X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fpipe.c;h=868c1f3de839dd71847604062ed063b0acb31b1d;hp=c8f00141574c3a6f11ce278a4c4a07d9cad1fa46;hb=7ca172c15891d4ff3f711dcc05f991fd2c094bc7;hpb=9c2bd8db1c70269d37537b7d02bae41ccab29056

diff --git a/src/common/pipe.c b/src/common/pipe.c
index c8f001415..868c1f3de 100644
--- a/src/common/pipe.c
+++ b/src/common/pipe.c
@@ -1,18 +1,8 @@
 /*
- * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * 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, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #define _LGPL_SOURCE
@@ -154,9 +144,28 @@ static int _pipe_set_flags(struct lttng_pipe *pipe, int flags)
 	}
 
 	for (i = 0; i < 2; i++) {
-		ret = fcntl(pipe->fd[i], F_SETFD, flags);
-		if (ret < 0) {
-			PERROR("fcntl lttng pipe %d", flags);
+		if (flags & O_NONBLOCK) {
+			ret = fcntl(pipe->fd[i], F_SETFL, O_NONBLOCK);
+			if (ret < 0) {
+				PERROR("fcntl lttng pipe %d", flags);
+				goto end;
+			}
+		}
+		if (flags & FD_CLOEXEC) {
+			ret = fcntl(pipe->fd[i], F_SETFD, FD_CLOEXEC);
+			if (ret < 0) {
+				PERROR("fcntl lttng pipe %d", flags);
+				goto end;
+			}
+		}
+		/*
+		 * We only check for O_NONBLOCK or FD_CLOEXEC, if another flag is
+		 * needed, we can add it, but for now just make sure we don't make
+		 * mistakes with the parameters we pass.
+		 */
+		if (!(flags & O_NONBLOCK) && !(flags & FD_CLOEXEC)) {
+			fprintf(stderr, "Unsupported flag\n");
+			ret = -1;
 			goto end;
 		}
 	}
@@ -227,7 +236,6 @@ struct lttng_pipe *lttng_pipe_named_open(const char *path, mode_t mode,
 	fd_r = open(path, O_RDONLY | O_NONBLOCK);
 	if (fd_r < 0) {
 		PERROR("open fifo");
-		ret = fd_r;
 		goto error;
 	}
 	pipe->fd[0] = fd_r;
@@ -236,7 +244,6 @@ struct lttng_pipe *lttng_pipe_named_open(const char *path, mode_t mode,
 	fd_w = open(path, O_WRONLY | O_NONBLOCK);
 	if (fd_w < 0) {
 		PERROR("open fifo");
-		ret = fd_w;
 		goto error;
 	}
 	pipe->fd[1] = fd_w;
@@ -404,3 +411,69 @@ error:
 	unlock_write_side(pipe);
 	return ret;
 }
+
+/*
+ * Return and release the read end of the pipe.
+ *
+ * This call transfers the ownership of the read fd of the underlying pipe
+ * to the caller if it is still open.
+ *
+ * Returns the fd of the read end of the pipe, or -1 if it was already closed or
+ * released.
+ */
+LTTNG_HIDDEN
+int lttng_pipe_release_readfd(struct lttng_pipe *pipe)
+{
+	int ret;
+
+	if (!pipe) {
+		ret = -1;
+		goto end;
+	}
+
+	lock_read_side(pipe);
+	if (!lttng_pipe_is_read_open(pipe)) {
+		ret = -1;
+		goto end_unlock;
+	}
+	ret = pipe->fd[0];
+	pipe->fd[0] = -1;
+	pipe->r_state = LTTNG_PIPE_STATE_CLOSED;
+end_unlock:
+	unlock_read_side(pipe);
+end:
+	return ret;
+}
+
+/*
+ * Return and release the write end of the pipe.
+ *
+ * This call transfers the ownership of the write fd of the underlying pipe
+ * to the caller if it is still open.
+ *
+ * Returns the fd of the write end of the pipe, or -1 if it was alwritey closed
+ * or released.
+ */
+LTTNG_HIDDEN
+int lttng_pipe_release_writefd(struct lttng_pipe *pipe)
+{
+	int ret;
+
+	if (!pipe) {
+		ret = -1;
+		goto end;
+	}
+
+	lock_write_side(pipe);
+	if (!lttng_pipe_is_write_open(pipe)) {
+		ret = -1;
+		goto end_unlock;
+	}
+	ret = pipe->fd[1];
+	pipe->fd[1] = -1;
+	pipe->w_state = LTTNG_PIPE_STATE_CLOSED;
+end_unlock:
+	unlock_write_side(pipe);
+end:
+	return ret;
+}