1 files changed, 85 insertions, 0 deletions
diff --git a/coroutine/amd64/Context.h b/coroutine/amd64/Context.h
new file mode 100644
index 0000000000..65aa638304
--- /dev/null
+++ b/coroutine/amd64/Context.h
@@ -0,0 +1,85 @@
+#ifndef COROUTINE_AMD64_CONTEXT_H
+#define COROUTINE_AMD64_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 __attribute__((noreturn)) void
+
+enum {COROUTINE_REGISTERS = 6};
+
+#if defined(__SANITIZE_ADDRESS__)
+    #define COROUTINE_SANITIZE_ADDRESS
+#elif defined(__has_feature)
+    #if __has_feature(address_sanitizer)
+        #define COROUTINE_SANITIZE_ADDRESS
+    #endif
+#endif
+
+#if defined(COROUTINE_SANITIZE_ADDRESS)
+#include <sanitizer/common_interface_defs.h>
+#include <sanitizer/asan_interface.h>
+#endif
+
+struct coroutine_context
+{
+    void **stack_pointer;
+    void *argument;
+
+#if defined(COROUTINE_SANITIZE_ADDRESS)
+    void *fake_stack;
+    void *stack_base;
+    size_t stack_size;
+#endif
+};
+
+typedef COROUTINE(* coroutine_start)(struct coroutine_context *from, struct coroutine_context *self);
+
+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);
+
+#if defined(COROUTINE_SANITIZE_ADDRESS)
+    context->fake_stack = NULL;
+    context->stack_base = stack;
+    context->stack_size = size;
+#endif
+
+    // Stack grows down. Force 16-byte alignment.
+    char * top = (char*)stack + size;
+    context->stack_pointer = (void**)((uintptr_t)top & ~0xF);
+
+    *--context->stack_pointer = NULL;
+    *--context->stack_pointer = (void*)(uintptr_t)start;
+
+    context->stack_pointer -= COROUTINE_REGISTERS;
+    memset(context->stack_pointer, 0, sizeof(void*) * COROUTINE_REGISTERS);
+}
+
+struct coroutine_context * coroutine_transfer(struct coroutine_context * current, struct coroutine_context * target);
+
+static inline void coroutine_destroy(struct coroutine_context * context)
+{
+    context->stack_pointer = NULL;
+}
+
+#endif /* COROUTINE_AMD64_CONTEXT_H */