---
title: "Async Aio workflow"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Async Aio workflow}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(collapse = TRUE, comment = "#>")
```

Ropendal’s async handles are **non-blocking by default** and are designed for
explicit waiting/inspection.

```{r}
library(Ropendal)

root <- file.path(tempdir(), "ropendal-aio")
unlink(root, recursive = TRUE)
dir.create(root, recursive = TRUE)
fs <- opendal("fs", root = root)

fs_write(fs, "value.bin", as.raw(1:4))
```

## Submit and wait

`*_aio()` variants return an `OpendalAio` handle.

```{r}
aio <- fs_read_aio(fs, "value.bin")
call_aio(aio)
val <- collect_aio(aio)
val
```

## Poll or race

`unresolved()` is a tiny sentinel/predicate for unfinished work. Local filesystem
operations may already be ready by the time R inspects them, so `FALSE` here is
normal.

```{r}
aio2 <- fs_exists_aio(fs, "value.bin")
unresolved(aio2$value)
race_aio(aio2, timeout = 100)
collect_aio(aio2)
```

## Coordinating several handles with condition variables

`cv()` is a lightweight wait gate that pairs with `aio_monitor()` for batched
completion.

```{r}
read_aio <- fs_read_aio(fs, "value.bin")
cv_gate <- cv()
mon <- aio_monitor(list(read = read_aio), cv = cv_gate)
cv_until(cv_gate, 1000)
read_monitor(mon)
collect_aio(read_aio)
```