[rfc] parallel marking

base/options.jl

@@ -14,6 +14,7 @@ struct JLOptions
     nthreads_per_pool::Ptr{Int16}
     nprocs::Int32
     machine_file::Ptr{UInt8}
+    parallel_marking::UInt8;
     project::Ptr{UInt8}
     isinteractive::Int8
     color::Int8

src/Makefile

@@ -44,8 +44,8 @@ SRCS := \
 	jltypes gf typemap smallintset ast builtins module interpreter symbol \
 	dlload sys init task array dump staticdata toplevel jl_uv datatype \
 	simplevector runtime_intrinsics precompile jloptions \
-	threading partr stackwalk gc gc-debug gc-pages gc-stacks gc-alloc-profiler method \
-	jlapi signal-handling safepoint timing subtype rtutils \
+	threading partr stackwalk gc gc-debug gc-pages gc-stacks gc-alloc-profiler wsqueue \
+	method jlapi signal-handling safepoint timing subtype rtutils \
 	crc32c APInt-C processor ircode opaque_closure codegen-stubs coverage runtime_ccall
 
 RT_LLVMLINK :=
@@ -98,7 +98,7 @@ ifeq ($(USE_SYSTEM_LIBUV),0)
 UV_HEADERS += uv.h
 UV_HEADERS += uv/*.h
 endif
-PUBLIC_HEADERS := $(BUILDDIR)/julia_version.h $(wildcard $(SRCDIR)/support/*.h) $(addprefix $(SRCDIR)/,julia.h julia_assert.h julia_threads.h julia_fasttls.h julia_locks.h julia_atomics.h jloptions.h)
+PUBLIC_HEADERS := $(BUILDDIR)/julia_version.h $(wildcard $(SRCDIR)/support/*.h) $(addprefix $(SRCDIR)/,julia.h julia_assert.h julia_threads.h julia_fasttls.h julia_locks.h julia_atomics.h jloptions.h options.h wsqueue.h)
 ifeq ($(OS),WINNT)
 PUBLIC_HEADERS += $(addprefix $(SRCDIR)/,win32_ucontext.h)
 endif

src/gc-debug.c

@@ -198,21 +198,21 @@ static void restore(void)
 
 static void gc_verify_track(jl_ptls_t ptls)
 {
-    jl_gc_mark_cache_t *gc_cache = &ptls->gc_cache;
     do {
-        jl_gc_mark_sp_t sp;
-        gc_mark_sp_init(gc_cache, &sp);
+        jl_gc_markqueue_t mq;
+        mq.current = mq.start = (ptls->mark_queue).start;
+        mq.end = (ptls->mark_queue).end;
         arraylist_push(&lostval_parents_done, lostval);
         jl_safe_printf("Now looking for %p =======\n", lostval);
         clear_mark(GC_CLEAN);
-        gc_mark_queue_all_roots(ptls, &sp);
-        gc_mark_queue_finlist(gc_cache, &sp, &to_finalize, 0);
+        gc_mark_queue_all_roots(ptls, &mq);
+        gc_mark_finlist(&mq, &to_finalize, 0);
         for (int i = 0;i < jl_n_threads;i++) {
             jl_ptls_t ptls2 = jl_all_tls_states[i];
-            gc_mark_queue_finlist(gc_cache, &sp, &ptls2->finalizers, 0);
+            gc_mark_finlist(&mq, &ptls2->finalizers, 0);
         }
-        gc_mark_queue_finlist(gc_cache, &sp, &finalizer_list_marked, 0);
-        gc_mark_loop(ptls, sp);
+        gc_mark_finlist(&mq, &finalizer_list_marked, 0);
+        gc_mark_loop_(ptls, &mq);
         if (lostval_parents.len == 0) {
             jl_safe_printf("Could not find the missing link. We missed a toplevel root. This is odd.\n");
             break;
@@ -246,22 +246,22 @@ static void gc_verify_track(jl_ptls_t ptls)
 
 void gc_verify(jl_ptls_t ptls)
 {
-    jl_gc_mark_cache_t *gc_cache = &ptls->gc_cache;
-    jl_gc_mark_sp_t sp;
-    gc_mark_sp_init(gc_cache, &sp);
+    jl_gc_markqueue_t mq;
+    mq.current = mq.start = (ptls->mark_queue).start;
+    mq.end = (ptls->mark_queue).end;
     lostval = NULL;
     lostval_parents.len = 0;
     lostval_parents_done.len = 0;
     clear_mark(GC_CLEAN);
     gc_verifying = 1;
-    gc_mark_queue_all_roots(ptls, &sp);
-    gc_mark_queue_finlist(gc_cache, &sp, &to_finalize, 0);
+    gc_mark_queue_all_roots(ptls, &mq);
+    gc_mark_finlist(&mq, &to_finalize, 0);
     for (int i = 0;i < jl_n_threads;i++) {
         jl_ptls_t ptls2 = jl_all_tls_states[i];
-        gc_mark_queue_finlist(gc_cache, &sp, &ptls2->finalizers, 0);
+        gc_mark_finlist(&mq, &ptls2->finalizers, 0);
     }
-    gc_mark_queue_finlist(gc_cache, &sp, &finalizer_list_marked, 0);
-    gc_mark_loop(ptls, sp);
+    gc_mark_finlist(&mq, &finalizer_list_marked, 0);
+    gc_mark_loop_(ptls, &mq);
     int clean_len = bits_save[GC_CLEAN].len;
     for(int i = 0; i < clean_len + bits_save[GC_OLD].len; i++) {
         jl_taggedvalue_t *v = (jl_taggedvalue_t*)bits_save[i >= clean_len ? GC_OLD : GC_CLEAN].items[i >= clean_len ? i - clean_len : i];
@@ -537,7 +537,6 @@ void gc_scrub_record_task(jl_task_t *t)
 
 static void gc_scrub_range(char *low, char *high)
 {
-    jl_ptls_t ptls = jl_current_task->ptls;
     jl_jmp_buf *old_buf = jl_get_safe_restore();
     jl_jmp_buf buf;
     if (jl_setjmp(buf, 0)) {
@@ -1269,10 +1268,11 @@ int gc_slot_to_arrayidx(void *obj, void *_slot)
     return (slot - start) / elsize;
 }
 
-// Print a backtrace from the bottom (start) of the mark stack up to `sp`
-// `pc_offset` will be added to `sp` for convenience in the debugger.
-NOINLINE void gc_mark_loop_unwind(jl_ptls_t ptls, jl_gc_mark_sp_t sp, int pc_offset)
+// Print a backtrace from the `mq->start` of the mark queue up to `mq->current`
+// `offset` will be added to `mq->current` for convenience in the debugger.
+NOINLINE void gc_mark_loop_unwind(jl_ptls_t ptls, jl_gc_markqueue_t *mq, int offset)
 {
+#ifdef GC_VERIFY
     jl_jmp_buf *old_buf = jl_get_safe_restore();
     jl_jmp_buf buf;
     jl_set_safe_restore(&buf);
@@ -1281,125 +1281,17 @@ NOINLINE void gc_mark_loop_unwind(jl_ptls_t ptls, jl_gc_mark_sp_t sp, int pc_off
         jl_set_safe_restore(old_buf);
         return;
     }
-    void **top = sp.pc + pc_offset;
-    jl_gc_mark_data_t *data_top = sp.data;
-    sp.data = ptls->gc_cache.data_stack;
-    sp.pc = ptls->gc_cache.pc_stack;
-    int isroot = 1;
-    while (sp.pc < top) {
-        void *pc = *sp.pc;
-        const char *prefix = isroot ? "r--" : " `-";
-        isroot = 0;
-        if (pc == gc_mark_label_addrs[GC_MARK_L_marked_obj]) {
-            gc_mark_marked_obj_t *data = gc_repush_markdata(&sp, gc_mark_marked_obj_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_safe_printf("%p: Root object: %p :: %p (bits: %d)\n        of type ",
-                           (void*)data, (void*)data->obj, (void*)data->tag, (int)data->bits);
-            jl_((void*)data->tag);
-            isroot = 1;
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_scan_only]) {
-            gc_mark_marked_obj_t *data = gc_repush_markdata(&sp, gc_mark_marked_obj_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_safe_printf("%p: Queued root: %p :: %p (bits: %d)\n        of type ",
-                           (void*)data, (void*)data->obj, (void*)data->tag, (int)data->bits);
-            jl_((void*)data->tag);
-            isroot = 1;
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_finlist]) {
-            gc_mark_finlist_t *data = gc_repush_markdata(&sp, gc_mark_finlist_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_safe_printf("%p: Finalizer list from %p to %p\n",
-                           (void*)data, (void*)data->begin, (void*)data->end);
-            isroot = 1;
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_objarray]) {
-            gc_mark_objarray_t *data = gc_repush_markdata(&sp, gc_mark_objarray_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_safe_printf("%p:  %s Array in object %p :: %p -- [%p, %p)\n        of type ",
-                           (void*)data, prefix, (void*)data->parent, ((void**)data->parent)[-1],
-                           (void*)data->begin, (void*)data->end);
-            jl_(jl_typeof(data->parent));
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_obj8]) {
-            gc_mark_obj8_t *data = gc_repush_markdata(&sp, gc_mark_obj8_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_datatype_t *vt = (jl_datatype_t*)jl_typeof(data->parent);
-            uint8_t *desc = (uint8_t*)jl_dt_layout_ptrs(vt->layout);
-            jl_safe_printf("%p:  %s Object (8bit) %p :: %p -- [%d, %d)\n        of type ",
-                           (void*)data, prefix, (void*)data->parent, ((void**)data->parent)[-1],
-                           (int)(data->begin - desc), (int)(data->end - desc));
-            jl_(jl_typeof(data->parent));
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_obj16]) {
-            gc_mark_obj16_t *data = gc_repush_markdata(&sp, gc_mark_obj16_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_datatype_t *vt = (jl_datatype_t*)jl_typeof(data->parent);
-            uint16_t *desc = (uint16_t*)jl_dt_layout_ptrs(vt->layout);
-            jl_safe_printf("%p:  %s Object (16bit) %p :: %p -- [%d, %d)\n        of type ",
-                           (void*)data, prefix, (void*)data->parent, ((void**)data->parent)[-1],
-                           (int)(data->begin - desc), (int)(data->end - desc));
-            jl_(jl_typeof(data->parent));
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_obj32]) {
-            gc_mark_obj32_t *data = gc_repush_markdata(&sp, gc_mark_obj32_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_datatype_t *vt = (jl_datatype_t*)jl_typeof(data->parent);
-            uint32_t *desc = (uint32_t*)jl_dt_layout_ptrs(vt->layout);
-            jl_safe_printf("%p:  %s Object (32bit) %p :: %p -- [%d, %d)\n        of type ",
-                           (void*)data, prefix, (void*)data->parent, ((void**)data->parent)[-1],
-                           (int)(data->begin - desc), (int)(data->end - desc));
-            jl_(jl_typeof(data->parent));
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_stack]) {
-            gc_mark_stackframe_t *data = gc_repush_markdata(&sp, gc_mark_stackframe_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_safe_printf("%p:  %s Stack frame %p -- %d of %d (%s)\n",
-                           (void*)data, prefix, (void*)data->s, (int)data->i,
-                           (int)data->nroots >> 1,
-                           (data->nroots & 1) ? "indirect" : "direct");
-        }
-        else if (pc == gc_mark_label_addrs[GC_MARK_L_module_binding]) {
-            // module_binding
-            gc_mark_binding_t *data = gc_repush_markdata(&sp, gc_mark_binding_t);
-            if ((jl_gc_mark_data_t *)data > data_top) {
-                jl_safe_printf("Mark stack unwind overflow -- ABORTING !!!\n");
-                break;
-            }
-            jl_safe_printf("%p:  %s Module (bindings) %p (bits %d) -- [%p, %p)\n",
-                           (void*)data, prefix, (void*)data->parent, (int)data->bits,
-                           (void*)data->begin, (void*)data->end);
-        }
-        else {
-            jl_safe_printf("Unknown pc %p --- ABORTING !!!\n", pc);
-            break;
-        }
+    jl_value_t **start = mq->start;
+    jl_value_t **end = mq->current + offset;
+    for (; start < end; start++) {
+        jl_value_t *obj = *start;
+        jl_taggedvalue_t *o = jl_astaggedvalue(obj);
+        jl_safe_printf("Queued object: %p :: (header: %zu) (bits: %zu)\n", obj, (uintptr_t)o->header,
+                        ((uintptr_t)o->header & 3));
+        jl_((void*)(jl_datatype_t *)(o->header & ~(uintptr_t)0xf));
     }
     jl_set_safe_restore(old_buf);
+#endif
 }
 
 static int gc_logging_enabled = 0;