On Wednesday, 13 July 2016 at 16:13:21 UTC, Adam Sansier wrote:
On Wednesday, 13 July 2016 at 11:39:11 UTC, Lodovico Giaretta
wrote:
On Wednesday, 13 July 2016 at 00:57:38 UTC, Adam Sansier wrote:
[...]
You shall use a static per-thread Region allocator[1] backed
by Mallocator[2].
Then you just make[3] exceptions inside it and throw them.
So you can allocate and chain exceptions until you end the
memory established on creation.
Whenever you don't need the exception chain anymore (i.e.: you
catched them and program is back in "normal" mode, you just
reset the region allocator, so you have all of your memory
again, for the next exception chain).
[1]
https://dlang.org/phobos/std_experimental_allocator_building_blocks_region.html
[2]
https://dlang.org/phobos/std_experimental_allocator_mallocator.html
[3] https://dlang.org/phobos/std_experimental_allocator.html
Am I going to have to do all this myself or is it already done
for me somewhere?
It's actually quite easy. Here's the code (untested):
================================================================
import std.experimental.allocator.building_blocks.region;
import std.experimental.allocator.mallocator;
import std.experimental.allocator;
Region(shared(Mallocator)) exception_allocator;
enum EXCEPTION_MEM_SIZE = 256*1024;
static this()
{
exception_allocator =
typeof(exception_allocator)(EXCEPTION_MEM_SIZE);
}
================================================================
And here is an usage example (untested, too):
================================================================
void throwingFunction()
{
// try to do something, but fail
throw exception_allocator.make!Exception("my wonderful error
message");
}
void throwingThrowingFunction()
{
try
{
// try to call function, which fails
throwingFunction;
}
catch (Exception exc)
{
// try to recover from failure, but generate other
exception (just to show chaining)
throw exception_allocator.make!Exception("I love
exception chaining");
}
}
void main()
{
try
{
// try to call function, which fails
throwingThrowingFunction;
}
catch (Exception exc)
{
// recover from failure, then deallocate the exceptions
no longer needed
exception_allocator.deallocateAll;
}
}
================================================================
