Merge pull request #893 from oleavr/api-suspend-resume

Add suspend and resume API

AUTHORS.rst

@@ -34,6 +34,7 @@ and agreed to irrevocably license their contributions under the Duktape
 * Ondřej Jirman (https://github.com/megous)
 * Saúl Ibarra Corretgé <saghul@gmail.com>
 * Jeremy HU <huxingyi@msn.com>
+* Ole André Vadla Ravnås (https://github.com/oleavr)
 
 Other contributions
 ===================
@@ -71,7 +72,6 @@ bugs, provided ideas, etc; roughly in order of appearance):
 * Michael Drake (https://github.com/tlsa)
 * https://github.com/chris-y
 * Laurent Zubiaur (https://github.com/lzubiaur)
-* Ole André Vadla Ravnås (https://github.com/oleavr)
 
 If you are accidentally missing from this list, send me an e-mail
 (``sami.vaarala@iki.fi``) and I'll fix the omission.

src/duk_api_heap.c

@@ -4,6 +4,15 @@
 
 #include "duk_internal.h"
 
+typedef struct duk_internal_thread_state duk_internal_thread_state;
+
+struct duk_internal_thread_state {
+	duk_ljstate lj;
+	duk_bool_t handling_error;
+	duk_hthread *curr_thread;
+	duk_int_t call_recursion_depth;
+};
+
 DUK_EXTERNAL
 duk_context *duk_create_heap(duk_alloc_function alloc_func,
                              duk_realloc_function realloc_func,
@@ -69,6 +78,55 @@ DUK_EXTERNAL void duk_destroy_heap(duk_context *ctx) {
 	duk_heap_free(heap);
 }
 
+DUK_EXTERNAL void duk_suspend(duk_context *ctx, duk_thread_state *state) {
+	duk_hthread *thr = (duk_hthread *) ctx;
+	duk_internal_thread_state *snapshot = (duk_internal_thread_state *) state;
+	duk_heap *heap;
+	duk_ljstate *lj;
+
+	DUK_ASSERT_CTX_VALID(ctx);
+	DUK_ASSERT(thr != NULL);
+	DUK_ASSERT(thr->heap != NULL);
+
+	heap = thr->heap;
+	lj = &heap->lj;
+
+	duk_push_tval(ctx, &lj->value1);
+	duk_push_tval(ctx, &lj->value2);
+
+	DUK_MEMMOVE((void *) &snapshot->lj, (const void *) lj, sizeof(duk_ljstate));
+	snapshot->handling_error = heap->handling_error;
+	snapshot->curr_thread = heap->curr_thread;
+	snapshot->call_recursion_depth = heap->call_recursion_depth;
+
+	lj->jmpbuf_ptr = NULL;
+	lj->type = DUK_LJ_TYPE_UNKNOWN;
+	DUK_TVAL_SET_UNDEFINED(&lj->value1);
+	DUK_TVAL_SET_UNDEFINED(&lj->value2);
+	heap->handling_error = 0;
+	heap->curr_thread = NULL;
+	heap->call_recursion_depth = 0;
+}
+
+DUK_EXTERNAL void duk_resume(duk_context *ctx, const duk_thread_state *state) {
+	duk_hthread *thr = (duk_hthread *) ctx;
+	const duk_internal_thread_state *snapshot = (const duk_internal_thread_state *) state;
+	duk_heap *heap;
+
+	DUK_ASSERT_CTX_VALID(ctx);
+	DUK_ASSERT(thr != NULL);
+	DUK_ASSERT(thr->heap != NULL);
+
+	heap = thr->heap;
+
+	DUK_MEMMOVE((void *) &heap->lj, (const void *) &snapshot->lj, sizeof(duk_ljstate));
+	heap->handling_error = snapshot->handling_error;
+	heap->curr_thread = snapshot->curr_thread;
+	heap->call_recursion_depth = snapshot->call_recursion_depth;
+
+	duk_pop_2(ctx);
+}
+
 /* XXX: better place for this */
 DUK_EXTERNAL void duk_set_global_object(duk_context *ctx) {
 	duk_hthread *thr = (duk_hthread *) ctx;

src/duk_api_public.h.in

@@ -32,6 +32,7 @@ extern "C" {
  *  in Duktape web documentation.
  */
 
+struct duk_thread_state;
 struct duk_memory_functions;
 struct duk_function_list_entry;
 struct duk_number_list_entry;
@@ -40,6 +41,7 @@ struct duk_time_components;
 /* duk_context is now defined in duk_config.h because it may also be
  * referenced there by prototypes.
  */
+typedef struct duk_thread_state duk_thread_state;
 typedef struct duk_memory_functions duk_memory_functions;
 typedef struct duk_function_list_entry duk_function_list_entry;
 typedef struct duk_number_list_entry duk_number_list_entry;
@@ -61,6 +63,10 @@ typedef void (*duk_debug_write_flush_function) (void *udata);
 typedef duk_idx_t (*duk_debug_request_function) (duk_context *ctx, void *udata, duk_idx_t nvalues);
 typedef void (*duk_debug_detached_function) (duk_context *ctx, void *udata);
 
+struct duk_thread_state {
+	char data[128];
+};
+
 struct duk_memory_functions {
 	duk_alloc_function alloc_func;
 	duk_realloc_function realloc_func;
@@ -256,6 +262,9 @@ duk_context *duk_create_heap(duk_alloc_function alloc_func,
                              duk_fatal_function fatal_handler);
 DUK_EXTERNAL_DECL void duk_destroy_heap(duk_context *ctx);
 
+DUK_EXTERNAL_DECL void duk_suspend(duk_context *ctx, duk_thread_state *state);
+DUK_EXTERNAL_DECL void duk_resume(duk_context *ctx, const duk_thread_state *state);
+
 #define duk_create_heap_default() \
 	duk_create_heap(NULL, NULL, NULL, NULL, NULL)