Add SynchronizedStdoutLogger for tests

mirai-core/src/androidTest/kotlin/test/initPlatform.android.kt

@@ -20,11 +20,6 @@ internal actual fun initPlatform() {
 }
 
 private val init: Unit by lazy {
-    MiraiLogger.setDefaultLoggerCreator {
-        @Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
-        net.mamoe.mirai.internal.utils.StdoutLogger(it)
-    }
-
     if (Security.getProvider(BouncyCastleProvider.PROVIDER_NAME) != null) {
         Security.removeProvider(BouncyCastleProvider.PROVIDER_NAME)
     }

mirai-core/src/commonTest/kotlin/network/framework/SynchronizedStdoutLogger.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2019-2021 Mamoe Technologies and contributors.
+ *
+ *  此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ *  Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ *  https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+package net.mamoe.mirai.internal.network.framework
+
+import kotlinx.atomicfu.locks.withLock
+import java.util.concurrent.locks.ReentrantLock
+
+private val lock = ReentrantLock()
+
+@Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE", "CANNOT_OVERRIDE_INVISIBLE_MEMBER")
+internal class SynchronizedStdoutLogger(override val identity: String?) : net.mamoe.mirai.internal.utils.StdoutLogger(
+    identity) {
+
+    override val output: (String) -> Unit = { str ->
+        lock.withLock { println(str) }
+    }
+}

mirai-core/src/commonTest/kotlin/test/initPlatform.common.kt

@@ -10,6 +10,8 @@
 package net.mamoe.mirai.internal.test
 
 import net.mamoe.mirai.IMirai
+import net.mamoe.mirai.internal.network.framework.SynchronizedStdoutLogger
+import net.mamoe.mirai.utils.MiraiLogger
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.Timeout
 import java.util.concurrent.TimeUnit
@@ -24,6 +26,10 @@ abstract class AbstractTest {
     init {
         initPlatform()
 
+        MiraiLogger.setDefaultLoggerCreator {
+            SynchronizedStdoutLogger(it)
+        }
+
         System.setProperty("mirai.debug.network.packet.logger", "true")
         System.setProperty("mirai.debug.network.state.observer.logging", "true")
         System.setProperty("mirai.debug.network.show.all.components", "true")