timers not getting reaped

[jcheng5]

Run the below, then un-comment the invalidateLater and run again, then comment it again and run once more. You'll find that the log messages are only printed once for the first run, many times for the second and third runs. This indicates that timerCallbacks$executeElapsed() continues to find things to do even after the second app is done running.

library(shiny)

ui <- fluidPage(
  textOutput("txt")
)

server <- function(input, output, session) {
  rv <- reactiveValues(x = 0)

  output$txt <- renderText({
    # invalidateLater(1000)
    print("rendering text")
    as.character(rv$x)
  })

  session$onFlushed(function() {
    print("onFlushed.")
    rv$x <- isolate(rv$x) + 1
  }, once = FALSE)
}

shinyApp(ui, server, options = list(launch.browser = paneViewer()))