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plafratt

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  1. Great, thank you. I was aware of ok_to_put(), but I think I had some confusion about how to use it in my situation. It looks like it should do what I need. Thanks!
  2. Well, I'm not sure something like deque will provide what is needed, because I still need process notifications when an entry is written or read. I think what I am not seeing is how to write into the fifo and then block the writer until the reader reads from it. I can write something custom based on deque or something else (or look for another class in sc_core or tlm) to provide this, but wanted to be sure that tlm_fifo didn't provide this first.
  3. I am using a tlm_fifo. When I put() into it and then immediately call nb_can_get(), it is returning false. Is this an invalid use of the tlm_fifo to call put() and nb_can_get() in the same delta? Or, have I made a mistake somewhere?
  4. I see now that the TLM2.0 LRM explicitly disallows this. (In the version of the LRM I have, this is in the section "4.1.2.6 The phase argument".) However, this text there does refer to the "base protocol." So, perhaps the way to allow what I am trying to do would be to define a new protocol. Any input on this is appreciated, though, in case that is the wrong way to go about this.
  5. With TLM2.0 nb_transport, is there a way for an initiator to tell an interconnect that it wants to preempt the last request the initiator sent? For example, say that the interconnect can buffer only 1 request. The initiator sends a low priority request R0 to the interconnect. Some time passes, and the initiator begins another, higher priority request R1. The initiator knows that the interconnect hasn't serviced R0 yet, because the initiator hasn't received a response for R0 yet. The initiator wants to tell the interconnect, "Throw out R0 and use R1 instead." I can achieve this by just having the initiator send R1 to the interconnect, and then having it send R0 again at a later time (after R1 is done being serviced). However, it isn't clear to me that TLM2.0 protocol allows the initiator to send R0 an arbitrary number of times in the BEGIN_REQ phase.
  6. Thank you for the thoughts. I am using acquire() and release() to ensure that the memory is safe while I am using the transaction in the target. The specific problem I am facing is that the initiator might call, for example, set_address() on the transaction after it receives the response, while the target is still using it. The target needs access to the original address.
  7. In systems where a target can send an early response, such as a posted write, and the initiator can change the transaction after it receives the response, how do most developers handle the transaction in the target while avoiding seeing the initiator's changes to that transaction? An obvious solution is for the target to do a deep copy of the transaction, but in a complex system with many modules, having each module potentially create its own copy of each transaction can make debug and performance analysis difficult. Another option is for the target to save the relevant information from the transaction in an extension when the target receives that transaction, but this has the problem that the developers of the target must always remember to use the accessors in the extension, rather than the standard ones for the transaction.
  8. Thank you for the responses. Sorry for the delay in my response. I'd gotten busy, and I am just now getting around to signing back in. We don't seem to be having this issue anymore. I am not sure if it because of code updates or because of a compiler upgrade. We recently switched from g++ 4.9.2 to 6.2.1, so that may have resolved the issue. The path in question is sc_fifo::read() -> sc_fifo::read(T& val_) -> sc_fifo<T>::buf_read( T& val_ ). On line 410, buf_read() returns false without setting val. None of the functions in the call chain set val, so when the original call to sc_fifo::read() returns, it is returning its locally-declared tmp variable, which was passed to sc_fifo::read(T& val), which never sets val. As I mentioned, though, this doesn't seem to be causing a problem for us at the moment. It may have been a compiler issue that got resolved when we upgraded. Thank You and Regards, Patrick
  9. I get the warning when building my code that uses sc_fifo.h, not when building systemc. I assume this is because the function is declared inline.
  10. For sc_fifo::read(), some versions of g++ give me a warning that the variable tmp is unset. I see there is a path through read() that leaves tmp unset, but I don't think it is possible that this path ever gets executed. Is there a way around this warning that doesn't require disabling the warning in g++ or changing sc_fifo.h?
  11. That is it. Thank you very much. Regards, Patrick
  12. I looked at the implementation of sc_fifo, as I'd guessed that in the read() function, it would just notify data_read_event, but the logic surrounding the notify looks a little more complex than that.
  13. I'm actually using read(), rather than nb_read(). Given the specification you posted, it seems like something unexpected is happening. I can see the fifo is getting read (I put a log statement in after the read() call), but I don't see the thread that is waiting on data_read_event getting woken up (I put a log statement there, too). The thread that is waiting on data_read_event does eventually get woken up when the last item is read off the fifo.
  14. I had been using the sc_fifo with the assumption that data_read_event would get notified whenever the receiver read from the fifo. However, I am seeing cases where the receiver reads from the fifo, but the data_read_event doesn't get notified. Is this the intended behavior?
  15. Is there a preferred way of adding an event to the static sensitivity list for a single wait? I think it would be possible by ORing the static sensitivity list with another event, and sending the result to a wait. The problem is that I don't see an accessor function for a thread's sensitivity list. I guess one approach is to hard-code an sc_event_or_list that includes the static sensitivity list, but that seems a little clunky. sc_event_or_list or_list; for (int i=0; i< 100; i++) or_list |= my_array_of_100_events; or_list |= new_event; wait( or_list ); Is there a better way to add an event to the sensitivity list for a single wait? Thanks, Patrick
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