Skip to content

Fix cancellation of async tasks that use the FTS5 full-text engine. #1839

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
groue merged 8 commits into from
Dec 10, 2025
Merged

Fix cancellation of async tasks that use the FTS5 full-text engine. #1839

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
2212a17
Failing test for #1838
groue Dec 8, 2025
5dba64d
Retry a rollback in case of SQLITE_INTERRUPT error
groue Dec 8, 2025
60ea109
Protect PRAGMA query_only = 0 against SQLITE_INTERRUPT
groue Dec 8, 2025
64a0240
Fix failing test for #1838 by reseting all prepared statements before…
groue Dec 8, 2025
361599a
Task cancellation should turn all SQLITE_INTERRUPT errors into Cancel…
groue Dec 9, 2025
3ee256e
Common API for statements that must ignore interruption errors
groue Dec 9, 2025
e281149
Simplify Issue1838Tests
groue Dec 10, 2025
ac2f2e8
Test that we recover from the FTS5 bug
groue Dec 10, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions GRDB.xcodeproj/project.pbxproj
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -292,6 +292,7 @@
56BB6EA91D3009B100A1CA52 /* SchedulingWatchdog.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56BB6EA81D3009B100A1CA52 /* SchedulingWatchdog.swift */; };
56BCA2622E6C28F800E4F08D /* DatabaseSchemaSourceTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56BCA2612E6C28EF00E4F08D /* DatabaseSchemaSourceTests.swift */; };
56BF2282241781C5003D86EB /* UtilsTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56BF2281241781C5003D86EB /* UtilsTests.swift */; };
56C7979B2EE99BD000AA265D /* Issue1838Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56C7979A2EE99BD000AA265D /* Issue1838Tests.swift */; };
56CC922C201DFFB900CB597E /* DropWhileCursorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56CC922B201DFFB900CB597E /* DropWhileCursorTests.swift */; };
56CC9243201E034D00CB597E /* PrefixWhileCursorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56CC9242201E034D00CB597E /* PrefixWhileCursorTests.swift */; };
56CC9246201E058100CB597E /* DropFirstCursorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56CC9245201E058000CB597E /* DropFirstCursorTests.swift */; };
Expand Down Expand Up @@ -802,6 +803,7 @@
56C3F7521CF9F12400F6A361 /* DatabaseSavepointTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DatabaseSavepointTests.swift; sourceTree = "<group>"; };
56C48E731C9A9923005DF1D9 /* module.modulemap */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.module-map"; path = module.modulemap; sourceTree = "<group>"; };
56C494401ED7255500CC72AF /* GRDBDeploymentTarget.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = GRDBDeploymentTarget.xcconfig; sourceTree = "<group>"; };
56C7979A2EE99BD000AA265D /* Issue1838Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Issue1838Tests.swift; sourceTree = "<group>"; };
56CC922B201DFFB900CB597E /* DropWhileCursorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DropWhileCursorTests.swift; sourceTree = "<group>"; };
56CC9242201E034D00CB597E /* PrefixWhileCursorTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PrefixWhileCursorTests.swift; sourceTree = "<group>"; };
56CC9245201E058000CB597E /* DropFirstCursorTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DropFirstCursorTests.swift; sourceTree = "<group>"; };
Expand Down Expand Up @@ -1448,6 +1450,7 @@
56B964C21DA521450002DA19 /* FTS5TableBuilderTests.swift */,
5698ACCA1DA62A2D0056AF8C /* FTS5TokenizerTests.swift */,
56ED8A7E1DAB8D6800BD0ABC /* FTS5WrapperTokenizerTests.swift */,
56C7979A2EE99BD000AA265D /* Issue1838Tests.swift */,
);
name = FTS;
sourceTree = "<group>";
Expand Down Expand Up @@ -2130,6 +2133,7 @@
56D496C11D81373A008276D7 /* DatabaseQueueBackupTests.swift in Sources */,
562393721DEE104400A6B01F /* MapCursorTests.swift in Sources */,
56D496571D81303E008276D7 /* FoundationDateComponentsTests.swift in Sources */,
56C7979B2EE99BD000AA265D /* Issue1838Tests.swift in Sources */,
568C3F7A2A5AB2C300A2309D /* ForeignKeyDefinitionTests.swift in Sources */,
56D496701D81309E008276D7 /* RecordPrimaryKeyRowIDTests.swift in Sources */,
5622060C1E420EB3005860AC /* DatabaseQueueConcurrencyTests.swift in Sources */,
Expand Down
21 changes: 21 additions & 0 deletions GRDB/Core/Database+Statements.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -513,6 +513,27 @@ extension Database {
publicStatementArguments: configuration.publicStatementArguments)
}

/// Always throws an error
func statementCompilationDidFail(
at statementStart: UnsafePointer<CChar>,
withResultCode resultCode: CInt
) throws -> Never {
switch ResultCode(rawValue: resultCode) {
case .SQLITE_INTERRUPT, .SQLITE_ABORT:
// The only error that a user sees when a Task is cancelled
// is CancellationError.
try suspensionMutex.load().checkCancellation()
default:
break
}

// Throw compilation failure
throw DatabaseError(
resultCode: resultCode,
message: lastErrorMessage,
sql: String(cString: statementStart))
}

private func checkForAutocommitTransition() {
if sqlite3_get_autocommit(sqliteConnection) == 0 {
if autocommitState == .on {
Expand Down
60 changes: 58 additions & 2 deletions GRDB/Core/Database.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -863,7 +863,16 @@ public final class Database: CustomStringConvertible, CustomDebugStringConvertib
readOnlyDepth -= 1
assert(readOnlyDepth >= 0, "unbalanced endReadOnly()")
if readOnlyDepth == 0 {
try internalCachedStatement(sql: "PRAGMA query_only = 0").execute()
// We MUST ignore interruptions when we leave the read-only mode,
// otherwise user could not write with this database
// connection again.
//
// It's OK to ignore interruption, since interruption is
// concurrent and we can pretend it occurred before or after
// the PRAGMA.
try ignoringInterruption {
try internalCachedStatement(sql: "PRAGMA query_only = 0").execute()
}
}
}

Expand Down Expand Up @@ -1300,6 +1309,31 @@ public final class Database: CustomStringConvertible, CustomDebugStringConvertib
return try value()
}

/// Returns the result of `value`. If `value` throws an interruption
/// error, it is retried a second time.
func ignoringInterruption<T>(_ value: () throws -> T) rethrows -> T {
do {
return try value()
}
catch is CancellationError,
DatabaseError.SQLITE_INTERRUPT,
DatabaseError.SQLITE_ABORT
{
// Maybe we were unlucky, and user has interrupted the database
// during `value` execution.
//
// Another possible cause for this error is the FTS5 bug
// described at <https://sqlite.org/forum/forumpost/137c7662b3>,
// which leaves the database in a sticky interrupted state.
// To workaround this bug, we must leave the interrupted state
// before retrying:
resetAllPreparedStatements()

// Retry
return try value()
}
}

/// Support for `checkForSuspensionViolation(from:)`
private func journalMode() throws -> String {
if let journalMode = journalModeCache {
Expand Down Expand Up @@ -1764,7 +1798,16 @@ public final class Database: CustomStringConvertible, CustomDebugStringConvertib
// which rollback errors should be ignored, and which rollback errors
// should be exposed to the library user.
if isInsideTransaction {
try execute(sql: "ROLLBACK TRANSACTION")
// We MUST ignore interruptions during the rollback, otherwise
// we could leave a transaction open, and trigger a fatal error in
// `SerializedDatabase.preconditionNoUnsafeTransactionLeft`.
//
// It's OK to ignore interruption, since interruption is
// concurrent and we can pretend it occurred before or after
// the rollback.
try ignoringInterruption {
try execute(sql: "ROLLBACK TRANSACTION")
}
}
assert(!isInsideTransaction)
}
Expand All @@ -1779,6 +1822,19 @@ public final class Database: CustomStringConvertible, CustomDebugStringConvertib
assert(sqlite3_get_autocommit(sqliteConnection) != 0)
}

/// Resets all prepared statements.
///
/// This method helps clearing the interrupted state, as a workaround
/// for https://sqlite.org/forum/forumpost/137c7662b3, discovered
/// in https://github.com/groue/GRDB.swift/issues/1838.
func resetAllPreparedStatements() {
var stmt: SQLiteStatement? = sqlite3_next_stmt(sqliteConnection, nil)
while stmt != nil {
sqlite3_reset(stmt)
stmt = sqlite3_next_stmt(sqliteConnection, stmt)
}
}

// MARK: - Memory Management

/// Frees as much memory as possible.
Expand Down
5 changes: 1 addition & 4 deletions GRDB/Core/Statement.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -150,10 +150,7 @@ public final class Statement {
&sqliteStatement, statementEnd)

guard code == SQLITE_OK else {
throw DatabaseError(
resultCode: code,
message: database.lastErrorMessage,
sql: String(cString: statementStart))
try database.statementCompilationDidFail(at: statementStart, withResultCode: code)
}

guard let sqliteStatement else {
Expand Down
4 changes: 4 additions & 0 deletions GRDBCustom.xcodeproj/project.pbxproj
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -287,6 +287,7 @@
56C0539722ACEECD0029D27D /* ValueReducer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56C0538C22ACEECD0029D27D /* ValueReducer.swift */; };
56C0539B22ACEECD0029D27D /* Map.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56C0538E22ACEECD0029D27D /* Map.swift */; };
56C0539D22ACEECD0029D27D /* RemoveDuplicates.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56C0538F22ACEECD0029D27D /* RemoveDuplicates.swift */; };
56C7979D2EE99BE900AA265D /* Issue1838Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56C7979C2EE99BE900AA265D /* Issue1838Tests.swift */; };
56C7A6AE1D2DFF6100EFB0C2 /* FoundationNSDateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56F0B98E1B6001C600A2F135 /* FoundationNSDateTests.swift */; };
56C9EB9B2495324700FE5D55 /* grdb_config.h in Headers */ = {isa = PBXBuildFile; fileRef = 56C9EB9A2495324700FE5D55 /* grdb_config.h */; settings = {ATTRIBUTES = (Private, ); }; };
56CC9234201E009000CB597E /* DropWhileCursorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 56CC9231201DFFF600CB597E /* DropWhileCursorTests.swift */; };
Expand Down Expand Up @@ -814,6 +815,7 @@
56C0538F22ACEECD0029D27D /* RemoveDuplicates.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = RemoveDuplicates.swift; sourceTree = "<group>"; };
56C3F7521CF9F12400F6A361 /* DatabaseSavepointTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DatabaseSavepointTests.swift; sourceTree = "<group>"; };
56C494421ED726C500CC72AF /* GRDBDeploymentTarget.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; name = GRDBDeploymentTarget.xcconfig; path = SQLiteCustom/GRDBDeploymentTarget.xcconfig; sourceTree = "<group>"; };
56C7979C2EE99BE900AA265D /* Issue1838Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Issue1838Tests.swift; sourceTree = "<group>"; };
56C9EB9A2495324700FE5D55 /* grdb_config.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = grdb_config.h; path = SQLiteCustom/grdb_config.h; sourceTree = "<group>"; };
56CC9231201DFFF600CB597E /* DropWhileCursorTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DropWhileCursorTests.swift; sourceTree = "<group>"; };
56CC923A201E033400CB597E /* PrefixWhileCursorTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PrefixWhileCursorTests.swift; sourceTree = "<group>"; };
Expand Down Expand Up @@ -1441,6 +1443,7 @@
5698AC3E1DA2BEBB0056AF8C /* FTS */ = {
isa = PBXGroup;
children = (
56C7979C2EE99BE900AA265D /* Issue1838Tests.swift */,
5698AC3F1DA2BED90056AF8C /* FTS3PatternTests.swift */,
5698AC481DA2D48A0056AF8C /* FTS3RecordTests.swift */,
5698AC881DA389380056AF8C /* FTS3TableBuilderTests.swift */,
Expand Down Expand Up @@ -2374,6 +2377,7 @@
562205FE1E420EA2005860AC /* DatabasePoolConcurrencyTests.swift in Sources */,
565EFAF11D0436CE00A8FA9D /* NumericOverflowTests.swift in Sources */,
56DF0017228DDB8300D611F3 /* AssociationPrefetchingRowTests.swift in Sources */,
56C7979D2EE99BE900AA265D /* Issue1838Tests.swift in Sources */,
F3BA812E1CFB3064003DC1BA /* RecordPrimaryKeyMultipleTests.swift in Sources */,
F3BA81021CFB3032003DC1BA /* CGFloatTests.swift in Sources */,
5676FBAA22F5CEB9004717D9 /* ValueObservationRegionRecordingTests.swift in Sources */,
Expand Down
37 changes: 37 additions & 0 deletions Tests/GRDBTests/DatabaseWriterTests.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -896,4 +896,41 @@ class DatabaseWriterTests : GRDBTestCase {
try await test(makeDatabasePool())
try await test(AnyDatabaseWriter(makeDatabaseQueue()))
}

// Regression test for https://github.com/groue/GRDB.swift/pull/1838
func test_cancellation_does_not_prevent_rollback() async throws {
func test(_ dbWriter: some DatabaseWriter) async throws {
// Numbers that have the test fail more or less reliably
// (on my machine) unless the #1838 patch is applied.
// When the test fails, we have a fatal error: A transaction has been left opened at the end of a database access.
let repeatCount = 400
let taskCount = 50
for _ in 0..<repeatCount {
try await withThrowingTaskGroup(of: Void.self) { group in
for _ in 0..<taskCount{
let task = Task {
try await dbWriter.writeWithoutTransaction { db in
try db.beginTransaction()
try db.rollback()
}
}
group.addTask {
Task {
// For the test to fail, we need to be lucky, here:
// Cancellation must occur during the compilation
// or the execution of the rollback statement.
task.cancel()
}
// Ignore expected CancellationError
try? await task.value
}
}
try await group.waitForAll()
}
}
}
try await test(makeDatabaseQueue())
try await test(makeDatabasePool())
try await test(AnyDatabaseWriter(makeDatabaseQueue()))
}
}
53 changes: 53 additions & 0 deletions Tests/GRDBTests/Issue1838Tests.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,53 @@
import GRDB
import XCTest

class Issue1838Tests: GRDBTestCase {
/// Regression test for <https://github.com/groue/GRDB.swift/issues/1838>.
///
/// This test passes since <https://github.com/groue/GRDB.swift/pull/1839>
/// which workarounds the SQLite bug described at
/// <https://sqlite.org/forum/forumpost/95413eb410>.
func test_interrupted_rollback() throws {
let dbQueue = try makeDatabaseQueue()

try dbQueue.inDatabase { db in
try db.execute(sql: "CREATE VIRTUAL TABLE documents USING FTS5(content)")
try db.inTransaction {
try db.execute(sql: "INSERT INTO documents(content) VALUES ('Document')")
dbQueue.interrupt()
return .rollback
}
}

let documentCount = try dbQueue.read { db in
try Int.fetchOne(db, sql: "SELECT COUNT(*) FROM documents")!
}
XCTAssertEqual(documentCount, 0)
}

/// Tests about how we handle the FTS5 bug <https://sqlite.org/forum/forumpost/95413eb410>
func test_interrupted_commit() throws {
let dbQueue = try makeDatabaseQueue()

try dbQueue.write { db in
try db.execute(sql: "CREATE VIRTUAL TABLE documents USING FTS5(content)")
}

do {
try dbQueue.write { db in
try db.execute(sql: "INSERT INTO documents(content) VALUES ('Document')")
dbQueue.interrupt()
}
// Do not assert that the above code throws, because the
// FTS5 bug might be fixed in the tested SQLite version.
} catch DatabaseError.SQLITE_INTERRUPT {
// Fine: That's the FTS5 bug.
}

// Make sure the interrupted state created by the FTS5 bug is no longer active.
let documentCount = try dbQueue.read { db in
try Int.fetchOne(db, sql: "SELECT COUNT(*) FROM documents")!
}
XCTAssertEqual(documentCount, 0)
}
}