INT64 __fastcall PfSnCancelTraceTimer(INT64 a1){
UINT64 v1;
UINT64 *v2;
unsigned __int8 v4;
unsigned __int64 v5;
bool v6;
v2 = (UINT64 *)(a1 + 272);
KeAcquireSpinLockRaiseToDpc((UINT64 *)(a1 + 272), v1);
*(_DWORD *)(a1 + 280) |= 2u;
v5 = v4;
v6 = KeCancelTimer((PKTIMER)(a1 + 136)) != 0;
KxReleaseSpinLock(v2);
__writecr8(v5);
if( v6 )
ExReleaseRundownProtection((PEX_RUNDOWN_REF)(a1 + 360));
return 0i64;
}