We have name fragmentation for this feature, including "shared GC",
"modular GC", and "external GC". This commit standardizes the feature
name to "modular GC" and the implementation to "GC library".
Let there be rooms for each GC implementations how to handle multi
threaded situations. They can be totally reentrant, or can have
their own mutex, or can rely on rb_thread_call_with_gvl.
In any ways the allocator (has been, but now officially is)
expected to run properly without a GVL. This means there need be
a way for them to inform the interpreter about their allocation
failures, without relying on raising exceptions.
Let them do so by returning NULL.
So that it doesn't get included in the generated binaries for builds
that don't support loading shared GC modules
Co-Authored-By: Peter Zhu <peter@peterzhu.ca>
```
compiling gc.c
In file included from gc.c:80:
/usr/include/sys/prctl.h:88:8: error: redefinition of 'struct prctl_mm_map'
88 | struct prctl_mm_map {
| ^~~~~~~~~~~~
In file included from gc.c:79:
/usr/include/linux/prctl.h:134:8: note: originally defined here
134 | struct prctl_mm_map {
| ^~~~~~~~~~~~
```
The first include is not needed and is what causes this issue.
Two other places in ruby exclusively use the sys import.
See https://github.com/seccomp/libseccomp/issues/19 for a similar problem.
This commit adds extconf.rb for both the default GC and and MMTk to build
the external GC. This allows common.mk to not need to contain any
implementation-specific build configuration.
db6a29b4a9
This commit implements the mark-sweep algorithm using MMTk and allows
customizing the plan using MMTK_PLAN.
6fea5e5ffc
Co-Authored-By: Matt Valentine-House <matt@eightbitraptor.com>
Use PR_SET_VMA_ANON_NAME to set human-readable names for anonymous
virtual memory areas mapped by `mmap()` when compiled and run on Linux
5.17 or higher. This makes it convenient for developers to debug mmap.
And a default and readonly key to the GC.config hash that names the
current GC implementation.
This is provided by each implementation by the API function
rb_gc_impl_active_gc_name
Shared GC might not use the private functions in gc/gc.h, so they will
show up as warnings for unused functions. This commit disables
-Wunused-function for these functions when building as shared GC.
Now that we've inlined the eden_heap into the size_pool, we should
rename the size_pool to heap. So that Ruby contains multiple heaps, with
different sized objects.
The term heap as a collection of memory pages is more in memory
management nomenclature, whereas size_pool was a name chosen out of
necessity during the development of the Variable Width Allocation
features of Ruby.
The concept of size pools was introduced in order to facilitate
different sized objects (other than the default 40 bytes). They wrapped
the eden heap and the tomb heap, and some related state, and provided a
reasonably simple way of duplicating all related concerns, to provide
multiple pools that all shared the same structure but held different
objects.
Since then various changes have happend in Ruby's memory layout:
* The concept of tomb heaps has been replaced by a global free pages list,
with each page having it's slot size reconfigured at the point when it
is resurrected
* the eden heap has been inlined into the size pool itself, so that now
the size pool directly controls the free_pages list, the sweeping
page, the compaction cursor and the other state that was previously
being managed by the eden heap.
Now that there is no need for a heap wrapper, we should refer to the
collection of pages containing Ruby objects as a heap again rather than
a size pool
After the individual tomb_heaps were removed in favour of a global list
of empty pages, the only instance of rb_heap_t left is the eden_heap
within each size pool.
This PR inlines the heap fields directly into rb_size_pool_t to remove
indirection and remove the SIZE_POOL_EDEN_HEAP macro
Fixes the following warning on WebAssembly:
gc/default.c:7306:1: warning: unused function 'desired_compaction_pages_i' [-Wunused-function]
desired_compaction_pages_i(struct heap_page *page, void *data)
If we are during heap traversal, we don't want to call rb_gc_impl_mark_weak.
This commit moves that check from rb_gc_impl_mark_weak to rb_gc_mark_weak.
