Full Solution Analysis smart toggling

[Therzok]

Consider adding a smart monitor in the IDE which toggles off full solution analysis in case we're using too much memory or so:
http://source.roslyn.io/#Microsoft.VisualStudio.LanguageServices/Implementation/VirtualMemoryNotificationListener.cs,61

We should probably look into how vm_stat reports virtual memory and trigger it off automatically and notify the user: https://opensource.apple.com/source/system_cmds/system_cmds-541/vm_stat.tproj/vm_stat.c

VS bug #621143

[Therzok]

So, we have the following options:

1. use sysctl to get vm.vm_page_free_target (optimal value) and check if vm.page_free_count is lower.

2. Set a OS dispatch

// void (*dispatch_function_t)(void *)

dispatch_function_t *myHandler; // get the data via dispatch_source_get_data
dispatch_source_t source = dispatch_source_create (
	DISPATCH_SOURCE_TYPE_MEMORYPRESSURE,
	0,
	DISPATCH_MEMORYPRESSURE_WARN | DISPATCH_MEMORYPRESSURE_CRITICAL | DISPATCH_MEMORYPRESSURE_NORMAL,
	dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
);
dispatch_source_set_event_handler (source, myHandler);
dispatch_resume (source);
// dispatch_suspend to temporarily disable a dispatch
// We also probably need retain/release semantics, but I think we'll hold the handler while the IDE is alive.
// And cancel when we want to take it off.
// If we hook anything else up (i.e. open resources), we also need to: dispatch_source_set_cancel_handler

And when we get to critical, we toggle off full solution analysis. Might be worth surfacing this as an IDE service. This could also help us monitor and flush whatever in-memory caches we have, to reduce memory footprint.

[mhutch]

How useful is it to enable Full Solution Analysis, considering we don't surface yet analysis errors through the errors list?

[Therzok]

@mhutch todo comments won't happen if full solution analysis is off, for example

[mhutch]

Ah fair enough. Feels like we're doing a lot of work that won't be surfaced though.

[Therzok]

At least, they will only show up for open files.

[xamarin-release-manager]

[sync] [VS-15] Comment by xamarinc

Fixed in version 8.6.0.802 (master)

Author: therzok
Commit: da75ae9 (xamarin/monodevelop)