1 files changed, 109 insertions, 0 deletions
diff --git a/rts/win32/MIOManager.h b/rts/win32/MIOManager.h
new file mode 100644
index 0000000000..cb876db9cc
--- /dev/null
+++ b/rts/win32/MIOManager.h
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+/* IOManager.h
+ *
+ * Non-blocking / asynchronous I/O for Win32.
+ *
+ * (c) sof, 2002-2003
+ *
+ * NOTE: This is the MIO manager, only used for --io-manager=posix.
+ *       For the WINIO manager see base in the GHC.Event modules.
+ */
+
+#pragma once
+
+#include <windows.h>
+
+/*
+ The IOManager subsystem provides a non-blocking view
+ of I/O operations. It lets one (or more) OS thread(s)
+ issue multiple I/O requests, which the IOManager then
+ handles independently of/concurrent to the thread(s)
+ that issued the request. Upon completion, the issuing
+ thread can inspect the result of the I/O operation &
+ take appropriate action.
+
+ The IOManager is intended used with the GHC RTS to
+ implement non-blocking I/O in Concurrent Haskell.
+ */
+
+/*
+ * Our WorkQueue holds WorkItems, encoding IO and
+ * delay requests.
+ *
+ */
+typedef void (*CompletionProc)(unsigned int requestID,
+                               int   fd,
+                               HsInt len,
+                               void* buf,
+                               HsInt errCode);
+
+/*
+ * Asynchronous procedure calls executed by a worker thread
+ * take a generic state argument pointer and return an int by
+ * default.
+ */
+typedef int (*DoProcProc)(void *param);
+
+typedef union workData {
+    struct {
+        int   fd;
+        HsInt len;
+        char *buf;
+    } ioData;
+    struct {
+        HsInt usecs;
+    } delayData;
+    struct {
+        DoProcProc proc;
+        void* param;
+    } procData;
+} WorkData;
+
+typedef struct WorkItem {
+  unsigned int     workKind;
+  WorkData         workData;
+  unsigned int     requestID;
+  CompletionProc   onCompletion;
+  unsigned int     abandonOp;
+  struct WorkItem  *link;
+} WorkItem;
+
+extern CompletionProc onComplete;
+
+/* the kind of operations supported; you could easily imagine
+ * that instead of passing a tag describing the work to be performed,
+ * a function pointer is passed instead. Maybe later.
+ */
+#define WORKER_READ        1
+#define WORKER_WRITE       2
+#define WORKER_DELAY       4
+#define WORKER_FOR_SOCKET  8
+#define WORKER_DO_PROC    16
+
+/*
+ * Starting up and shutting down.
+ */
+extern bool StartIOManager     ( void );
+extern void ShutdownIOManager  ( bool wait_threads );
+
+/*
+ * Adding I/O and delay requests. With each request a
+ * completion routine is supplied, which the worker thread
+ * will invoke upon completion.
+ */
+extern int AddDelayRequest ( HsInt          usecs,
+                             CompletionProc onCompletion);
+
+extern int AddIORequest ( int            fd,
+                          bool           forWriting,
+                          bool           isSocket,
+                          HsInt          len,
+                          char*          buffer,
+                          CompletionProc onCompletion);
+
+extern int AddProcRequest ( void*          proc,
+                            void*          data,
+                            CompletionProc onCompletion);
+
+extern void abandonWorkRequest ( int reqID );
+
+extern void interruptIOManagerEvent ( void );