mirrors/bitcoin
1
0
Fork 0
mirror of https://github.com/bitcoin/bitcoin.git synced 2025-03-27 02:36:47 +01:00
Code Issues Projects Releases Wiki Activity

refactor: Make FEELER_SLEEP_WINDOW type safe (std::chrono)

Browse source
This commit is contained in:
MacroFake 2022-05-10 09:08:49 +02:00
parent fa3b3cb9b5
commit fa74e726c4
No known key found for this signature in database
GPG key ID: CE2B75697E69A548
3 changed files with 27 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
src/net.cpp
View file

@ -86,8 +86,8 @@ static constexpr int DNSSEEDS_DELAY_PEER_THRESHOLD = 1000; // "many" vs "few" pe
/** The default timeframe for -maxuploadtarget. 1 day. */
static constexpr std::chrono::seconds MAX_UPLOAD_TIMEFRAME{60 * 60 * 24};
// We add a random period time (0 to 1 seconds) to feeler connections to prevent synchronization.
#define FEELER_SLEEP_WINDOW 1
// A random time period (0 to 1 seconds) is added to feeler connections to prevent synchronization.
static constexpr auto FEELER_SLEEP_WINDOW{1s};
/** Used to pass flags to the Bind() function */
enum BindFlags {
@ -1574,6 +1574,7 @@ int CConnman::GetExtraBlockRelayCount() const
void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
{
SetSyscallSandboxPolicy(SyscallSandboxPolicy::NET_OPEN_CONNECTION);
FastRandomContext rng;
// Connect to specific addresses
if (!connect.empty())
{
@ -1827,12 +1828,11 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
}
if (addrConnect.IsValid()) {
if (fFeeler) {
// Add small amount of random noise before connection to avoid synchronization.
int randsleep = GetRand<int>(FEELER_SLEEP_WINDOW * 1000);
if (!interruptNet.sleep_for(std::chrono::milliseconds(randsleep)))
if (!interruptNet.sleep_for(rng.rand_uniform_duration<CThreadInterrupt::Clock>(FEELER_SLEEP_WINDOW))) {
return;
}
LogPrint(BCLog::NET, "Making feeler connection to %s\n", addrConnect.ToString());
}

17
src/random.h
View file

@ -11,6 +11,7 @@
#include <span.h>
#include <uint256.h>
#include <cassert>
#include <chrono>
#include <cstdint>
#include <limits>
@ -236,13 +237,19 @@ public:
template <typename Tp>
Tp rand_uniform_delay(const Tp& time, typename Tp::duration range)
{
using Dur = typename Tp::duration;
Dur dur{range.count() > 0 ? /* interval [0..range) */ Dur{randrange(range.count())} :
range.count() < 0 ? /* interval (range..0] */ -Dur{randrange(-range.count())} :
/* interval [0..0] */ Dur{0}};
return time + dur;
return time + rand_uniform_duration<Tp>(range);
}
/** Generate a uniform random duration in the range from 0 (inclusive) to range (exclusive). */
template <typename Chrono>
typename Chrono::duration rand_uniform_duration(typename Chrono::duration range) noexcept
{
using Dur = typename Chrono::duration;
return range.count() > 0 ? /* interval [0..range) */ Dur{randrange(range.count())} :
range.count() < 0 ? /* interval (range..0] */ -Dur{randrange(-range.count())} :
/* interval [0..0] */ Dur{0};
};
// Compatibility with the C++11 UniformRandomBitGenerator concept
typedef uint64_t result_type;
static constexpr uint64_t min() { return 0; }

10
src/test/random_tests.cpp
View file

@ -53,6 +53,16 @@ BOOST_AUTO_TEST_CASE(fastrandom_tests)
BOOST_CHECK_EQUAL(ctx1.randbits(3), ctx2.randbits(3));
BOOST_CHECK(ctx1.rand256() == ctx2.rand256());
BOOST_CHECK(ctx1.randbytes(50) == ctx2.randbytes(50));
{
struct MicroClock {
using duration = std::chrono::microseconds;
};
FastRandomContext ctx{true};
// Check with clock type
BOOST_CHECK_EQUAL(47222, ctx.rand_uniform_duration<MicroClock>(1s).count());
// Check with time-point type
BOOST_CHECK_EQUAL(2782, ctx.rand_uniform_duration<SteadySeconds>(9h).count());
}
// Check that a nondeterministic ones are not
g_mock_deterministic_tests = false;