Merge bitcoin/bitcoin#21563: net: Restrict period when cs_vNodes mutex is locked

8c8237a4a10feb2ac9ce46f67b5d14bf879b670f net, refactor: Fix style in CConnman::StopNodes (Hennadii Stepanov)
229ac1892d807a1eea5a7c24ae0fe27dc913b1bd net: Combine two loops into one, and update comments (Hennadii Stepanov)
a3d090d1103cd6c25daf07afdf4e65febca6d3f7 net: Restrict period when cs_vNodes mutex is locked (Hennadii Stepanov)

Pull request description:

  This PR restricts the period when the `cs_vNodes` mutex is locked, prevents the only case when `cs_vNodes` could be locked before the `::cs_main`.

  This change makes the explicit locking of recursive mutexes in the explicit order redundant.

ACKs for top commit:
  jnewbery:
    utACK 8c8237a4a10feb2ac9ce46f67b5d14bf879b670f
  vasild:
    ACK 8c8237a4a10feb2ac9ce46f67b5d14bf879b670f
  ajtowns:
    utACK 8c8237a4a10feb2ac9ce46f67b5d14bf879b670f - logic seems sound
  MarcoFalke:
    review ACK 8c8237a4a10feb2ac9ce46f67b5d14bf879b670f 👢

Tree-SHA512: a8277924339622b188b12d260a100adf5d82781634cf974320cf6007341f946a7ff40351137c2f5369aed0d318f38aac2d32965c9b619432440d722a4e78bb73

1 files changed, 14 insertions, 11 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 5aa267f0d7..fe1a0dfded 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -2635,23 +2635,26 @@ void CConnman::StopNodes()
         }
     }
 
-    // Close sockets
-    LOCK(cs_vNodes);
-    for (CNode* pnode : vNodes)
+    // Delete peer connections.
+    std::vector<CNode*> nodes;
+    WITH_LOCK(cs_vNodes, nodes.swap(vNodes));
+    for (CNode* pnode : nodes) {
         pnode->CloseSocketDisconnect();
-    for (ListenSocket& hListenSocket : vhListenSocket)
-        if (hListenSocket.socket != INVALID_SOCKET)
-            if (!CloseSocket(hListenSocket.socket))
-                LogPrintf("CloseSocket(hListenSocket) failed with error %s\n", NetworkErrorString(WSAGetLastError()));
-
-    // clean up some globals (to help leak detection)
-    for (CNode* pnode : vNodes) {
         DeleteNode(pnode);
     }
+
+    // Close listening sockets.
+    for (ListenSocket& hListenSocket : vhListenSocket) {
+        if (hListenSocket.socket != INVALID_SOCKET) {
+            if (!CloseSocket(hListenSocket.socket)) {
+                LogPrintf("CloseSocket(hListenSocket) failed with error %s\n", NetworkErrorString(WSAGetLastError()));
+            }
+        }
+    }
+
     for (CNode* pnode : vNodesDisconnected) {
         DeleteNode(pnode);
     }
-    vNodes.clear();
     vNodesDisconnected.clear();
     vhListenSocket.clear();
     semOutbound.reset();