Process is existing as a dreference error during the sim
class processtest;
process p[]; event ev[];
function new();
p = new[5];
ev = new[5];
endfunction
task start_prcess(int idx,int delay);
fork
begin
$display("starting process for idx=%d tiem: %0t",idx, $time);
p[idx] = process::self;
wait(ev[idx].triggered);
$display("process is done idx=%d time: %0t",idx, $time );
end
join_none
endtask
function void process_accepted(int idx);
->ev[idx];
endfunction
function void print_process_status(int idx);
process::state pstat;
pstat = p[idx].status();
$display("idx=%d process_status=%d", idx,p[idx].status);
endfunction
endclass
module process_test;
initial begin
static processtest pt = new();
pt.start_prcess(0,100);
pt.start_prcess(1,100);
pt.start_prcess(2,10);
pt.start_prcess(3,1000);
pt.start_prcess(4,200);
pt.print_process_status(0);
pt.process_accepted(1);
endmodule
when I run this code I get following error which I am not able to explain. If I remove the pt.print_process_status(0); then this error goes away
S:Begin run-time elaboration and static initialization...=N:[dumpMXD] preparing MXD dump to 'waves.mxd'.=N:[dump] Dump started at time 0=N:Starting event scheduler...=F:[NullRef] null handle 'p' dereferenced @ testbench \processTest.sv:41:14=N:[dumpMXD] closing MXD dump=T:Simulation terminated due to null handle dereference.=N:Backtrace:
PS: is there a better way to put the code in the question?
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Altair EmployeeSubtle point: when you fork…join_none, the children do not start running until the parent blocks. In your code, you have the parent call print_process_status() immediately after forking. If no process has started at that point then the p array will be uninitialized.
Try adding a #0 just before the call to print_process_status() to see if behavior changes. That will delay the parent into the inactive region, allowing the children to start in the active region and initialize the array.
Yup this was the case. some other simulator ignored it . Thanks for catching it
Altair Employee@JainamShah Did d3jones comment resolve your issue? If so, could you please mark it as "Accepted"?
It is better to attach your source code as files rather than paste their contents as comments.
Did you look at line 41 of processTest.sv? That's what the error message says:
=F:[NullRef] null handle 'p' dereferenced @ testbench \processTest.sv:41:14
Did you initialize 'p'?