r20539: - split the common timer related events code into events_timed.c

- make it easier to plug in a new events backend

- add simpler 'select' and 'epoll' backends

This is part of the effort to add good AIO support. The events_aio.c
backend is done, but sometimes dies with a SEGV, which is why it isn't
enabled yet.
(This used to be commit 934f18283dbc7958944931a93a854526bcd54884)

1 files changed, 94 insertions, 4 deletions

diff --git a/source4/lib/events/events.c b/source4/lib/events/events.c
index 585fcb3112..52b431befa 100644
--- a/source4/lib/events/events.c
+++ b/source4/lib/events/events.c
@@ -57,6 +57,63 @@
 #include "includes.h"
 #include "lib/events/events.h"
 #include "lib/events/events_internal.h"
+#include "lib/util/dlinklist.h"
+#include "build.h"
+
+struct event_ops_list {
+	struct event_ops_list *next, *prev;
+	const char *name;
+	const struct event_ops *ops;
+};
+
+/* list of registered event backends */
+static struct event_ops_list *event_backends;
+
+/*
+  register an events backend
+*/
+NTSTATUS event_register_backend(const char *name, const struct event_ops *ops)
+{
+	struct event_ops_list *e;
+	e = talloc(talloc_autofree_context(), struct event_ops_list);
+	NT_STATUS_HAVE_NO_MEMORY(e);
+	e->name = name;
+	e->ops = ops;
+	DLIST_ADD(event_backends, e);
+	return NT_STATUS_OK;
+}
+
+/*
+  initialise backends if not already done
+*/
+static void event_backend_init(void)
+{
+	init_module_fn static_init[] = STATIC_LIBEVENTS_MODULES;
+	init_module_fn *shared_init;
+	if (event_backends) return;
+	shared_init = load_samba_modules(NULL, "LIBEVENTS");
+	run_init_functions(static_init);
+	run_init_functions(shared_init);
+}
+
+/*
+  list available backends
+*/
+const char **event_backend_list(TALLOC_CTX *mem_ctx)
+{
+	const char **list = NULL;
+	struct event_ops_list *e;
+
+	event_backend_init();
+
+	for (e=event_backends;e;e=e->next) {
+		list = str_list_add(list, e->name);
+	}
+
+	talloc_steal(mem_ctx, list);
+
+	return list;
+}
 
 /*
   create a event_context structure for a specific implemementation.
@@ -69,7 +126,8 @@
 
   NOTE: use event_context_init() inside of samba!
 */
-struct event_context *event_context_init_ops(TALLOC_CTX *mem_ctx, const struct event_ops *ops, void *private_data)
+static struct event_context *event_context_init_ops(TALLOC_CTX *mem_ctx, 
+						    const struct event_ops *ops)
 {
 	struct event_context *ev;
 	int ret;
@@ -79,7 +137,7 @@ struct event_context *event_context_init_ops(TALLOC_CTX *mem_ctx, const struct e
 
 	ev->ops = ops;
 
-	ret = ev->ops->context_init(ev, private_data);
+	ret = ev->ops->context_init(ev);
 	if (ret != 0) {
 		talloc_free(ev);
 		return NULL;
@@ -93,10 +151,29 @@ struct event_context *event_context_init_ops(TALLOC_CTX *mem_ctx, const struct e
   call, and all subsequent calls pass this event_context as the first
   element. Event handlers also receive this as their first argument.
 */
+struct event_context *event_context_init_byname(TALLOC_CTX *mem_ctx, const char *name)
+{
+	struct event_ops_list *e;
+
+	event_backend_init();
+
+	for (e=event_backends;e;e=e->next) {
+		if (strcmp(name, e->name) == 0) {
+			return event_context_init_ops(mem_ctx, e->ops);
+		}
+	}
+	return NULL;
+}
+
+
+/*
+  create a event_context structure. This must be the first events
+  call, and all subsequent calls pass this event_context as the first
+  element. Event handlers also receive this as their first argument.
+*/
 struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
 {
-	const struct event_ops *ops = event_standard_get_ops();
-	return event_context_init_ops(mem_ctx, ops, NULL);
+	return event_context_init_byname(mem_ctx, "standard");
 }
 
 /*
@@ -111,6 +188,19 @@ struct fd_event *event_add_fd(struct event_context *ev, TALLOC_CTX *mem_ctx,
 }
 
 /*
+  add a disk aio event
+*/
+struct aio_event *event_add_aio(struct event_context *ev,
+				TALLOC_CTX *mem_ctx,
+				struct iocb *iocb,
+				event_aio_handler_t handler,
+				void *private_data)
+{
+	if (ev->ops->add_aio == NULL) return NULL;
+	return ev->ops->add_aio(ev, mem_ctx, iocb, handler, private_data);
+}
+
+/*
   return the fd event flags
 */
 uint16_t event_get_fd_flags(struct fd_event *fde)