Rework reconnection, fixes #228

2025-03-14 07:10:09 +08:00 · 2020-04-15 16:46:39 +08:00 · 2020-04-15 16:46:39 +08:00 · 90ee9b441a
commit 90ee9b441a
parent f1ac53f115
11 changed files with 229 additions and 127 deletions
--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/QQAndroidBot.common.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/QQAndroidBot.common.kt
@ -7,7 +7,7 @@
 * https://github.com/mamoe/mirai/blob/master/LICENSE
 */

-@file:Suppress("EXPERIMENTAL_API_USAGE", "DEPRECATION_ERROR")
+@file:Suppress("EXPERIMENTAL_API_USAGE", "DEPRECATION_ERROR", "INVISIBLE_REFERENCE", "INVISIBLE_MEMBER")

 package net.mamoe.mirai.qqandroid

@ -28,6 +28,7 @@ import kotlinx.serialization.json.int
 import net.mamoe.mirai.Bot
 import net.mamoe.mirai.BotImpl
 import net.mamoe.mirai.LowLevelAPI
+import net.mamoe.mirai.ThisApiMustBeUsedInWithConnectionLockBlock
 import net.mamoe.mirai.contact.*
 import net.mamoe.mirai.data.*
 import net.mamoe.mirai.event.broadcast
@ -36,6 +37,7 @@ import net.mamoe.mirai.event.events.MessageRecallEvent
 import net.mamoe.mirai.event.events.NewFriendRequestEvent
 import net.mamoe.mirai.message.MessageReceipt
 import net.mamoe.mirai.message.data.*
+import net.mamoe.mirai.network.LoginFailedException
 import net.mamoe.mirai.qqandroid.contact.MemberInfoImpl
 import net.mamoe.mirai.qqandroid.contact.QQImpl
 import net.mamoe.mirai.qqandroid.contact.checkIsGroupImpl
@ -203,9 +205,14 @@ internal abstract class QQAndroidBotBase constructor(
        })
    }

+    /**
+     * Final process for 'login'
+     */
+    @ThisApiMustBeUsedInWithConnectionLockBlock
+    @Throws(LoginFailedException::class) // only
    override suspend fun relogin(cause: Throwable?) {
        client.useNextServers { host, port ->
-            network.relogin(host, port, cause)
+            network.closeEverythingAndRelogin(host, port, cause)
        }
    }

--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/network/QQAndroidBotNetworkHandler.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/network/QQAndroidBotNetworkHandler.kt
@ -37,6 +37,7 @@ import net.mamoe.mirai.qqandroid.network.protocol.packet.login.ConfigPushSvc
 import net.mamoe.mirai.qqandroid.network.protocol.packet.login.Heartbeat
 import net.mamoe.mirai.qqandroid.network.protocol.packet.login.StatSvc
 import net.mamoe.mirai.qqandroid.network.protocol.packet.login.WtLogin
+import net.mamoe.mirai.qqandroid.utils.NoRouteToHostException
 import net.mamoe.mirai.qqandroid.utils.PlatformSocket
 import net.mamoe.mirai.qqandroid.utils.io.readPacketExact
 import net.mamoe.mirai.qqandroid.utils.io.useBytes
@ -64,6 +65,11 @@ internal class QQAndroidBotNetworkHandler(bot: QQAndroidBot) : BotNetworkHandler

    private val packetReceiveLock: Mutex = Mutex()

+    override fun areYouOk(): Boolean {
+        return this.isActive && ::channel.isInitialized && channel.isOpen
+                && heartbeatJob?.isActive == true && _packetReceiverJob?.isActive == true
+    }
+
    private suspend fun startPacketReceiverJobOrKill(cancelCause: CancellationException? = null): Job {
        _packetReceiverJob?.cancel(cancelCause)
        _packetReceiverJob?.join()
@ -104,7 +110,7 @@ internal class QQAndroidBotNetworkHandler(bot: QQAndroidBot) : BotNetworkHandler
    }

    @OptIn(MiraiExperimentalAPI::class)
-    override suspend fun relogin(host: String, port: Int, cause: Throwable?) {
+    override suspend fun closeEverythingAndRelogin(host: String, port: Int, cause: Throwable?) {
        heartbeatJob?.cancel(CancellationException("relogin", cause))
        heartbeatJob?.join()
        if (::channel.isInitialized) {
@ -119,10 +125,16 @@ internal class QQAndroidBotNetworkHandler(bot: QQAndroidBot) : BotNetworkHandler
        channel = PlatformSocket()
        // TODO: 2020/2/14 连接多个服务器, #52

-        withTimeoutOrNull(3000) {
-            channel.connect(host, port)
-        } ?: error("timeout connecting server")
-        logger.info("Connected to server $host:$port")
+        while (isActive) {
+            try {
+                channel.connect(host, port)
+                break
+            } catch (e: NoRouteToHostException) {
+                logger.warning { "No route to host (Mostly due to no Internet connection). Retrying in 3s..." }
+                delay(3000)
+            }
+        }
+        logger.info { "Connected to server $host:$port" }
        startPacketReceiverJobOrKill(CancellationException("relogin", cause))

        var response: WtLogin.Login.LoginPacketResponse = WtLogin.Login.SubCommand9(bot.client).sendAndExpect()
@ -348,7 +360,7 @@ internal class QQAndroidBotNetworkHandler(bot: QQAndroidBot) : BotNetworkHandler
        Unit // dont remove. can help type inference
    }

-    suspend fun doHeartBeat(): Exception? {
+    private suspend fun doHeartBeat(): Exception? {
        val lastException: Exception?
        try {
            kotlin.runCatching {
@ -485,7 +497,7 @@ internal class QQAndroidBotNetworkHandler(bot: QQAndroidBot) : BotNetworkHandler
     * 处理从服务器接收过来的包. 这些包可能是粘在一起的, 也可能是不完整的. 将会自动处理.
     * 处理后的包会调用 [parsePacketAsync]
     */
-    internal fun processPacket(rawInput: ByteReadPacket) {
+    private fun processPacket(rawInput: ByteReadPacket) {
        if (rawInput.remaining == 0L) {
            return
        }
@ -563,6 +575,7 @@ internal class QQAndroidBotNetworkHandler(bot: QQAndroidBot) : BotNetworkHandler

    /**
     * 发送一个包, 但不期待任何返回.
+     * 不推荐使用它, 可能产生意外的情况.
     */
    suspend fun OutgoingPacket.sendWithoutExpect() {
        check(bot.isActive) { "bot is dead therefore can't send any packet" }
--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/network/QQAndroidClient.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/network/QQAndroidClient.kt
@ -15,6 +15,7 @@ import kotlinx.atomicfu.AtomicInt
 import kotlinx.atomicfu.atomic
 import kotlinx.io.core.*
 import net.mamoe.mirai.data.OnlineStatus
+import net.mamoe.mirai.network.LoginFailedException
 import net.mamoe.mirai.network.NoServerAvailableException
 import net.mamoe.mirai.qqandroid.BotAccount
 import net.mamoe.mirai.qqandroid.QQAndroidBot
@ -125,8 +126,7 @@ internal open class QQAndroidClient(
    lateinit var fileStoragePushFSSvcList: FileStoragePushFSSvcListFuckKotlin

    internal suspend inline fun useNextServers(crossinline block: suspend (host: String, port: Int) -> Unit) {
-        @Suppress("UNREACHABLE_CODE", "ThrowableNotThrown") // false positive
-        retryCatching(bot.client.serverList.size) {
+        retryCatching(bot.client.serverList.size, except = LoginFailedException::class) {
            val pair = bot.client.serverList.random()
            kotlin.runCatching {
                block(pair.first, pair.second)
--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/network/highway/HighwayHelper.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/network/highway/HighwayHelper.kt
@ -18,8 +18,10 @@ import io.ktor.http.content.OutgoingContent
 import io.ktor.http.userAgent
 import io.ktor.utils.io.ByteWriteChannel
 import kotlinx.coroutines.InternalCoroutinesApi
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.io.ByteReadChannel
+import kotlinx.coroutines.isActive
 import kotlinx.io.InputStream
 import kotlinx.io.core.Input
 import kotlinx.io.core.discardExact
@ -29,6 +31,7 @@ import kotlinx.serialization.InternalSerializationApi
 import net.mamoe.mirai.qqandroid.network.QQAndroidClient
 import net.mamoe.mirai.qqandroid.network.protocol.data.proto.CSDataHighwayHead
 import net.mamoe.mirai.qqandroid.utils.ByteArrayPool
+import net.mamoe.mirai.qqandroid.utils.NoRouteToHostException
 import net.mamoe.mirai.qqandroid.utils.PlatformSocket
 import net.mamoe.mirai.qqandroid.utils.io.serialization.readProtoBuf
 import net.mamoe.mirai.qqandroid.utils.io.withUse
@ -112,7 +115,14 @@ internal object HighwayHelper {
        // require(commandId == 2 || commandId == 1) { "bad commandId. Must be 1 or 2" }

        val socket = PlatformSocket()
-        socket.connect(serverIp, serverPort)
+        while (client.bot.network.isActive) {
+            try {
+                socket.connect(serverIp, serverPort)
+                break
+            } catch (e: NoRouteToHostException) {
+                delay(3000)
+            }
+        }
        socket.use {
            createImageDataPacketSequence(
                client = client,
--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/utils/PlatformSocket.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/utils/PlatformSocket.kt
@ -11,12 +11,14 @@ package net.mamoe.mirai.qqandroid.utils

 import kotlinx.io.core.ByteReadPacket
 import kotlinx.io.core.Closeable
-import net.mamoe.mirai.utils.MiraiInternalAPI
+import kotlinx.io.errors.IOException
+import net.mamoe.mirai.utils.Throws

 /**
 * 多平台适配的 TCP Socket.
 */
 internal expect class PlatformSocket() : Closeable {
+    @Throws(NoRouteToHostException::class)
    suspend fun connect(serverHost: String, serverPort: Int)

    /**
@ -37,4 +39,7 @@ internal expect class PlatformSocket() : Closeable {
    val isOpen: Boolean

    override fun close()
-}
+}
+
+expect open class SocketException : IOException
+expect class NoRouteToHostException : SocketException
--- a/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/utils/tryNTimes.kt
+++ b/mirai-core-qqandroid/src/commonMain/kotlin/net/mamoe/mirai/qqandroid/utils/tryNTimes.kt
@ -13,29 +13,26 @@

 package net.mamoe.mirai.qqandroid.utils

-import kotlin.contracts.ExperimentalContracts
-import kotlin.contracts.InvocationKind
-import kotlin.contracts.contract
 import kotlin.jvm.JvmMultifileClass
 import kotlin.jvm.JvmName
+import kotlin.reflect.KClass


@PublishedApi
 internal expect fun Throwable.addSuppressedMirai(e: Throwable)

-@OptIn(ExperimentalContracts::class)
@Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE", "RESULT_CLASS_IN_RETURN_TYPE")
@kotlin.internal.InlineOnly
-internal inline fun <R> retryCatching(n: Int, block: () -> R): Result<R> {
-    contract {
-        callsInPlace(block, InvocationKind.AT_LEAST_ONCE)
-    }
+internal inline fun <R> retryCatching(n: Int, except: KClass<out Throwable>? = null, block: () -> R): Result<R> {
    require(n >= 0) { "param n for retryCatching must not be negative" }
    var exception: Throwable? = null
    repeat(n) {
        try {
            return Result.success(block())
        } catch (e: Throwable) {
+            if (except?.isInstance(e) == true) {
+                return Result.failure(e)
+            }
            exception?.addSuppressedMirai(e)
            exception = e
        }
--- a/mirai-core-qqandroid/src/jvmMain/kotlin/net/mamoe/mirai/qqandroid/utils/PlatformSocket.kt
+++ b/mirai-core-qqandroid/src/jvmMain/kotlin/net/mamoe/mirai/qqandroid/utils/PlatformSocket.kt
@ -14,13 +14,13 @@ import kotlinx.coroutines.withContext
 import kotlinx.io.core.ByteReadPacket
 import kotlinx.io.core.Closeable
 import kotlinx.io.core.ExperimentalIoApi
+import kotlinx.io.errors.IOException
 import kotlinx.io.streams.readPacketAtMost
 import kotlinx.io.streams.writePacket
-import net.mamoe.mirai.utils.MiraiInternalAPI
 import java.io.BufferedInputStream
 import java.io.BufferedOutputStream
-import java.io.IOException
 import java.net.Socket
+import java.net.SocketException

 /**
 * 多平台适配的 TCP Socket.
@ -42,6 +42,7 @@ internal actual class PlatformSocket : Closeable {

    @PublishedApi
    internal lateinit var writeChannel: BufferedOutputStream
+
    @PublishedApi
    internal lateinit var readChannel: BufferedInputStream

@ -87,4 +88,8 @@ internal actual class PlatformSocket : Closeable {
            writeChannel = socket.getOutputStream().buffered()
        }
    }
-}
+}
+
+actual typealias NoRouteToHostException = java.net.NoRouteToHostException
+
+actual typealias SocketException = SocketException
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/BotImpl.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/BotImpl.kt
@ -22,7 +22,7 @@ import net.mamoe.mirai.network.ForceOfflineException
 import net.mamoe.mirai.network.LoginFailedException
 import net.mamoe.mirai.network.closeAndJoin
 import net.mamoe.mirai.utils.*
-import net.mamoe.mirai.utils.internal.tryNTimesOrException
+import net.mamoe.mirai.utils.internal.retryCatching
 import kotlin.coroutines.CoroutineContext

 /*
@ -83,102 +83,135 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
    @Suppress("PropertyName")
    internal lateinit var _network: N

+    /**
+     * Close server connection, resend login packet, BUT DOESN'T [BotNetworkHandler.init]
+     */
+    @ThisApiMustBeUsedInWithConnectionLockBlock
+    @Throws(LoginFailedException::class) // only
    protected abstract suspend fun relogin(cause: Throwable?)

    @Suppress("unused")
-    private val offlineListener: Listener<BotOfflineEvent> = this.subscribeAlways { event ->
-        when (event) {
-            is BotOfflineEvent.Dropped,
-            is BotOfflineEvent.RequireReconnect
-            -> {
-                if (!_network.isActive) {
-                    return@subscribeAlways
-                }
-                bot.logger.info("Connection dropped by server or lost, retrying login")
-
-                tryNTimesOrException(configuration.reconnectionRetryTimes) { tryCount ->
-                    if (tryCount != 0) {
-                        delay(configuration.reconnectPeriodMillis)
+    private val offlineListener: Listener<BotOfflineEvent> =
+        this@BotImpl.subscribeAlways(concurrency = Listener.ConcurrencyKind.LOCKED) { event ->
+            if (network.areYouOk()) {
+                // avoid concurrent re-login tasks
+                return@subscribeAlways
+            }
+            when (event) {
+                is BotOfflineEvent.Dropped,
+                is BotOfflineEvent.RequireReconnect
+                -> {
+                    if (!_network.isActive) {
+                        // normally closed
+                        return@subscribeAlways
+                    }
+                    bot.logger.info { "Connection dropped by server or lost, retrying login" }
+
+                    retryCatching(configuration.reconnectionRetryTimes,
+                        except = LoginFailedException::class) { tryCount, _ ->
+                        if (tryCount != 0) {
+                            delay(configuration.reconnectPeriodMillis)
+                        }
+                        network.withConnectionLock {
+                            /**
+                             * [BotImpl.relogin] only, no [BotNetworkHandler.init]
+                             */
+                            @OptIn(ThisApiMustBeUsedInWithConnectionLockBlock::class)
+                            relogin((event as? BotOfflineEvent.Dropped)?.cause)
+                        }
+                        logger.info { "Reconnected successfully" }
+                        BotReloginEvent(bot, (event as? BotOfflineEvent.Dropped)?.cause).broadcast()
+                        return@subscribeAlways
+                    }.getOrElse {
+                        logger.info { "Cannot reconnect" }
+                        throw it
                    }
-                    relogin((event as? BotOfflineEvent.Dropped)?.cause)
-                    logger.info("Reconnected successfully")
-                    BotReloginEvent(bot, (event as? BotOfflineEvent.Dropped)?.cause).broadcast()
-                    return@subscribeAlways
-                }?.let {
-                    logger.info("Cannot reconnect")
-                    throw it
                }
-            }
-            is BotOfflineEvent.Active -> {
-                val msg = if (event.cause == null) {
-                    ""
-                } else {
-                    " with exception: " + event.cause.message
+                is BotOfflineEvent.Active -> {
+                    val msg = if (event.cause == null) {
+                        ""
+                    } else {
+                        " with exception: " + event.cause.message
+                    }
+                    bot.logger.info { "Bot is closed manually$msg" }
+                    closeAndJoin(CancellationException(event.toString()))
+                }
+                is BotOfflineEvent.Force -> {
+                    bot.logger.info { "Connection occupied by another android device: ${event.message}" }
+                    closeAndJoin(ForceOfflineException(event.toString()))
                }
-                bot.logger.info { "Bot is closed manually$msg" }
-                closeAndJoin(CancellationException(event.toString()))
-            }
-            is BotOfflineEvent.Force -> {
-                bot.logger.info { "Connection occupied by another android device: ${event.message}" }
-                closeAndJoin(ForceOfflineException(event.toString()))
            }
        }
-    }

+    /**
+     * **Exposed public API**
+     * [BotImpl.relogin] && [BotNetworkHandler.init]
+     */
    final override suspend fun login() {
-        logger.info("Logging in...")
-        reinitializeNetworkHandler(null)
-        logger.info("Login successful")
-    }
-
-    private suspend fun reinitializeNetworkHandler(
-        cause: Throwable?
-    ) {
-        suspend fun doRelogin() {
-            while (true) {
-                _network = createNetworkHandler(this.coroutineContext)
-                try {
-                    relogin(null)
-                    return
-                } catch (e: LoginFailedException) {
-                    throw e
-                } catch (e: Exception) {
-                    network.logger.error(e)
-                    _network.closeAndJoin(e)
-                }
-                logger.warning("Login failed. Retrying in 3s...")
-                delay(3000)
-            }
-        }
-
-        suspend fun doInit() {
-            tryNTimesOrException(2, onRetry = {
-                if (!isActive) {
-                    logger.error("Cannot init due to fatal error")
-                    logger.error(it)
-                }
-            }) {
-                if (it != 0) {
-                    logger.warning("Init failed. Retrying in 3s...")
+        @ThisApiMustBeUsedInWithConnectionLockBlock
+        suspend fun reinitializeNetworkHandler(cause: Throwable?) {
+            suspend fun doRelogin() {
+                while (true) {
+                    _network = createNetworkHandler(this.coroutineContext)
+                    try {
+                        @OptIn(ThisApiMustBeUsedInWithConnectionLockBlock::class)
+                        relogin(null)
+                        return
+                    } catch (e: LoginFailedException) {
+                        throw e
+                    } catch (e: Exception) {
+                        network.logger.error(e)
+                        _network.closeAndJoin(e)
+                    }
+                    logger.warning("Login failed. Retrying in 3s...")
                    delay(3000)
                }
-                _network.init()
-            }?.let {
-                network.logger.error(it)
-                logger.error("Cannot init. some features may be affected")
            }
-        }

-        // logger.info("Initializing BotNetworkHandler")
+            suspend fun doInit() {
+                retryCatching(2) { count, lastException ->
+                    if (count != 0) {
+                        if (!isActive) {
+                            logger.error("Cannot init due to fatal error")
+                            if (lastException == null) {
+                                logger.error("<no exception>")
+                            } else {
+                                logger.error(lastException)
+                            }
+                        }
+                        logger.warning("Init failed. Retrying in 3s...")
+                        delay(3000)
+                    }
+                    _network.init()
+                }.getOrElse {
+                    network.logger.error(it)
+                    logger.error("Cannot init. some features may be affected")
+                }
+            }
+
+            // logger.info("Initializing BotNetworkHandler")
+
+            if (::_network.isInitialized) {
+                BotReloginEvent(this, cause).broadcast()
+                doRelogin()
+                return
+            }

-        if (::_network.isInitialized) {
-            BotReloginEvent(this, cause).broadcast()
            doRelogin()
-            return
+            doInit()
        }

-        doRelogin()
-        doInit()
+        logger.info("Logging in...")
+        if (::_network.isInitialized) {
+            network.withConnectionLock {
+                @OptIn(ThisApiMustBeUsedInWithConnectionLockBlock::class)
+                reinitializeNetworkHandler(null)
+            }
+        } else {
+            @OptIn(ThisApiMustBeUsedInWithConnectionLockBlock::class)
+            reinitializeNetworkHandler(null)
+        }
+        logger.info("Login successful")
    }

    protected abstract fun createNetworkHandler(coroutineContext: CoroutineContext): N
@ -203,6 +236,9 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
            // already cancelled
            return
        }
+        this.launch {
+            BotOfflineEvent.Active(this@BotImpl, cause).broadcast()
+        }
        if (cause == null) {
            this.cancel()
        } else {
@ -210,3 +246,7 @@ abstract class BotImpl<N : BotNetworkHandler> constructor(
        }
    }
 }
+
+
+@RequiresOptIn(level = RequiresOptIn.Level.ERROR)
+internal annotation class ThisApiMustBeUsedInWithConnectionLockBlock
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/network/BotNetworkHandler.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/network/BotNetworkHandler.kt
@ -15,9 +15,12 @@ import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CompletableJob
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import net.mamoe.mirai.Bot
 import net.mamoe.mirai.utils.MiraiInternalAPI
 import net.mamoe.mirai.utils.MiraiLogger
+import net.mamoe.mirai.utils.WeakRefProperty

 /**
 * Mirai 的网络处理器, 它承担所有数据包([Packet])的处理任务.
@ -34,12 +37,23 @@ import net.mamoe.mirai.utils.MiraiLogger
 * - 所有数据包处理和发送
 *
 * [BotNetworkHandler.close] 时将会 [取消][Job.cancel] 所有此作用域下的协程
+ *
+ * @suppress 此为**内部 API**, 可能在任意时刻被改动, 且不会给出任何警告.
 */
@Suppress("PropertyName")
 abstract class BotNetworkHandler : CoroutineScope {
+
+    /*
+    此为**内部 API**, 可能在任意时刻被改动, 且不会给出任何警告.
+    此为**内部 API**, 可能在任意时刻被改动, 且不会给出任何警告.
+    此为**内部 API**, 可能在任意时刻被改动, 且不会给出任何警告.
+     */
+
+
    /**
     * 所属 [Bot]. 为弱引用
     */
+    @WeakRefProperty
    abstract val bot: Bot

    /**
@ -67,7 +81,7 @@ abstract class BotNetworkHandler : CoroutineScope {
     */
    @Suppress("SpellCheckingInspection")
    @MiraiInternalAPI
-    abstract suspend fun relogin(host: String, port: Int, cause: Throwable? = null)
+    abstract suspend fun closeEverythingAndRelogin(host: String, port: Int, cause: Throwable? = null)

    /**
     * 初始化获取好友列表等值.
@ -84,6 +98,14 @@ abstract class BotNetworkHandler : CoroutineScope {
     */
    abstract suspend fun join()

+    abstract fun areYouOk(): Boolean
+
+
+    private val connectionLock: Mutex = Mutex()
+    internal suspend inline fun withConnectionLock(block: BotNetworkHandler.() -> Unit) {
+        connectionLock.withLock { if (areYouOk()) return else block() }
+    }
+
    /**
     * 关闭网络接口, 停止所有有关协程和任务
     *
--- a/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/internal/tryNTimes.kt
+++ b/mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/internal/tryNTimes.kt
@ -9,31 +9,34 @@

 package net.mamoe.mirai.utils.internal

-import net.mamoe.mirai.utils.MiraiInternalAPI
+import kotlin.reflect.KClass

@PublishedApi
 internal expect fun Throwable.addSuppressedMirai(e: Throwable)

-@MiraiInternalAPI
-@Suppress("DuplicatedCode")
-internal inline fun <R> tryNTimesOrException(
-    repeat: Int,
-    onRetry: (Throwable?) -> Unit = {},
-    block: (Int) -> R
-): Throwable? {
-    var lastException: Throwable? = null

-    repeat(repeat) {
-        try {
-            block(it)
-            return null
-        } catch (e: Throwable) {
-            if (lastException == null) {
-                lastException = e
-            } else lastException!!.addSuppressedMirai(e)
-        }
-        onRetry(lastException)
+// Currently we can't share internal code between modules.
+@Suppress("DuplicatedCode", "INVISIBLE_MEMBER", "INVISIBLE_REFERENCE", "RESULT_CLASS_IN_RETURN_TYPE")
+@kotlin.internal.InlineOnly
+internal inline fun <R> retryCatching(
+    n: Int,
+    except: KClass<out Throwable>? = null,
+    block: (count: Int, lastException: Throwable?) -> R
+): Result<R> {
+    require(n >= 0) {
+        "param n for retryCatching must not be negative"
    }
-
-    return lastException!!
+    var exception: Throwable? = null
+    repeat(n) {
+        try {
+            return Result.success(block(it, exception))
+        } catch (e: Throwable) {
+            if (except?.isInstance(e) == true) {
+                return Result.failure(e)
+            }
+            exception?.addSuppressedMirai(e)
+            exception = e
+        }
+    }
+    return Result.failure(exception!!)
 }
--- a/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/BotJavaFriendlyAPI.kt
+++ b/mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/BotJavaFriendlyAPI.kt
@ -40,7 +40,7 @@ actual abstract class BotJavaFriendlyAPI actual constructor() {
     *
     * 一般情况下不需要重新登录. Mirai 能够自动处理掉线情况.
     *
-     * 最终调用 [net.mamoe.mirai.network.BotNetworkHandler.relogin]
+     * 最终调用 [net.mamoe.mirai.network.BotNetworkHandler.closeEverythingAndRelogin]
     *
     * @throws LoginFailedException
     */