winio: core threaded I/O manager

1 files changed, 40 insertions, 0 deletions

diff --git a/libraries/base/include/winio_structs.h b/libraries/base/include/winio_structs.h
new file mode 100644
index 0000000000..da9dab05b7
--- /dev/null
+++ b/libraries/base/include/winio_structs.h
@@ -0,0 +1,40 @@
+/*
+ * (c) Tamar Christina, 2019.
+ *
+ * Structures supporting the IOCP based I/O Manager or Windows.
+ */
+
+#include <Windows.h>
+#include <stdint.h>
+
+#if defined(_WIN64)
+#  define ALIGNMENT __attribute__ ((aligned (8)))
+#elif defined(_WIN32)
+#  define ALIGNMENT __attribute__ ((aligned (8)))
+#else
+#  error "unknown environment, can't determine alignment"
+#endif
+
+/* Completion data structure.  Must be kept in sync with that in
+   GHC.Event.Windows or horrible things happen.  */
+typedef struct _CompletionData {
+  /* The Handle to the object for which the I/O operation is in progress.  */
+  HWND cdHandle;
+  /* Handle to the callback routine to call to notify that an operation has
+     finished.  This value is opaque as it shouldn't be accessible
+     outside the Haskell world.  */
+  uintptr_t cdCallback;
+} CompletionData, *LPCompletionData;
+
+/* The Windows API Requires an OVERLAPPED struct for asynchronous access,
+   however if we pad the structure we can give extra book keeping information
+   without needing to look these up later.  Do not modify this struct unless
+   you know what you're doing.   */
+typedef struct _HASKELL_OVERLAPPED {
+  /* Windows OVERLAPPED structure.  NOTE: MUST BE FIRST element.  */
+  OVERLAPPED hoOverlapped;
+  /* Pointer to additional payload in Haskell land.  This will contain a
+     foreign pointer.  We only use atomic operations to access this field in
+     order to correctly handle multiple threads using it.  */
+  LPCompletionData hoData ALIGNMENT;
+} HASKELL_OVERLAPPED;