From: David Goulet <dgoulet@efficios.com>
Date: Fri, 15 Jun 2012 15:00:11 +0000 (-0400)
Subject: Add pipe creation to utils facility
X-Git-Tag: v2.1.0-rc1~109
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=ef599319218f03ff160778e577cd8389a165f47c;p=lttng-tools.git

Add pipe creation to utils facility

Three new functions are added to create a pipe, create a pipe with
CLOEXEC flag and close a pipe.

Those functions are now used in the session daemon for all pipes and
cleanup.

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index a9d538c7c..452b7ba7e 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -407,7 +407,7 @@ static void stop_threads(void)
  */
 static void cleanup(void)
 {
-	int ret, i;
+	int ret;
 	char *cmd;
 	struct ltt_session *sess, *stmp;
 
@@ -457,34 +457,9 @@ static void cleanup(void)
 		DBG("Unloading kernel modules");
 		modprobe_remove_lttng_all();
 	}
-
-	/*
-	 * Closing all pipes used for communication between threads.
-	 */
-	for (i = 0; i < 2; i++) {
-		if (kernel_poll_pipe[i] >= 0) {
-			ret = close(kernel_poll_pipe[i]);
-			if (ret) {
-				PERROR("close");
-			}
-		}
-	}
-	for (i = 0; i < 2; i++) {
-		if (thread_quit_pipe[i] >= 0) {
-			ret = close(thread_quit_pipe[i]);
-			if (ret) {
-				PERROR("close");
-			}
-		}
-	}
-	for (i = 0; i < 2; i++) {
-		if (apps_cmd_pipe[i] >= 0) {
-			ret = close(apps_cmd_pipe[i]);
-			if (ret) {
-				PERROR("close");
-			}
-		}
-	}
+	utils_close_pipe(kernel_poll_pipe);
+	utils_close_pipe(thread_quit_pipe);
+	utils_close_pipe(apps_cmd_pipe);
 
 	/* <fun> */
 	DBG("%c[%d;%dm*** assert failed :-) *** ==> %c[%dm%c[%d;%dm"
@@ -4167,58 +4142,6 @@ end:
 	return ret;
 }
 
-/*
- * Create the pipe used to wake up the kernel thread.
- * Closed in cleanup().
- */
-static int create_kernel_poll_pipe(void)
-{
-	int ret, i;
-
-	ret = pipe(kernel_poll_pipe);
-	if (ret < 0) {
-		PERROR("kernel poll pipe");
-		goto error;
-	}
-
-	for (i = 0; i < 2; i++) {
-		ret = fcntl(kernel_poll_pipe[i], F_SETFD, FD_CLOEXEC);
-		if (ret < 0) {
-			PERROR("fcntl kernel_poll_pipe");
-			goto error;
-		}
-	}
-
-error:
-	return ret;
-}
-
-/*
- * Create the application command pipe to wake thread_manage_apps.
- * Closed in cleanup().
- */
-static int create_apps_cmd_pipe(void)
-{
-	int ret, i;
-
-	ret = pipe(apps_cmd_pipe);
-	if (ret < 0) {
-		PERROR("apps cmd pipe");
-		goto error;
-	}
-
-	for (i = 0; i < 2; i++) {
-		ret = fcntl(apps_cmd_pipe[i], F_SETFD, FD_CLOEXEC);
-		if (ret < 0) {
-			PERROR("fcntl apps_cmd_pipe");
-			goto error;
-		}
-	}
-
-error:
-	return ret;
-}
-
 /*
  * Create the lttng run directory needed for all global sockets and pipe.
  */
@@ -4617,12 +4540,12 @@ int main(int argc, char **argv)
 	}
 
 	/* Setup the kernel pipe for waking up the kernel thread */
-	if ((ret = create_kernel_poll_pipe()) < 0) {
+	if ((ret = utils_create_pipe_cloexec(kernel_poll_pipe)) < 0) {
 		goto exit;
 	}
 
 	/* Setup the thread apps communication pipe. */
-	if ((ret = create_apps_cmd_pipe()) < 0) {
+	if ((ret = utils_create_pipe_cloexec(apps_cmd_pipe)) < 0) {
 		goto exit;
 	}
 
diff --git a/src/bin/lttng-sessiond/utils.c b/src/bin/lttng-sessiond/utils.c
index ce2e97561..d0c8dd16f 100644
--- 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");
+		}
+	}
+}
diff --git a/src/bin/lttng-sessiond/utils.h b/src/bin/lttng-sessiond/utils.h
index d4bd8c286..a63d0a3dc 100644
--- a/src/bin/lttng-sessiond/utils.h
+++ b/src/bin/lttng-sessiond/utils.h
@@ -20,5 +20,8 @@
 
 const char *get_home_dir(void);
 int notify_thread_pipe(int wpipe);
+int utils_create_pipe_cloexec(int *dst);
+int utils_create_pipe(int *dst);
+void utils_close_pipe(int *src);
 
 #endif /* _LTT_UTILS_H */