I want to read values of objects on current method frame (on method exit event).
But I am unable to find functions to do so in JVM ti. There are functions to read primitive types eg. getlocalfloat, but once we get a jobject using get local object() or we read a localvariabletable entry for an object it is not possible to obtain the value of the object, i.e. all its members.
How to read references to other objects from one object?
Related
When I create a custom type summary using a Python script, it is possible to access ivars using value.GetChildMemberByName("<child-name>"). However, this does not work for computed properties or functions.
With the frame variable command, the script that generates the summary can evaluate expressions in the current frame (e.g. value.GetFrame().EvaluateExpression(value.GetName() + ".description"))
However, this will not work when using p <some-expression>/expression -- <some-expression> as there is no frame, so the above statement will fail to produce any results.
Is there a way to call functions or evaluate computed properties in a type summary when using p (expression --)?
You might what to use SBValue.CreateValueFromExpression instead of either the frame or the target EvaluateExpression calls for data formatters.
SBValues remember the context they were defined in, and SBValue.CreateValueFromExpression funnels that context back to the expression evaluator. Since the Variable formatters always receive the SBValue that they are acting on, CreateValueFromExpression allows a simple way to forward that context to the new expression.
The EvaluateExpression function is available on the target as well as on frames. Try value.GetTarget().EvaluateExpression(...).
I am new to UVM and I am trying to verify a memory design where I am trying to run a write sequence multiple times followed by read sequence same number of times so that I could read the same addresses I am writing to, and compare. For this I tried to create a new class extended from uvm_object with a queue to store the addresses I am writing to, so that I could use them in read seq and I am instantiating this class in the scoreboard and then sending the handle of class to the read sequence via uvm_config_db, now the issue is I am able to store addresses in queue but unable to get the class handle in read sequence ......Is this the right way of checking or is there some better way to check the write and read back from memory, please help me !
entire code link (yet to complete): https://www.edaplayground.com/x/3iTr
Relevant code snippets:
This is the class I created to store the addresses
class address_list extends uvm_object;
reg[7:0]addr_q[$];
function new(string name);
super.new(name);
endfunction
endclass;
In my scoreboard, I am passing the handle of class with address queue to the read sequence, here is the snippet from scoreboard
virtual function void write(mem_seq_item pkt);
if(pkt.wr_en==1)
begin
pkt_qu_write.push_back(pkt);
addr.addr_q.push_back(pkt.addr);
uvm_config_db#(address_list)::set(uvm_root::get(),"*","address",addr);
end
if(pkt.rd_en==1)
pkt_qu_read.push_back(pkt);
`uvm_info(get_type_name(),$sformatf("Adder list is
%p",addr.addr_q),UVM_LOW)
endfunction : write
In my read sequence, I am trying to get the handle
virtual task body();
repeat(3)
`uvm_do(wr_seq)
if(!uvm_config_db#(address_list)::get(this, " ", "address", addr_))
`uvm_fatal("NO_VIF",{"virtual interface must be set for:",get_full_name(),".addr_"});
`uvm_info(get_type_name(),$sformatf("ADDR IS %p",addr_),UVM_LOW)
repeat(3)
`uvm_do(rd_seq)
endtask
Error-[ICTTFC] Incompatible complex type usage
mem_sequence.sv, 137 {line where i try to get from uvm_config_db}
Incompatible complex type usage in task or function call.
The following expression is incompatible with the formal parameter of the
function. The type of the actual is 'class $unit::wr_rd_sequence', while
the
type of the formal is 'class uvm_pkg::uvm_component'. Expression: this
Source info: uvm_config_db#
(_vcs_unit__3308544630::address_list)::get(this,
" ", "address", this.addr_)
There are two problems with this line:
if(!uvm_config_db#(address_list)::get(this, " ", "address", addr_))
One is causing your error. One might lead to you not being able to find what you're looking for in the database.
This (literally this) is causing your error. You are calling get from a class derived from uvm_sequence. The first argument to get is expecting a class derived from uvm_component. Your problem is that a sequence is not part of the testbench hierarchy, so you cannot use a sequence as the first argument to a call to get (or set) in a uvm_config_db. Instead the convention is to use the sequencer that the sequence is running on, which is returned by a call to the sequence's get_sequencer() method. This solves your problem:
if(!uvm_config_db#(address_list)::get(get_sequencer(), "", "address", addr_))
This works because you used a wildcard when you called set.
Notice that I also removed the space from between the quotes. That might not give you a problem, because you used the wildcard when you called set, but in general this string should either be empty or should be a real hierarchical path. (The hierarchy input to the set and get calls is split between the first argument - a SystemVerilog hierarchical path - and the second - a string representing a hierarchical path).
uvm_config_db is basically for passing configuration between components.
For purpose of passing data from scoreboard to sequence, you can use uvm_event.
Trigger event in scoreboard using event.trigger(address_list)
sequence wait for event using event.wait_for_trigger_data(address_list)
Python allows hash values only for immutable objects. For example,
hash((1,2,3))
works, but
hash([1,2,3])
raises a TypeError: unhashable type: 'list'. See the Python documentation. However, when I wrap a C++ class in Boost.Python via the usual boost::python::class_<> function, every generated Python class has a default hash function, where the hash value is related to the object's location in memory. (On my 64-bit OS, the hash value is the location divided by 8.)
When I expose a class to Python whose members can be changed (any mutable data structure, so this is a very common situation!), I do not want a default hash function but want a call to hash() raise the same TypeError as users receive for Python's own mutable data types. In particular, users shouldn't be able to accidentally use mutable objects as dictionary keys. How can I achieve this in the C++ code?
I found out how it goes:
boost::python::class_<MyClass>("MyClass")
.setattr("__hash__", boost::python::object());
A boost::python::object which is initialized with no arguments corresponds to None. The procedure for disabling hash generation in the pure Python C API is a little more complicated, as is described in the Python documentation. However, the above code snippet apparently does the job in boost::python.
On a sidenote: The Boost.Python behaviour mirrors the default behaviour of classes in Python, where objects are basically hashable as of object id (derived from id(x)):
>>> hash(object())
8795488122377
>>> class MyClass(object): pass
...
>>> hash(MyClass)
878579
>>> hash(MyClass())
8795488082665
>>>
I am trying to connect a simulator to the MATLAB. The simulator program exposes a COM object interface.
I have connected to the COM object by the following command and can perform most of it methods:
h=actxserver(ProgID)
But some of its methods need passing of a Variant* type as output.
Here is the signature of one of the methods indicated by "invoke" method:
ReadOutputImage=Variant(Pointer) ReadOutputImage(handle, int32, int32, `ImageDataTypeConstants, Variant(Pointer))`
I have called this method with several syntax's, but none of them work:
a=uint8([0]) %means unsigned integer array with 1 member
h.ReadOutputImage(0,1,2,a) % 0 ,1 ,2 are contants pointing to the position, number of elements to read and size of elemnts while 2 shows Byte element (VT_UI2 COM type).
Other syntax's that I have tried and has no result are: using uint16, uint32, int8, int16, int32 for all of the followings:
logical types (like a=[false]),
cell arrays (like a={uint8([0])} )
empty cell array {}
empty array []
empty sring ''
I have used libpointer as well:
a=libpointer;
also a=libpointer('uint8Ptr',0)
also a=libpointer('bool',false)
also a=libpointer('bool',[0])
The problem is that I am not sure about the following items:
What is the similar type of " Variant(Pointer) " in MATLAB?
What is the method of passing a variable as output to a COM method in MATLAB?
Is it even possible to get a value from a COM object method result as a pointer in MATLAB?
To find how the data appears in other clients, I have imported the same dll file into Delphi and the signature of the type library for the above method is like this:
procedure ReadOutputImage(StartIndex: Integer; ElementsToRead: Integer;
DataType: ImageDataTypeConstants; var pData: OleVariant);
Yes Siemens has provided a guide for this com server (prosim) and based on such documentation I have connected and performed most of its methods. But the methods which read I/o data are not working. In documentation the method signature is specified as follows: (in VB)
STDMETHOD(CS7Prosim::ReadOutputImage)(long startindex,long elementstoread, imagedatatypeconstants DtaType, VARIANT* pData)
What about your application, was it working? Did it contains variant pointers as the returning argument? Did you have simillar methods in that application?
Thank you
I can help with #2 in your question. I just worked through this myself. Basically, any pass by reference to COM object you to access after it is modified, Matlab just spits back as an output.
[var1 a]=thisObject.DB.Execute(queryString,a)
See here
"The syntax shown here shows a server function being called by the MATLAB client. The function's return value is shown as retval. The function's output arguments (out1, out2, ...) follow this:
[retval out1 out2 ...] = handle.functionname(in1, in2, ...);
MATLAB makes use of the pass by reference capabilities in COM to implement this feature. Note that pass by reference is a COM feature. It is not available in MATLAB at this time."
Two R questions:
What is the difference between the type (returned by typeof) and the class (returned by class) of a variable? Is the difference similar to that in, say, C++ language?
What are possible types and classes of variables?
In R every "object" has a mode and a class. The former represents how an object is stored in memory (numeric, character, list and function) while the later represents its abstract type. For example:
d <- data.frame(V1=c(1,2))
class(d)
# [1] "data.frame"
mode(d)
# [1] "list"
typeof(d)
# list
As you can see data frames are stored in memory as list but they are wrapped into data.frame objects. The latter allows for usage of member functions as well as overloading functions such as print with a custom behavior.
typeof(storage.mode) will usually give the same information as mode but not always. Case in point:
typeof(c(1,2))
# [1] "double"
mode(c(1,2))
# [1] "numeric"
The reasoning behind this can be found here:
The R specific function typeof returns the type of an R object
Function mode gives information about the mode of an object in the sense of Becker, Chambers & Wilks (1988), and is more compatible with other implementations of the S language
The link that I posted above also contains a list of all native R basic types (vectors, lists etc.) and all compound objects (factors and data.frames) as well as some examples of how mode, typeof and class are related for each type.
type really refers to the different data structures available in R. This discussion in the R Language Definition manual may get you started on objects and types.
On the other hand, class means something else in R than what you may expect. From
the R Language Definition manual (that came with your version of R):
2.2.4 Classes
R has an elaborate class system1, principally controlled via the class attribute. This attribute is a character vector containing the list
of classes that an object inherits from. This forms the basis of the “generic methods” functionality in R.
This attribute can be accessed and manipulated virtually without restriction by users. There is no checking that an object actually contains the components that class methods expect. Thus, altering the class attribute should be done with caution, and when they are available specific creation and coercion functions should be preferred.