From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 16 Jul 2013 00:16:07 +0000 (-0400)
Subject: Introduce utils_create_pipe_cloexec_nonblock()
X-Git-Tag: v2.3.0-rc1~23
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=094f381cd5b1fa8588098b840bcc26bc974ea3d9;p=lttng-tools.git

Introduce utils_create_pipe_cloexec_nonblock()

Reviewed-by: Julien Desfossez <julien.desfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/src/common/utils.c b/src/common/utils.c
index cfb6555a1..b345100ea 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -142,6 +142,48 @@ error:
 	return ret;
 }
 
+/*
+ * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
+ *
+ * Make sure the pipe opened by this function are closed at some point. Use
+ * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
+ * support OSes other than Linux 2.6.23+.
+ */
+LTTNG_HIDDEN
+int utils_create_pipe_cloexec_nonblock(int *dst)
+{
+	int ret, i;
+
+	if (dst == NULL) {
+		return -1;
+	}
+
+	ret = utils_create_pipe(dst);
+	if (ret < 0) {
+		goto error;
+	}
+
+	for (i = 0; i < 2; i++) {
+		ret = fcntl(dst[i], F_SETFD, FD_CLOEXEC);
+		if (ret < 0) {
+			PERROR("fcntl pipe cloexec");
+			goto error;
+		}
+		/*
+		 * Note: we override any flag that could have been
+		 * previously set on the fd.
+		 */
+		ret = fcntl(dst[i], F_SETFL, O_NONBLOCK);
+		if (ret < 0) {
+			PERROR("fcntl pipe nonblock");
+			goto error;
+		}
+	}
+
+error:
+	return ret;
+}
+
 /*
  * Close both read and write side of the pipe.
  */
diff --git a/src/common/utils.h b/src/common/utils.h
index 06aef4f1a..7d8d70b5c 100644
--- a/src/common/utils.h
+++ b/src/common/utils.h
@@ -29,6 +29,7 @@
 char *utils_expand_path(const char *path);
 int utils_create_pipe(int *dst);
 int utils_create_pipe_cloexec(int *dst);
+int utils_create_pipe_cloexec_nonblock(int *dst);
 void utils_close_pipe(int *src);
 char *utils_strdupdelim(const char *begin, const char *end);
 int utils_set_fd_cloexec(int fd);