device_sensors: make sure to clear the shared memory buffer on each start.

device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

This patch adds robustness to platform dependent fetcher
implementations e.g. when the buffer is live and its data
is updated incrementally as soon as it becomes available.
It also allows to correctly handle cases when sensors are
disabled or go offline.

BUG=609533
Committed: https://crrev.com/9b8b3e34a3251fba6019857b1299e0bae7892662
Cr-Commit-Position: refs/heads/master@{#392386}

[timvolodine, 2016-05-05 17:56:26]

Description was changed from

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

This shouldn't change current behaviour, but adds robustness for
platform dependent implementations of fetchers and cases when sensors
are disabled or offline.

BUG=609533
==========

to

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

Under normal circumstances this patch shouldn't change current
behavior. It does add robustness to platform dependent
implementations of fetchers and allows to correctly handle
cases when sensors are disabled or go offline.

BUG=609533
==========

[timvolodine, 2016-05-05 17:57:06]

Description was changed from

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

Under normal circumstances this patch shouldn't change current
behavior. It does add robustness to platform dependent
implementations of fetchers and allows to correctly handle
cases when sensors are disabled or go offline.

BUG=609533
==========

to

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

Under normal circumstances this patch shouldn't change current
behavior. However it does add robustness to platform dependent
implementations of fetchers and allows to correctly handle
cases when sensors are disabled or go offline.

BUG=609533
==========

[timvolodine, 2016-05-05 17:57:31]

timvolodine@chromium.org changed reviewers:
+ mvanouwerkerk@chromium.org

[timvolodine, 2016-05-05 18:17:14]

Description was changed from

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

Under normal circumstances this patch shouldn't change current
behavior. However it does add robustness to platform dependent
implementations of fetchers and allows to correctly handle
cases when sensors are disabled or go offline.

BUG=609533
==========

to

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

This patch adds robustness to platform dependent fetcher
implementations e.g. when the buffer is live and its data
is updated incrementally as soon as it becomes available.
It also allows to correctly handle cases when sensors are
disabled or go offline.

BUG=609533
==========

[Michael van Ouwerkerk, 2016-05-09 12:34:43]

lgtm

[timvolodine, 2016-05-09 18:08:49]

The CQ bit was checked by timvolodine@chromium.org

[commit-bot: I haz the power, 2016-05-09 18:09:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1954753002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1954753002/1

[commit-bot: I haz the power, 2016-05-09 18:58:55]

Description was changed from

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

This patch adds robustness to platform dependent fetcher
implementations e.g. when the buffer is live and its data
is updated incrementally as soon as it becomes available.
It also allows to correctly handle cases when sensors are
disabled or go offline.

BUG=609533
==========

to

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

This patch adds robustness to platform dependent fetcher
implementations e.g. when the buffer is live and its data
is updated incrementally as soon as it becomes available.
It also allows to correctly handle cases when sensors are
disabled or go offline.

BUG=609533
==========

[commit-bot: I haz the power, 2016-05-09 18:58:55]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-09 19:00:22]

Description was changed from

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

This patch adds robustness to platform dependent fetcher
implementations e.g. when the buffer is live and its data
is updated incrementally as soon as it becomes available.
It also allows to correctly handle cases when sensors are
disabled or go offline.

BUG=609533
==========

to

==========
device_sensors: make sure to clear the shared memory buffer on each start.

DataFetcherSharedMemoryBase::StartFetchingDeviceData(ConsumerType)
should clear the shared memory buffer before each start to make
sure there are no stale values.

This patch adds robustness to platform dependent fetcher
implementations e.g. when the buffer is live and its data
is updated incrementally as soon as it becomes available.
It also allows to correctly handle cases when sensors are
disabled or go offline.

BUG=609533

Committed: https://crrev.com/9b8b3e34a3251fba6019857b1299e0bae7892662
Cr-Commit-Position: refs/heads/master@{#392386}
==========

[commit-bot: I haz the power, 2016-05-09 19:00:23]

Patchset 1 (id:??) landed as
https://crrev.com/9b8b3e34a3251fba6019857b1299e0bae7892662
Cr-Commit-Position: refs/heads/master@{#392386}