wasm/fiber.h

   1 #ifndef RB_WASM_SUPPORT_FIBER_H
   2 #define RB_WASM_SUPPORT_FIBER_H
   3
   4 #include <stdbool.h>
   5
   6 #ifndef WASM_FIBER_STACK_BUFFER_SIZE
   7 # define WASM_FIBER_STACK_BUFFER_SIZE 6144
   8 #endif
   9
  10 struct __rb_wasm_asyncify_fiber_ctx {
  11     void* top;
  12     void* end;
  13     char buffer[WASM_FIBER_STACK_BUFFER_SIZE];
  14 };
  15
  16 // Fiber execution context needed to perform context switch
  17 typedef struct {
  18     // Fiber entry point called when the fiber started for the first time.
  19     // NULL if the entry point is main
  20     void (*entry_point)(void *, void *);
  21     // Opaque argument pointers passed to the entry point function
  22     void *arg0, *arg1;
  23
  24     // Internal asyncify buffer space
  25     struct __rb_wasm_asyncify_fiber_ctx asyncify_buf;
  26
  27     bool is_rewinding;
  28     bool is_started;
  29 } rb_wasm_fiber_context;
  30
  31 // Initialize a given fiber context to be ready to pass to `rb_wasm_swapcontext`
  32 void rb_wasm_init_context(rb_wasm_fiber_context *fcp, void (*func)(void *, void *), void *arg0, void *arg1);
  33
  34 // Swap the execution control with `target_fiber` and save the current context in `old_fiber`
  35 // NOTE: `old_fiber` must be the current executing fiber context
  36 void rb_wasm_swapcontext(rb_wasm_fiber_context *old_fiber, rb_wasm_fiber_context *target_fiber);
  37
  38 // Returns the Asyncify buffer of next fiber if unwound for fiber context switch.
  39 // Used by the top level Asyncify handling in wasm/runtime.c
  40 void *rb_wasm_handle_fiber_unwind(void (**new_fiber_entry)(void *, void *),
  41                                   void **arg0, void **arg1, bool *is_new_fiber_started);
  42
  43 #endif