# Create an asynchronous backend.
backend <- start_backend(cores = 2, cluster_type = "psock", backend_type = "async")
# Check that the backend is active.
backend$active
# Check if there is anything on the backend.
peek(backend)
# Create a dummy variable.
name <- "parabar"
# Export the `name` variable in the current environment to the backend.
export(backend, "name", environment())
# Remove the dummy variable from the current environment.
rm(name)
# Check the backend to see that the variable has been exported.
peek(backend)
# Run an expression on the backend.
# Note that the symbols in the expression are resolved on the backend.
evaluate(backend, {
# Print the name.
print(paste0("Hello, ", name, "!"))
})
# Clear the backend.
clear(backend)
# Check that there is nothing on the backend.
peek(backend)
# Use a basic progress bar (i.e., see `parabar::Bar`).
configure_bar(type = "basic", style = 3)
# Run a task in parallel (i.e., approx. 1.25 seconds).
output <- par_sapply(backend, x = 1:10, fun = function(x) {
# Sleep a bit.
Sys.sleep(0.25)
# Compute and return.
return(x + 1)
})
# Print the output.
print(output)
# Stop the backend.
stop_backend(backend)
# Check that the backend is not active.
backend$active
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