From c3e9c4c6febdea6b999db5ddc150782f3da5f78a Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?=
 <jeremie.galarneau@efficios.com>
Date: Fri, 22 Nov 2019 18:52:03 -0500
Subject: [PATCH] fd-tracker: add pipe management wrappers to fd-tracker
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Add wrappers to allow the creation of a pipe the two ends of
which are tracked by an fd-tracker.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---
 src/common/fd-tracker/utils.c | 55 +++++++++++++++++++++++++++++++++++
 src/common/fd-tracker/utils.h |  7 +++++
 2 files changed, 62 insertions(+)

diff --git a/src/common/fd-tracker/utils.c b/src/common/fd-tracker/utils.c
index ac4e882c7..cd4418ed2 100644
--- a/src/common/fd-tracker/utils.c
+++ b/src/common/fd-tracker/utils.c
@@ -16,9 +16,64 @@
  */
 
 #include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <common/fd-tracker/utils.h>
+#include <common/utils.h>
+
+static
+int open_pipe_cloexec(void *data, int *fds)
+{
+	int ret;
+
+	ret = utils_create_pipe_cloexec(fds);
+	if (ret < 0) {
+		goto end;
+	}
+end:
+	return ret;
+}
+
+static
+int close_pipe(void *data, int *pipe)
+{
+	utils_close_pipe(pipe);
+	pipe[0] = pipe[1] = -1;
+	return 0;
+}
 
 int fd_tracker_util_close_fd(void *unused, int *fd)
 {
 	return close(*fd);
 }
+
+int fd_tracker_util_pipe_open_cloexec(struct fd_tracker *tracker,
+		const char *name, int *pipe)
+{
+	int ret;
+	const char *name_prefix;
+	char *names[2];
+
+	name_prefix = name ? name : "Unknown pipe";
+	ret = asprintf(&names[0], "%s (read end)", name_prefix);
+	if (ret < 0) {
+		goto end;
+	}
+	ret = asprintf(&names[1], "%s (write end)", name_prefix);
+	if (ret < 0) {
+		goto end;
+	}
+
+        ret = fd_tracker_open_unsuspendable_fd(tracker, pipe,
+			(const char **) names, 2, open_pipe_cloexec, NULL);
+	free(names[0]);
+	free(names[1]);
+end:
+	return ret;
+}
+
+int fd_tracker_util_pipe_close(struct fd_tracker *tracker, int *pipe)
+{
+        return fd_tracker_close_unsuspendable_fd(tracker,
+			pipe, 2, close_pipe, NULL);
+}
diff --git a/src/common/fd-tracker/utils.h b/src/common/fd-tracker/utils.h
index 86af3c6e1..e250f4af0 100644
--- a/src/common/fd-tracker/utils.h
+++ b/src/common/fd-tracker/utils.h
@@ -28,6 +28,13 @@ struct lttng_poll_event;
  */
 int fd_tracker_util_close_fd(void *, int *fd);
 
+/*
+ * Create a pipe and track its underlying fds.
+ */
+int fd_tracker_util_pipe_open_cloexec(struct fd_tracker *tracker,
+		const char *name, int *pipe);
+int fd_tracker_util_pipe_close(struct fd_tracker *tracker, int *pipe);
+
 /*
  * Create a poll event and track its underlying fd, if applicable.
  */
-- 
2.34.1