fdev: Introduce fdev for file event handling

[src/app-framework-binder.git] / src / fdev.c

diff --git a/src/fdev.c b/src/fdev.c
new file mode 100644 (file)
index 0000000..5c31d31
--- /dev/null
+++ b/src/fdev.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#define FDEV_PROVIDER
+#include "fdev.h"
+
+struct fdev
+{
+       int fd;
+       uint32_t events;
+       int repeat;
+       unsigned refcount;
+       struct fdev_itf *itf;
+       void *closure_itf;
+       void (*callback)(void*,uint32_t,struct fdev*);
+       void *closure_callback;
+};
+
+struct fdev *fdev_create(int fd)
+{
+       struct fdev *fdev;
+
+       fdev = calloc(1, sizeof *fdev);
+       if (!fdev)
+               errno = ENOMEM;
+       else {
+               fdev->fd = fd;
+               fdev->refcount = 3; /* set autoclose by default */
+               fdev->repeat = -1;
+       }
+       return fdev;
+}
+
+void fdev_set_itf(struct fdev *fdev, struct fdev_itf *itf, void *closure_itf)
+{
+       fdev->itf = itf;
+       fdev->closure_itf = closure_itf;
+}
+
+void fdev_dispatch(struct fdev *fdev, uint32_t events)
+{
+       if (fdev->repeat > 0 && !--fdev->repeat && fdev->itf)
+               fdev->itf->disable(fdev->closure_itf, fdev);
+       if (fdev->callback)
+               fdev->callback(fdev->closure_callback, events, fdev);
+}
+
+struct fdev *fdev_addref(struct fdev *fdev)
+{
+       if (fdev)
+               __atomic_add_fetch(&fdev->refcount, 2, __ATOMIC_RELAXED);
+       return fdev;
+}
+
+void fdev_unref(struct fdev *fdev)
+{
+       if (fdev && __atomic_sub_fetch(&fdev->refcount, 2, __ATOMIC_RELAXED) <= 1) {
+               if (fdev->itf) {
+                       fdev->itf->disable(fdev->closure_itf, fdev);
+                       fdev->itf->unref(fdev->closure_itf);
+               }
+               if (fdev->refcount)
+                       close(fdev->fd);
+               free(fdev);
+       }
+}
+
+int fdev_fd(const struct fdev *fdev)
+{
+       return fdev->fd;
+}
+
+uint32_t fdev_events(const struct fdev *fdev)
+{
+       return fdev->events;
+}
+
+int fdev_repeat(const struct fdev *fdev)
+{
+       return fdev->repeat;
+}
+
+int fdev_autoclose(const struct fdev *fdev)
+{
+       return 1 & fdev->refcount;
+}
+
+static inline int is_active(struct fdev *fdev)
+{
+       return fdev->repeat && fdev->callback;
+}
+
+static inline void update_activity(struct fdev *fdev, int old_active)
+{
+       if (is_active(fdev)) {
+               if (!old_active)
+                       fdev->itf->enable(fdev->closure_itf, fdev);
+       } else {
+               if (old_active)
+                       fdev->itf->disable(fdev->closure_itf, fdev);
+       }
+}
+
+void fdev_set_callback(struct fdev *fdev, void (*callback)(void*,uint32_t,struct fdev*), void *closure)
+{
+       int oa;
+
+       oa = is_active(fdev);
+       fdev->callback = callback;
+       fdev->closure_callback = closure;
+       update_activity(fdev, oa);
+}
+
+void fdev_set_events(struct fdev *fdev, uint32_t events)
+{
+       if (events != fdev->events) {
+               fdev->events = events;
+               if (is_active(fdev))
+                       fdev->itf->enable(fdev->closure_itf, fdev);
+       }
+}
+
+void fdev_set_repeat(struct fdev *fdev, int count)
+{
+       int oa;
+
+       oa = is_active(fdev);
+       fdev->repeat = count;
+       update_activity(fdev, oa);
+}
+
+void fdev_set_autoclose(struct fdev *fdev, int autoclose)
+{
+       if (autoclose)
+               fdev->refcount |= 1;
+       else
+               fdev->refcount &= -2;
+}
+