[browser] mono_wasm_enable_gc and pump_count cleanup (dotnet#111198)

src/mono/browser/runtime/runtime.c

@@ -62,8 +62,6 @@
 #define EMSCRIPTEN_KEEPALIVE
 #endif
 
-int mono_wasm_enable_gc = 1;
-
 /* Missing from public headers */
 char *mono_fixup_symbol_name (const char *prefix, const char *key, const char *suffix);
 void mono_icall_table_init (void);

src/mono/browser/runtime/runtime.h

@@ -13,8 +13,6 @@
 #include <mono/metadata/object.h>
 #include <mono/metadata/debug-helpers.h>
 
-extern int mono_wasm_enable_gc;
-
 MonoDomain *mono_wasm_load_runtime_common (int debug_level, MonoLogCallback log_callback, const char *interp_opts);
 MonoAssembly *mono_wasm_assembly_load (const char *name);
 MonoClass *mono_wasm_assembly_find_class (MonoAssembly *assembly, const char *namespace, const char *name);

src/mono/browser/runtime/scheduling.ts

@@ -8,7 +8,6 @@ import { Module, loaderHelpers } from "./globals";
 import { forceThreadMemoryViewRefresh } from "./memory";
 
 let spread_timers_maximum = 0;
-let pump_count = 0;
 
 export function prevent_timer_throttling (): void {
     if (WasmEnableThreads) return;
@@ -37,7 +36,6 @@ function prevent_timer_throttling_tick () {
     }
     try {
         cwraps.mono_wasm_execute_timer();
-        pump_count++;
     } catch (ex) {
         loaderHelpers.mono_exit(1, ex);
     }
@@ -46,24 +44,24 @@ function prevent_timer_throttling_tick () {
 
 function mono_background_exec_until_done () {
     if (WasmEnableThreads) return;
+    lastScheduledBackground = undefined;
     Module.maybeExit();
+    if (!loaderHelpers.is_runtime_running()) {
+        return;
+    }
     try {
-        while (pump_count > 0) {
-            --pump_count;
-            if (!loaderHelpers.is_runtime_running()) {
-                return;
-            }
-            cwraps.mono_background_exec();
-        }
+        cwraps.mono_background_exec();
     } catch (ex) {
         loaderHelpers.mono_exit(1, ex);
     }
 }
 
+let lastScheduledBackground: any = undefined;
 export function schedule_background_exec (): void {
     if (WasmEnableThreads) return;
-    ++pump_count;
-    Module.safeSetTimeout(mono_background_exec_until_done, 0);
+    if (!lastScheduledBackground) {
+        lastScheduledBackground = Module.safeSetTimeout(mono_background_exec_until_done, 0);
+    }
 }
 
 let lastScheduledTimeoutId: any = undefined;
@@ -86,7 +84,6 @@ function mono_wasm_schedule_timer_tick () {
     lastScheduledTimeoutId = undefined;
     try {
         cwraps.mono_wasm_execute_timer();
-        pump_count++;
     } catch (ex) {
         loaderHelpers.mono_exit(1, ex);
     }

src/mono/mono/metadata/sgen-mono.c

@@ -2067,10 +2067,6 @@ pin_handle_stack_interior_ptrs (void **ptr_slot, void *user_data)
 	sgen_conservatively_pin_objects_from (ptr_slot, ptr_slot+1, ud->start_nursery, ud->end_nursery, PIN_TYPE_STACK);
 }
 
-#if defined(HOST_WASM) || defined(HOST_WASI)
-extern gboolean mono_wasm_enable_gc;
-#endif
-
 /*
  * Mark from thread stacks and registers.
  */
@@ -2079,11 +2075,6 @@ sgen_client_scan_thread_data (void *start_nursery, void *end_nursery, gboolean p
 {
 	scan_area_arg_start = start_nursery;
 	scan_area_arg_end = end_nursery;
-#if defined(HOST_WASM) || defined(HOST_WASI)
-	//Under WASM we don't scan thread stacks and we can't trust the values we find there either.
-	if (!mono_wasm_enable_gc)
-		return;
-#endif
 
 	SGEN_TV_DECLARE (scan_thread_data_start);
 	SGEN_TV_DECLARE (scan_thread_data_end);

src/mono/mono/sgen/sgen-gc.c

@@ -2733,32 +2733,9 @@ gc_pump_callback (void)
 }
 #endif
 
-#if defined(HOST_BROWSER) || defined(HOST_WASI)
-extern gboolean mono_wasm_enable_gc;
-#endif
-
 void
 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean forced_serial, gboolean stw)
 {
-#if defined(HOST_BROWSER) && defined(DISABLE_THREADS)
-	if (!mono_wasm_enable_gc) {
-		g_assert (stw); //can't handle non-stw mode (IE, domain unload)
-		//we ignore forced_serial
-
-		//There's a window for racing where we're executing other bg jobs before the GC, they trigger a GC request and it overrides this one.
-		//I belive this case to be benign as it will, in the worst case, upgrade a minor to a major collection.
-		if (gc_request.generation_to_collect <= generation_to_collect) {
-			gc_request.requested_size = requested_size;
-			gc_request.generation_to_collect = generation_to_collect;
-			gc_request.reason = reason;
-			sgen_client_schedule_background_job (gc_pump_callback);
-		}
-
-		sgen_degraded_mode = 1; //enable degraded mode so allocation can continue
-		return;
-	}
-#endif
-
 	sgen_perform_collection_inner (requested_size, generation_to_collect, reason, forced_serial, stw);
 }
 /*