lib: Enhance poll_funcs_tevent for multiple tevent_contexts

With this patch it will be possible to use nested event contexts with
messaging_filtered_read_send/recv. Before this patchset only the one and only
event context a messaging_context is initialized with is able to receive
datagrams from the unix domain socket. So if you want to code a synchronous
RPC-like operation using a nested event context, you will not see the reply,
because the nested event context does not have the required tevent_fd's.
Unfortunately, this patchset has to add some advanced array voodoo. The idea
is that state->watches[] contains what we hand out with watch_new, and
state->contexts contains references to the tevent_contexts. For every watch we
need a tevent_fd in every event context, and the routines make sure that the
arrays are properly maintained.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

3 files changed, 38 insertions, 12 deletions

diff --git a/source3/lib/unix_msg/test_drain.c b/source3/lib/unix_msg/test_drain.c
index 6fe8c188367..c2568b6646b 100644
--- a/source3/lib/unix_msg/test_drain.c
+++ b/source3/lib/unix_msg/test_drain.c
@@ -16,7 +16,7 @@ static void recv_cb(struct unix_msg_ctx *ctx,
 
 int main(int argc, const char *argv[])
 {
-	struct poll_funcs funcs;
+	struct poll_funcs *funcs;
 	const char *sock;
 	struct unix_msg_ctx *ctx;
 	struct tevent_context *ev;
@@ -37,10 +37,13 @@ int main(int argc, const char *argv[])
 		perror("tevent_context_init failed");
 		return 1;
 	}
-	poll_funcs_init_tevent(&funcs, ev);
+	funcs = poll_funcs_init_tevent(ev);
+	if (funcs == NULL) {
+		fprintf(stderr, "poll_funcs_init_tevent failed\n");
+		return 1;
+	}
 
-	ret = unix_msg_init(sock, &funcs, 256, 1,
-			    recv_cb, &state, &ctx);
+	ret = unix_msg_init(sock, funcs, 256, 1, recv_cb, &state, &ctx);
 	if (ret != 0) {
 		fprintf(stderr, "unix_msg_init failed: %s\n",
 			strerror(ret));
diff --git a/source3/lib/unix_msg/test_source.c b/source3/lib/unix_msg/test_source.c
index bfafee1fd33..94984d88523 100644
--- a/source3/lib/unix_msg/test_source.c
+++ b/source3/lib/unix_msg/test_source.c
@@ -5,7 +5,8 @@
 
 int main(int argc, const char *argv[])
 {
-	struct poll_funcs funcs;
+	struct poll_funcs *funcs;
+	void *tevent_handle;
 	struct unix_msg_ctx **ctxs;
 	struct tevent_context *ev;
 	struct iovec iov;
@@ -26,7 +27,16 @@ int main(int argc, const char *argv[])
 		perror("tevent_context_init failed");
 		return 1;
 	}
-	poll_funcs_init_tevent(&funcs, ev);
+	funcs = poll_funcs_init_tevent(NULL);
+	if (funcs == NULL) {
+		fprintf(stderr, "poll_funcs_init_tevent failed\n");
+		return 1;
+	}
+	tevent_handle = poll_funcs_tevent_register(NULL, funcs, ev);
+	if (tevent_handle == NULL) {
+		fprintf(stderr, "poll_funcs_tevent_register failed\n");
+		return 1;
+	}
 
 	ctxs = talloc_array(ev, struct unix_msg_ctx *, num_ctxs);
 	if (ctxs == NULL) {
@@ -35,7 +45,7 @@ int main(int argc, const char *argv[])
 	}
 
 	for (i=0; i<num_ctxs; i++) {
-		ret = unix_msg_init(NULL, &funcs, 256, 1, NULL, NULL,
+		ret = unix_msg_init(NULL, funcs, 256, 1, NULL, NULL,
 				    &ctxs[i]);
 		if (ret != 0) {
 			fprintf(stderr, "unix_msg_init failed: %s\n",
diff --git a/source3/lib/unix_msg/tests.c b/source3/lib/unix_msg/tests.c
index 2a4cf862347..29d5dcb3745 100644
--- a/source3/lib/unix_msg/tests.c
+++ b/source3/lib/unix_msg/tests.c
@@ -32,7 +32,8 @@ static void expect_messages(struct tevent_context *ev, struct cb_state *state,
 
 int main(void)
 {
-	struct poll_funcs funcs;
+	struct poll_funcs *funcs;
+	void *tevent_handle;
 	const char *sock1 = "sock1";
 	const char *sock2 = "sock2";
 	struct unix_msg_ctx *ctx1, *ctx2;
@@ -52,9 +53,19 @@ int main(void)
 		perror("tevent_context_init failed");
 		return 1;
 	}
-	poll_funcs_init_tevent(&funcs, ev);
 
-	ret = unix_msg_init(sock1, &funcs, 256, 1,
+	funcs = poll_funcs_init_tevent(ev);
+	if (funcs == NULL) {
+		fprintf(stderr, "poll_funcs_init_tevent failed\n");
+		return 1;
+	}
+	tevent_handle = poll_funcs_tevent_register(ev, funcs, ev);
+	if (tevent_handle == NULL) {
+		fprintf(stderr, "poll_funcs_register_tevent failed\n");
+		return 1;
+	}
+
+	ret = unix_msg_init(sock1, funcs, 256, 1,
 			    recv_cb, &state, &ctx1);
 	if (ret != 0) {
 		fprintf(stderr, "unix_msg_init failed: %s\n",
@@ -62,7 +73,7 @@ int main(void)
 		return 1;
 	}
 
-	ret = unix_msg_init(sock1, &funcs, 256, 1,
+	ret = unix_msg_init(sock1, funcs, 256, 1,
 			    recv_cb, &state, &ctx1);
 	if (ret == 0) {
 		fprintf(stderr, "unix_msg_init succeeded unexpectedly\n");
@@ -74,7 +85,7 @@ int main(void)
 		return 1;
 	}
 
-	ret = unix_msg_init(sock2, &funcs, 256, 1,
+	ret = unix_msg_init(sock2, funcs, 256, 1,
 			    recv_cb, &state, &ctx2);
 	if (ret != 0) {
 		fprintf(stderr, "unix_msg_init failed: %s\n",
@@ -201,6 +212,8 @@ int main(void)
 
 	unix_msg_free(ctx1);
 	unix_msg_free(ctx2);
+	talloc_free(tevent_handle);
+	talloc_free(funcs);
 	talloc_free(ev);
 
 	return 0;