druntime: opt-in thread-local GC (tgc)

changelog/druntime.tgc.dd

@@ -0,0 +1,17 @@
+Opt-in thread-local GC (`tgc`)
+
+A new garbage collector implementation can be selected with
+`--DRT-gcopt=gc:tgc`.
+
+Each attached thread owns a private heap arena. Collection scans and sweeps only
+that thread's stack, TLS, and blocks — it does not issue a process-wide
+stop-the-world pause. Threads detached via `thread_detachThis()` are never
+paused by `tgc` collections.
+
+Cross-thread sharing of GC pointers is unsupported in this first version except
+through ownership transfer that returns memory via a remote free list. Prefer
+copy or `immutable` message passing (`std.concurrency`). Partitioned shared
+regions are planned as a later phase.
+
+Informally this collector is sometimes called a "realtime GC" because it avoids
+global pauses; the registered name is `tgc` (thread garbage collection).

druntime/Makefile

@@ -203,6 +203,9 @@ $(DOC_OUTPUT_DIR)/core_internal_gc_impl_conservative_%.html : import/core/intern
 $(DOC_OUTPUT_DIR)/core_internal_gc_impl_manual_%.html : import/core/internal/gc/impl/manual/%.d $(DMD)
 	$(DMD) $(DDOCFLAGS) -Df$@ project.ddoc $(DOCFMT) $<
 
+$(DOC_OUTPUT_DIR)/core_internal_gc_impl_tgc_%.html : import/core/internal/gc/impl/tgc/%.d $(DMD)
+	$(DMD) $(DDOCFLAGS) -Df$@ project.ddoc $(DOCFMT) $<
+
 $(DOC_OUTPUT_DIR)/core_internal_gc_impl_proto_%.html : import/core/internal/gc/impl/proto/%.d $(DMD)
 	$(DMD) $(DDOCFLAGS) -Df$@ project.ddoc $(DOCFMT) $<
 

druntime/mak/COPY

@@ -79,6 +79,7 @@ COPY=\
 	$(IMPDIR)\core\internal\gc\proxy.d \
 	$(IMPDIR)\core\internal\gc\impl\conservative\gc.d \
 	$(IMPDIR)\core\internal\gc\impl\manual\gc.d \
+	$(IMPDIR)\core\internal\gc\impl\tgc\gc.d \
 	$(IMPDIR)\core\internal\gc\impl\proto\gc.d \
 	\
 	$(IMPDIR)\core\internal\container\array.d \

druntime/mak/DOCS

@@ -551,6 +551,7 @@ DOCS=\
 	$(DOCDIR)\core_internal_gc_proxy.html \
 	$(DOCDIR)\core_internal_gc_impl_conservative_gc.html \
 	$(DOCDIR)\core_internal_gc_impl_manual_gc.html \
+	$(DOCDIR)\core_internal_gc_impl_tgc_gc.html \
 	$(DOCDIR)\core_internal_gc_impl_proto_gc.html \
 	\
 	$(DOCDIR)\rt_aApply.html \

druntime/mak/SRCS

@@ -82,6 +82,7 @@ SRCS=\
 	src\core\internal\gc\proxy.d \
 	src\core\internal\gc\impl\conservative\gc.d \
 	src\core\internal\gc\impl\manual\gc.d \
+	src\core\internal\gc\impl\tgc\gc.d \
 	src\core\internal\gc\impl\proto\gc.d \
 	\
 	src\core\internal\util\array.d \