The SCM can be locked by NT. While traditionally any process could lock
the SCM using "LockServiceDatabase", Microsoft removed this
functionality because it created so many bugs, and that function now
does nothing. However, the system itself, via the "NT Service Control
Manager", is still allowed to lock the SCM.
For example, at boot time on Windows 8.1, the SCM is locked after a
service is started until that service reports itself in a running state.
This poses a bit of a problem: it's useful to install device drivers
from inside services as part of their initialization, and mark the
service as having started only after the device has installed. But
device installation might potentially load new drivers, and drivers
themselves exist as a special type of service. This means that if a
driver is installed before marking the service as started, the entire
SCM will deadlock, and the OS will be partially unresponsive for a
minute or two.
Fortunately Microsoft supplies an API for exactly this purpose. The
solution is to mark the service as started before installing device
drivers, only under the circumstance that the SCM is locked. So, this
commit adds the proper API for determining this. It can be used like
this:
if m, err := mgr.Connect(); err == nil {
if lockStatus, err := m.LockStatus(); err == nil && lockStatus.IsLocked {
log.Printf("SCM locked for %v by %s, marking service as started", lockStatus.Age, lockStatus.Owner)
changes <- svc.Status{State: svc.Running}
}
m.Disconnect()
}
deviceDriver.Install()
This creates messages like the following, indicating that this API
works:
SCM locked for 1s by .\NT Service Control Manager, marking service as started
Change-Id: Ic2f5b387e23efc3a287b2ab96ff84b357b712e36
Reviewed-on: https://go-review.googlesource.com/c/sys/+/180977
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
This adds a number of useful comments for ChangeServiceConfig2. It looks
like the MingW headers have these in two different places, awkwardly,
and whoever imported these constants missed the second half of them,
whereas the real Microsoft header files have them all together in one
place.
Change-Id: I723c4bcd86e5a1b905cb738c5c2b49805a354af4
Reviewed-on: https://go-review.googlesource.com/c/sys/+/177842
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This lays the groundwork for service notification and tracking by adding
the required API functions. Users can make notifiers directly using it,
or later if we're feeling ambitious, we can see if we can come up with a
generalized solution in x/windows/svc.
Change-Id: I80503cc27970fbb23bf17cd8bc50eaa7787aa6bd
Reviewed-on: https://go-review.googlesource.com/c/sys/+/176624
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
While the types_windows file previously had a small handful of types,
this forced application code to have an awkward mixture of artisanal
error constants and factory-ready ones. This commit adds the missing
ones and separates them into a new file, since they are quite numerous.
These also preserve the order of winerr.h, which should make it somewhat
easier to import new ones in the future.
Fixesgolang/go#31360
Change-Id: If2abc507a8884ec1641f0b17fe0c612a950d3644
Reviewed-on: https://go-review.googlesource.com/c/sys/+/170918
Reviewed-by: Jason Donenfeld <Jason@zx2c4.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Added configuration options for a windows service recovery settings.
Current configurations include modifying actions taken when a service
fails, setting the reset period, and getting the current recovery
settings.
Updates golang/go#23239
Change-Id: I4e91b2068122731e6eba3332afb0fe300b298c97
Reviewed-on: https://go-review.googlesource.com/104635
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
