Make sure rate-limiting code is thread-safe

This commit is contained in:
Gavin Andresen 2011-03-13 14:38:07 -04:00
parent 5de8b54c51
commit 88abf70386

View file

@ -739,21 +739,28 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi
return error("AcceptToMemoryPool() : not enough fees");
// Continuously rate-limit free transactions
// This mitigates 'penny-flooding' -- sending thousands of free transactions just to
// be annoying or make other's transactions take longer to confirm.
if (nFees < CENT)
{
static CCriticalSection cs;
static double dFreeCount;
static int64 nLastTime;
int64 nNow = GetTime();
// Use an exponentially decaying ~10-minute window:
dFreeCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime));
nLastTime = nNow;
// -limitfreerelay unit is thousand-bytes-per-minute
// At default rate it would take over a month to fill 1GB
if (dFreeCount > GetArg("-limitfreerelay", 15)*10*1000 && !IsFromMe())
return error("AcceptToMemoryPool() : free transaction rejected by rate limiter");
if (fDebug)
printf("Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
dFreeCount += nSize;
CRITICAL_BLOCK(cs)
{
// Use an exponentially decaying ~10-minute window:
dFreeCount *= pow(1.0 - 1.0/600.0, (double)(nNow - nLastTime));
nLastTime = nNow;
// -limitfreerelay unit is thousand-bytes-per-minute
// At default rate it would take over a month to fill 1GB
if (dFreeCount > GetArg("-limitfreerelay", 15)*10*1000 && !IsFromMe())
return error("AcceptToMemoryPool() : free transaction rejected by rate limiter");
if (fDebug)
printf("Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
dFreeCount += nSize;
}
}
}