Merge bitcoin#34728: test: Fix intermittent issue in wallet_assumeutxo.py

faa68ed test: Fix intermittent issue in wallet_assumeutxo.py (MarcoFalke)

Pull request description:

  The test has many issues:

  * It fails intermittently, due to the use of `-stopatheight` (bitcoin#34710)
  * Using `-stopatheight` is expensive, because it requires two restarts, making the test slow
  * The overwritten `def setup_network` does not store the extra args via the `add_nodes` call, so if code is added in the future to restart a node, it may not pick up its global extra args.

  Fix all issues by:

  * Adding and using a fast `dumb_sync_blocks` util helper to achieve what `-stopatheight` doesn't achieve
  * Calling `self.add_nodes(self.num_nodes, self.extra_args)` in the overridden `setup_network`

  Can be tested via this diff:

  ```diff
  diff --git a/src/node/kernel_notifications.cpp b/src/node/kernel_notifications.cpp
  index ab0e5cc..49384c1 100644
  --- a/src/node/kernel_notifications.cpp
  +++ b/src/node/kernel_notifications.cpp
  @@ -61,2 +61,3 @@ kernel::InterruptResult KernelNotifications::blockTip(SynchronizationState state
       if (m_stop_at_height && index.nHeight >= m_stop_at_height) {
  +        LogInfo("Send shutdown signal after reaching stop height");
           if (!m_shutdown_request()) {
  diff --git a/src/util/tokenpipe.cpp b/src/util/tokenpipe.cpp
  index c982fa6..a5565ebd36 100644
  --- a/src/util/tokenpipe.cpp
  +++ b/src/util/tokenpipe.cpp
  @@ -4,2 +4,3 @@
   #include <util/tokenpipe.h>
  +#include <util/time.h>

  @@ -60,2 +61,3 @@ int TokenPipeEnd::TokenRead()
           ssize_t result = read(m_fd, &token, 1);
  +        UninterruptibleSleep(500ms);
           if (result < 0) {
  ```

  On master: The test fails
  On this pull: The test passes

  Fixes bitcoin#34710

ACKs for top commit:
  kevkevinpal:
    ACK [faa68ed](bitcoin@faa68ed)
  achow101:
    ACK faa68ed
  w0xlt:
    ACK faa68ed

Tree-SHA512: 6fcd52b6f6a5fa5a5e41e7b3cf5c733af62af9c60271e7d22c266aca90f2af67f91ffe80a3ed8b8d1a91d001700870f493207998bac988c4e3671a3a0dba7ba7

Author: achow101

test/functional/test_framework/util.py

@@ -721,6 +721,16 @@ def find_vout_for_address(node, txid, addr):
     raise RuntimeError("Vout not found for address: txid=%s, addr=%s" % (txid, addr))
 
 
+def dumb_sync_blocks(*, src, dst, height=None):
+    """Sync blocks between `src` and `dst` nodes via RPC submitblock up to height."""
+    height = height or src.getblockcount()
+    for i in range(dst.getblockcount() + 1, height + 1):
+        block_hash = src.getblockhash(i)
+        block = src.getblock(blockhash=block_hash, verbose=0)
+        dst.submitblock(block)
+    assert_equal(dst.getblockcount(), height)
+
+
 def sync_txindex(test_framework, node):
     test_framework.log.debug("Waiting for node txindex to sync")
     sync_start = int(time.time())

test/functional/wallet_assumeutxo.py

@@ -12,8 +12,8 @@
 from test_framework.util import (
     assert_equal,
     assert_greater_than,
-    assert_greater_than_or_equal,
     assert_raises_rpc_error,
+    dumb_sync_blocks,
     ensure_for,
 )
 from test_framework.wallet import MiniWallet
@@ -42,8 +42,8 @@ def set_test_params(self):
     def setup_network(self):
         """Start with the nodes disconnected so that one can generate a snapshot
         including blocks the other hasn't yet seen."""
-        self.add_nodes(4)
-        self.start_nodes(extra_args=self.extra_args)
+        self.add_nodes(self.num_nodes, self.extra_args)
+        self.start_nodes()
 
     def import_descriptor(self, node, wallet_name, key, timestamp):
         import_request = [{"desc": descsum_create("pkh(" + key.pubkey + ")"),
@@ -227,32 +227,18 @@ def loading_error(height):
 
         PAUSE_HEIGHT = FINAL_HEIGHT - 40
 
-        self.log.info("Restarting node to stop at height %d", PAUSE_HEIGHT)
-        self.restart_node(1, extra_args=[
-            f"-stopatheight={PAUSE_HEIGHT}", *self.extra_args[1]])
+        self.log.info(f"Unload wallets and sync node up to height {PAUSE_HEIGHT}")
+        n1.unloadwallet("w")
+        n1.unloadwallet(wallet_name)
+        dumb_sync_blocks(src=n0, dst=n1, height=PAUSE_HEIGHT)
 
-        # Finally connect the nodes and let them sync.
-        #
-        # Set `wait_for_connect=False` to avoid a race between performing connection
-        # assertions and the -stopatheight tripping.
-        self.connect_nodes(0, 1, wait_for_connect=False)
-
-        n1.wait_until_stopped(timeout=5)
-
-        self.log.info(
-            "Restarted node before snapshot validation completed, reloading...")
-        self.restart_node(1, extra_args=self.extra_args[1])
-
-        self.log.info("Verify node state after restart during background sync")
+        self.log.info("Verify node state during background sync")
         # Verify there are still two chainstates (background validation not complete)
         chainstates = n1.getchainstates()['chainstates']
         assert_equal(len(chainstates), 2)
         # The background chainstate should still be at START_HEIGHT
         assert_equal(chainstates[0]['blocks'], START_HEIGHT)
-        # The snapshot chainstate should be at least PAUSE_HEIGHT. It may be
-        # higher because stopatheight may allow additional blocks to be
-        # processed during shutdown (per stopatheight documentation).
-        assert_greater_than_or_equal(chainstates[1]['blocks'], PAUSE_HEIGHT)
+        assert_equal(chainstates[1]["blocks"], PAUSE_HEIGHT)
 
         # After restart, wallets that existed before cannot be loaded because
         # the wallet loading code checks if required blocks are available for