READ THE CODE

Inside Bitcoin

The code behind the network, with room to understand it.

Stable release v32.1bitcoin/bitcoin · f0de87f04062 ↗3,020 source files · 47.5 MB stored on the server440 file guides

Release published 2026-10-28 · Snapshot fetched 2026-11-01. Latest stable release at fetch time; development branches and Git history are excluded. Only the selected code window and visible folders load here.

17,908 bytes · SHA-256 fbfdbb13c9778aff… · View upstream ↗

1#!/usr/bin/env python3
2# Copyright (c) 2022-present The Bitcoin Core developers
3# Distributed under the MIT software license, see the accompanying
4# file COPYING or http://www.opensource.org/licenses/mit-license.php.
5
6""" Tests the utxocache:* tracepoint API interface.
7    See https://github.com/bitcoin/bitcoin/blob/master/doc/tracing.md#context-utxocache
8"""
9
10import ctypes
11# Test will be skipped if we don't have bcc installed
12try:
13    from bcc import BPF, USDT # type: ignore[import]
14except ImportError:
15    pass
16from test_framework.messages import COIN
17from test_framework.test_framework import BitcoinTestFramework
18from test_framework.util import (
19    assert_equal,
20    bpf_cflags,
21)
22from test_framework.wallet import MiniWallet
23
24utxocache_changes_program = """
25#include <uapi/linux/ptrace.h>
26
27typedef signed long long i64;
28
29struct utxocache_change
30{
31    char        txid[32];
32    u32         index;
33    u32         height;
34    i64         value;
35    bool        is_coinbase;
36};
37
38BPF_PERF_OUTPUT(utxocache_add);
39int trace_utxocache_add(struct pt_regs *ctx) {
40    struct utxocache_change add = {};
41    void *ptxid = NULL;
42    bpf_usdt_readarg(1, ctx, &ptxid);
43    bpf_probe_read_user(&add.txid, sizeof(add.txid), ptxid);
44    bpf_usdt_readarg(2, ctx, &add.index);
45    bpf_usdt_readarg(3, ctx, &add.height);
46    bpf_usdt_readarg(4, ctx, &add.value);
47    bpf_usdt_readarg(5, ctx, &add.is_coinbase);
48    utxocache_add.perf_submit(ctx, &add, sizeof(add));
49    return 0;
50}
51
52BPF_PERF_OUTPUT(utxocache_spent);
53int trace_utxocache_spent(struct pt_regs *ctx) {
54    struct utxocache_change spent = {};
55    void *ptxid = NULL;
56    bpf_usdt_readarg(1, ctx, &ptxid);
57    bpf_probe_read_user(&spent.txid, sizeof(spent.txid), ptxid);
58    bpf_usdt_readarg(2, ctx, &spent.index);
59    bpf_usdt_readarg(3, ctx, &spent.height);
60    bpf_usdt_readarg(4, ctx, &spent.value);
61    bpf_usdt_readarg(5, ctx, &spent.is_coinbase);
62    utxocache_spent.perf_submit(ctx, &spent, sizeof(spent));
63    return 0;
64}
65
66BPF_PERF_OUTPUT(utxocache_uncache);
67int trace_utxocache_uncache(struct pt_regs *ctx) {
68    struct utxocache_change uncache = {};
69    void *ptxid = NULL;
70    bpf_usdt_readarg(1, ctx, &ptxid);
71    bpf_probe_read_user(&uncache.txid, sizeof(uncache.txid), ptxid);
72    bpf_usdt_readarg(2, ctx, &uncache.index);
73    bpf_usdt_readarg(3, ctx, &uncache.height);
74    bpf_usdt_readarg(4, ctx, &uncache.value);
75    bpf_usdt_readarg(5, ctx, &uncache.is_coinbase);
76    utxocache_uncache.perf_submit(ctx, &uncache, sizeof(uncache));
77    return 0;
78}
79"""
80
81utxocache_flushes_program = """
82#include <uapi/linux/ptrace.h>
83
84typedef signed long long i64;
85
86struct utxocache_flush
87{
88    i64         duration;
89    u32         mode;
90    u64         size;
91    u64         memory;
92    bool        for_prune;
93};
94
95BPF_PERF_OUTPUT(utxocache_flush);
96int trace_utxocache_flush(struct pt_regs *ctx) {
97    struct utxocache_flush flush = {};
98    bpf_usdt_readarg(1, ctx, &flush.duration);
99    bpf_usdt_readarg(2, ctx, &flush.mode);
100    bpf_usdt_readarg(3, ctx, &flush.size);
101    bpf_usdt_readarg(4, ctx, &flush.memory);
102    bpf_usdt_readarg(5, ctx, &flush.for_prune);
103    utxocache_flush.perf_submit(ctx, &flush, sizeof(flush));
104    return 0;
105}
106"""
107
108FLUSHMODE_NAME = {
109    0: "NONE",
110    1: "IF_NEEDED",
111    2: "PERIODIC",
112    3: "FORCE_FLUSH",
113    4: "FORCE_SYNC",
114}
115
116
117class UTXOCacheChange(ctypes.Structure):
118    _fields_ = [
119        ("txid", ctypes.c_ubyte * 32),
120        ("index", ctypes.c_uint32),
121        ("height", ctypes.c_uint32),
122        ("value", ctypes.c_uint64),
123        ("is_coinbase", ctypes.c_bool),
124    ]
125
126    def __repr__(self):
127        return f"UTXOCacheChange(outpoint={bytes(self.txid[::-1]).hex()}:{self.index}, height={self.height}, value={self.value}sat, is_coinbase={self.is_coinbase})"
128
129
130class UTXOCacheFlush(ctypes.Structure):
131    _fields_ = [
132        ("duration", ctypes.c_int64),
133        ("mode", ctypes.c_uint32),
134        ("size", ctypes.c_uint64),
135        ("memory", ctypes.c_uint64),
136        ("for_prune", ctypes.c_bool),
137    ]
138
139    def __repr__(self):
140        return f"UTXOCacheFlush(duration={self.duration}, mode={FLUSHMODE_NAME[self.mode]}, size={self.size}, memory={self.memory}, for_prune={self.for_prune})"
141
142
143class UTXOCacheTracepointTest(BitcoinTestFramework):
144    def set_test_params(self):
145        self.setup_clean_chain = False
146        self.num_nodes = 1
147        self.extra_args = [["-txindex"]]
148
149    def skip_test_if_missing_module(self):
150        self.skip_if_platform_not_linux()
151        self.skip_if_no_bitcoind_tracepoints()
152        self.skip_if_no_python_bcc()
153        self.skip_if_no_bpf_permissions()
154        self.skip_if_running_under_valgrind()
155
156    def run_test(self):
157        self.wallet = MiniWallet(self.nodes[0])
158
159        self.test_uncache()
160        self.test_add_spent()
161        self.test_flush()
162
163    def test_uncache(self):
164        """ Tests the utxocache:uncache tracepoint API.
165        https://github.com/bitcoin/bitcoin/blob/master/doc/tracing.md#tracepoint-utxocacheuncache
166        """
167        # To trigger an UTXO uncache from the cache, we create an invalid transaction
168        # spending a not-cached, but existing UTXO. During transaction validation, this
169        # the UTXO is added to the utxo cache, but as the transaction is invalid, it's
170        # uncached again.
171        self.log.info("testing the utxocache:uncache tracepoint API")
172
173        # Retrieve the txid for the UTXO created in the first block. This UTXO is not
174        # in our UTXO cache.
175        EARLY_BLOCK_HEIGHT = 1
176        block_1_hash = self.nodes[0].getblockhash(EARLY_BLOCK_HEIGHT)
177        block_1 = self.nodes[0].getblock(block_1_hash)
178        block_1_coinbase_txid = block_1["tx"][0]
179
180        # Create a transaction and invalidate it by changing the txid of the previous
181        # output to the coinbase txid of the block at height 1.
182        invalid_tx = self.wallet.create_self_transfer()["tx"]
183        invalid_tx.vin[0].prevout.hash = int(block_1_coinbase_txid, 16)
184
185        self.log.info("hooking into the utxocache:uncache tracepoint")
186        ctx = USDT(pid=self.nodes[0].process.pid)
187        ctx.enable_probe(probe="utxocache:uncache",
188                         fn_name="trace_utxocache_uncache")
189        bpf = BPF(text=utxocache_changes_program, usdt_contexts=[ctx], debug=0, cflags=bpf_cflags())
190
191        # The handle_* function is a ctypes callback function called from C. When
192        # we assert in the handle_* function, the AssertError doesn't propagate
193        # back to Python. The exception is ignored. We manually count and assert
194        # that the handle_* functions succeeded.
195        EXPECTED_HANDLE_UNCACHE_SUCCESS = 1
196        handle_uncache_succeeds = 0
197
198        def handle_utxocache_uncache(_, data, __):
199            nonlocal handle_uncache_succeeds
200            event = ctypes.cast(data, ctypes.POINTER(UTXOCacheChange)).contents
201            self.log.info(f"handle_utxocache_uncache(): {event}")
202            try:
203                assert_equal(block_1_coinbase_txid, bytes(event.txid[::-1]).hex())
204                assert_equal(0, event.index)  # prevout index
205                assert_equal(EARLY_BLOCK_HEIGHT, event.height)
206                assert_equal(50 * COIN, event.value)
207                assert_equal(True, event.is_coinbase)
208            except AssertionError:
209                self.log.exception("Assertion failed")
210            else:
211                handle_uncache_succeeds += 1
212
213        bpf["utxocache_uncache"].open_perf_buffer(handle_utxocache_uncache)
214
215        self.log.info(
216            "testmempoolaccept the invalid transaction to trigger an UTXO-cache uncache")
217        result = self.nodes[0].testmempoolaccept(
218            [invalid_tx.serialize().hex()])[0]
219        assert_equal(result["allowed"], False)
220
221        bpf.perf_buffer_poll(timeout=100)
222        bpf.cleanup()
223
224        self.log.info(
225            f"check that we successfully traced {EXPECTED_HANDLE_UNCACHE_SUCCESS} uncaches")
226        assert_equal(EXPECTED_HANDLE_UNCACHE_SUCCESS, handle_uncache_succeeds)
227
228    def test_add_spent(self):
229        """ Tests the utxocache:add utxocache:spent tracepoint API
230            See https://github.com/bitcoin/bitcoin/blob/master/doc/tracing.md#tracepoint-utxocacheadd
231            and https://github.com/bitcoin/bitcoin/blob/master/doc/tracing.md#tracepoint-utxocachespent
232        """
233
234        self.log.info(
235            "test the utxocache:add and utxocache:spent tracepoint API")
236
237        self.log.info("create an unconfirmed transaction")
238        self.wallet.send_self_transfer(from_node=self.nodes[0])
239
240        # We mine a block to trace changes (add/spent) to the active in-memory cache
241        # of the UTXO set (see CoinsTip() of CCoinsViewCache). However, in some cases
242        # temporary clones of the active cache are made. For example, during mining with
243        # the generate RPC call, the block is first tested in TestBlockValidity(). There,
244        # a clone of the active cache is modified during a test ConnectBlock() call.
245        # These are implementation details we don't want to test here. Thus, after
246        # mining, we invalidate the block, start the tracing, and then trace the cache
247        # changes to the active utxo cache.
248        self.log.info("mine and invalidate a block that is later reconsidered")
249        block_hash = self.generate(self.wallet, 1)[0]
250        self.nodes[0].invalidateblock(block_hash)

src/wallet/receive.cpp

src/wallet/coinselection.cpp

src/consensus/validation.h

src/primitives/transaction.cpp

src/script/descriptor.cpp

src/bitcoin-cli.cpp

src/rpc/blockchain.cpp

src/rpc/rawtransaction.cpp

src/init.cpp

src/crypto/sha256.cpp

src/consensus/merkle.h

src/consensus/tx_check.h

src/consensus/tx_verify.h

src/policy/feerate.h

src/policy/feerate.cpp

src/primitives/transaction_identifier.h

src/chainparamsbase.h

src/chainparamsbase.cpp

src/util/moneystr.cpp

src/crypto/ripemd160.h

src/crypto/sha1.h

src/crypto/sha512.h

src/crypto/hmac_sha256.h

src/crypto/hmac_sha512.h

src/crypto/hmac_sha256.cpp

src/crypto/hmac_sha512.cpp

src/crypto/hkdf_sha256_32.h

src/crypto/hkdf_sha256_32.cpp

src/support/cleanse.h

src/support/cleanse.cpp

src/crypto/siphash.cpp

src/crypto/muhash.h

src/crypto/chacha20.h

src/crypto/poly1305.h

src/crypto/chacha20poly1305.h

src/crypto/chacha20poly1305.cpp

src/util/chaintype.cpp

src/util/obfuscation.h

src/util/byte_units.h

src/util/overflow.h

src/blockencodings.cpp

src/net_permissions.cpp

src/policy/packages.cpp

src/policy/rbf.cpp

src/policy/truc_policy.cpp

src/policy/ephemeral_policy.cpp

src/policy/settings.cpp

src/policy/policy.cpp

src/node/transaction.cpp

src/node/coin.cpp

src/rpc/client.cpp

src/rpc/external_signer.cpp

src/rpc/request.cpp

src/rpc/server_util.cpp

src/rpc/fees.cpp

src/rpc/output_script.cpp

src/rpc/rawtransaction_util.cpp

src/rpc/rawtransaction_util.h

src/rpc/register.h

src/rpc/request.h

src/rpc/server_util.h

src/rpc/protocol.h

src/rpc/server.h

src/rpc/signmessage.cpp

src/rpc/txoutproof.cpp

src/rpc/util.cpp

src/rpc/util.h

src/wallet/rpc/addresses.cpp

src/wallet/rpc/backup.cpp

src/wallet/rpc/coins.cpp

src/wallet/rpc/encrypt.cpp

src/wallet/rpc/signmessage.cpp

src/wallet/rpc/util.cpp

src/wallet/rpc/util.h

src/wallet/coincontrol.cpp

src/wallet/coincontrol.h

src/wallet/context.cpp

src/wallet/context.h

src/wallet/crypter.cpp

src/wallet/crypter.h

src/wallet/db.cpp

src/wallet/export.cpp

src/wallet/external_signer_scriptpubkeyman.cpp

src/wallet/rpc/spend.cpp

src/wallet/rpc/transactions.cpp

src/wallet/rpc/wallet.cpp

src/wallet/feebumper.cpp

src/wallet/feebumper.h

src/index/base.h

src/index/base.cpp

src/index/txindex.h

src/index/txindex.cpp

src/index/txindex_key.h

src/index/txospenderindex.h

src/index/txospenderindex.cpp

src/index/blockfilterindex.h

src/index/blockfilterindex.cpp

src/index/coinstatsindex.h

src/index/coinstatsindex.cpp

src/index/db_key.h

src/index/disktxpos.h

src/kernel/chain.cpp

src/kernel/chain.h

src/kernel/checks.cpp

src/kernel/checks.h

src/kernel/context.cpp

src/kernel/context.h

src/kernel/cs_main.cpp

src/kernel/cs_main.h

src/kernel/disconnected_transactions.cpp

src/kernel/disconnected_transactions.h

src/kernel/mempool_removal_reason.cpp

src/kernel/mempool_removal_reason.h

src/kernel/coinstats.cpp

src/kernel/coinstats.h

src/kernel/chainparams.cpp

src/kernel/chainparams.h

src/wallet/sqlite.cpp

src/wallet/sqlite.h

src/wallet/transaction.cpp

src/wallet/transaction.h

src/wallet/dump.cpp

src/wallet/dump.h

src/wallet/init.cpp

src/wallet/walletutil.cpp

src/wallet/walletutil.h

src/wallet/wallettool.cpp

src/wallet/wallettool.h

src/wallet/export.h

src/wallet/migrate.cpp

src/wallet/migrate.h

src/wallet/db.h

src/wallet/walletdb.cpp

src/wallet/interfaces.cpp

src/wallet/scriptpubkeyman.cpp

src/wallet/scriptpubkeyman.h

src/kernel/bitcoinkernel.cpp

src/kernel/bitcoinkernel.h

src/kernel/bitcoinkernel_wrapper.h

src/node/chainstate.cpp

src/node/chainstate.h

src/node/blockstorage.cpp

src/node/blockstorage.h

src/node/mempool_persist.cpp

src/node/mempool_persist.h

src/node/utxo_snapshot.cpp

src/node/utxo_snapshot.h

src/node/kernel_notifications.cpp

src/node/kernel_notifications.h

src/node/blockmanager_args.cpp

src/kernel/blockmanager_opts.h

src/util/expected.cpp

src/policy/settings.h

src/util/types.h

src/kernel/messagestartchars.h

src/kernel/warning.h

src/util/exception.h

src/common/license_info.h

src/node/coins_view_args.h

src/node/database_args.h

src/util/batchpriority.h

src/util/ui_change_type.h

src/node/coins_view_args.cpp

src/node/peerman_args.h

src/util/serfloat.h

src/node/blockmanager_args.h

src/node/database_args.cpp

src/util/overloaded.h

src/interfaces/types.h

src/node/chainstatemanager_args.h

src/node/minisketchwrapper.h

src/util/macros.h

src/util/syserror.h

src/common/run_command.h

src/util/bytevectorhash.cpp

src/node/mempool_persist_args.cpp

src/util/exec.h

src/util/rbf.h

src/crypto/hex_base.h

src/node/mempool_persist_args.h

src/interfaces/echo.h

src/util/any.h

src/util/batchpriority.cpp

src/util/threadnames.h

src/node/coin.h

src/node/mempool_args.h

src/util/asmap.h

src/util/bytevectorhash.h

src/node/context.cpp

src/util/insert.h

src/util/readwritefile.h

src/node/peerman_args.cpp

src/node/interface_ui.cpp

src/interfaces/handler.h

src/node/mining_args.h

src/util/hasher.cpp

src/common/init.h

src/kernel/mempool_limits.h

src/common/system.h

src/crypto/sha3.h

src/util/threadinterrupt.cpp

src/node/protocol_version.h

src/util/exception.cpp

src/common/messages.h

src/node/connection_types.cpp

src/util/bip32.h

src/common/license_info.cpp

src/util/stdmutex.h

src/common/run_command.cpp

src/util/check.cpp

src/util/golombrice.h

src/node/types.h

src/node/timeoffsets.h

src/util/readwritefile.cpp

src/util/fastrange.h

src/util/signalinterrupt.h

src/util/task_runner.h

src/util/syserror.cpp

src/common/interfaces.cpp

src/common/types.h

src/util/threadinterrupt.h

src/kernel/chainstatemanager_opts.h

src/node/psbt.h

src/policy/ephemeral_policy.h

src/util/trace.h

src/common/url.cpp

src/kernel/mempool_options.h

src/util/serfloat.cpp

src/kernel/notifications_interface.h

src/node/timeoffsets.cpp

src/node/warnings.cpp

src/util/hash_type.h

src/crypto/hex_base.cpp

src/node/eviction.h

src/util/tokenbucket.h

src/crypto/aes.h

src/common/pcp.h

src/util/feefrac.cpp

src/node/transaction.h

src/util/threadnames.cpp

src/common/signmessage.h

src/util/exec.cpp

src/util/signalinterrupt.cpp

src/clientversion.cpp

src/common/signmessage.cpp

src/compat/assumptions.h

src/compat/byteswap.h

src/deploymentinfo.cpp

src/deploymentinfo.h

src/deploymentstatus.cpp

src/deploymentstatus.h

src/dummywallet.cpp

src/external_signer.h

src/init/bitcoin-gui.cpp

src/init/bitcoin-node.cpp

src/init/bitcoin-qt.cpp

src/init/bitcoin-wallet.cpp

src/init/bitcoind.cpp

src/init/common.h

src/interfaces/init.h

src/interfaces/ipc.h

src/key_io.h

src/logging/categories.h

src/logging/timer.h

src/mapport.h

src/musig.h

src/net_permissions.h

src/netgroup.h

src/netmessagemaker.h

src/node/chainstatemanager_args.cpp

src/node/connection_types.h

src/node/context.h

src/node/interface_ui.h

src/node/mempool_args.cpp

src/node/mining_args.cpp

src/node/minisketchwrapper.cpp

src/node/txreconciliation.h

src/policy/fees/estimator_args.cpp

src/policy/fees/estimator_args.h

src/policy/fees/estimator_man.cpp

src/policy/fees/estimator_man.h

src/policy/packages.h

src/policy/rbf.h

src/policy/truc_policy.h

src/pow.h

src/primitives/block.cpp

src/randomenv.h

src/rest.h

src/script/keyorigin.h

src/script/parsing.cpp

src/script/parsing.h

src/script/script_error.h

src/script/sigcache.cpp

src/script/sigcache.h

src/script/solver.h

src/script/verify_flags.h

src/semaphore_grant.h

src/signet.h

src/span.h

src/support/allocators/secure.h

src/support/allocators/zeroafterfree.h

src/util/tokenpipe.cpp

src/util/translation.h

src/util/vector.h

src/versionbits.h

src/versionbits_impl.h

src/wallet/external_signer_scriptpubkeyman.h

src/wallet/fees.h

src/wallet/load.h

src/wallet/receive.h

src/wallet/rpc/wallet.h

src/wallet/types.h

src/walletinitinterface.h

src/zmq/zmqabstractnotifier.cpp

Independent explanations by MyBitcoinExplorer. Not affiliated with or endorsed by Bitcoin Core. Guides are educational and do not replace the source or its tests.

Bitcoin Core source © its contributors, distributed under the MIT license. Original notices and bundled third-party licenses are retained in the source tree.