[thread.barrier.general]

# 32 Concurrency support library [[thread]](./#thread)

## 32.9 Coordination types [[thread.coord]](thread.coord#thread.barrier.general)

### 32.9.3 Barriers [[thread.barrier]](thread.barrier#general)

#### 32.9.3.1 General [thread.barrier.general]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/threads.tex#L10845)

A barrier is a thread coordination mechanism
whose lifetime consists of a sequence of barrier phases,
where each phase allows at most an expected number of threads to block
until the expected number of threads arrive at the barrier[.](#1.sentence-1)

[*Note [1](#note-1)*:

A barrier is useful for managing repeated tasks
that are handled by multiple threads[.](#1.sentence-2)

â *end note*]
