Commit Graph

206 Commits

Author SHA1 Message Date
Daniel P. Berrange
3fc73cd339 Reset the 'quit' flag in virNetServerRun
To allow virNetServerRun/virNetServerQuit to be invoked multiple
times, we must reset the 'quit' flag in virNetServerRun

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-19 10:18:26 +01:00
Daniel P. Berrange
be873da538 If in delay close mode for an RPC client, don't read further data
In the delayed close mode, we're just waiting for final data to
be written back to the client. While waiting, we should not
bother to read more data from the client.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-19 10:18:26 +01:00
Guannan Ren
5b924be906 rpc: remove trailing whitespace character in error string
Instead of only removing the ending newline character, it is
better to remove all of standard whitespace character for the
sake of log format.

One example that we have to do this is:
After three times incorrect password input, virsh command
virsh -c qemu://remoteserver/system will report error like:

: Connection reset by peerey,gssapi-keyex,gssapi-with-mic,password).

But it should be:
Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
: Connection reset by peer

The reason is that we dropped the newline, but have a '\r' left.
The terminal interprets it as "move the cursor back to the start
of the current line", so the error string is messed up.
2012-07-19 11:22:52 +08:00
Daniel P. Berrange
7c45ad4ba2 Convert all files in src/rpc/ to use virReportError()
This rmoves all the per-file error reporting macros
from the code in src/rpc/

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-18 16:31:40 +01:00
Daniel P. Berrange
8a89c08069 Fix bogus cast to (int) in virNetServerMDNSTimeoutNew
The virNetServerMDNSTimeoutNew method was casting a long long
to an int when reporting errors. This should just be using
%lld instead of %d, avoiding the need to cast

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-18 16:31:31 +01:00
Christophe Fergeau
efe6c80211 Fix daemon auto-spawning
Commit 32a9aac switched libvirt to use the XDG base directories
to locate most of its data/config. In particular, the per-user socket
for qemu:///session is now stored in the XDG runtime directory.
This directory is located by looking at the XDG_RUNTIME_DIR environment
variable, with a fallback to ~/.cache/libvirt if this variable is not
set.

When the daemon is autospawned because a client application wants
to use qemu:///session, the daemon is ran in a clean environment
which does not contain XDG_RUNTIME_DIR. It will create its socket
in ~/.cache/libvirt. If the client application has XDG_RUNTIME_DIR
set, it will not look for the socket in the fallback place, and will
fail to connect to the autospawned daemon.

This patch adds XDG_RUNTIME_DIR to the daemon environment before
auto-starting it. I've done this in virNetSocketForkDaemon rather
than in virCommandAddEnvPassCommon as I wasn't sure we want to pass
these variables to other commands libvirt spawns. XDG_CACHE_HOME
and XDG_CONFIG_HOME are also added to the daemon env as it makes use
of those as well.
2012-07-12 13:52:36 +02:00
Daniel P. Berrange
dff6d809fb Allow RPC server to run single threaded
Refactor the RPC server dispatcher code so that if 'max_workers==0'
the entire server will run single threaded. This is useful for
use cases where there will only ever be 1 client connected
which serializes its requests

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-05 10:46:09 +01:00
Daniel P. Berrange
c6b2d5d082 Add a opaque parameter to the RPC client init callback
The callback that is invoked when a new RPC client is
initialized does not have any opaque parameter. Add
one so that custom data can be passed into the callback

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-07-05 10:46:09 +01:00
Hu Tao
9c77bf04b0 fix a bug of ref count in virnetserver.c
The test of ref count is not protected by lock, which is unsafe because
the ref count may have been changed by other threads during the test.

This patch fixes this.
2012-06-22 12:13:42 -06:00
Jim Fehlig
0dda594da9 Fix deadlock on libvirtd shutdown
When shutting down libvirtd, the virNetServer shutdown can deadlock
if there are in-flight jobs being handled by virNetServerHandleJob().
virNetServerFree() will acquire the virNetServer lock and call
virThreadPoolFree() to terminate the workers, waiting for the workers
to finish.  But in-flight workers will attempt to acquire the
virNetServer lock, resulting in deadlock.

Fix the deadlock by unlocking the virNetServer lock before calling
virThreadPoolFree().  This is safe since the virNetServerPtr object
is ref-counted and only decrementing the ref count needs to be
protected.  Additionally, there is no need to re-acquire the lock
after virThreadPoolFree() completes as all the workers have
terminated.
2012-06-21 11:38:51 -06:00
Daniel P. Berrange
5d490603a6 client rpc: Fix error checking after poll()
First 'poll' can't return EWOULDBLOCK, and second, we're checking errno
so far away from the poll() call that we've probably already trashed the
original errno value.
2012-06-13 16:01:27 +02:00
Jiri Denemark
4d971dc7ef client rpc: Send keepalive requests from IO event loop
In addition to keepalive responses, we also need to send keepalive
requests from client IO loop to properly detect dead connection in case
a libvirt API is called from the main loop, which prevents any timers to
be called.
2012-06-13 15:58:47 +02:00
Jiri Denemark
d9ad416698 server rpc: Remove APIs for manipulating filters on locked client
We don't need to add or remove filters when client object is already
locked anymore. There's no reason to keep the *Locked variants of those
APIs.
2012-06-13 15:56:41 +02:00
Jiri Denemark
0ec514b359 rpc: Remove unused parameter in virKeepAliveStopInternal
The previous commit removed the only usage of ``all'' parameter in
virKeepAliveStopInternal, which was actually the only reason for having
virKeepAliveStopInternal. This effectively reverts most of commit
6446a9e20c.
2012-06-13 15:53:09 +02:00
Jiri Denemark
bb85f2298e rpc: Do not use timer for sending keepalive responses
When a libvirt API is called from the main event loop (which seems to be
common in event-based glib apps), the client IO loop would properly
handle keepalive requests sent by a server but will not actually send
them because the main event loop is blocked with the API. This patch
gets rid of response timer and the thread which is processing keepalive
requests is also responsible for queueing responses for delivery.
2012-06-13 15:50:55 +02:00
Jiri Denemark
c57103e567 client rpc: Separate call creation from running IO loop
This makes it possible to create and queue new calls while we are
running IO loop.
2012-06-13 15:48:31 +02:00
Jiri Denemark
28c75382b0 rpc: Add APIs for direct triggering of keepalive timer
Add virKeepAliveTimeout and virKeepAliveTrigger APIs that can be used to
set poll timeouts and trigger keepalive timer. virKeepAliveTrigger
checks if it is called to early and does nothing in that case.
2012-06-13 15:46:07 +02:00
Jiri Denemark
a2ba868632 rpc: Refactor keepalive timer code
The code that needs to be run every keepalive interval of inactivity was
only called from a timer and thus from the main event loop. We will need
to call the code directly from another place.
2012-06-13 15:43:45 +02:00
Jiri Denemark
ca9b13e373 client rpc: Drop unused return value of virNetClientSendNonBlock
As we never drop non-blocking calls, the return value that used to
indicate a call was dropped is no longer needed.
2012-06-13 15:41:33 +02:00
Jiri Denemark
ef392614aa client rpc: Just queue non-blocking call if another thread has the buck
As non-blocking calls are no longer dropped, we don't really need to
care that much about their fate and wait for the thread with the buck
to process them. If another thread has the buck, we can just push a
non-blocking call to the queue and be done with it.
2012-06-13 15:39:20 +02:00
Jiri Denemark
78602c4e83 client rpc: Don't drop non-blocking calls
So far, we were dropping non-blocking calls whenever sending them would
block. In case a client is sending lots of stream calls (which are not
supposed to generate any reply), the assumption that having other calls
in a queue is sufficient to get a reply from the server doesn't work. I
tried to fix this in b1e374a7ac but
failed and reverted that commit.

With this patch, non-blocking calls are never dropped (unless the
connection is being closed) and will always be sent.
2012-06-13 15:35:31 +02:00
Jiri Denemark
9e747e5c50 client rpc: Use event loop for writing
Normally, when every call has a thread associated with it, the thread
may get the buck and be in charge of sending all calls until its own
call is done. When we introduced non-blocking calls, we had to add
special handling of new non-blocking calls. This patch uses event loop
to send data if there is no thread to get the buck so that any
non-blocking calls left in the queue are properly sent without having to
handle them specially. It also avoids adding even more cruft to client
IO loop in the following patches.

With this change in, non-blocking calls may see unpredictable delays in
delivery when the client has no event loop registered. However, the only
non-blocking calls we have are keepalives and we already require event
loop for them, which makes this a non-issue until someone introduces new
non-blocking calls.
2012-06-13 15:32:29 +02:00
Jiri Denemark
71689f95ce client rpc: Improve debug messages in virNetClientIO
When analyzing our debug log, I'm always confused about what each of the
pointers mean. Let's be explicit.
2012-06-13 15:24:18 +02:00
Michal Privoznik
539e9b34b9 rpc: Fix memleak in virNetMessageEncodeHeader
My latest patch for RPC rework (a2c304f687) introduced a memory leak.
virNetMessageEncodeHeader() is calling VIR_ALLOC_N(msg->buffer, ...)
despite fact, that msg->buffer isn't VIR_FREE()'d on all paths calling
the function. Therefore, rather than injecting free statement switch to
VIR_REALLOC_N().
2012-06-11 17:02:49 +02:00
Michal Privoznik
eb635de1fe rpc: Size up RPC limits
Since we are allocating RPC buffer dynamically, we can increase limits
for max. size of RPC message and RPC string. This is needed to cover
some corner cases where libvirt is run on such huge machines that their
capabilities XML is 4 times bigger than our current limit. This leaves
users with inability to even connect.
2012-06-05 17:48:40 +02:00
Michal Privoznik
a2c304f687 rpc: Switch to dynamically allocated message buffer
Currently, we are allocating buffer for RPC messages statically.
This is not such pain when RPC limits are small. However, if we want
ever to increase those limits, we need to allocate buffer dynamically,
based on RPC message len (= the first 4 bytes). Therefore we will
decrease our mem usage in most cases and still be flexible enough in
corner cases.
2012-06-05 17:48:40 +02:00
Radu Caragea
107f51b69c Fix sync issue in virNetClientStreamEventRemoveCallback
The stream lock is unlocked twice instead of being locked and then
unlocked. Probably a typo.
2012-06-04 09:32:37 +02:00
Daniel P. Berrange
517368a377 Remove uid param from directory lookup APIs
Remove the uid param from virGetUserConfigDirectory,
virGetUserCacheDirectory, virGetUserRuntimeDirectory,
and virGetUserDirectory

These functions were universally called with the
results of getuid() or geteuid(). To make it practical
to port to Win32, remove the uid parameter and hardcode
geteuid()

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-05-28 10:55:06 +01:00
Daniel P. Berrange
54c4d9d90b Fix check for socket existance / daemon spawn
When you try to connect to a socket in the abstract namespace,
the error will be ECONNREFUSED for a non-listening daemon. With
the non-abstract namespace though, you instead get ENOENT. Add
a check for this extra errno when auto-spawning the daemon

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-05-28 10:43:09 +01:00
Jiri Denemark
63643f67ab Revert "rpc: Discard non-blocking calls only when necessary"
This reverts commit b1e374a7ac, which was
rather bad since I failed to consider all sides of the issue. The main
things I didn't consider properly are:

- a thread which sends a non-blocking call waits for the thread with
  the buck to process the call
- the code doesn't expect non-blocking calls to remain in the queue
  unless they were already partially sent

Thus, the reverted patch actually breaks more than what it fixes and
clients (which may even be libvirtd during p2p migrations) will likely
end up in a deadlock.
2012-05-22 23:33:11 +02:00
Jiri Denemark
b1e374a7ac rpc: Discard non-blocking calls only when necessary
Currently, non-blocking calls are either sent immediately or discarded
in case sending would block. This was implemented based on the
assumption that the non-blocking keepalive call is not needed as there
are other calls in the queue which would keep the connection alive.
However, if those calls are no-reply calls (such as those carrying
stream data), the remote party knows the connection is alive but since
we don't get any reply from it, we think the connection is dead.

This is most visible in tunnelled migration. If it happens to be longer
than keepalive timeout (30s by default), it may be unexpectedly aborted
because the connection is considered to be dead.

With this patch, we only discard non-blocking calls when the last call
with a thread is completed and thus there is no thread left to keep
sending the remaining non-blocking calls.
2012-04-26 16:30:23 +02:00
Peter Krempa
6446a9e20c keepalive: Add ability to disable keepalive messages
The docs for virConnectSetKeepAlive() advertise that this function
should be able to disable keepalives on negative or zero interval time.

This patch removes the check that prohibited this and adds code to
disable keepalives on negative/zero interval.

* src/libvirt.c: virConnectSetKeepAlive(): - remove check for negative
                                             values
* src/rpc/virnetclient.c
* src/rpc/virnetclient.h: - add virNetClientKeepAliveStop() to disable
                            keepalive messages
* src/remote/remote_driver.c: remoteSetKeepAlive(): -add ability to
                                                     disable keepalives
2012-04-26 11:35:34 +02:00
Eric Blake
f43461735e virnetserver: handle sigaction correctly
POSIX says that sa_sigaction is only safe to use if sa_flags
includes SA_SIGINFO; conversely, sa_handler is only safe to
use when flags excludes that bit.  Gnulib doesn't guarantee
an implementation of SA_SIGINFO, but does guarantee that
if SA_SIGINFO is undefined, we can safely define it to 0 as
long as we don't dereference the 2nd or 3rd argument of
any handler otherwise registered via sa_sigaction.

Based on a report by Wen Congyang.

* src/rpc/virnetserver.c (SA_SIGINFO): Stub for mingw.
(virNetServerSignalHandler): Avoid bogus dereference.
(virNetServerFatalSignal, virNetServerNew): Set flags properly.
(virNetServerAddSignalHandler): Drop unneeded #ifdef.
2012-04-19 22:07:21 -06:00
Daniel P. Berrange
2223ea984c The policy kit and HAL node device drivers both require a
DBus connection. The HAL device code further requires that
the DBus connection is integrated with the event loop and
provides such glue logic itself.

The forthcoming FirewallD integration also requires a
dbus connection with event loop integration. Thus we need
to pull the current event loop glue out of the HAL driver.

Thus we create src/util/virdbus.{c,h} files. This contains
just one method virDBusGetSystemBus() which obtains a handle
to the single shared system bus instance, with event glue
automagically setup.
2012-04-19 17:03:10 +01:00
Daniel P. Berrange
20171c8dc0 Fix comment about GNUTLS initialization/cleanup 2012-04-10 13:42:22 +01:00
Daniel P. Berrange
ec8cae93db Consistent style for usage of sizeof operator
The code is splattered with a mix of

  sizeof foo
  sizeof (foo)
  sizeof(foo)

Standardize on sizeof(foo) and add a syntax check rule to
enforce it

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-03-30 11:47:24 +01:00
Eric Blake
4d2e8355cb rpc: generalize solution for VPATH builds
Commit 5d4b0c4c80 tried to fix certain classes of VPATH builds,
but was too limited.  In particular, Guannan Ren reported:

>    For example: The libvirt source code resides in /home/testuser,
>                 I make dist in /tmp/buildvpath, the XDR routine .c file will
>                 include full path of the header file like:
>
>                 #include "/home/testuser/src/rpc/virnetprotocol.h"
>                 #include "internal.h"
>                 #include <arpa/inet.h>
>
>    If we distribute the tarball to another machine to compile,
>    it will report error as follows:
>
>    rpc/virnetprotocol.c:7:59: fatal error:
>    /home/testuser/src/rpc/virnetprotocol.h: No such file or directory

* src/rpc/genprotocol.pl: Fix more include lines.
2012-03-08 08:49:38 -07:00
Eric Blake
73b9977140 xml: use long long internally, to centralize overflow checks
On 64-bit platforms, unsigned long and unsigned long long are
identical, so we don't have to worry about overflow checks.
On 32-bit platforms, anywhere we narrow unsigned long long back
to unsigned long, we have to worry about overflow; it's easier
to do this in one place by having most of the code use the same
or wider types, and only doing the narrowing at the last minute.
Therefore, the memory set commands remain unsigned long, and
the memory get command now centralizes the overflow check into
libvirt.c, so that drivers don't have to repeat the work.

This also fixes a bug where xen returned the wrong value on
failure (most APIs return -1 on failure, but getMaxMemory
must return 0 on failure).

* src/driver.h (virDrvDomainGetMaxMemory): Use long long.
* src/libvirt.c (virDomainGetMaxMemory): Raise overflow.
* src/test/test_driver.c (testGetMaxMemory): Fix driver.
* src/rpc/gendispatch.pl (name_to_ProcName): Likewise.
* src/xen/xen_hypervisor.c (xenHypervisorGetMaxMemory): Likewise.
* src/xen/xen_driver.c (xenUnifiedDomainGetMaxMemory): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xend_internal.h (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xm_internal.c (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xm_internal.h (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.c (xenStoreDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.h (xenStoreDomainGetMaxMemory): Likewise.
* src/xenapi/xenapi_driver.c (xenapiDomainGetMaxMemory):
Likewise.
* src/esx/esx_driver.c (esxDomainGetMaxMemory): Likewise.
* src/libxl/libxl_driver.c (libxlDomainGetMaxMemory): Likewise.
* src/qemu/qemu_driver.c (qemudDomainGetMaxMemory): Likewise.
* src/lxc/lxc_driver.c (lxcDomainGetMaxMemory): Likewise.
* src/uml/uml_driver.c (umlDomainGetMaxMemory): Likewise.
2012-03-07 18:24:43 -07:00
Jiri Denemark
720bee3008 rpc: Fix client crash on connection close
A multi-threaded client with event loop may crash if one of its threads
closes a connection while event loop is in the middle of sending
keep-alive message (either request or response). The right place for it
is inside virNetClientIOEventLoop() between poll() and
virNetClientLock(). We should only close a connection directly if no-one
is using it and defer the closing to the last user otherwise. So far we
only did so if the close was initiated by keep-alive timeout.
2012-03-05 11:30:02 +01:00
Eric Blake
355ec28167 build: fix output of pid values
Nuke the last vestiges of printing pid_t values with the wrong
types, at least in code compiled on mingw64.  There may be other
places, but for now they are only compiled on systems where the
existing %d doesn't trigger gcc warnings.

* src/rpc/virnetsocket.c (virNetSocketNew): Use %lld and casting,
rather than assuming any particular int type for pid_t.
* src/util/command.c (virCommandRunAsync, virPidWait)
(virPidAbort): Likewise.
(verify): Drop a now stale assertion.
2012-03-02 06:57:57 -07:00
Philipp Hahn
99d24ab2e0 virterror.c: Fix several spelling mistakes
compat{a->i}bility
erron{->e}ous
nec{c->}essary.
Either "the" or "a".

Signed-off-by: Philipp Hahn <hahn@univention.de>
2012-02-03 11:32:51 -07:00
Eric Blake
a7cfd709f4 build: prohibit raw malloc and free
Our HACKING discourages use of malloc and free, for at least
a couple of years now.  But we weren't enforcing it, until now :)

For now, I've exempted python and tests, and will clean those up
in subsequent patches.  Examples should be permanently exempt,
since anyone copying our examples won't have use of our
internal-only memory.h via libvirt_util.la.

* cfg.mk (sc_prohibit_raw_allocation): New rule.
(exclude_file_name_regexp--sc_prohibit_raw_allocation): and
exemptions.
* src/cpu/cpu.c (cpuDataFree): Avoid false positive.
* src/conf/network_conf.c (virNetworkDNSSrvDefParseXML): Fix
offenders.
* src/libxl/libxl_conf.c (libxlMakeDomBuildInfo, libxlMakeVfb)
(libxlMakeDeviceModelInfo): Likewise.
* src/rpc/virnetmessage.c (virNetMessageSaveError): Likewise.
* tools/virsh.c (_vshMalloc, _vshCalloc): Likewise.
2012-02-03 10:41:45 -07:00
Eric Blake
99fd69c3de block rebase: add new API virDomainBlockRebase
Qemu is adding the ability to do a partial rebase.  That is, given:

base <- intermediate <- current

virDomainBlockPull will produce:

current

but qemu now has the ability to leave base in the chain, to produce:

base <- current

Note that current qemu can only do a forward merge, and only with
the current image as the destination, which is fully described by
this API without flags.  But in the future, it may be possible to
enhance this API for additional scenarios by using flags:

Merging the current image back into a previous image (that is,
undoing a live snapshot), could be done by passing base as the
destination and flags with a bit requesting a backward merge.

Merging any other part of the image chain, whether forwards (the
backing image contents are pulled into the newer file) or backwards
(the deltas recorded in the newer file are merged back into the
backing file), could also be done by passing a new flag that says
that base should be treated as an XML snippet rather than an
absolute path name, where the XML could then supply the additional
instructions of which part of the image chain is being merged into
any other part.

* include/libvirt/libvirt.h.in (virDomainBlockRebase): New
declaration.
* src/libvirt.c (virDomainBlockRebase): Implement it.
* src/libvirt_public.syms (LIBVIRT_0.9.10): Export it.
* src/driver.h (virDrvDomainBlockRebase): New driver callback.
* src/rpc/gendispatch.pl (long_legacy): Add exemption.
* docs/apibuild.py (long_legacy_functions): Likewise.
2012-02-01 15:21:56 -07:00
Michal Privoznik
8f8b080263 Introduce virDomainPMSuspendForDuration API
This API allows a domain to be put into one of S# ACPI states.
Currently, S3 and S4 are supported. These states are shared
with virNodeSuspendForDuration.
However, for now we don't support any duration other than zero.
The same apply for flags.
2012-01-28 10:20:46 +01:00
Daniel P. Berrange
91f79d27cc Fix rpc generator to anchor matches for method names
The RPC generator transforms methods matching certain
patterns like 'id' or 'uuid', etc but does not anchor
its matches to the end of the word. So if a method
contains 'id' in the middle (eg virIdentity) then the
RPC generator munges that.

* src/rpc/gendispatch.pl: Anchor matches
2012-01-19 15:39:54 +00:00
Daniel P. Berrange
2f9dc36d49 Rename APIs for fetching UNIX socket credentials
To avoid a namespace clash with forthcoming identity APIs,
rename the virNet*GetLocalIdentity() APIs to have the form
virNet*GetUNIXIdentity()

* daemon/remote.c, src/libvirt_private.syms: Update
  for renamed APIs
* src/rpc/virnetserverclient.c, src/rpc/virnetserverclient.h,
  src/rpc/virnetsocket.c, src/rpc/virnetsocket.h: s/LocalIdentity/UNIXIdentity/
2012-01-19 15:39:52 +00:00
Daniel P. Berrange
59cf039815 Also retrieve GID from SO_PEERCRED
* daemon/remote.c, src/rpc/virnetserverclient.c,
  src/rpc/virnetserverclient.h, src/rpc/virnetsocket.c,
  src/rpc/virnetsocket.h: Add gid parameter
2012-01-19 13:30:03 +00:00
Michal Privoznik
833b901cb7 stream: Check for stream EOF
If client stream does not have any data to sink and neither received
EOF, a dummy packet is sent to the daemon signalising client is ready to
sink some data. However, after we added event loop to client a race may
occur:

Thread 1 calls virNetClientStreamRecvPacket and since no data are cached
nor stream has EOF, it decides to send dummy packet to server which will
sent some data in turn. However, during this decision and actual message
exchange with server -

Thread 2 receives last stream data from server. Therefore an EOF is set
on stream and if there is a call waiting (which is not yet) it is woken
up. However, Thread 1 haven't sent anything so far, so there is no call
to be woken up. So this thread sent dummy packet to daemon, which
ignores that as no stream is associated with such packet and therefore
no reply will ever come.

This race causes client to hang indefinitely.
2012-01-12 12:02:40 +01:00
Eric Blake
4e394dea1f rpc: handle param_int, plug memory leaks
The RPC code had several latent memory leaks and an attempt to
free the wrong string, but thankfully nothing triggered them
(blkiotune was the only one returning a string, and always as
the last parameter).  Also, our cleanups for rpcgen ended up
nuking a line of code that renders VIR_TYPED_PARAM_INT broken,
because it was the only use of 'i' in a function, even though
it was a member usage rather than a standalone declaration.

* daemon/remote.c (remoteSerializeTypedParameters): Free the
correct array element.
(remoteDispatchDomainGetSchedulerParameters)
(remoteDispatchDomainGetSchedulerParametersFlags)
(remoteDispatchDomainBlockStatsFlags)
(remoteDispatchDomainGetMemoryParameters): Don't leak strings.
* src/rpc/genprotocol.pl: Don't nuke member-usage of 'buf' or 'i'.
2011-12-20 08:41:10 -07:00
Daniel P. Berrange
e970863746 Fix updating of haveTheBuck in RPC client to be race-free
When one thread passes the buck to another thread, it uses
virCondSignal to wake up the target thread. The variable
'haveTheBuck' is not updated in a race-free manner when
this occurs. The current thread sets it to false, and the
woken up thread sets it to true. There is a window where
a 3rd thread can come in and grab the buck.

Even if this didn't lead to crashes & deadlocks, this would
still result in unfairness in the buckpassing algorithm.

A better solution is to *never* set haveTheBuck to false
when we're passing the buck. Only set it to false when there
is no further thread waiting for the buck.

* src/rpc/virnetclient.c: Only set haveTheBuck to false
  if no thread is waiting
2011-12-08 11:27:19 +08:00