Workqueues using pthread

Question

In Linux kernel, workqueues are useful to schedule asynchronous execution of tasks. In pseudo code,

while(condition) {
  read data
  add to linked list
  schedule_work(&write_data)
}

schedules the asynchronous execution of the function write_data, where write_data does the following:

write_data() {
  write data from first node of linked list
  link to next node
  free first node
}

In userspace, I want to achieve the same thing. However pthread seems to be a little different and confusing to me. I wanted to do the following:

while(condition) {
  read data
  add to linked list
  schedule writing of data
}

I want the writing of data to be asynchronous. How do I achieve this using pthread?

Answer 1

I did the following which suits my purpose:

write_data_thread() {
  wait for flag
  write data if flag is set
  reset flag
  sleep
}

while(condition) {
  read data
  add to linked list
  set flag
}

I needed to use mutex to control access to the flag.