events

[Tanja]

Hello,

 

is there a way to create vectors of events (sc_event)??

 

Thank you

[ralph.goergen]

Hi Tanja. 

 

A vector of events is not supported (afaik).

 

You cannot use sc_vector because sc_event is not derived from sc_object. 

You cannot use std::vector<sc_event> because you are not allowed to copy sc_event objects. 

 

But: SystemC offers event lists (sc_event_or_list, sc_event_and_list). 

See: IEEE 1666-2011, Section 5.8 for more info.

 

Greetings

Ralph

[Tanja]

Thanks Ralph. But the event lists won't help!

 

I am looking for a way to generate a certain number of events depending on the number of modules i have.

Let's assume, i have a top-module T1 with two modules: M1 with a thread process P1 and another one with a thread process P2. Process P2 is dynamically sensitive to an event ev1. P1 notify ev1 when it is executed.

 

I want to instantiate another top-module T2 with the same modules and processes but here i need a different event as ev1. so Process P2 in T2 should wait for ev2 to be resumed.  

 

How can i achieved this without writing the same code twice? (P1 and P2 have to be in different modules)

 

Thank you very much in advance!

[ralph.goergen]

Three ideas, but actually none of it really satisfying. 

 

1.: Use an std::vector<sc_event*>. 

The pointers work in std::vector because they are default constructible and copyable. 

Then you can allocate the necessary events dynamically in a for-loop (with all the drawbacks of pointers and dynamic memory allocation). 

 

2.: Use a dummy module only containing a single event:

SC_MODULE(ev_holder){sc_event ev;};

Then, you can use an sc_vector of these modules. 

 

3.: sc_vector<sc_event> (with custom creator?)

sc_vector works in some circumstances with objects that are nor sc_objects. 

Since sc_event has a constructor which takes a char* argument, it might work. But I am not sure. 

 

Greetings

Ralph

[Tanja]

Hi Ralph,

 

3. it had tried it already. it does't work. sc_event cannot acces the private member of sc_event!

 

1. I implemented it. it works for the first array. I added a second one, now i got an exception: one heap has been corrupted! The code stops by the fonction 

void free(pblock)

 

 

What i am doing wrong? 

 

std::vector< sc_core::sc_event* > ev_vector   ;

for (int i = 1; i<=n; i++)
{
	std::string str = std::to_string((unsigned long long)i);
	str = "event_nr" + str;
	ev_vector.push_back(new sc_core::sc_event(str.c_str()));

}

in P1:

ev_vector.at(pos)->notify();

in P2:

wait( *ev_vector.at(pos) )

 

Greetings

[ralph.goergen]

Hard to say. That is the pain with pointers and dynamic memory allocation. 

 

Do you delete the allocated events manually? Where and how?

Some unintended assignment to the pointers?

How do you create and fill the second vector?

 

Two further hints: 

 

1: Version 3 might work if you initialize the sc_vector at construction time. Individual assignment doesn't work since you are not allowed to copy events. 

sc_vector<sc_event> sc_ev_vec("ev_vector",n);

 

2: Naming the events in your solution is easier with stringstreams instead of strings. 

#include <iomanip>
for (int i = 1; i<=n; ++i)
{
  std::stringstream str;
  str << "event_nr" << std::setfill('0') << std::setw(5) << i;
  ev_vector.push_back(new sc_core::sc_event(str.str().c_str()));
}

[Tanja]

1. I do not delete the allocated events! Should i? i need them till the end of the simulation

2. no assignment to the pointers

3. as same as i did for the first pointer

[ralph.goergen]

It is not necessary to delete the events because the program exits at the end of the simulation. 

But someone tries to free some memory.

 

My only remaining idea is to try to locate the problem in a debugger. 

 

gdb [program]

catch throw (to stop at the point where the exception is thrown) 

run

bt (to show the backtrace) 

 

Is it possible to post a striped-down version of your example?

[Tanja]

Hi Ralph,

 

version 3 worked fine.

 

Thank you vry much