A future that failed due to the 'callr' worker process was terminated

is now considerred interrupted, which for instance means that it can
be `reset()`.

Author: HenrikBengtsson

DESCRIPTION

@@ -1,5 +1,5 @@
 Package: future.callr
-Version: 0.8.2-9205
+Version: 0.8.2-9206
 Depends:
     R (>= 3.4.0),
     future (>= 1.40.0)

NEWS.md

@@ -3,6 +3,11 @@
 ## New Features
 
  * Now 'callr' futures can be interrupted using `interrupt()`.
+   An interrupted future can be `reset()` and relaunched.
+
+ * A future that failed due to the 'callr' worker process was
+   terminated is now considerred interrupted, which for instance
+   means that it can be `reset()`.
 
 
 # Version 0.8.2 [2023-08-08]

R/CallrFutureBackend-class.R

@@ -346,34 +346,47 @@ await <- function(future, ...) {
 
   ## Failed?
   if (inherits(result, "error")) {
+    label <- future[["label"]]
+    if (is.null(label)) label <- "<none>"
+    pid <- process$get_pid()
+    exit_code <- tryCatch(process$get_exit_status(), error = function(e) NA_integer_)
+    alive <- process$is_alive()
+    
+    ## Remove future from FutureRegistry?
+    if (!alive) {
+      reg <- backend[["reg"]]
+      if (FutureRegistry(reg, action = "contains", future = future)) {
+        FutureRegistry(reg, action = "remove", future = future)
+      }
+    }
+
+    ## Failed to launch?
+    if (inherits(result, "FutureLaunchError")) {
+      future[["result"]] <- result
+      stop(result)
+    }
+
+    ## Was the future explicitly interrupted?
     if (future[["state"]] == "interrupted") {
       if (debug) mdebugf("- Detected interrupted %s whose result cannot be retrieved", sQuote(class(future)[1]))
-      label <- future[["label"]]
-      if (is.null(label)) label <- "<none>"
-      process <- future[["process"]]
-      pid <- process$get_pid()
-      msg <- sprintf("A future ('%s') of class %s was interrupted, while running on localhost (pid %d)", label, class(future)[1], pid)
+      msg <- sprintf("A future ('%s') of class %s was interrupted (exit code %d), while running on localhost (pid %d)", label, class(future)[1], exit_code, pid)
       result <- FutureInterruptError(msg, future = future)
       future[["result"]] <- result
       stop(result)
     }
 
-    if (inherits(result, "FutureLaunchError")) {
+    ## Was the future implicitly interrupted?
+    if (!alive) {
+      msg <- sprintf("A future ('%s') of class %s was interrupted for unknown reasons (exit code %s), while running on localhost (pid %d)", label, class(future)[1], exit_code, pid)
+      result <- FutureInterruptError(msg, future = future)
+      future[["state"]] <- "interrupted"
       future[["result"]] <- result
       stop(result)
     }
 
+    ## Other, unknown reason for callr failure
     msg <- post_mortem_failure(result, future = future)
     ex <- CallrFutureError(msg, future = future)
-
-    ## Remove future from FutureRegistry?
-    if (!process$is_alive()) {
-      reg <- backend[["reg"]]
-      if (FutureRegistry(reg, action = "contains", future = future)) {
-        FutureRegistry(reg, action = "remove", future = future)
-      }
-    }
-    
     stop(ex)
   }
 

inst/testme/test-callr,launch-failure.R

@@ -28,13 +28,13 @@ repeat {
 }
 print(res)
 stopifnot(inherits(res, "error"), inherits(res, "FutureError"),
-          inherits(res, "CallrFutureError"))
+          inherits(res, c("FutureInterruptError", "CallrFutureError")))
 
 message("  - Getting results")
 res <- tryCatch(result(f), error = identity)
 print(res)
 stopifnot(inherits(res, "error"), inherits(res, "FutureError"),
-          inherits(res, "CallrFutureError"))
+          inherits(res, c("FutureInterruptError", "CallrFutureError")))
 
 file.remove(tf)