Initial implementation of seatd and libseat

1 files changed, 137 insertions, 0 deletions

diff --git a/include/poller.h b/include/poller.h
new file mode 100644
index 0000000..f867df9
--- /dev/null
+++ b/include/poller.h
@@ -0,0 +1,137 @@
+#ifndef _SEATD_POLLER_H
+#define _SEATD_POLLER_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+struct poller;
+struct event_source_fd;
+struct event_source_signal;
+
+/*
+ * These are the event types available from the poller.
+ */
+#define EVENT_READABLE 0x1
+#define EVENT_WRITABLE 0x4
+#define EVENT_ERROR    0x8
+#define EVENT_HANGUP   0x10
+
+/**
+ * The callback type used by event_source_fd, passed to poller_add_fd.
+ */
+typedef int (*event_source_fd_func_t)(int fd, uint32_t mask, void *data);
+
+/**
+ * The interface that an event_source_fd must implement.
+ */
+struct event_source_fd_impl {
+	int (*update)(struct event_source_fd *event_source, uint32_t mask);
+	int (*destroy)(struct event_source_fd *event_source);
+};
+
+/**
+ * The fd poller base class. This must be created by poller_add_fd.
+ */
+struct event_source_fd {
+	const struct event_source_fd_impl *impl;
+	event_source_fd_func_t func;
+
+	int fd;
+	uint32_t mask;
+	void *data;
+};
+
+/**
+ * Removes the event_source_fd from the poller and frees the structure.
+ */
+int event_source_fd_destroy(struct event_source_fd *event_source);
+
+/**
+ * Updates the poll mask applied to this fd, effective on the next poll.
+ */
+int event_source_fd_update(struct event_source_fd *event_source, uint32_t mask);
+
+/**
+ * The callback type used by event_source_signal, passed to poller_add_signal.
+ */
+typedef int (*event_source_signal_func_t)(int signal, void *data);
+
+/**
+ * The interface that an event_source_signal must implement.
+ */
+struct event_source_signal_impl {
+	int (*destroy)(struct event_source_signal *event_source);
+};
+
+/*
+ * The signal poller base class. This must be created by poller_add_signal.
+ */
+struct event_source_signal {
+	const struct event_source_signal_impl *impl;
+	event_source_signal_func_t func;
+
+	int signal;
+	void *data;
+};
+
+/**
+ * Removes the event_source_siganl from the poller and frees the structure.
+ */
+int event_source_signal_destroy(struct event_source_signal *event_source);
+
+/**
+ * The interface that a poll backend must implement.
+ */
+struct poll_impl {
+	struct poller *(*create)(void);
+	int (*destroy)(struct poller *);
+
+	struct event_source_fd *(*add_fd)(struct poller *, int fd, uint32_t mask,
+					  event_source_fd_func_t func, void *data);
+	struct event_source_signal *(*add_signal)(struct poller *, int signal,
+						  event_source_signal_func_t func, void *data);
+
+	int (*poll)(struct poller *);
+};
+
+/**
+ * The poller base class. This must be created by poller_create.
+ */
+struct poller {
+	const struct poll_impl *impl;
+};
+
+/**
+ * Creates a poller with the best available polling backend. This poller must
+ * be torn down with poller_destroy when it is no longer needed.
+ */
+struct poller *poller_create(void);
+
+/**
+ * Destroys the poller. This destroys all remaining event sources, tears down
+ * the poller and frees the structure.
+ */
+int poller_destroy(struct poller *poller);
+
+/**
+ * Create an fd event source with the provided initial parameters. This event
+ * source must be torn down with event_source_fd_destroy when it is no longer
+ * needed.
+ */
+struct event_source_fd *poller_add_fd(struct poller *poller, int fd, uint32_t mask,
+				      event_source_fd_func_t func, void *data);
+
+/**
+ * Create  signal event source with the provided initial parameters. This event
+ * source must be torn down with event_source_signal_destroy when it is no
+ * longer needed.
+ */
+struct event_source_signal *poller_add_signal(struct poller *poller, int signal,
+					      event_source_signal_func_t func, void *data);
+
+/**
+ * Poll the poller. I don't know what you were expecting.
+ */
+int poller_poll(struct poller *poller);
+
+#endif