Workaround for weird threading issue on Linux

See #327

DESCRIPTION

@@ -27,6 +27,7 @@ Suggests:
  testthat (>= 1.0.0),
  knitr,
  jsonlite,
+ later,
  rmarkdown,
  magrittr,
  httpuv (>= 1.4.4),

NEWS

@@ -1,6 +1,7 @@
 5.2.0
  - The CURL_CA_BUNDLE envvar is now also used on non-Windows.
  - curl_echo() now uses a random available port to run httpuv
+ - Add workaround for slowness in curl_echo() on Linux
  - Fix a few printf format warnings
 
 5.1.0

R/echo.R

@@ -65,6 +65,10 @@ curl_echo <- function(handle, port = find_port(), progress = interactive(), file
  # Workaround bug in httpuv on windows that keeps protecting handler until next startServer()
  on.exit(rm(handle), add = TRUE)
 
+ # Workaround for weird threading issue on Linux
+ # See: https://github.com/jeroen/curl/issues/327
+ wait <- ifelse(isTRUE(grepl('linux', R.version$platform)), 0.001, 0)
+
  # Post data from curl
  xfer <- function(down, up){
  if(progress){
@@ -75,8 +79,7 @@ curl_echo <- function(handle, port = find_port(), progress = interactive(), file
  as.integer(100 * up[2] / up[1])), file = stderr())
  }
  }
- # Need very low wait to prevent gridlocking!
- httpuv::service(NA)
+ later::run_now(wait)
  TRUE
  }
  handle_setopt(handle, connecttimeout = 2, xferinfofunction = xfer, noprogress = FALSE, forbid_reuse = TRUE)