Stop sweep thread when compiling JIT code

Author: luke-gruber

gc.c

@@ -610,6 +610,7 @@ typedef struct gc_function_map {
     void (*start)(void *objspace_ptr, bool full_mark, bool immediate_mark, bool immediate_sweep, bool compact);
     bool (*during_gc_p)(void *objspace_ptr);
     void (*prepare_heap)(void *objspace_ptr);
+    void (*wait_for_background_sweep)(void *objspace_ptr);
     void (*gc_enable)(void *objspace_ptr);
     void (*gc_disable)(void *objspace_ptr, bool finish_current_gc);
     bool (*gc_enabled_p)(void *objspace_ptr);
@@ -789,6 +790,7 @@ ruby_modular_gc_init(void)
     load_modular_gc_func(start);
     load_modular_gc_func(during_gc_p);
     load_modular_gc_func(prepare_heap);
+    load_modular_gc_func(wait_for_background_sweep);
     load_modular_gc_func(gc_enable);
     load_modular_gc_func(gc_disable);
     load_modular_gc_func(gc_enabled_p);
@@ -877,6 +879,7 @@ ruby_modular_gc_init(void)
 # define rb_gc_impl_start rb_gc_functions.start
 # define rb_gc_impl_during_gc_p rb_gc_functions.during_gc_p
 # define rb_gc_impl_prepare_heap rb_gc_functions.prepare_heap
+# define rb_gc_impl_wait_for_background_sweep rb_gc_functions.wait_for_background_sweep
 # define rb_gc_impl_gc_enable rb_gc_functions.gc_enable
 # define rb_gc_impl_gc_disable rb_gc_functions.gc_disable
 # define rb_gc_impl_gc_enabled_p rb_gc_functions.gc_enabled_p
@@ -5846,6 +5849,12 @@ rb_gc_before_fork(void)
     rb_gc_impl_before_fork(rb_gc_get_objspace());
 }
 
+void
+rb_gc_wait_for_background_sweep(void)
+{
+    rb_gc_impl_wait_for_background_sweep(rb_gc_get_objspace());
+}
+
 void
 rb_gc_after_fork(rb_pid_t pid)
 {

gc/default/default.c

@@ -11368,6 +11368,15 @@ gc_malloc_allocations(VALUE self)
 }
 #endif
 
+void
+rb_gc_impl_wait_for_background_sweep(void *objspace_ptr)
+{
+#if USE_PARALLEL_SWEEP
+    rb_objspace_t *objspace = objspace_ptr;
+    wait_for_background_sweeping_to_finish(objspace, true, false, "impl_wait_for_background_sweep");
+#endif
+}
+
 void
 rb_gc_impl_before_fork(void *objspace_ptr)
 {

gc/gc_impl.h

@@ -47,6 +47,7 @@ GC_IMPL_FN void rb_gc_impl_ractor_cache_free(void *objspace_ptr, void *cache);
 GC_IMPL_FN void rb_gc_impl_start(void *objspace_ptr, bool full_mark, bool immediate_mark, bool immediate_sweep, bool compact);
 GC_IMPL_FN bool rb_gc_impl_during_gc_p(void *objspace_ptr);
 GC_IMPL_FN void rb_gc_impl_prepare_heap(void *objspace_ptr);
+GC_IMPL_FN void rb_gc_impl_wait_for_background_sweep(void *objspace_ptr);
 GC_IMPL_FN void rb_gc_impl_gc_enable(void *objspace_ptr);
 GC_IMPL_FN void rb_gc_impl_gc_disable(void *objspace_ptr, bool finish_current_gc);
 GC_IMPL_FN bool rb_gc_impl_gc_enabled_p(void *objspace_ptr);

gc/mmtk/mmtk.c

@@ -1391,6 +1391,12 @@ rb_gc_impl_shutdown_call_finalizer(void *objspace_ptr)
     gc_run_finalizers(objspace);
 }
 
+void
+rb_gc_impl_wait_for_background_sweep(void *objspace_ptr)
+{
+    // MMTk has no background sweep thread.
+}
+
 // Forking
 
 void

gc/wbcheck/wbcheck.c

@@ -1735,6 +1735,12 @@ rb_gc_impl_shutdown_call_finalizer(void *objspace_ptr)
     RB_GC_VM_UNLOCK(lev);
 }
 
+void
+rb_gc_impl_wait_for_background_sweep(void *objspace_ptr)
+{
+    // Stub implementation
+}
+
 // Forking
 void
 rb_gc_impl_before_fork(void *objspace_ptr)

ruby.c

@@ -1833,6 +1833,9 @@ ruby_opt_init(ruby_cmdline_options_t *opt)
 
     // Register JIT-optimized builtin CMEs before the prelude, which may
     // redefine core methods (e.g. Kernel.prepend via bundler/setup).
+#if USE_YJIT || USE_ZJIT
+    rb_gc_wait_for_background_sweep();
+#endif
 #if USE_YJIT
     rb_yjit_init_builtin_cmes();
 #endif
@@ -1877,6 +1880,9 @@ ruby_opt_init(ruby_cmdline_options_t *opt)
     ruby_init_prelude();
 
     // Enable JITs after ruby_init_prelude() to avoid JITing prelude code.
+#if USE_YJIT || USE_ZJIT
+    rb_gc_wait_for_background_sweep();
+#endif
 #if USE_YJIT
     rb_yjit_init(opt->yjit);
 #endif

yjit.c

@@ -398,6 +398,7 @@ rb_yjit_compile_iseq(const rb_iseq_t *iseq, rb_execution_context_t *ec, bool jit
 {
     RB_VM_LOCKING() {
         rb_vm_barrier();
+        rb_gc_wait_for_background_sweep();
 
         // Compile a block version starting at the current instruction
         uint8_t *rb_yjit_iseq_gen_entry_point(const rb_iseq_t *iseq, rb_execution_context_t *ec, bool jit_exception); // defined in Rust

zjit.c

@@ -39,6 +39,7 @@ rb_zjit_compile_iseq(const rb_iseq_t *iseq, rb_execution_context_t *ec, bool jit
 {
     RB_VM_LOCKING() {
         rb_vm_barrier();
+        rb_gc_wait_for_background_sweep();
 
         // Compile a block version starting at the current instruction
         uint8_t *rb_zjit_iseq_gen_entry_point(const rb_iseq_t *iseq, rb_execution_context_t *ec, bool jit_exception); // defined in Rust