What are the specific data of the thread?
Thread-specific data (TSD) is maintained per thread. TSD is the only way to define and reference data that is private to a thread. Each thread-specific data item is associated with a key that is global to all threads in the process.
Table of Contents
What is Pthread_key_create used for?
Use pthread_key_create(3THR) to assign a key that is used to identify thread-specific data in a process. The key is global to all threads in the process, and all threads initially have the NULL value associated with the key when it is created. Call pthread_key_create() once for each key before using the key.
What is a thread in network programming?
A thread is a separate computational process that can run in parallel with other threads. When a program uses threads to perform network communication, it is possible for some threads to block, waiting for incoming messages, but other threads can still continue to do useful work.
When does a user thread make a blocking system call?
When the thread makes a blocking system call, the entire process will be blocked. Only one thread can access the Kernel at a time, so multiple threads cannot run in parallel on multiprocessors.
How does Pthread_key_create work?
The pthread_key_create() function creates a thread-specific data key that is available to all threads in the process and binds an optional destructor function destructor to the key. If the function completes successfully, the new key is returned in key.
What is thread and process?
A process, in the simplest terms, is a running program. One or more threads run in the context of the process. A thread is the basic unit to which the operating system allocates processor time. A thread can execute any part of the code in the process, including the parts that another thread is currently executing.
What is #include pthreadH?
On a Unix/Linux operating system, the C/C++ languages provide the standard POSIX threading API (application program interface) (pthread) for all thread-related functions. We must include the pthread. h header file at the beginning of the script to use all the functions of the pthreads library.
What is an example of thread-specific data?
You can use pthread_cleanup_push to schedule a cleanup routine to deallocate any data structures you have associated with the thread-specific key, and you can use pthread_key_destroy when the key is no longer in use. The errno variable from the original C runtime library is a good example.
When to use thread-specific data in GCC?
Actually, thread-specific data is for when you do NOT want to share data between threads; with thread-specific data, each thread can use the same variable name, but that variable refers to different storage. With gcc, you can declare a variable as thread-specific using the “__thread” attribute.
How does multithreading work in a C program?
Multithreading in C. Threads are not independent of each other, as processes, as a result, threads share their code section, data section, and operating system resources, such as open files and signals, with other threads. But, like a process, a thread has its own program counter (PC), register set, and stack space.
How is data sent in a multi-threaded application?
Each of these threads could use the same function to send a large amount of data (not a technical term) to the client. The data to be sent, the details of the client to be sent to, the priority and the type of data to be sent could be held in global variables, yet different values will be used by each thread.