Docs: add timeout example

docs/api-output.md

@@ -589,6 +589,20 @@ Time spent waiting for a libuv thread to become available is not included.
 
     *   `options.seconds` **[number][12]** Number of seconds after which processing will be stopped
 
+### Examples
+
+```javascript
+// Ensure processing takes no longer than 3 seconds
+try {
+  const data = await sharp(input)
+    .blur(1000)
+    .timeout({ seconds: 3 })
+    .toBuffer();
+} catch (err) {
+  if (err.message.includes('timeout')) { ... }
+}
+```
+
 Returns **Sharp** 
 
 **Meta**

lib/output.js

@@ -1050,6 +1050,17 @@ function tile (options) {
  * The clock starts when libvips opens an input image for processing.
  * Time spent waiting for a libuv thread to become available is not included.
  *
+ * @example
+ * // Ensure processing takes no longer than 3 seconds
+ * try {
+ *   const data = await sharp(input)
+ *     .blur(1000)
+ *     .timeout({ seconds: 3 })
+ *     .toBuffer();
+ * } catch (err) {
+ *   if (err.message.includes('timeout')) { ... }
+ * }
+ *
  * @since 0.29.2
  *
  * @param {Object} options

src/common.cc

@@ -638,7 +638,6 @@ namespace sharp {
     Event listener for progress updates, used to detect timeout
   */
   void VipsProgressCallBack(VipsImage *im, VipsProgress *progress, int *timeout) {
-    // printf("VipsProgressCallBack progress=%d run=%d timeout=%d\n", progress->percent, progress->run, *timeout);
     if (*timeout > 0 && progress->run >= *timeout) {
       vips_image_set_kill(im, TRUE);
       vips_error("timeout", "%d%% complete", progress->percent);