Process, thread, and socket are operating system terms. Node is very close to the OS in abstraction so that's why you should be versed with how the OS works to be effective with node.
Practically, a process is a program. It has it's own memory space, the operating system runs it on whichever CPU core is available. It can move between cores. This is all automatic and done by the system. Node doesn't schedule processes. A process can be killed, it can spawn new child processes using a node API. A process usually has some communication channels. On posix systems like Linux, OSX, BSD, and Solaris there is usually stdin, stdout, and stderr (standard input, output, error). These can be pipes, files, sockets, but they basically are data channels. Threads are parallel execution threads within a single process. They are like new processes except they share memory with each other. Node does not use threads for the main logic. They are used some as implementation details for things like fs access, but for the most part, node is single-threaded. Meaning there is only one thread you need to worry about. This is a good thing because multiple threads in a single namespace are very dangerous and require manual locking and unlocking of shared data to prevent corruption. Node avoids this problem by only having one main thread. The down side if your node thread cannot use more than one CPU core so you're limited to the amount of CPU power a single node process can use. Sockets can be network sockets (usually TCP) or local sockets. Data gets written to one end and comes out the other end. They are often duplex meaning information can travel both direction. Pipes are very similar. I'm not sure of the technical difference. An HTTP server (webserver) is a TCP server listening on some know port and parsing incoming data as HTTP protocol traffic. It then responds with HTTP responses controlled by your node code. Workers are an idea from the browser (which is also single threaded and event based). They are kinda like threads in that they can run in parallel, but don't share data. They communicate only through data channels. In node this is usually done with extra processes communicating over serialized data channels. For deeper understanding take an Operating Systems course at university or research online on Wikipedia and other places. On Wed, May 16, 2012 at 1:33 AM, randomnick <[email protected]> wrote: > i'v been playing around with node for quite a while, did some > applications in express, > but coming from php i'm having hard time to understand > > what is > process, thread, socket, workers etc.... > > where can i find this information, what good books really explains > node > without telling me its evented io on v8 javascript, i want to > understand the terms > that come with node. > > thanks. > > -- > Job Board: http://jobs.nodejs.org/ > Posting guidelines: > https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines > You received this message because you are subscribed to the Google > Groups "nodejs" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/nodejs?hl=en?hl=en > -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
