NAME

quark_queue_block — block waiting for quark events

SYNOPSIS

#include <quark.h>

int
quark_queue_block(struct quark_queue *qq);

DESCRIPTION

quark_queue_block blocks the calling process until there would be events to be read with quark_queue_get_events(3).

Internally this will call epoll_wait(2) on the descriptor returned by quark_queue_get_epollfd(3), the call is also arranged with a reasonable timeout, this is needed because perf-ring file descriptors only become readable once a certain amount of data surpasses a threshold. On the return from quark_queue_block, the caller should call quark_queue_get_events(3) until it returns zero, signifying there are no more events to be read. See quark(7) for an example.

RETURN VALUES

Zero on success, -1 otherwise and errno is set.

SEE ALSO

quark_event_dump(3), quark_process_lookup(3), quark_queue_close(3), quark_queue_default_attr(3), quark_queue_get_epollfd(3), quark_queue_get_events(3), quark_queue_get_stats(3), quark_queue_open(3), quark(7), quark-btf(8), quark-mon(8)