bug: Transactions do not work on Android platform

[caspinos]

Bug Report

Transactions seem to not work correctly on Android.
It is visible also in example app.

Capacitor Version

   Capacitor Doctor   

Latest Dependencies:

  @capacitor/cli: 8.2.0
  @capacitor/core: 8.2.0
  @capacitor/android: 8.2.0
  @capacitor/ios: 8.2.0

Installed Dependencies:

  @capacitor/cli: 8.2.0
  @capacitor/android: 8.2.0
  @capacitor/ios: 8.2.0
  @capacitor/core: 8.2.0

[success] Android looking great! 👌
[error] Xcode is not installed

Plugin Version

▲   💊   Capgo Doctor  💊
│
●   App Name: FastSQL Example
│
●   App ID: com.capgo.fastsql.example
│
●   App Version: 1.0.0
│
●   Web Dir: dist
│
●   OS: win32 Windows 11 Pro
│
●   Node: v22.20.0
│
●   Installed Dependencies:
│
●     @capgo/cli: 7.88.9
│
●     @capgo/capacitor-fast-sql: 8.0.24
│
◇  Latest Dependencies:
│
●     @capgo/cli: 7.88.9
│
●     @capgo/capacitor-fast-sql: 8.0.24
│
◆  ✅ All dependencies are up to date

Platform(s)

Android

Current Behavior

In "example app" after transaction is started execute operation hangs due to deadlock(?)

In Andorid Studio logcat:

2026-03-25 13:56:42.087 14487-14599 ProfileInstaller        com.capgo.fastsql.example            D  Installing profile for com.capgo.fastsql.example
2026-03-25 13:56:49.052 14487-14487 Capacitor/Console       com.capgo.fastsql.example            I  File:  - Line 349 - Msg: [object Object]
2026-03-25 13:56:49.056 14487-14487 Capacitor/Plugin        com.capgo.fastsql.example            V  To native (Capacitor plugin): callbackId: 18532855, pluginId: CapgoCapacitorFastSql, methodName: connect
2026-03-25 13:56:49.056 14487-14487 Capacitor               com.capgo.fastsql.example            V  callback: 18532855, pluginId: CapgoCapacitorFastSql, methodName: connect, methodData: {"database":"example-db"}
2026-03-25 13:56:49.178 14487-14487 Capacitor/Console       com.capgo.fastsql.example            I  File:  - Line 333 - Msg: {"port":9000,"token":"d0dfa08577f794535c3ff6bc8c9e9c49c9837df1f1196bf2194251c60937c998","database":"example-db"}
2026-03-25 13:56:49.208 14487-14493 fastsql.example         com.capgo.fastsql.example            I  Background concurrent mark compact GC freed 10MB AllocSpace bytes, 43(1432KB) LOS objects, 81% free, 5439KB/29MB, paused 807us,11.370ms total 175.658ms
2026-03-25 13:56:57.082 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 4.0020003 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:01.084 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 8.0060005 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:05.085 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 12.008 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:09.087 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 16.01 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:13.090 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 20.013 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:17.092 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 24.014002 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:21.094 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 28.016 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:25.096 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 32.018 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:29.098 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 36.021 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.
2026-03-25 13:57:33.100 14487-14610 SQLiteConnectionPool    com.capgo.fastsql.example            W  The connection pool for database '/data/user/0/com.capgo.fastsql.example/files/example-db.db' has been unable to grant a connection to thread 1467 (NanoHttpd Request Processor (#2)) with flags 0x2 for 40.023003 seconds.
                                                                                                    Connections: 0 active, 1 idle, 0 available.

Expected Behavior

SQL in transactions should be executed.

Code Reproduction

Reproducible in plugin's repo example app.
Run Android app, click button "Connect" and then "Run transaction".

Other Technical Details

npm --version output: 11.8.0

node --version output: v22.20.0

pod --version output (iOS issues only):

Additional Context

[caspinos]

Pull request #22 didn’t fix the issue.

I have a solution that I tested myself: using a dedicated executor thread for database operations. However, I now need to recreate my pull request.

Before I do that: @riderx, do you want to revert the changes from #22, since they didn’t help?

[riderx]

can you try latest release?

[caspinos]

I've run example application on current main branch and transactions still don't work.
The deadlock does not occur, but now there are HTTP request errors on transaction endpoints.

CORS error reported by the browser is misleading in this instance. I've traced the issue to not reading request body for these requests in HTTP server code on keep-alive connections. There are leftover bytes in TCP socket which causes next request to fail to be parsed correctly.
I've fixed the bug and created pull request #27. I've tested that transactions start to work after changes from this pull request.

[riderx]

thanks for the PR i merged it !