From f84a3ba77c61a351e1d7efb67bd40db23a435281 Mon Sep 17 00:00:00 2001
From: Mattias Andrée <m@maandree.se>
Date: Sun, 16 Mar 2025 22:36:46 +0100
Subject: Refactor
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Signed-off-by: Mattias Andrée <m@maandree.se>
---
 src/util.c | 49 ++++++++++++++++++++++++++++++++++---------------
 1 file changed, 34 insertions(+), 15 deletions(-)

(limited to 'src/util.c')

diff --git a/src/util.c b/src/util.c
index fc6dc2c..a562fd2 100644
--- a/src/util.c
+++ b/src/util.c
@@ -186,47 +186,66 @@ try_path_opendir(const struct env_path *path_spec, const char **path_out, char *
 }
 
 
+
+#ifndef WINDOWS
 int
-pipe_nonblock(int pipefds[2])
+pipe_rdnonblock(int pipefds[2])
 {
-#ifdef WINDOWS
-	(void) pipefds;
-	return -1;
-#else
-
 	int i, flags;
 
+	/* Try to use pipe2(2) create O_CLOEXEC pipe, preferably with O_DIRECT */
 # if defined(__linux__) && !defined(MISSING_PIPE2)
-	if (!pipe2(pipefds, O_NONBLOCK)) {
-		return 0;
+	if (!pipe2(pipefds, O_CLOEXEC | O_DIRECT)) {
+		goto apply_nonblock;
+	} else if (errno == EINVAL) {
+		if (!pipe2(pipefds, O_CLOEXEC)) {
+			goto apply_nonblock;
+		} else if (errno != ENOSYS) {
+			weprintf("pipe2 <buffer> O_CLOEXEC:");
+			return -1;
+		}
 	} else if (errno != ENOSYS) {
-		weprintf("pipe2 <buffer> O_NONBLOCK:");
+		weprintf("pipe2 <buffer> O_CLOEXEC|O_DIRECT:");
 		return -1;
 	}
 # endif
 
+	/* Fallback for when pipe2(2) is not available (also indicates O_DIRECT cannot be used) */
 	if (pipe(pipefds)) {
 		weprintf("pipe:");
 		return -1;
 	}
-
 	for (i = 0; i < 2; i++) {
-		flags = fcntl(pipefds[0], F_GETFL);
+		flags = fcntl(pipefds[i], F_GETFD);
 		if (flags == -1) {
-			weprintf("fcntl <pipe> F_GETFL:");
+			weprintf("fcntl <pipe> F_GETFD:");
 			goto fail;
 		}
-		if (fcntl(pipefds[0], F_SETFL, flags | O_NONBLOCK)) {
-			weprintf("fcntl <pipe> F_SETFL +O_NONBLOCK:");
+		if (fcntl(pipefds[i], F_SETFD, flags | O_CLOEXEC)) {
+			weprintf("fcntl <pipe> F_SETFD +O_CLOEXEC:");
 			goto fail;
 		}
 	}
 
+	/* Make the read-end non-blocking */
+# if defined(__linux__) && !defined(MISSING_PIPE2)
+apply_nonblock:
+# endif
+	flags = fcntl(pipefds[0], F_GETFL);
+	if (flags == -1) {
+		weprintf("fcntl <pipe> F_GETFL:");
+		goto fail;
+	}
+	if (fcntl(pipefds[0], F_SETFL, flags | O_NONBLOCK)) {
+		weprintf("fcntl <pipe> F_SETFL +O_NONBLOCK:");
+		goto fail;
+	}
+
 	return 0;
 
 fail:
 	close(pipefds[0]);
 	close(pipefds[1]);
 	return -1;
-#endif
 }
+#endif
-- 
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