Add pipe creation to utils facility

[lttng-tools.git] / src / bin / lttng-sessiond / utils.c

diff --git a/src/bin/lttng-sessiond/utils.c b/src/bin/lttng-sessiond/utils.c
index ce2e97561f0170c3dbdb072370e79b1e5ec502ae..d0c8dd16f62571618db8118759d7a8ee4e650a76 100644 (file)
--- a/src/bin/lttng-sessiond/utils.c
+++ b/src/bin/lttng-sessiond/utils.c
@@ -18,6 +18,7 @@
 
 #define _GNU_SOURCE
 #include <errno.h>
+#include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -52,3 +53,77 @@ const char *get_home_dir(void)
 {
        return ((const char *) getenv("HOME"));
 }
+
+/*
+ * Create a pipe in dst.
+ */
+int utils_create_pipe(int *dst)
+{
+       int ret;
+
+       if (dst == NULL) {
+               return -1;
+       }
+
+       ret = pipe(dst);
+       if (ret < 0) {
+               PERROR("create pipe");
+       }
+
+       return ret;
+}
+
+/*
+ * Create pipe and set CLOEXEC flag to both fd.
+ *
+ * Make sure the pipe opened by this function are closed at some point. Use
+ * utils_close_pipe().
+ */
+int utils_create_pipe_cloexec(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;
+               }
+       }
+
+error:
+       return ret;
+}
+
+/*
+ * Close both read and write side of the pipe.
+ */
+void utils_close_pipe(int *src)
+{
+       int i, ret;
+
+       if (src == NULL) {
+               return;
+       }
+
+       for (i = 0; i < 2; i++) {
+               /* Safety check */
+               if (src[i] < 0) {
+                       continue;
+               }
+
+               ret = close(src[i]);
+               if (ret) {
+                       PERROR("close pipe");
+               }
+       }
+}