56 lines
2.2 KiB
Diff
56 lines
2.2 KiB
Diff
From e72c338a9fe72a45e6687174fddf1a1725b5949b Mon Sep 17 00:00:00 2001
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From: Franck Bui <fbui@suse.com>
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Date: Wed, 8 Feb 2017 20:56:22 +0100
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Subject: [PATCH] sd-event: "when exiting no signal event are pending" is a
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wrong assertion (#5271)
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The code make the following assertion: when freeing a event loop object
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(usually it's done after exiting from the main event loop), no signal events
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are still queued and are pending.
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This assertion can be found in event_unmask_signal_data() with
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"assert(!d->current);" assertion.
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It appears that this assertion can be wrong at least in a specific case
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described below.
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Consider the following example which is inspired from udev: a process defines 3
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source events: 2 are created by sd_event_add_signal() and 1 is created by
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sd_event_add_post().
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1. the process receives the 2 signals consecutively so that signal 'A' source
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event is queued and pending. Consequently the post source event is also
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queued and pending. This is done by sd_event_wait().
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2. The callback for signal 'A' is called by sd_event_dispatch().
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3. The next call to sd_event_wait() will queue signal 'B' source event.
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4. The callback for the post source event is called and calls sd_event_exit().
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5. the event loop is exited.
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6. freeing the event loop object will lead to the assertion failure in
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event_unmask_signal_data().
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This patch simply removes this assertion as it doesn't seem to be a
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bug if the signal data still reference a signal source at this point.
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(cherry picked from commit 4470860388e12a5dda1d65773e411a349221a3e9)
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---
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src/libsystemd/sd-event/sd-event.c | 1 -
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1 file changed, 1 deletion(-)
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diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
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index 9857f8b1fc..41ce91fa79 100644
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--- a/src/libsystemd/sd-event/sd-event.c
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+++ b/src/libsystemd/sd-event/sd-event.c
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@@ -730,7 +730,6 @@ static void event_unmask_signal_data(sd_event *e, struct signal_data *d, int sig
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/* If all the mask is all-zero we can get rid of the structure */
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hashmap_remove(e->signal_data, &d->priority);
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- assert(!d->current);
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safe_close(d->fd);
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free(d);
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return;
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