Merge bitcoin/bitcoin#24560: wallet: Use single FastRandomContext when creating a wallet tx

fa7deaa0464576a229b5a6ab13ad033c16d0dada wallet: Pass FastRandomContext& to coin selection (MarcoFalke)
77773b061cb13229a8afb46f6f3ab89fc70eabe3 wallet: Pass FastRandomContext& to DiscourageFeeSniping (MarcoFalke)

Pull request description:

  Passing around a single randomness context shouldn't come with any downsides, but documents better where randomness is used and allows the unit test to be deterministic, if they wish to be so.

ACKs for top commit:
  achow101:
    ACK fa7deaa0464576a229b5a6ab13ad033c16d0dada
  promag:
    Code review ACK fa7deaa0464576a229b5a6ab13ad033c16d0dada.
  glozow:
    light code review ACK fa7deaa0464576a229b5a6ab13ad033c16d0dada

Tree-SHA512: c16287708cc82ce58311710595d0127af42fb156c93fbcaa5bde634ce323d325f4d8c99a74af24423ab22b5ad58163dd771e8b1a0e7d6bff39c9fb2a1cb21bc7

1 files changed, 37 insertions, 13 deletions

diff --git a/src/wallet/test/coinselector_tests.cpp b/src/wallet/test/coinselector_tests.cpp
index b9f12158ca..f0c799b43e 100644
--- a/src/wallet/test/coinselector_tests.cpp
+++ b/src/wallet/test/coinselector_tests.cpp
@@ -164,10 +164,17 @@ inline std::vector<OutputGroup>& GroupCoins(const std::vector<COutput>& coins)
 
 inline std::vector<OutputGroup>& KnapsackGroupOutputs(const std::vector<COutput>& coins, CWallet& wallet, const CoinEligibilityFilter& filter)
 {
-    CoinSelectionParams coin_selection_params(/* change_output_size= */ 0,
-                                              /* change_spend_size= */ 0, /* effective_feerate= */ CFeeRate(0),
-                                              /* long_term_feerate= */ CFeeRate(0), /* discard_feerate= */ CFeeRate(0),
-                                              /* tx_noinputs_size= */ 0, /* avoid_partial= */ false);
+    FastRandomContext rand{};
+    CoinSelectionParams coin_selection_params{
+        rand,
+        /* change_output_size= */ 0,
+        /* change_spend_size= */ 0,
+        /* effective_feerate= */ CFeeRate(0),
+        /* long_term_feerate= */ CFeeRate(0),
+        /* discard_feerate= */ CFeeRate(0),
+        /* tx_noinputs_size= */ 0,
+        /* avoid_partial= */ false,
+    };
     static std::vector<OutputGroup> static_groups;
     static_groups = GroupOutputs(wallet, coins, coin_selection_params, filter, /*positive_only=*/false);
     return static_groups;
@@ -176,6 +183,7 @@ inline std::vector<OutputGroup>& KnapsackGroupOutputs(const std::vector<COutput>
 // Branch and bound coin selection tests
 BOOST_AUTO_TEST_CASE(bnb_search_test)
 {
+    FastRandomContext rand{};
     // Setup
     std::vector<CInputCoin> utxo_pool;
     SelectionResult expected_result(CAmount(0));
@@ -301,10 +309,16 @@ BOOST_AUTO_TEST_CASE(bnb_search_test)
     }
 
     // Make sure that effective value is working in AttemptSelection when BnB is used
-    CoinSelectionParams coin_selection_params_bnb(/* change_output_size= */ 0,
-                                                  /* change_spend_size= */ 0, /* effective_feerate= */ CFeeRate(3000),
-                                                  /* long_term_feerate= */ CFeeRate(1000), /* discard_feerate= */ CFeeRate(1000),
-                                                  /* tx_noinputs_size= */ 0, /* avoid_partial= */ false);
+    CoinSelectionParams coin_selection_params_bnb{
+        rand,
+        /* change_output_size= */ 0,
+        /* change_spend_size= */ 0,
+        /* effective_feerate= */ CFeeRate(3000),
+        /* long_term_feerate= */ CFeeRate(1000),
+        /* discard_feerate= */ CFeeRate(1000),
+        /* tx_noinputs_size= */ 0,
+        /* avoid_partial= */ false,
+    };
     {
         std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", m_args, CreateMockWalletDatabase());
         wallet->LoadWallet();
@@ -351,6 +365,9 @@ BOOST_AUTO_TEST_CASE(bnb_search_test)
 
 BOOST_AUTO_TEST_CASE(knapsack_solver_test)
 {
+    FastRandomContext rand{};
+    const auto temp1{[&rand](std::vector<OutputGroup>& g, const CAmount& v) { return KnapsackSolver(g, v, rand); }};
+    const auto KnapsackSolver{temp1};
     std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", m_args, CreateMockWalletDatabase());
     wallet->LoadWallet();
     LOCK(wallet->cs_wallet);
@@ -660,6 +677,7 @@ BOOST_AUTO_TEST_CASE(knapsack_solver_test)
 
 BOOST_AUTO_TEST_CASE(ApproximateBestSubset)
 {
+    FastRandomContext rand{};
     std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", m_args, CreateMockWalletDatabase());
     wallet->LoadWallet();
     LOCK(wallet->cs_wallet);
@@ -673,7 +691,7 @@ BOOST_AUTO_TEST_CASE(ApproximateBestSubset)
         add_coin(coins, *wallet, 1000 * COIN);
     add_coin(coins, *wallet, 3 * COIN);
 
-    const auto result = KnapsackSolver(KnapsackGroupOutputs(coins, *wallet, filter_standard), 1003 * COIN);
+    const auto result = KnapsackSolver(KnapsackGroupOutputs(coins, *wallet, filter_standard), 1003 * COIN, rand);
     BOOST_CHECK(result);
     BOOST_CHECK_EQUAL(result->GetSelectedValue(), 1003 * COIN);
     BOOST_CHECK_EQUAL(result->GetInputSet().size(), 2U);
@@ -714,10 +732,16 @@ BOOST_AUTO_TEST_CASE(SelectCoins_test)
         CAmount target = rand.randrange(balance - 1000) + 1000;
 
         // Perform selection
-        CoinSelectionParams cs_params(/* change_output_size= */ 34,
-                                      /* change_spend_size= */ 148, /* effective_feerate= */ CFeeRate(0),
-                                      /* long_term_feerate= */ CFeeRate(0), /* discard_feerate= */ CFeeRate(0),
-                                      /* tx_noinputs_size= */ 0, /* avoid_partial= */ false);
+        CoinSelectionParams cs_params{
+            rand,
+            /* change_output_size= */ 34,
+            /* change_spend_size= */ 148,
+            /* effective_feerate= */ CFeeRate(0),
+            /* long_term_feerate= */ CFeeRate(0),
+            /* discard_feerate= */ CFeeRate(0),
+            /* tx_noinputs_size= */ 0,
+            /* avoid_partial= */ false,
+        };
         CCoinControl cc;
         const auto result = SelectCoins(*wallet, coins, target, cc, cs_params);
         BOOST_CHECK(result);