Benchmark nil context execution

benchmark_test.go

@@ -14,9 +14,14 @@ func BenchmarkConnect(b *testing.B) {
 	benchmarks := []struct {
 		name string
 		env  string
+		ctx  context.Context
 	}{
-		{"Unix socket", "PGX_TEST_UNIX_SOCKET_CONN_STRING"},
-		{"TCP", "PGX_TEST_TCP_CONN_STRING"},
+		// The first benchmark in the list sometimes executes faster, no matter how
+		// you reorder it. Nil context is still faster on average.
+		{"Unix socket", "PGX_TEST_UNIX_SOCKET_CONN_STRING", context.Background()},
+		{"TCP", "PGX_TEST_TCP_CONN_STRING", context.Background()},
+		{"Unix socket nil context", "PGX_TEST_UNIX_SOCKET_CONN_STRING", nil},
+		{"TCP nil context", "PGX_TEST_TCP_CONN_STRING", nil},
 	}
 
 	for _, bm := range benchmarks {
@@ -28,10 +33,10 @@ func BenchmarkConnect(b *testing.B) {
 			}
 
 			for i := 0; i < b.N; i++ {
-				conn, err := pgconn.Connect(context.Background(), connString)
+				conn, err := pgconn.Connect(bm.ctx, connString)
 				require.Nil(b, err)
 
-				err = conn.Close(context.Background())
+				err = conn.Close(bm.ctx)
 				require.Nil(b, err)
 			}
 		})
@@ -39,16 +44,26 @@ func BenchmarkConnect(b *testing.B) {
 }
 
 func BenchmarkExec(b *testing.B) {
-	conn, err := pgconn.Connect(context.Background(), os.Getenv("PGX_TEST_CONN_STRING"))
+	expectedValues := [][]byte{[]byte("hello"), []byte("42"), []byte("2019-01-01")}
+	benchmarks := []struct {
+		name string
+		ctx  context.Context
+	}{
+		{"background context", context.Background()},
+		{"nil context", nil},
+	}
+
+	for _, bm := range benchmarks {
+		bm := bm
+		b.Run(bm.name, func(b *testing.B) {
+			conn, err := pgconn.Connect(bm.ctx, os.Getenv("PGX_TEST_CONN_STRING"))
 			require.Nil(b, err)
 			defer closeConn(b, conn)
 
-	expectedValues := [][]byte{[]byte("hello"), []byte("42"), []byte("2019-01-01")}
-
 			b.ResetTimer()
 
 			for i := 0; i < b.N; i++ {
-		mrr := conn.Exec(context.Background(), "select 'hello'::text as a, 42::int4 as b, '2019-01-01'::date")
+				mrr := conn.Exec(bm.ctx, "select 'hello'::text as a, 42::int4 as b, '2019-01-01'::date")
 
 				for mrr.NextResult() {
 					rr := mrr.ResultReader()
@@ -80,6 +95,8 @@ func BenchmarkExec(b *testing.B) {
 					b.Fatal(err)
 				}
 			}
+		})
+	}
 }
 
 func BenchmarkExecPossibleToCancel(b *testing.B) {
@@ -130,19 +147,30 @@ func BenchmarkExecPossibleToCancel(b *testing.B) {
 }
 
 func BenchmarkExecPrepared(b *testing.B) {
-	conn, err := pgconn.Connect(context.Background(), os.Getenv("PGX_TEST_CONN_STRING"))
+	expectedValues := [][]byte{[]byte("hello"), []byte("42"), []byte("2019-01-01")}
+
+	benchmarks := []struct {
+		name string
+		ctx  context.Context
+	}{
+		{"background context", context.Background()},
+		{"nil context", nil},
+	}
+
+	for _, bm := range benchmarks {
+		bm := bm
+		b.Run(bm.name, func(b *testing.B) {
+			conn, err := pgconn.Connect(bm.ctx, os.Getenv("PGX_TEST_CONN_STRING"))
 			require.Nil(b, err)
 			defer closeConn(b, conn)
 
-	_, err = conn.Prepare(context.Background(), "ps1", "select 'hello'::text as a, 42::int4 as b, '2019-01-01'::date", nil)
+			_, err = conn.Prepare(bm.ctx, "ps1", "select 'hello'::text as a, 42::int4 as b, '2019-01-01'::date", nil)
 			require.Nil(b, err)
 
-	expectedValues := [][]byte{[]byte("hello"), []byte("42"), []byte("2019-01-01")}
-
 			b.ResetTimer()
 
 			for i := 0; i < b.N; i++ {
-		rr := conn.ExecPrepared(context.Background(), "ps1", nil, nil, nil)
+				rr := conn.ExecPrepared(bm.ctx, "ps1", nil, nil, nil)
 
 				rowCount := 0
 				for rr.NextRow() {
@@ -165,6 +193,8 @@ func BenchmarkExecPrepared(b *testing.B) {
 					b.Fatalf("unexpected rowCount: %d", rowCount)
 				}
 			}
+		})
+	}
 }
 
 func BenchmarkExecPreparedPossibleToCancel(b *testing.B) {