Fix Data Race with TraceLog

[stampy88]

• a DATA RACE was introduced with pgx 5.7.0 when using a pgxpool.Pool when minConns > 0. Changed from using lazy initialization to return the defaultTimeKey when the tl.Config is nil. Below are the stack traces emitted by the race detector:

  
  ==================
  WARNING: DATA RACE
  Read at 0x00c00094ca58 by goroutine 4079:
  github.com/jackc/pgx/v5/tracelog.(*TraceLog).ensureConfig()
    /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:142 +0x87
  github.com/jackc/pgx/v5/tracelog.(*TraceLog).TraceConnectEnd()
    /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:279 +0x7f
  github.com/xxxx//internal/pkg/pg.compositeTracer.TraceConnectEnd()
    /home/dave/go/pkg/mod/github.com/xxxx/@v1.80.1-0.20240906184531-58ce8cae9811/internal/pkg/pg/composite.go:66 +0xdd
  github.com/xxxx//internal/pkg/pg.(*compositeTracer).TraceConnectEnd()
    <autogenerated>:1 +0x37
  github.com/jackc/pgx/v5.connect.func1()
    /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:244 +0xa1
  runtime.deferreturn()
    /home/dave/go/go1.22.2/src/runtime/panic.go:602 +0x5d
  github.com/jackc/pgx/v5.ConnectConfig()
    /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:159 +0x144
  github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func1()
    /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:227 +0x266
  github.com/jackc/puddle/v2.(*Pool[go.shape.*uint8]).CreateResource()
    /home/dave/go/pkg/mod/github.com/jackc/puddle/v2@v2.2.1/pool.go:614 +0x1a2
  github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources.func1()
    /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:490 +0x76

Previous write at 0x00c00094ca58 by goroutine 4080: github.com/jackc/pgx/v5/tracelog.(TraceLog).ensureConfig() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:143 +0xe5 github.com/jackc/pgx/v5/tracelog.(TraceLog).TraceConnectEnd() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:279 +0x7f github.com/xxxx//internal/pkg/pg.compositeTracer.TraceConnectEnd() /home/dave/go/pkg/mod/github.com/xxxx/@v1.80.1-0.20240906184531-58ce8cae9811/internal/pkg/pg/composite.go:66 +0xdd github.com/xxxx//internal/pkg/pg.(*compositeTracer).TraceConnectEnd()

:1 +0x37 github.com/jackc/pgx/v5.connect.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:244 +0xa1 runtime.deferreturn() /home/dave/go/go1.22.2/src/runtime/panic.go:602 +0x5d github.com/jackc/pgx/v5.ConnectConfig() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:159 +0x144 github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:227 +0x266 github.com/jackc/puddle/v2.(*Pool[go.shape.*uint8]).CreateResource() /home/dave/go/pkg/mod/github.com/jackc/puddle/v2@v2.2.1/pool.go:614 +0x1a2 github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:490 +0x76 Goroutine 4079 (running) created at: github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:489 +0xf6 github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func3() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:274 +0x5d Goroutine 4080 (finished) created at: github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:489 +0xf6 github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func3() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:274 +0x5d ================== ================== WARNING: DATA RACE Read at 0x00c001433700 by goroutine 4079: github.com/jackc/pgx/v5/tracelog.(*TraceLog).TraceConnectEnd() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:304 +0x472 github.com/xxxx//internal/pkg/pg.compositeTracer.TraceConnectEnd() /home/dave/go/pkg/mod/github.com/xxxx/@v1.80.1-0.20240906184531-58ce8cae9811/internal/pkg/pg/composite.go:66 +0xdd github.com/xxxx//internal/pkg/pg.(*compositeTracer).TraceConnectEnd() :1 +0x37 github.com/jackc/pgx/v5.connect.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:244 +0xa1 runtime.deferreturn() /home/dave/go/go1.22.2/src/runtime/panic.go:602 +0x5d github.com/jackc/pgx/v5.ConnectConfig() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:159 +0x144 github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:227 +0x266 github.com/jackc/puddle/v2.(*Pool[go.shape.*uint8]).CreateResource() /home/dave/go/pkg/mod/github.com/jackc/puddle/v2@v2.2.1/pool.go:614 +0x1a2 github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:490 +0x76 Previous write at 0x00c001433700 by goroutine 4080: github.com/jackc/pgx/v5/tracelog.DefaultTraceLogConfig() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:128 +0xb0 github.com/jackc/pgx/v5/tracelog.(*TraceLog).ensureConfig() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:143 +0xdc github.com/jackc/pgx/v5/tracelog.(*TraceLog).TraceConnectEnd() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/tracelog/tracelog.go:279 +0x7f github.com/xxxx//internal/pkg/pg.compositeTracer.TraceConnectEnd() /home/dave/go/pkg/mod/github.com/xxxx/@v1.80.1-0.20240906184531-58ce8cae9811/internal/pkg/pg/composite.go:66 +0xdd github.com/xxxx//internal/pkg/pg.(*compositeTracer).TraceConnectEnd() :1 +0x37 github.com/jackc/pgx/v5.connect.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:244 +0xa1 runtime.deferreturn() /home/dave/go/go1.22.2/src/runtime/panic.go:602 +0x5d github.com/jackc/pgx/v5.ConnectConfig() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/conn.go:159 +0x144 github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:227 +0x266 github.com/jackc/puddle/v2.(*Pool[go.shape.*uint8]).CreateResource() /home/dave/go/pkg/mod/github.com/jackc/puddle/v2@v2.2.1/pool.go:614 +0x1a2 github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources.func1() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:490 +0x76 Goroutine 4079 (running) created at: github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:489 +0xf6 github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func3() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:274 +0x5d Goroutine 4080 (finished) created at: github.com/jackc/pgx/v5/pgxpool.(*Pool).createIdleResources() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:489 +0xf6 github.com/jackc/pgx/v5/pgxpool.NewWithConfig.func3() /home/dave/go/pkg/mod/github.com/jackc/pgx/v5@v5.7.0/pgxpool/pool.go:274 +0x5d

[jackc]

Thanks for the report. I ended up fixing it via Sync.Once instead in ce66b1dae4d1e9fc68d576c029463562e2324d63. Fix is released in v5.7.1.