Re: [libvirt] [PATCH 2/5] add qemuAgentCommand()
On 08/07/2012 06:04 PM, MATSUDA, Daiki wrote:
Add qemuAgentCommand() for general qemu agent command.
include/libvirt/libvirt-qemu.h | 5 +++++
src/qemu/qemu_agent.c | 38 ++++++++++++++++++++++++++++++++++++++
src/qemu/qemu_agent.h | 5 +++++
3 files changed, 48 insertions(+)
Causes a compiler warning:
CC libvirt_driver_qemu_impl_la-qemu_agent.lo
qemu/qemu_agent.c: In function 'qemuAgentQemuAgentCommand':
qemu/qemu_agent.c:1411:9: error: variable 'seconds' set but not used
[-Werror=unused-but-set-variable]
diff --git a/include/libvirt/libvirt-qemu.h
b/include/libvirt/libvirt-qemu.h
index a37f897..ffc5ae5 100644
--- a/include/libvirt/libvirt-qemu.h
+++ b/include/libvirt/libvirt-qemu.h
@@ -44,6 +44,11 @@ virDomainPtr virDomainQemuAttach(virConnectPtr domain,
unsigned int pid_value,
unsigned int flags);
+typedef enum {
+ VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK = -1,
+ VIR_DOMAIN_QEMU_AGENT_COMMAND_NOWAIT = 0,
+} virDomainQemuAgentCommandTimeoutFlags;
These aren't flags, but special timeout values. Maybe s/Flags/Values/
+
+int qemuAgentQemuAgentCommand(qemuAgentPtr mon,
This name sounds funny; maybe qemuAgentArbitraryCommand might be nicer.
+ const char *cmd_str,
+ char **result,
+ int timeout)
+{
+ int ret = -1;
+ int seconds;
+ virJSONValuePtr cmd;
+ virJSONValuePtr reply = NULL;
+
+ cmd = virJSONValueFromString(cmd_str);
+ if (!cmd)
+ return ret;
+
+ if (result == NULL) {
+ seconds = 0;
+ } else if (timeout == VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) {
+ seconds = 5;
Why 5 seconds here,
+ } else {
+ seconds = timeout;
but the user's timeout here? If you are looping while waiting for a
response, then 5 seconds is too long between loops; you will feel
unresponsive; and if the user passes a timeout of 10, you end up waiting
10 seconds.
+ }
+
+repeat:
+ ret = qemuAgentCommand(mon, cmd, &reply, timeout);
Won't work - this starts a new agent command every time repeat is
reached, rather than waiting for the completion of an existing command.
+
+ if (ret == 0) {
+ ret = qemuAgentCheckError(cmd, reply);
+ *result = virJSONValueToString(reply);
+ } else {
+ if (timeout == VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) goto repeat;
Typical formatting would be to split this to two lines:
if (timeout == VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK)
goto repeat;
> + *result = NULL;
> + }
> +
> + virJSONValueFree(cmd);
> + virJSONValueFree(reply);
> + return ret;
> +}
> diff --git a/src/qemu/qemu_agent.h b/src/qemu/qemu_agent.h
> index 2fdebb2..fc19c2f 100644
> --- a/src/qemu/qemu_agent.h
> +++ b/src/qemu/qemu_agent.h
> @@ -77,4 +77,9 @@ int qemuAgentFSThaw(qemuAgentPtr mon);
>
> int qemuAgentSuspend(qemuAgentPtr mon,
> unsigned int target);
+
+int qemuAgentQemuAgentCommand(qemuAgentPtr mon,
> +
const char *cmd,
> + char **result,
> + int timeout);
> #endif /* __QEMU_AGENT_H__ */
>
Definitely needs some work before this function will handle timeout
properly.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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