Merge bitcoin/bitcoin#35206: doc: fix doxygen links to threads in developer-notes.md

d5adb9d09b doc: fix doxygen links to threads in developer-notes.md (Matthew Zipkin)

Pull request description:

  The "threads" section of `developer-notes.md` has links to anchor tags in the code generated by doxygen. As far as I can tell this was introduced in #18645 and changes to this section of this document have continued the pattern. The problem is, the content at `https://doxygen.bitcoincore.org` gets re-rendered daily and those anchor tags are generated internally by doxygen, so they are all broken now.

  This PR adds doxygen syntax `\anchor XXXX` comments in the code where functions that run in these threads are defined, and then those stable, human-readable anchor tags are applied to the links in the doc.

  I have generated the doxygen output from this branch, hosted it on my own web server, and created a modified `developer-notes.md` with these anchor tags and my server as host for demonstration:

  https://gist.github.com/pinheadmz/ed3dda7d3c8d589e3989040519190b84#threads

  Just note when looking at this:
  - `main` is at the bottom of the html page so it might not look right at first
  - `initload` is a lambda inside `AppInitMain` so thats where doxygen renders the anchor

ACKs for top commit:
  fanquake:
    ACK d5adb9d09b
  rkrux:
    lgtm ACK d5adb9d

Tree-SHA512: c5517823a2d668b01318b3dae3d76fdd9db8a74d8c721aeb748e4f4a6cb56cb4d24e34b2590a41f8553992005cab368fca4ce322a4f204cec16ce338337ae9ee

doc/developer-notes.md

@@ -694,55 +694,55 @@ and its `cs_KeyStore` lock for example).
 
 ## Threads
 
-- [Main thread (`bitcoind`)](https://doxygen.bitcoincore.org/bitcoind_8cpp.html#a0ddf1224851353fc92bfbff6f499fa97)
+- [Main thread (`bitcoind`)](https://doxygen.bitcoincore.org/bitcoind_8cpp.html#main)
   : Started from `main()` in `bitcoind.cpp`. Responsible for starting up and
   shutting down the application.
 
-- [Init load (`b-initload`)](https://doxygen.bitcoincore.org/namespacenode.html#ab4305679079866f0f420f7dbf278381d)
+- [Init load (`b-initload`)](https://doxygen.bitcoincore.org/init_8cpp.html#initload)
   : Performs various loading tasks that are part of init but shouldn't block the node from being started: external block import,
    reindex, reindex-chainstate, main chain activation, spawn indexes background sync threads and mempool load.
 
-- [CCheckQueue::Loop (`b-scriptch.x`)](https://doxygen.bitcoincore.org/class_c_check_queue.html#a6e7fa51d3a25e7cb65446d4b50e6a987)
+- [CCheckQueue::Loop (`b-scriptch.x`)](https://doxygen.bitcoincore.org/class_c_check_queue.html#checkqueue)
   : Parallel script validation threads for transactions in blocks.
 
-- [ThreadHTTP (`b-http`)](https://doxygen.bitcoincore.org/httpserver_8cpp.html#abb9f6ea8819672bd9a62d3695070709c)
+- [ThreadHTTP (`b-http`)](https://doxygen.bitcoincore.org/httpserver_8cpp.html#http)
   : Libevent thread to listen for RPC and REST connections.
 
-- [HTTP worker threads (`b-http_pool_x`)](https://doxygen.bitcoincore.org/httpserver_8cpp.html#a2ad0a49dc9b5e8117c0dee98c24187d8)
+- [HTTP worker threads (`b-http_pool_x`)](https://doxygen.bitcoincore.org/httpserver_8cpp.html#http_pool)
   : Threads to service RPC and REST requests.
 
-- [Indexer threads (`b-txindex`, etc)](https://doxygen.bitcoincore.org/class_base_index.html#a96a7407421fbf877509248bbe64f8d87)
+- [Indexer threads (`b-txindex`, etc)](https://doxygen.bitcoincore.org/class_base_index.html#index_sync)
   : One thread per indexer.
 
-- [SchedulerThread (`b-scheduler`)](https://doxygen.bitcoincore.org/class_c_scheduler.html#a14d2800815da93577858ea078aed1fba)
+- [SchedulerThread (`b-scheduler`)](https://doxygen.bitcoincore.org/class_c_scheduler.html#scheduler)
   : Does asynchronous background tasks like dumping wallet contents, dumping
   addrman and running asynchronous validationinterface callbacks.
 
-- [TorControlThread (`b-torcontrol`)](https://doxygen.bitcoincore.org/torcontrol_8cpp.html#a52a3efff23634500bb42c6474f306091)
+- [TorControlThread (`b-torcontrol`)](https://doxygen.bitcoincore.org/class_tor_controller.html#torcontrol)
   : Libevent thread for tor connections.
 
 - Net threads:
 
-  - [ThreadMessageHandler (`b-msghand`)](https://doxygen.bitcoincore.org/class_c_connman.html#aacdbb7148575a31bb33bc345e2bf22a9)
+  - [ThreadMessageHandler (`b-msghand`)](https://doxygen.bitcoincore.org/class_c_connman.html#msghand)
     : Application level message handling (sending and receiving). Almost
     all net_processing and validation logic runs on this thread.
 
-  - [ThreadDNSAddressSeed (`b-dnsseed`)](https://doxygen.bitcoincore.org/class_c_connman.html#aa7c6970ed98a4a7bafbc071d24897d13)
+  - [ThreadDNSAddressSeed (`b-dnsseed`)](https://doxygen.bitcoincore.org/class_c_connman.html#dnsseed)
     : Loads addresses of peers from the DNS.
 
-  - ThreadMapPort (`b-mapport`)
+  - [ThreadMapPort (`b-mapport`)](https://doxygen.bitcoincore.org/mapport_8cpp.html#mapport)
     : Universal plug-and-play startup/shutdown.
 
-  - [ThreadSocketHandler (`b-net`)](https://doxygen.bitcoincore.org/class_c_connman.html#a765597cbfe99c083d8fa3d61bb464e34)
+  - [ThreadSocketHandler (`b-net`)](https://doxygen.bitcoincore.org/class_c_connman.html#net)
     : Sends/Receives data from peers on port 8333.
 
-  - [ThreadOpenAddedConnections (`b-addcon`)](https://doxygen.bitcoincore.org/class_c_connman.html#a0b787caf95e52a346a2b31a580d60a62)
+  - [ThreadOpenAddedConnections (`b-addcon`)](https://doxygen.bitcoincore.org/class_c_connman.html#addcon)
     : Opens network connections to added nodes.
 
-  - [ThreadOpenConnections (`b-opencon`)](https://doxygen.bitcoincore.org/class_c_connman.html#a55e9feafc3bab78e5c9d408c207faa45)
+  - [ThreadOpenConnections (`b-opencon`)](https://doxygen.bitcoincore.org/class_c_connman.html#opencon)
     : Initiates new connections to peers.
 
-  - [ThreadI2PAcceptIncoming (`b-i2paccept`)](https://doxygen.bitcoincore.org/class_c_connman.html#a57787b4f9ac847d24065fbb0dd6e70f8)
+  - [ThreadI2PAcceptIncoming (`b-i2paccept`)](https://doxygen.bitcoincore.org/class_c_connman.html#i2paccept)
     : Listens for and accepts incoming I2P connections through the I2P SAM proxy.
 
 ## General Bitcoin Core

src/bitcoind.cpp

@@ -259,6 +259,7 @@ static bool AppInit(NodeContext& node)
     return fRet;
 }
 
+/// \anchor main
 MAIN_FUNCTION
 {
     NodeContext node;

src/checkqueue.h

@@ -68,6 +68,7 @@ private:
     std::vector<std::thread> m_worker_threads;
     bool m_request_stop GUARDED_BY(m_mutex){false};
 
+    /// \anchor checkqueue
     /** Internal function that does bulk of the verification work. If fMaster, return the final result. */
     std::optional<R> Loop(bool fMaster) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
     {

src/httpserver.cpp

@@ -74,6 +74,7 @@ static GlobalMutex g_httppathhandlers_mutex;
 static std::vector<HTTPPathHandler> pathHandlers GUARDED_BY(g_httppathhandlers_mutex);
 //! Bound listening sockets
 static std::vector<evhttp_bound_socket *> boundSockets;
+/// \anchor http_pool
 //! Http thread pool - future: encapsulate in HttpContext
 static ThreadPool g_threadpool_http("http");
 static int g_max_queue_depth{100};
@@ -295,6 +296,7 @@ static void http_reject_request_cb(struct evhttp_request* req, void*)
     evhttp_send_error(req, HTTP_SERVUNAVAIL, nullptr);
 }
 
+/// \anchor http
 /** Event dispatcher thread */
 static void ThreadHTTP(struct event_base* base)
 {

src/index/base.h

@@ -167,6 +167,7 @@ public:
     /// Starts the initial sync process on a background thread.
     [[nodiscard]] bool StartBackgroundSync();
 
+    /// \anchor index_sync
     /// Sync the index with the block index starting from the current best block.
     /// Intended to be run in its own thread, m_thread_sync, and can be
     /// interrupted with m_interrupt. Once the index gets in sync, the m_synced

src/init.cpp

@@ -2031,6 +2031,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         vImportFiles.push_back(fs::PathFromString(strFile));
     }
 
+    /// \anchor initload
     node.background_init_thread = std::thread(&util::TraceThread, "initload", [=, &chainman, &args, &node] {
         ScheduleBatchPriority();
         // Import blocks and ActivateBestChain()

src/mapport.cpp

@@ -119,6 +119,7 @@ static void ProcessPCP()
     // we rather just choose a fairly short expiry time.
 }
 
+/// \anchor mapport
 static void ThreadMapPort()
 {
     do {

src/net.h

@@ -1425,6 +1425,7 @@ private:
     bool Bind(const CService& addr, unsigned int flags, NetPermissionFlags permissions);
     bool InitBinds(const Options& options);
 
+    /// \anchor addcon
     void ThreadOpenAddedConnections() EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex,
                                                                !m_nodes_mutex,
                                                                !m_reconnections_mutex,
@@ -1436,6 +1437,7 @@ private:
                                                      !m_nodes_mutex,
                                                      !m_unused_i2p_sessions_mutex);
 
+    /// \anchor opencon
     void ThreadOpenConnections(std::vector<std::string> connect, std::span<const std::string> seed_nodes)
         EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex,
                                  !m_addr_fetches_mutex,
@@ -1443,7 +1445,9 @@ private:
                                  !m_reconnections_mutex,
                                  !m_unused_i2p_sessions_mutex);
 
+    /// \anchor msghand
     void ThreadMessageHandler() EXCLUSIVE_LOCKS_REQUIRED(!m_nodes_mutex, !mutexMsgProc);
+    /// \anchor i2paccept
     void ThreadI2PAcceptIncoming() EXCLUSIVE_LOCKS_REQUIRED(!m_nodes_mutex);
     void ThreadPrivateBroadcast() EXCLUSIVE_LOCKS_REQUIRED(!m_nodes_mutex, !m_unused_i2p_sessions_mutex);
     void AcceptConnection(const ListenSocket& hListenSocket) EXCLUSIVE_LOCKS_REQUIRED(!m_nodes_mutex);
@@ -1495,7 +1499,9 @@ private:
     void SocketHandlerListening(const Sock::EventsPerSock& events_per_sock)
         EXCLUSIVE_LOCKS_REQUIRED(!m_nodes_mutex);
 
+    /// \anchor net
     void ThreadSocketHandler() EXCLUSIVE_LOCKS_REQUIRED(!m_total_bytes_sent_mutex, !mutexMsgProc, !m_nodes_mutex, !m_reconnections_mutex);
+    /// \anchor dnsseed
     void ThreadDNSAddressSeed() EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex, !m_nodes_mutex);
 
     uint64_t CalculateKeyedNetGroup(const CNetAddr& ad) const;

src/scheduler.h

@@ -70,6 +70,7 @@ public:
     void MockForward(std::chrono::seconds delta_seconds) EXCLUSIVE_LOCKS_REQUIRED(!newTaskMutex);
 
     /**
+     * \anchor scheduler
      * Services the queue 'forever'. Should be run in a thread.
      */
     void serviceQueue() EXCLUSIVE_LOCKS_REQUIRED(!newTaskMutex);

src/torcontrol.h

@@ -151,7 +151,8 @@ private:
     std::vector<uint8_t> m_cookie;
     /** ClientNonce for SAFECOOKIE auth */
     std::vector<uint8_t> m_client_nonce;
-    /** Main control thread */
+
+    /// \anchor torcontrol
     void ThreadControl();
 
 public: