coroutines: fix segfaults with GC (part 1) (#20549)

thirdparty/photon/photonwrapper.h

@@ -19,24 +19,39 @@
 #include <iostream>
 
 extern "C" {
-// using namespace photon;
+
 // WorkPool* work_pool;
-// WorkPool* new_photon_work_pool();
 photon::WorkPool* work_pool;
+
+// using namespace photon;
+// typedef WorkPool PhotonWorkPool;
+// typedef photon::WorkPool PhotonWorkPool1;
 #else
 #endif
 
+// using namespace photon;
+// typedef WorkPool PhotonWorkPool;
+// typedef photon::WorkPool PhotonWorkPool;
+// typedef WorkPool PhotonWorkPool;
+// typedef PhotonWorkPool1 PhotonWorkPool;
+// PhotonWorkPool* new_photon_work_pool();
+void* new_photon_work_pool(size_t);
+// void delete_photon_work_pool(void*);
+void delete_photon_work_pool();
 // custom v functions
 void init_photon_work_pool(size_t);
+// void photon_thread_migrate();
+// void photon_thread_migrate(void*);
 void photon_thread_create_and_migrate_to_work_pool(void* (* f)(void*), void* arg);
+// void photon_thread_create_and_migrate_to_work_pool(void*, void* (* f)(void*), void* arg);
 // direct wrappers to photon functions
 int photon_init_default();
 void photon_thread_create(void* (* f)(void*), void* arg);
 void photon_sleep_s(int n);
 void photon_sleep_ms(int n);
 
-// void* default_photon_thread_stack_alloc(void*, size_t size);
-// void default_photon_thread_stack_dealloc(void*, void* ptr, size_t size);
+void* default_photon_thread_stack_alloc(void*, size_t size);
+void default_photon_thread_stack_dealloc(void*, void* ptr, size_t size);
 void set_photon_thread_stack_allocator(
     void* (*alloc_func)(void*, size_t),
     void (*dealloc_func)(void*, void*, size_t)

vlib/builtin/builtin_d_gcboehm.c.v

@@ -143,5 +143,16 @@ pub fn gc_check_leaks() {
 fn C.GC_get_heap_usage_safe(pheap_size &usize, pfree_bytes &usize, punmapped_bytes &usize, pbytes_since_gc &usize, ptotal_bytes &usize)
 fn C.GC_get_memory_use() usize
 
+pub struct C.GC_stack_base {
+	mem_base voidptr
+	// reg_base voidptr
+}
+
+// pub struct C.GC_stack_base{}
+
+fn C.GC_get_stack_base(voidptr)
+fn C.GC_register_my_thread(voidptr) int
+fn C.GC_unregister_my_thread() int
+
 fn C.GC_add_roots(voidptr, voidptr)
 fn C.GC_remove_roots(voidptr, voidptr)

vlib/coroutines/coroutines.c.v

@@ -11,45 +11,77 @@ import time
 
 #include "photonwrapper.h"
 
-// struct C.WorkPool {}
-// fn C.new_photon_work_pool) C.WorkPool
+fn C.set_photon_thread_stack_allocator(fn (voidptr, int) voidptr, fn (voidptr, voidptr, int))
+fn C.default_photon_thread_stack_alloc(voidptr, int) voidptr
+fn C.default_photon_thread_stack_dealloc(voidptr, voidptr, int)
+fn C.new_photon_work_pool(int) voidptr
+fn C.delete_photon_work_pool()
 fn C.init_photon_work_pool(int)
-
-// fn C.photon_thread_create_and_migrate_to_work_pool(f voidptr, arg voidptr)
+fn C.init_photon_manual(int, fn ())
+fn C.init_photon_manual2(fn (), fn ())
+fn C.photon_thread_create_and_migrate_to_work_pool(f voidptr, arg voidptr)
 fn C.photon_thread_create(f voidptr, arg voidptr)
+fn C.photon_thread_migrate()
+
+// fn C.photon_thread_migrate(work_pool voidptr)
 fn C.photon_init_default() int
+
 fn C.photon_sleep_s(n int)
 fn C.photon_sleep_ms(n int)
-fn C.set_photon_thread_stack_allocator(fn (voidptr, int) voidptr, fn (voidptr, voidptr, int))
 
 // sleep is coroutine-safe version of time.sleep()
 pub fn sleep(duration time.Duration) {
 	C.photon_sleep_ms(duration.milliseconds())
 }
 
-fn init() {
-	alloc := fn (_ voidptr, stack_size int) voidptr {
-		unsafe {
-			stack_ptr := malloc(stack_size)
-			$if gcboehm ? {
-				C.GC_add_roots(stack_ptr, charptr(stack_ptr) + stack_size)
-			}
-			return stack_ptr
+fn alloc(_ voidptr, stack_size int) voidptr {
+	// println('## alloc called')
+	unsafe {
+		// thread_id := C.pthread_self()
+		// println('## Thread ID: $thread_id')
+
+		// $if gcboehm ? {
+		// 	mut sb := C.GC_stack_base{}
+		// 	C.GC_get_stack_base(&sb)
+		// 	C.GC_register_my_thread(&sb)
+		// 	// res = C.GC_register_my_thread(&sb)
+		// 	// println('## RES: $res')
+		// }
+
+		// NOTE: when using malloc (GC_MALLOC) we get a segfault
+		// when migrating from a new thread to a work pool thread
+		// stack_ptr := malloc(stack_size)
+		// stack_ptr := C.malloc(stack_size)
+		stack_ptr := C.default_photon_thread_stack_alloc(nil, stack_size)
+
+		$if gcboehm ? {
+			C.GC_add_roots(stack_ptr, charptr(stack_ptr) + stack_size)
 		}
+
+		return stack_ptr
 	}
-	dealloc := fn (_ voidptr, stack_ptr voidptr, stack_size int) {
-		unsafe {
-			$if gcboehm ? {
-				C.GC_remove_roots(stack_ptr, charptr(stack_ptr) + stack_size)
-			}
-			free(stack_ptr)
+}
+
+fn dealloc(_ voidptr, stack_ptr voidptr, stack_size int) {
+	// println('## dealloc called')
+	unsafe {
+		$if gcboehm ? {
+			// C.GC_unregister_my_thread()
+			C.GC_remove_roots(stack_ptr, charptr(stack_ptr) + stack_size)
 		}
+		// free(stack_ptr)
+		C.default_photon_thread_stack_dealloc(nil, stack_ptr, stack_size)
 	}
+}
+
+fn init() {
 	C.set_photon_thread_stack_allocator(alloc, dealloc)
 	ret := C.photon_init_default()
-	if util.nr_jobs > 0 {
+
+	if util.nr_jobs >= 1 {
 		C.init_photon_work_pool(util.nr_jobs)
 	}
+
 	if ret < 0 {
 		panic('failed to initialize coroutines via photon (ret=${ret})')
 	}

vlib/v/gen/c/cgen.v

@@ -6173,6 +6173,9 @@ fn (mut g Gen) write_init_function() {
 	for x in cleaning_up_array.reverse() {
 		g.writeln(x)
 	}
+	if g.pref.use_coroutines {
+		g.writeln('\tdelete_photon_work_pool();')
+	}
 	g.writeln('}')
 	if g.pref.printfn_list.len > 0 && '_vcleanup' in g.pref.printfn_list {
 		println(g.out.after(fn_vcleanup_start_pos))

vlib/v/gen/c/cmain.v

@@ -110,7 +110,10 @@ fn (mut g Gen) gen_c_main_header() {
 			g.writeln('\tGC_set_find_leak(1);')
 		}
 		g.writeln('\tGC_set_pages_executable(0);')
+		// NOTE: required when using GC_MALLOC & GC_register_my_thread
+		// g.writeln('\tGC_allow_register_threads();')
 		g.writeln('\tGC_INIT();')
+
 		if g.pref.gc_mode in [.boehm_incr, .boehm_incr_opt] {
 			g.writeln('\tGC_enable_incremental();')
 		}
@@ -242,6 +245,8 @@ pub fn (mut g Gen) gen_c_main_for_tests() {
 			g.writeln('\tGC_set_find_leak(1);')
 		}
 		g.writeln('\tGC_set_pages_executable(0);')
+		// NOTE: required when using GC_MALLOC & GC_register_my_thread
+		// g.writeln('\tGC_allow_register_threads();')
 		g.writeln('\tGC_INIT();')
 		if g.pref.gc_mode in [.boehm_incr, .boehm_incr_opt] {
 			g.writeln('\tGC_enable_incremental();')

vlib/v/gen/c/spawn_and_go.v

@@ -162,7 +162,7 @@ fn (mut g Gen) spawn_and_go_expr(node ast.SpawnExpr, mode SpawnGoMode) {
 			}
 		}
 	} else if is_go {
-		if util.nr_jobs > 0 {
+		if util.nr_jobs > 1 {
 			g.writeln('photon_thread_create_and_migrate_to_work_pool((void*)${wrapper_fn_name}, &${arg_tmp_var});')
 		} else {
 			g.writeln('photon_thread_create((void*)${wrapper_fn_name}, &${arg_tmp_var});')