s3: Add tevent_wait_send/recv

To me it seems that we might have this functionality already somewere... I
just can't find it. Metze, do you have an idea?

Signed-off-by: Jeremy Allison <jra@samba.org>

source3/Makefile.in

@@ -495,6 +495,7 @@ LIB_OBJ = $(LIBSAMBAUTIL_OBJ) $(UTIL_OBJ) $(CRYPTO_OBJ) $(LIBTSOCKET_OBJ) \
 	  lib/fncall.o \
 	  libads/krb5_errs.o lib/system_smbd.o lib/audit.o $(LIBNDR_OBJ) \
 	  lib/file_id.o lib/idmap_cache.o \
+	  lib/tevent_wait.o \
 	  ../libcli/security/dom_sid.o ../libcli/security/security_descriptor.o \
 	  ../libcli/security/security_token.o ../libcli/security/util_sid.o \
 	  ../libcli/smb/util.o ../lib/util/idtree.o

source3/lib/tevent_wait.c

@@ -0,0 +1,83 @@
+/*
+   Unix SMB/CIFS implementation.
+   Implement a send/recv interface to wait for an external trigger
+   Copyright (C) Volker Lendecke 2012
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "lib/replace/replace.h"
+#include "talloc.h"
+#include "tevent.h"
+#include "tevent_wait.h"
+#include "lib/util/tevent_unix.h"
+
+struct tevent_wait_state {
+	struct tevent_immediate *im;
+	struct tevent_context *ev;
+};
+
+struct tevent_req *tevent_wait_send(TALLOC_CTX *mem_ctx,
+				    struct tevent_context *ev)
+{
+	struct tevent_req *req;
+	struct tevent_wait_state *state;
+
+	req = tevent_req_create(mem_ctx, &state, struct tevent_wait_state);
+	if (req == NULL) {
+		return NULL;
+	}
+	state->ev = ev;
+	state->im = tevent_create_immediate(state);
+	if (tevent_req_nomem(state->im, req)) {
+		return tevent_req_post(req, ev);
+	}
+	return req;
+}
+
+static void tevent_wait_trigger(struct tevent_context *ctx,
+				struct tevent_immediate *im,
+				void *private_data);
+
+void tevent_wait_done(struct tevent_req *req)
+{
+	struct tevent_wait_state *state;
+
+	if (req == NULL) {
+		return;
+	}
+	state = tevent_req_data(req, struct tevent_wait_state);
+
+	tevent_schedule_immediate(state->im, state->ev,
+				  tevent_wait_trigger, req);
+}
+
+static void tevent_wait_trigger(struct tevent_context *ctx,
+				struct tevent_immediate *im,
+				void *private_data)
+{
+	struct tevent_req *req = talloc_get_type_abort(
+		private_data, struct tevent_req);
+	tevent_req_done(req);
+}
+
+int tevent_wait_recv(struct tevent_req *req)
+{
+	int err;
+
+	if (tevent_req_is_unix_error(req, &err)) {
+		return err;
+	}
+	return 0;
+}

source3/lib/tevent_wait.h

@@ -0,0 +1,37 @@
+/*
+   Unix SMB/CIFS implementation.
+   Implement a send/recv interface to wait for an external trigger
+   Copyright (C) Volker Lendecke 2012
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _TEVENT_WAIT_H
+#define _TEVENT_WAIT_H
+
+#include "talloc.h"
+#include "tevent.h"
+
+/*
+ * Just wait for getting a tevent_wait_done. tevent_wait_done can deal with a
+ * NULL request.
+ */
+
+struct tevent_req *tevent_wait_send(TALLOC_CTX *mem_ctx,
+				    struct tevent_context *ev);
+int tevent_wait_recv(struct tevent_req *req);
+
+void tevent_wait_done(struct tevent_req *req);
+
+#endif /* _TEVENT_WAIT_H */

source3/wscript_build

@@ -67,6 +67,7 @@ LIB_SRC = '''
           lib/ldap_escape.c
           lib/fncall.c
           libads/krb5_errs.c lib/system_smbd.c lib/audit.c
+	  lib/tevent_wait.c
           lib/idmap_cache.c'''
 
 LIB_UTIL_SRC = '''