(At the time of writing, PHP 7.1 users will need to install from the master branch of the pthreads repo – see this article’s section for details on building third-party extensions from source.)
This will require a ZTS (Zend Thread Safety) version of PHP 7.x installed, along with the pthreads v3 installed. In this article, we will be taking a look at how threading can be achieved in PHP with the pthreads extension. The appeal of the simplicity of synchronous, single-threaded programming certainly is high, but sometimes the usage of a little concurrency can bring some worthwhile performance improvements. PHP developers seem to rarely utilise parallelism. Thanks to all of SitePoint’s peer reviewers for making SitePoint content the best it can be! In practice, we use mutex to tell if the task is locked or unlocked.This article was peer reviewed by Christopher Pitt. Mutex can be used to lock the other threads. In this case we should lock the other threads in order to not overload the hard drive with tasks that can corrupt the file. If three threads want to write a single file at the same time, it would be a problem because an hard drive can't go as fast as a CPU does.
It literally makes the program stops in order to wait for the end of the selected thread.ĭoing multiple operations on one target at the same time is very dangerous, the best example I can give is for databases. Pthread_join is used to link the current thread process to another thread. It requires a pthread_t, which is the thread descriptor, a pointer to a void function and some other parameters that I will not describe here, the function's arguments for instance. Pthread_create function is called to create the thread. Then we include unistd.h which is containing the sleep() function. The main thread continued and printed a message while the created thread was operating and it's only one line to call a function in a new thread, pretty easy for C uh? Maybe you're a little lost, I will explain the code.įirst of all, we include the pthread.h library, like said above, it contains all the functions needed to perform multithreading tasks. On POSIX operating systems, there is a library named pthread.h, which does exactly what it says, create threads! To use it under compilers, you'll need to link it with -lpthread argument (ex: gcc -lpthread main.c). Like said in the title, this post will talk about multithreading in C, so we will do C! Each thread is new tasks that can be run indefinitely and in parallel to the other threads. A process we can have multiple threads and threads can run other threads and so on.īy default a process runs on a single thread. That's what we call multithreading, not to be confused with asynchronous operations that can be performed in only one thread that does multiple tasks.Ī thread is a task that runs linked to a process. In some cases you'll need to do multiple instructions at a time, a graphical interface for instance, will not stop when it performs an action related to a button's click.
Parrallel copy pthread c example code#
C is a language that runs on one thread by default, which means that the code will only run one instruction at a time.
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