Rename ioev to aio. Eliminate generic cancel handling (not needed).

We will still need some kind of specific handling of cancellation for
msg queues, but it will be simpler to just implement that for the queues,
and not worry about cancellation in the general case around poll etc.
(The low level poll and I/O routines will get notified by their underlying
transport pipes/descriptors closing.)

1 files changed, 90 insertions, 0 deletions

diff --git a/src/core/aio.h b/src/core/aio.h
new file mode 100644
index 00000000..15746fc3
--- /dev/null
+++ b/src/core/aio.h
@@ -0,0 +1,90 @@
+//
+// Copyright 2017 Garrett D'Amore <garrett@damore.org>
+//
+// This software is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+#ifndef CORE_AIO_H
+#define CORE_AIO_H
+
+#include "core/defs.h"
+#include "core/list.h"
+#include "core/thread.h"
+
+typedef struct nni_aio_ops	nni_aio_ops;
+typedef struct nni_aio		nni_aio;
+
+
+// An nni_aio is an async I/O handle.
+struct nni_aio {
+	int		a_result;       // Result code (nng_errno)
+	size_t		a_count;        // Bytes transferred (I/O only)
+	nni_cb		a_cb;           // User specified callback.
+	void *		a_cbarg;        // Callback argument.
+
+	// These fields are private to the io events framework.
+	nni_mtx		a_lk;
+	nni_cv		a_cv;
+	unsigned	a_flags;
+
+	// Read/write operations.
+	nni_iov		a_iov[4];
+	int		a_niov;
+
+	// Sendmsg operation.
+	nni_msg *	a_msg;
+
+	// Recvmsg operation.
+	nni_msg **	a_msgp;
+
+	// TBD: Resolver operations.
+
+	// Provider-use fields.
+	void *		a_prov_data;
+	nni_list_node	a_prov_node;
+};
+
+// nni_aio_init initializes an aio object.  The callback is called with
+// the supplied argument when the operation is complete.  If NULL is
+// supplied for the callback, then nni_aio_wake is used in its place,
+// and the aio is used for the argument.
+extern void nni_aio_init(nni_aio *, nni_cb, void *);
+
+// nni_aio_fini finalizes the aio, releasing resources (locks)
+// associated with it.  The caller is responsible for ensuring that any
+// associated I/O is unscheduled or complete.
+extern void nni_aio_fini(nni_aio *);
+
+// nni_aio_result returns the result code (0 on success, or an NNG errno)
+// for the operation.  It is only valid to call this when the operation is
+// complete (such as when the callback is executed or after nni_aio_wait
+// is performed).
+extern int nni_aio_result(nni_aio *);
+
+// nni_aio_count returns the number of bytes of data transferred, if any.
+// As with nni_aio_result, it is only defined if the I/O operation has
+// completed.
+extern size_t nni_aio_count(nni_aio *);
+
+// nni_aio_wake wakes any threads blocked in nni_aio_wait.  This is the
+// default callback if no other is supplied.  If a user callback is supplied
+// then that code must call this routine to wake any waiters (unless the
+// user code is certain that there are no such waiters).
+extern void nni_aio_wake(nni_aio *);
+
+// nni_aio_wait blocks the caller until the operation is complete, as indicated
+// by nni_aio_wake being called.  (Recall nni_aio_wake is the default
+// callback if none is supplied.)  If a user supplied callback is provided,
+// and that callback does not call nni_aio_wake, then this routine may
+// block the caller indefinitely.
+extern void nni_aio_wait(nni_aio *);
+
+// nni_aio_finish is called by the provider when an operation is complete.
+// The provider gives the result code (0 for success, an NNG errno otherwise),
+// and the amount of data transferred (if any).
+extern void nni_aio_finish(nni_aio *, int, size_t);
+
+#endif // CORE_AIO_H