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Bugzilla – Full Text Bug Listing |
| Summary: | GetInteger overflow | ||
|---|---|---|---|
| Product: | ns-3 | Reporter: | Tom Henderson <tomh> |
| Component: | core | Assignee: | Tom Henderson <tomh> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | ns-bugs, pdbarnes |
| Priority: | P5 | ||
| Version: | pre-release | ||
| Hardware: | PC | ||
| OS: | Linux | ||
Call is to double GetValue (double, double); So force the arguments to double before the addition: return static_cast<uint32_t> ( GetValue (min, max + 1.0) ); Explicitly: return static_cast<uint32_t> ( GetValue ((double)(min), (double)(max) + 1.0) ); fixed in 10935:8c52d989750b |
Ruben Martinez reported the below to me; I'm opening a bug so I don't forget it. Below text is from Ruben: I'm using a UniformRandomVariable::GetInteger to generate LTP Session Ids, like this: number->GetInteger(SessionId::MIN_SESSION_NUMBER,SessionId::MAX_SESSION_NUMBER) Where: * Session numbers chosen by LTP senders shall be in the range [1, 2^32-1] */ static const uint32_t MIN_SESSION_NUMBER = 1; static const uint32_t MAX_SESSION_NUMBER = 4294967295U; I noticed that when called with those parameters GetInteger always returns a 0. After checking the source code for RandomVariable, I found that the max parameter is increased by 1 (and thus it becomes 2^32 = 0 ). random-variable-stream.cc 183 UniformRandomVariable::GetInteger (uint32_t min, uint32_t max) 184 { 185 NS_LOG_FUNCTION (this << min << max); 186 NS_ASSERT (min <= max); 187 return static_cast<uint32_t> ( GetValue (min, max + 1) ); 188 } I had to substract 1 to MAX_SESSION_NUMBER in the call to GetInteger to get a return value within the range. Doesn't look like this behaviour was intended.