On 12/4/19 3:10 AM, Erdem wrote:
I am used to have cool tools like valgrid massif to visualize the memory
usage from C++ but in D it seems I am blind folded looking for the problem.
Until now I tried:
--vgc option which show million things which makes it not useful
--build=profile-gc
which seems to slow down my program like *200 times and I have some
operation depending on time which makes creating the real case of the
application impossible. The observation itself effect the experiment
very badly.
Since this options are not useful for me, I tried to put debug logs in
critical places to estimate where I am losing memory. I couldn't find a
D native call to get the memory usage of the program. I had to call a
shell command which also slows down the app. This slow down causes me to
not be able to put this debug log too many places or in critical loops.
I manage to narrow it down a bit. Than I wanted to check the object
instances to find out which objects are getting bigger. I tried
GC.sizeOf(&object) which always prints 0. GC.sizeOf also does not works
with associative arrays , I don't see any usefull case than
GC.sizeOf(array.ptr).
That is the background of my questions and my questions are:
Is there a better way to visualize the memory in D something like
valgrid massif?
profile-gc literally makes to program not do anything due to slow down
is there any way to profile-gc in a faster fashion?
Is there a native function which will return the memory usage of my
program?
If it's total GC memory only you are interested in, then try the D
runtime switch for the GC: --DRT-gcopt=profile:1
This will print out a summary of GC usage at the end of your program,
and shouldn't significantly affect runtime.
Is there a function to return sizes of AAs and even class instances ?
Class instances have a compiler-defined size. Try
__traits(classInstanceSize, SomeClass)
This is the compile-time size of that specific type. If you have a class
instance, and you want the actual class size, in the case of a derived
instance, you may retrieve that using
typeid(classInstance).initializer.length.
Note also that this is not necessarily the size consumed from the GC! If
you want *that* size, you need to use GC.sizeof(cast(void*)object) (you
were almost correct, what you did was get the GC size of the *class
reference* which is really a pointer, and really lives on the stack,
hence the 0).
-Steve
