83 lines
3.0 KiB
Diff
83 lines
3.0 KiB
Diff
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From 4ff3734ff5748cbc53f7b89c7148a4e3daba3230 Mon Sep 17 00:00:00 2001
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From: Will Thompson <will@willthompson.co.uk>
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Date: Mon, 26 Nov 2018 16:04:10 +0000
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Subject: [PATCH 307/682] g_timeout_*_seconds: don't overflow for large
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intervals
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Previously, the `guint interval` parameter, measured in seconds, was
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multiplied by 1000 and stored in another `guint` field. For intervals
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greater than (G_MAXUINT / 1000) seconds, this would overflow; the
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timeout would fire much sooner than intended.
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Since GTimeoutSource already keeps track of whether it was created at
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millisecond or second resolution, always store the passed interval
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directly. We later convert the interval to microseconds, stored in a
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gint64, so can move the `* 1000` to there.
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The eagle-eyed reader might notice that there is no obvious guarantee
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that the source's expiration time in microseconds won't overflow the
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gint64, but I don't think this is a new problem. Previously, the
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monotonic time would have to reach (2 ** 63 - 2 ** 32) microseconds for
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this overflow to occur; now it would have to reach approximately (2 **
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63 - 2 ** 42) microseconds. Both of these are 292.47 millennia to 5
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significant figures.
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Fixes #1600.
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---
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glib/gmain.c | 11 ++++++++---
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1 file changed, 8 insertions(+), 3 deletions(-)
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diff --git a/glib/gmain.c b/glib/gmain.c
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index 5e849b9ac..347882551 100644
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--- a/glib/gmain.c
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+++ b/glib/gmain.c
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@@ -315,6 +315,7 @@ struct _GMainLoop
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struct _GTimeoutSource
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{
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GSource source;
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+ /* Measured in seconds if 'seconds' is TRUE, or milliseconds otherwise. */
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guint interval;
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gboolean seconds;
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};
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@@ -4615,8 +4616,6 @@ g_timeout_set_expiration (GTimeoutSource *timeout_source,
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{
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gint64 expiration;
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- expiration = current_time + (guint64) timeout_source->interval * 1000;
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-
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if (timeout_source->seconds)
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{
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gint64 remainder;
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@@ -4638,6 +4637,8 @@ g_timeout_set_expiration (GTimeoutSource *timeout_source,
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timer_perturb = 0;
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}
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+ expiration = current_time + (guint64) timeout_source->interval * 1000 * 1000;
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+
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/* We want the microseconds part of the timeout to land on the
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* 'timer_perturb' mark, but we need to make sure we don't try to
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* set the timeout in the past. We do this by ensuring that we
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@@ -4653,6 +4654,10 @@ g_timeout_set_expiration (GTimeoutSource *timeout_source,
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expiration -= remainder;
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expiration += timer_perturb;
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}
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+ else
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+ {
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+ expiration = current_time + (guint64) timeout_source->interval * 1000;
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+ }
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g_source_set_ready_time ((GSource *) timeout_source, expiration);
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}
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@@ -4735,7 +4740,7 @@ g_timeout_source_new_seconds (guint interval)
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GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource));
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GTimeoutSource *timeout_source = (GTimeoutSource *)source;
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- timeout_source->interval = 1000 * interval;
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+ timeout_source->interval = interval;
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timeout_source->seconds = TRUE;
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g_timeout_set_expiration (timeout_source, g_get_monotonic_time ());
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--
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2.19.1
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