multithreaded map()

[vladak]

Implement a function:

void map(size_t pool_size, int (*func)(char *), char **paths, size_t npaths);

• that will create and maintain thread pool and distribute the work to thread pool and will wait for completion of all jobs

  • the idea is that npaths can be strictly bigger than pool_size
  • the work is calling the function (given by the pointer to function 'func') on given path
    • test case: each thread will count the number of characters in the file

• hint: each worker thread will loop until it cannot get an item from the queue

  • obviously, the queue access needs to be synchronized

• overall progress (percentage computed from total number of files vs. number of files processed)
  will be reported to stdout by the main thread (use '\r' to overwrite)

• variant: each worker will return whether or not it completed the processing of the item

• make the workers randomly return error (i.e. do not complete the processing) in which case the job will be submitted again