1 files changed, 76 insertions, 0 deletions
diff --git a/coroutine/win64/Context.h b/coroutine/win64/Context.h
new file mode 100644
index 0000000000..23b21b5c1c
--- /dev/null
+++ b/coroutine/win64/Context.h
@@ -0,0 +1,76 @@
+#ifndef COROUTINE_WIN64_CONTEXT_H
+#define COROUTINE_WIN64_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.
+*/
+
+#pragma once
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#define COROUTINE __declspec(noreturn) void
+#define COROUTINE_DECL void
+
+enum {
+    COROUTINE_REGISTERS = 8,
+    COROUTINE_XMM_REGISTERS = 1+10*2,
+};
+
+struct coroutine_context
+{
+    void **stack_pointer;
+    void *argument;
+};
+
+typedef void(* coroutine_start)(struct coroutine_context *from, struct coroutine_context *self);
+
+void coroutine_trampoline(void);
+
+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
+) {
+    assert(start && stack && size >= 1024);
+
+    // Stack grows down. Force 16-byte alignment.
+    char * top = (char*)stack + size;
+    context->stack_pointer = (void**)((uintptr_t)top & ~0xF);
+
+    /* Win64 ABI requires space for arguments */
+    context->stack_pointer -= 4;
+
+    /* Return address */
+    *--context->stack_pointer = 0;
+    *--context->stack_pointer = (void*)(uintptr_t)start;
+    *--context->stack_pointer = (void*)coroutine_trampoline;
+
+    /* Windows Thread Information Block */
+    /* *--context->stack_pointer = 0; */ /* gs:[0x00] is not used */
+    *--context->stack_pointer = (void*)top; /* gs:[0x08] */
+    *--context->stack_pointer = (void*)stack;  /* gs:[0x10] */
+
+    context->stack_pointer -= COROUTINE_REGISTERS;
+    memset(context->stack_pointer, 0, sizeof(void*) * COROUTINE_REGISTERS);
+    memset(context->stack_pointer - COROUTINE_XMM_REGISTERS, 0, sizeof(void*) * COROUTINE_XMM_REGISTERS);
+}
+
+struct coroutine_context * coroutine_transfer(struct coroutine_context * current, struct coroutine_context * target);
+
+static inline void coroutine_destroy(struct coroutine_context * context)
+{
+}
+
+#endif /* COROUTINE_WIN64_CONTEXT_H */