Frozen after saving 3000+ files at the same time

[mjbvz]

Issue Type: Bug

1. In the VS Code codebase
2. Do a workspace search for /*---------------------------------------------------------------------------------------------
3. Replace it with: /*--------------------------------------------------------------------------------------------*
4. Make sure auto save is disabled
5. Accept the replacement.
6. Now run, save all

Bug
The editor freezes

I tested this on OSS with extensions disabled

VS Code version: Code - Insiders 1.50.0-insider (2289738, 2020-10-01T05:28:37.293Z)
OS version: Darwin x64 19.6.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz (16 x 2400)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	4, 5, 4
Memory (System)	32.00GB (0.02GB free)
Process Argv	--crash-reporter-id cc7f0c9b-aa2b-4a45-8baa-81ffda32679e
Screen Reader	no
VM	13%

[mjbvz]

Having trouble collecting a perf profile for this since it freezes the window. However this warning is being continuous printed to the console:

[15693:1001/162209.666255:INFO:CONSOLE(344)] "[d17] potential listener LEAK detected, having 351 listeners already. MOST frequent listener (177):", source: file:///Users/matb/projects/vscode/out/vs/base/common/event.js (344)
[15693:1001/162209.666441:INFO:CONSOLE(345)] "    at file:///Users/matb/projects/vscode/out/vs/base/common/event.js:20:26
    at file:///Users/matb/projects/vscode/out/vs/workbench/services/progress/browser/progressService.js:197:69
    at ProgressService.withWindowProgress (file:///Users/matb/projects/vscode/out/vs/workbench/services/progress/browser/progressService.js:74:29)
    at createWindowProgress (file:///Users/matb/projects/vscode/out/vs/workbench/services/progress/browser/progressService.js:177:22)
    at onVisibilityChange (file:///Users/matb/projects/vscode/out/vs/workbench/services/progress/browser/progressService.js:251:52)
    at Emitter.fire (file:///Users/matb/projects/vscode/out/vs/base/common/event.js:456:38)
    at file:///Users/matb/projects/vscode/out/vs/workbench/common/notifications.js:47:99
    at Emitter.fire (file:///Users/matb/projects/vscode/out/vs/base/common/event.js:456:38)
    at NotificationViewItem.updateVisibility (file:///Users/matb/projects/vscode/out/vs/workbench/common/notifications.js:384:45)
    at NotificationsToasts.updateToastVisibility (file:///Users/matb/projects/vscode/out/vs/workbench/browser/parts/notifications/notificationsToasts.js:424:24)
    at file:///Users/matb/projects/vscode/out/vs/workbench/browser/parts/notifications/notificationsToasts.js:404:22
    at Array.forEach (<anonymous>)
    at NotificationsToasts.layoutContainer (file:///Users/matb/projects/vscode/out/vs/workbench/browser/parts/notifications/notificationsToasts.js:391:63)
    at NotificationsToasts.addToast (file:///Users/matb/projects/vscode/out/vs/workbench/browser/parts/notifications/notificationsToasts.js:126:18)
    at NotificationsToasts.onDidChangeNotification (file:///Users/matb/projects/vscode/out/vs/workbench/browser/parts/notifications/notificationsToasts.js:72:33)
    at file:///Users/matb/projects/vscode/out/vs/workbench/browser/parts/notifications/notificationsToasts.js:50:77
    at Emitter.fire (file:///Users/matb/projects/vscode/out/vs/base/common/event.js:456:38)
    at NotificationsModel.addNotification (file:///Users/matb/projects/vscode/out/vs/workbench/common/notifications.js:103:43)
    at NotificationService.notify (file:///Users/matb/projects/vscode/out/vs/workbench/services/notification/common/notificationService.js:83:33)
    at createNotification (file:///Users/matb/projects/vscode/out/vs/workbench/services/progress/browser/progressService.js:233:63)
    at file:///Users/matb/projects/vscode/out/vs/workbench/services/progress/browser/progressService.js:286:89", source: file:///Users/matb/projects/vscode/out/vs/base/common/event.js (345)
[15693:1001/162210.017958:INFO:CONSOLE(344)] "[cf1] potential listener LEAK detected, having 439 listeners already. MOST frequent listener (265):", source: file:///Users/matb/projects/vscode/out/vs/base/common/event.js (344)

[mjbvz]

The trimTrailingWhitespace setting was slowing down saving, however I still see a large slowdown after disabling that setting.

It seems we try to show a saving 'file.ts' notification for every single file being saved. Not sure if this is the cause of the performance issue but it does seem to cause the notifications to get into a very odd state:

[mjbvz]

I don't see this performance issue when working with 1000 files instead of 3000 (and only with the full 3000 files do I start seeing the file save notifications)

[bpasero]

I would think that leak warning can maybe be explained due to the fact that we simple instantiate so many notifications.

The notification spam seems to originate from here:

vscode/src/vs/workbench/services/textfile/common/textFileSaveParticipant.ts

Lines 36 to 41 in 3f0e5b4

	return this.progressService.withProgress({
	title: localize('saveParticipants', "Saving '{0}'", model.name),
	location: ProgressLocation.Notification,
	cancellable: true,
	delay: model.isDirty() ? 3000 : 5000
	}, async progress => {

[bpasero]

One idea maybe is to keep 1 notification for each file that is saved by simply updating an existing notification that is already showing. That would mean when "Cancel" is clicked, all those save operations would cancel.