1 files changed, 37 insertions, 32 deletions

diff --git a/coroutine/win32/Context.h b/coroutine/win32/Context.h
index 30cb5a982d..c1c8fbcd13 100644
--- a/coroutine/win32/Context.h
+++ b/coroutine/win32/Context.h
@@ -1,61 +1,66 @@
+#ifndef COROUTINE_WIN32_CONTEXT_H
+#define COROUTINE_WIN32_CONTEXT_H 1
+
 /*
  *  This file is part of the "Coroutine" project and released under the MIT License.
  *
  *  Created by Samuel Williams on 10/5/2018.
- *  Copyright, 2018, by Samuel Williams. All rights reserved.
+ *  Copyright, 2018, by Samuel Williams.
 */
 
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
-#if __cplusplus
-extern "C" {
-#endif
-
-#define COROUTINE void __fastcall
+#define COROUTINE __declspec(noreturn) void __fastcall
+#define COROUTINE_DECL void __fastcall
+#define COROUTINE_LIMITED_ADDRESS_SPACE
 
-const size_t COROUTINE_REGISTERS = 4;
+/* This doesn't include thread information block */
+enum {COROUTINE_REGISTERS = 4};
 
 struct coroutine_context
 {
-	void **stack_pointer;
+    void **stack_pointer;
+    void *argument;
 };
 
-typedef void(__fastcall * coroutine_start)(coroutine_context *from, coroutine_context *self);
+typedef void(__fastcall * coroutine_start)(struct coroutine_context *from, struct coroutine_context *self);
 
-inline void coroutine_initialize(
-	coroutine_context *context,
-	coroutine_start start,
-	void *stack_pointer,
-	size_t stack_size
+static inline void coroutine_initialize_main(struct coroutine_context * context) {
+    context->stack_pointer = NULL;
+}
+
+static inline void coroutine_initialize(
+    struct coroutine_context *context,
+    coroutine_start start,
+    void *stack,
+    size_t size
 ) {
-	context->stack_pointer = (void**)stack_pointer;
+    assert(start && stack && size >= 1024);
 
-	if (!start) {
-		assert(!context->stack_pointer);
-		/* We are main coroutine for this thread */
-		return;
-	}
+    // Stack grows down. Force 16-byte alignment.
+    char * top = (char*)stack + size;
+    context->stack_pointer = (void**)((uintptr_t)top & ~0xF);
 
-	/* Windows Thread Information Block */
-	*--context->stack_pointer = 0;
-	*--context->stack_pointer = stack_pointer;
-	*--context->stack_pointer = (void*)stack_size;
+    *--context->stack_pointer = (void*)(uintptr_t)start;
 
-	*--context->stack_pointer = (void*)start;
+    /* Windows Thread Information Block */
+    *--context->stack_pointer = (void*)0xFFFFFFFF; /* fs:[0] */
+    *--context->stack_pointer = (void*)top; /* fs:[4] */
+    *--context->stack_pointer = (void*)stack;  /* fs:[8] */
 
-	context->stack_pointer -= COROUTINE_REGISTERS;
-	memset(context->stack_pointer, 0, sizeof(void*) * COROUTINE_REGISTERS);
+    context->stack_pointer -= COROUTINE_REGISTERS;
+    memset(context->stack_pointer, 0, sizeof(void*) * COROUTINE_REGISTERS);
 }
 
-coroutine_context * __fastcall coroutine_transfer(coroutine_context * current, coroutine_context * target);
+struct coroutine_context * __fastcall coroutine_transfer(struct coroutine_context * current, struct coroutine_context * target);
 
-inline void coroutine_destroy(coroutine_context * context)
+static inline void coroutine_destroy(struct coroutine_context * context)
 {
 }
 
-#if __cplusplus
-}
-#endif
\ No newline at end of file
+#endif /* COROUTINE_WIN32_CONTEXT_H */