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[PATCH 11/14] upload-pack: Run rev-list in an asynchronous function.

From
Johannes Sixt <johannes.sixt@telecom.at>
Date
Oct 19, 2007, 19:48 UTC
Message-ID
<1192823286-9654-12-git-send-email-johannes.sixt@telecom.at>
In-Reply-To
<1192823286-9654-11-git-send-email-johannes.sixt@telecom.at>
This gets rid of an explicit fork().

Since upload-pack has to coordinate two processes (rev-list and pack-objects), we cannot use the normal finish_async(), but have to monitor the process explicitly. Hence, there are no changes at this front.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
---
 upload-pack.c |   46 ++++++++++++++++++----------------------------
 1 files changed, 18 insertions(+), 28 deletions(-)
diff --git a/upload-pack.c b/upload-pack.c
index ccdc306..6799468 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -97,11 +97,12 @@ static void show_edge(struct commit *commit)
 	fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
 }
 
-static void do_rev_list(int create_full_pack)
+static int do_rev_list(int fd, void *create_full_pack)
 {
 	int i;
 	struct rev_info revs;
 
+	pack_pipe = fdopen(fd, "w");
 	if (create_full_pack)
 		use_thin_pack = 0; /* no point doing it */
 	init_revisions(&revs, NULL);
@@ -131,14 +132,12 @@ static void do_rev_list(int create_full_pack)
 	prepare_revision_walk(&revs);
 	mark_edges_uninteresting(revs.commits, &revs, show_edge);
 	traverse_commit_list(&revs, show_commit, show_object);
+	return 0;
 }
 
 static void create_pack_file(void)
 {
-	/* Pipe from rev-list to pack-objects
-	 */
-	int lp_pipe[2];
-	pid_t pid_rev_list;
+	struct async rev_list;
 	struct child_process pack_objects;
 	int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 	char data[8193], progress[128];
@@ -148,22 +147,12 @@ static void create_pack_file(void)
 	const char *argv[10];
 	int arg = 0;
 
-	if (pipe(lp_pipe) < 0)
-		die("git-upload-pack: unable to create pipe");
-	pid_rev_list = fork();
-	if (pid_rev_list < 0)
+	rev_list.proc = do_rev_list;
+	/* .data is just a boolean: any non-NULL value will do */
+	rev_list.data = create_full_pack ? &rev_list : NULL;
+	if (start_async(&rev_list))
 		die("git-upload-pack: unable to fork git-rev-list");
 
-	if (!pid_rev_list) {
-		close(lp_pipe[0]);
-		pack_pipe = fdopen(lp_pipe[1], "w");
-		do_rev_list(create_full_pack);
-		exit(0);
-	}
-
-	/* writable pipe end must not be inherited by pack_objects */
-	close(lp_pipe[1]);
-
 	argv[arg++] = "pack-objects";
 	argv[arg++] = "--stdout";
 	if (!no_progress)
@@ -173,14 +162,15 @@ static void create_pack_file(void)
 	argv[arg++] = NULL;
 
 	memset(&pack_objects, 0, sizeof(pack_objects));
-	pack_objects.in = lp_pipe[0];	/* start_command closes it */
+	pack_objects.in = rev_list.out;	/* start_command closes it */
 	pack_objects.out = -1;
 	pack_objects.err = -1;
 	pack_objects.git_cmd = 1;
 	pack_objects.argv = argv;
+
 	if (start_command(&pack_objects)) {
 		/* daemon sets things up to ignore TERM */
-		kill(pid_rev_list, SIGKILL);
+		kill(rev_list.pid, SIGKILL);
 		die("git-upload-pack: unable to fork git-pack-objects");
 	}
 
@@ -280,11 +270,11 @@ static void create_pack_file(void)
 		}
 
 		/* See if the children are still there */
-		if (pid_rev_list || pack_objects.pid) {
+		if (rev_list.pid || pack_objects.pid) {
 			pid = waitpid(-1, &status, WNOHANG);
 			if (!pid)
 				continue;
-			who = ((pid == pid_rev_list) ? "git-rev-list" :
+			who = ((pid == rev_list.pid) ? "git-rev-list" :
 			       (pid == pack_objects.pid) ? "git-pack-objects" :
 			       NULL);
 			if (!who) {
@@ -302,11 +292,11 @@ static void create_pack_file(void)
 				      who);
 				goto fail;
 			}
-			if (pid == pid_rev_list)
-				pid_rev_list = 0;
+			if (pid == rev_list.pid)
+				rev_list.pid = 0;
 			if (pid == pack_objects.pid)
 				pack_objects.pid = 0;
-			if (pid_rev_list || pack_objects.pid)
+			if (rev_list.pid || pack_objects.pid)
 				continue;
 		}
 
@@ -329,8 +319,8 @@ static void create_pack_file(void)
  fail:
 	if (pack_objects.pid)
 		kill(pack_objects.pid, SIGKILL);
-	if (pid_rev_list)
-		kill(pid_rev_list, SIGKILL);
+	if (rev_list.pid)
+		kill(rev_list.pid, SIGKILL);
 	send_client_data(3, abort_msg, sizeof(abort_msg));
 	die("git-upload-pack: %s", abort_msg);
 }
-- 
1.5.3.4.315.g2ce38
Previous: Johannes SixtNext: Johannes Sixt
Message 12 of 18 in “fork/exec removal series”
  1. 0/14 fork/exec removal seriesJohannes Sixt, Oct 19, 2007
  2. 01/14 Change git_connect() to return a struct child_process instead of a pid_t.Johannes Sixt, Oct 19, 2007
  3. 02/14 Use start_command() in git_connect() instead of explicit fork/exec.Johannes Sixt, Oct 19, 2007
  4. 03/14 Use start_command() to run content filters instead of explicit fork/exec.Johannes Sixt, Oct 19, 2007
  5. 04/14 Use run_command() to spawn external diff programs instead of fork/exec.Johannes Sixt, Oct 19, 2007
  6. 05/14 Use start_comand() in builtin-fetch-pack.c instead of explicit fork/exec.Johannes Sixt, Oct 19, 2007
  7. 06/14 Have start_command() create a pipe to read the stderr of the child.Johannes Sixt, Oct 19, 2007
  8. 07/14 upload-pack: Use start_command() to run pack-objects in create_pack_file().Johannes Sixt, Oct 19, 2007
  9. 08/14 Add infrastructure to run a function asynchronously.Johannes Sixt, Oct 19, 2007
  10. 09/14 Use the asyncronous function infrastructure in builtin-fetch-pack.c.Johannes Sixt, Oct 19, 2007
  11. 10/14 upload-pack: Move the revision walker into a separate function.Johannes Sixt, Oct 19, 2007
  12. 11/14 upload-pack: Run rev-list in an asynchronous function.Johannes Sixt, Oct 19, 2007
  13. 12/14 t0021-conversion.sh: Test that the clean filter really cleans content.Johannes Sixt, Oct 19, 2007
  14. 13/14 Avoid a dup2(2) in apply_filter() - start_command() can do it for us.Johannes Sixt, Oct 19, 2007
  15. 14/14 Use the asyncronous function infrastructure to run the content filter.Johannes Sixt, Oct 19, 2007
  16. Shawn O. PearceOct 20, 2007
  17. Johannes SixtOct 20, 2007
  18. Shawn O. PearceOct 21, 2007

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