Bash fifo queue
Queues are designed to operate in a First-In-First-Out context (FIFO), where elements are inserted into one end of the container and extracted from the other..push() add an element at the end of the queue..pop() remove the element at the front of the queue.. 现在我想更进一步: 程序需要用户的输入,我希望通过我的小bash脚本自动提供这些输入。例如,它会提示用户输入特定文件的路径。我的小bash脚本知道路径,bash脚本知道程序何时等待输入(因为打印出来的最后一行包含“灰色”的内容)。. Can flock be set up to be a fifo queue instead of "whoever grabs it first" lock? For instance, if three processes are running the following code: exec 200>/var/tmp/mylock flock -e 200 # blocks until lock is obtained echo "($$) has the lock" sleep 5 # replace with awesome code echo "($$) releasing the lock" flock -u 200 && echo "($$) released the lock" # Other code that. exec 200>/var/tmp/mylock flock -e 200 # blocks until lock is obtained echo " ($$) has the lock" sleep 5 # replace with awesome code echo " ($$) releasing the lock" flock -u 200 && echo " ($$) released the lock" # Other code that doesn't require a lock When the first process obtains the lock, it will enter the sleep. * Recent changes (master) @ 2018-09-21 12:00 Jens Axboe 0 siblings, 0 replies; 1118+ messages in thread From: Jens Axboe @ 2018-09-21 12:00 UTC (permalink / raw) To: fio The follo. I have this "generic" implementation of an array-based FIFO-queue. As I have written very little code in C, I don't have an idea what to ask, so. GitHub is where people build software. More than 73 million people use GitHub to discover, fork, and contribute to over 200 million projects. Actions Codespaces Packages Security Code review Issues Integrations GitHub Sponsors Customer stories Team Enterprise Explore Explore GitHub Learn and contribute Topics Collections Trending Skills GitHub Sponsors Open source guides Connect with others The ReadME Project Events Community forum GitHub Education GitHub Stars. FIFO Queue: Support high number (3,000 msg/ps with batching and 300 msg/ps without batching) of transactions per second (TPS) per API action. Support "Exactly-Once" message processing in which a message is delivered once and remains available until a consumer processes and deletes it. Support "First-In-First-Out" delivery where the. Queue follows the principle of First-in First-out but Priority Queue performs functions according to the Priority of the elements. The best way to implement Priority Queue is by using Heaps. Priority Queue Algorithm can be used in balancing the load, in stacks, and in Dijkstra’s algorithm for finding the shortest distance. Recommended Articles. exec 200>/var/tmp/mylock flock -e 200 # blocks until lock is obtained echo " ($$) has the lock" sleep 5 # replace with awesome code echo " ($$) releasing the lock" flock -u 200 && echo " ($$) released the lock" # Other code that doesn't require a lock When the first process obtains the lock, it will enter the sleep. A fifo is a first in first out UNIX pipe ( see man fifo ). A flock ( see man flock) is a "file lock" which lets the queue support multiple readers. This queue may or may not work for other shells as it relies on the BASH built in read. You will need to consult the man pages for your shell to determine if this will work for you. Simple lockless job queue in Bash using a FIFO submission This is a response to this post, which manages a job queue using a lockfile. That approach is difficult because it's hard to get the lock handling right without being susceptible to race conditions or deadlocks. Fortunately, that's not necessary. GitHub is where people build software. More than 73 million people use GitHub to discover, fork, and contribute to over 200 million projects. If it fails, test to see if it's because the directory already exists. If it does not, there's a problem, report and abort. If it succeeds, open a FIFO in that directory named with the PID of the script, and write its command line arguments there. Maybe add the PID. Then clear the args, fork a child, and wait. On SIGCHLD go read the FIFO again.
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