Arena and threads

[Pierre Abbat]

On Wednesday, 30 October 2019 15.26.01 EDT Matthew Dillon wrote:
> Generally speaking the allocation algorithm depends on the language, the OS
> doesn't have a lot to do with it.  Anything linked against libc (that is,
> any C program), however, will use the allocator in libc which we do
> control.  That allocator allocates per-thread zones.
> 
> That said, the memory allocator itself, no matter what the language, is
> still just allocating memory that is shared across all the threads.  No
> copying is involved.  All the threads share the same address space.  Any
> locking is up to the program (or the language) itself.

It's C++. My concern is whether there's a way to return the memory to the OS 
if it was allocated in a thread (say the program has been idle for a minute). 
In Linux, only the main thread can do that. The main thread allocates with 
brk; the other threads allocate with mmap.

Pierre

-- 
gau do li'i co'e kei do