old_select - Used to monitor multiple file descriptors for a synchronous event.
old_select is used to monitor multiple file descriptors for a synchronous event. This can be useful for waiting for data on a network connection or for handling multiple file descriptors at the same time. old_select will block until one of the file descriptors is ready or a timeout is reached. It has the same function as the newer select() system call, but with a slightly different interface.
One of the main drawbacks of the old_select system call is that it is vulnerable to the time-of-check-time-of-use (TOCTOU) race condition. This is because old_select doesn't have the ability to atomically check the file descriptors and set the timeout. This can lead to a process missing out on data if the data has already been read before the timeout is set.
int- The number of file descriptors to be monitored.
fd_set*[K] - Pointer to a set of file descriptor sets that will be checked for readability.
fd_set*[K] - Pointer to a set of file descriptor sets that will be checked for writability.
fd_set*[K] - Pointer to a set of file descriptor sets that will be checked for out of band data.
struct timeval*[K] - Timeout value, as a
struct timeval. If
nullptris passed, the call is blocking.
- K - Originated from kernel-space.
To monitor the different conditions of the fd sets that are passed in the selector call.
Example Use Case¶
old_select is useful for monitoring multiple file descriptors in a synchronous setting. For example, an application might use it to monitor a network connection for incoming data and multiple local file descriptors for requests from other processes.
The main issue with the old_select system call is that it is vulnerable to time-of-check-time-of-use (TOCTOU) race conditions. This means that it is possible for requests to be missed as the condition might already have changed before the timeout is set.
- new_select - The newer version of the select system call, which is not vulnerable to TOCTOU race conditions.
- poll - Function to monitor set of file descriptors for activity.
- epoll - Similar to the poll system call, but with better integration with the I/O event loop.
This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.