wasm/machine.c

   1 #include <stdlib.h>
   2 #include "wasm/machine.h"
   3 #include "wasm/asyncify.h"
   4
   5 #ifndef WASM_SCAN_STACK_BUFFER_SIZE
   6 # define WASM_SCAN_STACK_BUFFER_SIZE 6144
   7 #endif
   8
   9 struct asyncify_buf {
  10     void *top;
  11     void *end;
  12     uint8_t buffer[WASM_SCAN_STACK_BUFFER_SIZE];
  13 };
  14
  15 static void
  16 init_asyncify_buf(struct asyncify_buf* buf)
  17 {
  18     buf->top = &buf->buffer[0];
  19     buf->end = &buf->buffer[WASM_SCAN_STACK_BUFFER_SIZE];
  20 }
  21
  22 static void *_rb_wasm_active_scan_buf = NULL;
  23
  24 void
  25 rb_wasm_scan_locals(rb_wasm_scan_func scan)
  26 {
  27     static struct asyncify_buf buf;
  28     static int spilling = 0;
  29     if (!spilling) {
  30         spilling = 1;
  31         init_asyncify_buf(&buf);
  32         _rb_wasm_active_scan_buf = &buf;
  33         asyncify_start_unwind(&buf);
  34     } else {
  35         asyncify_stop_rewind();
  36         spilling = 0;
  37         _rb_wasm_active_scan_buf = NULL;
  38         scan(buf.top, buf.end);
  39     }
  40 }
  41
  42 static void *rb_wasm_stack_base = NULL;
  43
  44 __attribute__((constructor))
  45 int
  46 rb_wasm_record_stack_base(void)
  47 {
  48     rb_wasm_stack_base = rb_wasm_get_stack_pointer();
  49     return 0;
  50 }
  51
  52 void *
  53 rb_wasm_stack_get_base(void)
  54 {
  55     return rb_wasm_stack_base;
  56 }
  57
  58 void *
  59 rb_wasm_handle_scan_unwind(void)
  60 {
  61     return _rb_wasm_active_scan_buf;
  62 }