1 files changed, 56 insertions, 0 deletions
diff --git a/src/coro.c b/src/coro.c
new file mode 100644
index 0000000..4e651d3
--- /dev/null
+++ b/src/coro.c
@@ -0,0 +1,56 @@
+#include <u.h>
+
+// -----------------------------------------------------------------------
+//  Assembly routines.
+
+extern void    _newcoro(coro *co, uintptr (*func)(coro*, uintptr), void *stk);
+extern uintptr _coroyield(coro *co, uintptr arg);
+
+struct coro
+{
+    void*   sp;
+    void*   bp;
+    uintptr size;
+    void*   user;
+};
+
+coro*
+coro·New(uintptr stk, uintptr (*func)(coro*, uintptr))
+{
+    if (!func) return nil;
+
+    if (stk == 0) stk = 8192;
+
+    byte *block = malloc(stk);
+    coro *co    = (coro*)&block[stk - sizeof(coro)];
+    co->bp      = block;
+    co->size    = stk;
+
+    _newcoro(co, func, co);
+    return co;
+}
+
+error
+coro·Free(coro *co)
+{
+    enum
+    {
+        GOOD,
+        NIL,
+        EMPTY,
+        LOST,
+    };
+
+    if (!co) return NIL;
+    if (!co->bp) return LOST;
+    if (co->size == 0) return EMPTY;
+
+    free(co->bp);
+    return GOOD;
+}
+
+uintptr
+coro·Yield(coro *c, uintptr arg)
+{
+    return _coroyield(c, arg);
+}