Multi-threaded linux connection to multiple Bluetooth devices at the same time

Multi-thread implementation in linux connects multiple Bluetooth devices at the same time-Linux general technology-Linux programming and kernel information. The following is a detailed description. Author: Rainy0415

In linux, Bluetooth transmission is implemented based on the bluez and openobex libraries. The basic process is as follows:

Inquiry ---> obtain the target channel through SDP ---> Create thread

The thread sends a file to the queried bluetooth device. The main operations include creating an obex instance handle, socket processing, establishing a connection, and sending a file;

During the actual test, the connection fails frequently due to unstable conditions. The number of Bluetooth devices that can be connected at the same time is not fixed, the error message "Device or resource busy" appears when the connection fails. The error message is "Device or resource busy", which is depressing. It is found that there is no problem in the creation and binding of sockt, but there is a problem when implementing socket connect, you can't go in and check it out.

Today, I talked to a friend on msn about this problem, but it was broken by a phrase (of course I still don't fully understand it, but I know what's going on, he said that, due to the influence of the Bluetooth frequency hopping technique, the frequency hopping sequence between the two bluetooth devices is uncertain before the two bluetooth devices establish a connection, and the connection will interfere with each other, therefore, the establishment of Bluetooth connections should be implemented in sequence, but after the connection is established, the frequency hopping sequence between the two bluetooth devices is determined, but data transmission at the same time is no problem.