run trie generation thread with QOS set to background (#3502)

tomerd · web-flow · commit 485caed9acfb · 2021-05-18T09:43:07.000-07:00
motivation: build the trie should not interrupt other threads

changes: set QOS of trie thread to background
diff --git a/Sources/PackageCollections/Storage/SQLitePackageCollectionsStorage.swift b/Sources/PackageCollections/Storage/SQLitePackageCollectionsStorage.swift
@@ -760,7 +760,7 @@ final class SQLitePackageCollectionsStorage: PackageCollectionsStorage, Closable
     }
 
     internal func populateTargetTrie(callback: @escaping (Result<Void, Error>) -> Void = { _ in }) {
-        DispatchQueue.sharedConcurrent.async {
+        DispatchQueue.sharedConcurrent.async(group: nil, qos: .background, flags: .assignCurrentContext, execute: {
             self.targetTrieReady.memoize {
                 do {
                     // Use FTS to build the trie
@@ -794,7 +794,7 @@ final class SQLitePackageCollectionsStorage: PackageCollectionsStorage, Closable
                     return false
                 }
             }
-        }
+        })
     }
 
     // for testing

Original file line number	Diff line number	Diff line change
`@@ -760,7 +760,7 @@ final class SQLitePackageCollectionsStorage: PackageCollectionsStorage, Closable`
`760`	`760`	`}`
`761`	`761`
`762`	`762`	`internal func populateTargetTrie(callback: @escaping (Result<Void, Error>) -> Void = { _ in }) {`
`763`		`- DispatchQueue.sharedConcurrent.async {`
	`763`	`+ DispatchQueue.sharedConcurrent.async(group: nil, qos: .background, flags: .assignCurrentContext, execute: {`
`764`	`764`	`self.targetTrieReady.memoize {`
`765`	`765`	`do {`
`766`	`766`	`// Use FTS to build the trie`
`@@ -794,7 +794,7 @@ final class SQLitePackageCollectionsStorage: PackageCollectionsStorage, Closable`
`794`	`794`	`return false`
`795`	`795`	`}`
`796`	`796`	`}`
`797`		`- }`
	`797`	`+ })`
`798`	`798`	`}`
`799`	`799`
`800`	`800`	`// for testing`