Inter thread data transfer - Linux

Question

My program has two threads created from the main thread. Each thread runs on a separate external communication device.

main thread thread_1 thread_2 

Thread_1 receives a data packet from an external device. Each data packet is a structure of 20 bytes each.

Now I want thread_2 to read the data received by stream_1 and transfer it to the device connected to it.

How can we transfer data between my two streams.

What exact linux variable type name is used in this case?

Answer 1

Your problem is a classic example. The consumer problem of the manufacturer .

There are several possible ways to implement this depending on the context: your post is tagged with both pthreads and linux-device-drivers . Is this space kernel-space, user space, or kernel space->?

Kernel space

The solution will probably use a ring buffer (if you expect several messages between threads to be in flight at once) and a semaphore.

Chapter 5 Linux Device Drivers 3rd Edition is a good place to start.

User space

If both threads are in user space, the producer-consumer pattern in the same process is usually implemented with the pthread variable. A pthread example of how to do this is here

Core Space → User Space

The general approach used by Linux is to thread the user space thread_2 to lock the registration system object passed through the kernel space thread_1 . Typically, the registration system object in question is located in /dev or /sys . LDD3 has examples of both approaches.