11:27 p.m.
(2012/08/09 11:08), Eric Blake wrote:
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]
Sorry, it has a mistake on calling qemuAgentCommand() with not seconds but timeout.
> 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,
Becuase I realize the infinite waiting as you suggested.
* If @result is NULL, then don't wait for a result (and
@timeout
* must be 0). Otherwise, wait for @timeout seconds for a
* successful result to be populated into *@result, with
* VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK (-1) meaning to block
* forever waiting for a result.
But it is difficult. So, I used 'repeat' tag and 5 seconds is default value.
#define QEMU_AGENT_WAIT_TIME (1000ull * 5)
> + } 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.
And I attached fixed patch, but it is not completed. After receiving all comments,
I will resend new patches.
include/libvirt/libvirt-qemu.h | 5 ++++
src/qemu/qemu_agent.c | 47 ++++++++++++++++++++++++++++++++++++++++-
src/qemu/qemu_agent.h | 5 ++++
3 files changed, 56 insertions(+), 1 deletion(-)
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,
+} virDomainQemuAgentCommandTimeoutValues;
+
# ifdef __cplusplus
}
# endif
diff --git a/src/qemu/qemu_agent.c b/src/qemu/qemu_agent.c
index 7699042..1cfcafc 100644
--- a/src/qemu/qemu_agent.c
+++ b/src/qemu/qemu_agent.c
@@ -830,7 +830,8 @@ void qemuAgentClose(qemuAgentPtr mon)
virObjectUnref(mon);
}
-#define QEMU_AGENT_WAIT_TIME (1000ull * 5)
+#define QEMU_AGENT_WAIT_DEFAULT 5
+#define QEMU_AGENT_WAIT_TIME (1000ull * QEMU_AGENT_WAIT_DEFAULT)
/**
* qemuAgentSend:
@@ -1401,3 +1401,47 @@ qemuAgentSuspend(qemuAgentPtr mon,
virJSONValueFree(reply);
return ret;
}
+
+int qemuAgentArbitraryCommand(qemuAgentPtr mon,
+ const char *cmd_str,
+ char **result,
+ int timeout)
+{
+ int ret = -1;
+ int seconds;
+ virJSONValuePtr cmd;
+ virJSONValuePtr reply = NULL;
+
+ if (timeout < -1)
+ return ret;
+
+ cmd = virJSONValueFromString(cmd_str);
+ if (!cmd)
+ return ret;
+
+ if (result == NULL) {
+ seconds = VIR_DOMAIN_QEMU_AGENT_COMMAND_NOWAIT;
+ } else if (timeout == VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) {
+ seconds = QEMU_AGENT_WAIT_DEFAULT;
+ } else {
+ seconds = timeout;
+ }
+
+repeat:
+ ret = qemuAgentCommand(mon, cmd, &reply, seconds);
+
+ if (ret == 0) {
+ ret = qemuAgentCheckError(cmd, reply);
+ *result = virJSONValueToString(reply);
+ } else {
+ if (timeout == VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) {
+ virJSONValueFree(reply);
+ 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 qemuAgentArbitraryCommand(qemuAgentPtr mon,
+ const char *cmd,
+ char **result,
+ int timeout);
#endif /* __QEMU_AGENT_H__ */