU and industrial HMI. It supports the wireless communication mode of WIFI Bluetooth module and 4G all Netcom module, and provides multiple functi ...

shell script multitasking concurrent execution Transferred from: https://blog.51cto.com/yttitan/2409618 Normally, the commands in the Shell script are executed serially. When a command is executed, the next command will be executed. For example, the following code: #!/bin/bash for i in {1..10};do echo $i done echo "END" Execution results: ...

c + + compiling mode under linux         Under win, visual studio has carried out a large number of encapsulation for us, and designed a large number of easy-to-use configurations and interfaces, so that developers pay too much attention to the underlying compilation and linking process, and only need to pay attention to t ...

There are two main ways to implement the delay involved in the kernel: busy waiting or sleep waiting. The former blocks the program and occupies the CPU until the delay time arrives, while the latter suspends the process (sets the process to sleep and releases CPU resources). Therefore, the former is generally used for accurate delay with delay ...

Summary: It is not difficult to build an MQTT server on linux CentOS. It mainly uses mosquitto, a message broker service software. It adopts publish / subscribe mode transmission mechanism, which is lightweight, simple, open and easy to implement. It is widely used in the Internet of things. MQTT is a client server based message publish / ...

1. Basic grammar [condition] (note that there should be spaces before and after the condition) Note: if the condition is not empty, it is true, [666] returns true and [] returns false. 2. Common judgment conditions (1) Comparison between two integers = string comparison -lt less than -le less than or equal -eq equals (equal) -gt greater than ...

Great! Someone introduced Ansible Playbook like this! After a series of basic training and honing, it finally came to the application of relatively tall. (Nani is just starting to review his future: https://blog.csdn.net/qq_41765918/category_11512932.html) 1. What is playbook Chinese Name: script, which is an automatic processing script. P ...

Great! Someone introduced Ansible Playbook like this! After a series of basic training and honing, it finally came to the application of relatively tall. (Nani is just starting to review his future: https://blog.csdn.net/qq_41765918/category_11512932.html) 1. What is playbook Chinese Name: script, which is an automatic processing script. P ...

Linux device driver learning notes - Advanced Character driver operations - Note.4 [blocking I/O] LINUX DEVICE DRIVERS，3RD EDITIONMany of them are extracted from the Linux kernel source code 6.2 blocking I/O The driver should (by default) block the process and put it to sleep until the request can continue. This section shows how to put a p ...