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Philipp A Hartmann

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Everything posted by Philipp A Hartmann

  1. Kahn Process Networks (KPN) with SystemC

    Hi Matthias, IIRC, KPNs require that inputs are available on all incoming connections for an actor to fire. In your model, you already consume tokens from some inputs while being then blocked at others. This can be the reason that you don't see the deadlock in your model. But of course, you can also have deadlocks under this approach. Maybe you can trigger it by just switching the order of some of the read statements in your multi-input actors. As a general solution, you need to use a similar pattern as recently discussed in the following thread: Here's an example for one of your processes: void kpn::p7() // merge { static const int f7_n = 1; // number of tokens needed from each input static const int f8_n = 1; while( true ) { while( f7.num_available() < f7_n || f8.num_available() < f8_n ) { // at least one side is blocking, wait for activity on either side wait( f7.data_written_event() | f8.data_read_event() ); } // forwarding possible, process tokens - will not block on inputs unsigned int u = f7.read(); unsigned int v = f8.read(); // ... // may still block out outputs } } Greetings from Duisburg, Philipp
  2. Passthrough Module -- Fifo Implementation

    Hi Patrick, You can use every Copyable/CopyAssignable type with sc_fifo or tlm_fifo, as entries are always copied in and out of the fifo slots. There is no special support for e.g. move-only types, yet. It might be a nice to explore options to add such support in order to reduce the cost for passing complex types through fifos. So yes, you can pass std::shared_ptr and std::vector, but e.g. not std::unique_ptr. Greetings from Duisburg, Philipp
  3. Passthrough Module -- Fifo Implementation

    The model you describe is not "just" a passthrough model though, as you assume that tokens can be both intercepted (other processes reading from incoming_fifo) and injected (other processes than B writing to outgoing_fifo). From my experience, it is very difficult to design robust models with multiple readers and writers for FIFOs, at least without higher-level synchronization orchestrating the accesses somehow. That said, let's assume these arbitrary FIFO accesses are needed and OK for your use case. I would suggest to indeed use the non-blocking APIs to do the forwarding: while( true ) { if( incoming_fifo.num_available() > 0 && outgoing_fifo.num_free() > 0 ) { // forwarding possible, process token - will never block outgoing_fifo.write( incoming_fifo.read() ); } // at least one side is blocking, wait for activity on either side wait( incoming_fifo.data_written_event() | outgoing_fifo.data_read_event() ); } This will not lead to an additional implicit slot in the passthrough block, but the forwarding is "non-greedy" now, i.e. happens only if a slot is available on both sides. Together with arbitrary other readers/writers on the FIFOs, your passthrough model might never succeed to forward a single token. See above. Minor comment: Your thread_A pseudo code above looks like Java/SystemVerilog and would have a memory leak in C++. You should not put dynamically allocated objects into a FIFO. Hope that helps, Philipp
  4. problems regresson tests

    When you use MSVC 2015/2017, did you make sure to use SystemC 2.3.2? Earlier SystemC versions did not support such recent versions of MSVC. When you say "regression tests", do you mean the SystemC regression test suite? If so, please check the accompanying README_windows.txt for any steps you might have missed. If this still doesn't help, please post some more details on what exact errors you see. Greetings from Duisburg, Philipp
  5. how do I terminate all threads at end of simulation ?

    Ok, now I understand your concern: It's also about stack-allocated variables in your threads that are not cleaned up at the end of the simulation, as their stacks are not unwound and dynamic process stacks may not even be explicitly deallocated. I'm not sure, if these cases qualify as real memory leaks, though. Small comment: instead of throwing an (non-standard) sc_halt object, you can simply call : h.kill(SC_INCLUDE_DESCENDANTS); // also kills all child processes There is currently no way to obtain (or kill) all running processes in the simulation, but you can roll your own function to recurse over the object hierarchy via get_child_objects() convert objects to process handles, if valid() and !terminated() call kill(SC_INCLUDE_DESCENDANTS) /Philipp
  6. Explicit parent object

    If you invert the logic and add a function add_initiator to the interconnect, temporarily storing the pointer to the to-be-connected initiator socket (and maybe a name, although this can be derived from the given socket or its parent), you can complete the binding and target socket creation in the interconnect's before_end_of_elaboration hook. Sockets instantiated in this function will be placed correctly in the hierarchy and this approach is fully standards-compliant.
  7. Install SystemC on Visual Studio 2017

    Starting with SystemC 2.3.2, the MSVC project files shipped with the package use the DLL-based runtime library. Therefore it is not necessary (instead rather harmful) to select the statically linked runtime library in your application. Secondly, you should not set the SC_SIGNAL_WRITE_CHECK environment variable to DISABLE (unrelated to your current issue, but suggested in the video above). More instructions on using MSVC with SystemC can be found in the INSTALL file shipped with the proof-of-concept simulator. Hope that helps, Philipp
  8. Explicit parent object

    As said above, for the TLM-2.0 interconnect case, you can just use multi sockets on don't add additional sockets to the interconnect model at all. My question hasn't been on the "surrounding side", but on the usage of the sockets inside the interconnect and the cpu/mem/uart models. Thes modules actually have to make use of the "injected sockets", which likely requires some additional hacks. How does the memory handle a second "tgt()" socket during simulation? How does the CPU suddenly leverage a second initiator?
  9. how do I terminate all threads at end of simulation ?

    While most of the things in the referenced discussion still hold, we slightly extended the "thread cleanup" in the recently released SystemC 2.3.2. Can you please try, if the behavior improves when using the new version? Thanks, Philipp
  10. Explicit parent object

    To me, this approach still looks backwards. If you need to finalize things in the model after the configuration is complete (e.g. spawning threads, etc), you can use the before_end_of_elaboration hook. You can even do the instantiation itself there, if needed, by just storing the pointer to the master and doing both instantiation and process spawning during before_end_of_elaboration. Adding emplace_back to sc_vector would just reduce the boilerplate of the delayed instantiation of structural members. But there are already ways to achieve all of this without any changes to the language.
  11. Explicit parent object

    Both versions are non-portable, as the SystemC simcontext is not part of the standard either. I am even surprised that the hierarchy_push/pop functions are not restricted (as they should be). So the first solution might in fact break in future versions of SystemC as you shall not mess with the object hierarchy stack yourself. Whether or not the "hierarchy scope guard" can be extended to become a standardized solution will likely require some discussions first, especially how to avoid breaking the object hierarchy. Certainly, this internal hierarchy stack is not something to arbitrarily use from the model side, other than from the sc_module_name usage today. For the particular use case, you can now look into the new "optionally bound convenience sockets" in SystemC 2.3.2, which you can safely leave unbound when not used. An arbitrary number of sockets can be bound to the multi_passthrough_*_socket, without having to do any such magic above. For a generic pattern to request additional structural things to "appear later", you can use an sc_vector with delayed initialization (since SystemC 2.3.2). This is (currently) limited to a single call, but I could envision to extend this to support distributed emplace_back() calls during elaboration. Such an approach would at least restrict the external modification of the hierarchy to much more controllable contexts. Regarding your current use case: How does the destination module actually use these newly added ports/sockets? /Philipp
  12. Converting sc_signal<T1> to sc_signal<T2>

    Any eventual copy returned from read() by value will never be optimized away, as the source location continues to exist in the signal. The simplest solution is to change your signal converter as follows (untested): template <typename Treal, typename Tcasted> class signal_interface_converter : public sc_core::sc_signal<Treal> , public sc_core::sc_signal_in_if<Tcasted> // only read allowed { typedef sc_core::sc_signal<Treal> real_type; public: explicit signal_interface_converter(const char* nm) : real_type(nm), casted_val() {} const Tcasted &read() const override { return casted_val; } private: void update() override { real_type::update(); casted_val = static_cast<Tcasted>(real_type::read()); ] Tcasted casted_val; }; So the idea is basically to leverage the update phase to update the casted value. If the above doesn't work due to read() overloads based on the return type only, you may need to wrap it differently to separate the two conflicting interfaces (e.g. by using an internal signal with an overridden update() function, triggering the update of the casted value in the converter). Hope that helps, Philipp
  13. Problems using sca_tdf::sc_in<bool>

    My crystal ball guess would be the linker ordering between -lsystemc and -lsystemc-ams. Please make sure to put -lsystemc right of -lsystemc-ams in your linker command. Can you share the build setup, especially the final linker command line? /Philipp
  14. Why SC_MANY_WRITERS is not default SC_DEFAULT_WRITER_POLICY?

    Two things are to be noted here: IEEE 1666-2011 added support for writer policies, IEEE 1666-2005 required to have conflict detection. So keeping the default behavior was a natural choice back then SC_DEFAULT_WRITER_POLICY is not part of the IEEE Std. 1666-2011, but an extension in the proof-of-concept implementation Last but not least, you can always use your own signal template alias: template<typename T> using sc_signal_mw = sc_core::sc_signal<T, sc_core::SC_MANY_WRITERS> Hope that helps, Philipp
  15. unresolved external

    You might want to read this "C++ Super FAQ" entry: https://isocpp.org/wiki/faq/templates#templates-defn-vs-decl Hope that helps, Philipp
  16. You would need to describe your actual question in a bit more detail. Is it about the logic inside the target (i.e. not performing the write)? Sure, you can check the state of the control bit in b_transport before processing the command. Is it about informing the initiator that this happened? Then you need to either use the response status or an extension. /Philipp
  17. Your options depend on what you mean by "reject/block". For example, you can reject the transaction by setting an error response in the transaction. See IEEE Std. 1666-2011, 14.17 for the available status codes and their meaning. // tlm::tlm_generic_payload& trans trans.set_response_status( tlm::TLM_GENERIC_ERROR_RESPONSE ); Hope that helps, Philipp
  18. Execution Trace Generation

    Hi Adiga, at the end, SystemC simulations are plain C++ programs. Therefore, you can use any program trace tool that meets your needs. One example could be the Linux perf tool, see https://perf.wiki.kernel.org. Your favorite SystemC simulator may have additional analysis features. You might want to ask your vendor about this. Hope that helps, Philipp
  19. sc method over sc thread

    I wouldn't say that in this generality. Both process types have their advantages, depending on the use case.
  20. multiple event in next trigger

    I cannot tell, if I understand your question at all. I'll just add the comment that you can use next_trigger(); without any arguments to restore the static sensitivity. Hope that helps, Philipp
  21. segmentation fault with async_reset_signal_is()

    Hi Avihai, I can confirm this behavior with the latest SystemC 2.3.2 pre-release and would classify this as a bug. As a short-term workaround, you can mark affected threads with dont_initialize(), which happens not to trigger this misbehavior: SC_THREAD(thread1); sensitive << thread1_event; async_reset_signal_is(reset_in,true); dont_initialize(); // avoid crash when starting in reset state I'll forward this issue to the Language Working Group for further analysis. Greetings from Duisburg, Phiipp
  22. Left shift with zero results in

    Can you please post a complete, self-contained example to demonstrate the issue? Reading your post, I still cannot infer what actual values, types, ... are involved and not even where you changed the "line" to sc_uint<5>. The following code works for me: #include <systemc> int sc_main (int, char *[]) { using namespace sc_dt; #define CORE_BUS_WIDTH 5 #define MASK_WIDTH 32 { sc_uint<CORE_BUS_WIDTH> id; sc_uint<MASK_WIDTH> mask(1 << id); std::cout << "id=" << id << "\t- mask=" << mask.to_string(SC_BIN) << std::endl; } { sc_uint<CORE_BUS_WIDTH> id(-1); sc_uint<MASK_WIDTH> mask(1 << id); std::cout << "id=" << id << "\t- mask=" << mask.to_string(SC_BIN) << std::endl; } return 0; } From your original error message, it looks more like an issue with MASK_WIDTH or CORE_BUS_WIDTH to me. Do you see any compiler warnings? Hope that helps, Philipp
  23. Left shift with zero results in

    Shifting by zero should of course be supported. Can you provide a self-contained example demonstrating the problem? Instead, the error message indicates, that you try to create an sc_uint<-2147483648> (or rather an sc_uint_base with the dynamic width of this value, e.g.), which is not allowed. What's the definition of MASK_WIDTH? What's the definition of ID? Hope that helps, Philipp
  24. debug problem systemc

    The error message is an indication, that you might miss the /vmg switch in your the MSVC project. Quoting from the SystemC INSTALL file (emphasis mine): Hope that helps, Philipp
  25. Usage of Sc_event_or_list

    Yes, there is currently no explicit function for this. But you can assign an empty one first: _orEvents = sc_event_or_list(); There is a caveat that this might break processes that are currently waiting for the previous elements in the list. But if you're sure that nothing is currently waiting of the list, the above example Should Work™. Hope that (still) helps, Philipp
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