diff mbox

[v4,2/3] watchdog.h: Drop local redefinition of actions enum

Message ID 9fe40ce91ada6dfdade83f32940f420e8b373db2.1504696921.git.mprivozn@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Michal Privoznik Sept. 6, 2017, 11:24 a.m. UTC
We already have enum that enumerates all the action that a
watchdog can take when hitting its timeout: WatchdogAction.
Use that instead of inventing our own.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 hw/watchdog/watchdog.c    | 42 +++++++++++++++++-------------------------
 hw/watchdog/wdt_diag288.c |  6 +++---
 include/sysemu/watchdog.h | 12 ++----------
 3 files changed, 22 insertions(+), 38 deletions(-)

Comments

Eric Blake Sept. 6, 2017, 3:37 p.m. UTC | #1
On 09/06/2017 06:24 AM, Michal Privoznik wrote:
> We already have enum that enumerates all the action that a

s/action/actions/

> watchdog can take when hitting its timeout: WatchdogAction.
> Use that instead of inventing our own.
> 
> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
> ---

> @@ -77,27 +77,16 @@ int select_watchdog(const char *p)
>  
>  int select_watchdog_action(const char *p)
>  {
> -    if (strcasecmp(p, "reset") == 0)
> -        watchdog_action = WDT_RESET;

The old code was case-insensitive,

> +    action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL);

the new code is not.  Do we care?  (I don't, but we could be breaking
someone's control flow).  Should qapi_enum_parse be taught to be
case-insensitive?  Or perhaps we answer related questions first: Do we
have any QAPI enums that have values differing only in case? Do we
prevent such QAPI definitions, to give us the potential of making the
parsing insensitive?
Markus Armbruster Sept. 6, 2017, 5:25 p.m. UTC | #2
Eric Blake <eblake@redhat.com> writes:

> On 09/06/2017 06:24 AM, Michal Privoznik wrote:
>> We already have enum that enumerates all the action that a
>
> s/action/actions/
>
>> watchdog can take when hitting its timeout: WatchdogAction.
>> Use that instead of inventing our own.
>> 
>> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
>> ---
>
>> @@ -77,27 +77,16 @@ int select_watchdog(const char *p)
>>  
>>  int select_watchdog_action(const char *p)
>>  {
>> -    if (strcasecmp(p, "reset") == 0)
>> -        watchdog_action = WDT_RESET;
>
> The old code was case-insensitive,
>
>> +    action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL);
>
> the new code is not.  Do we care?  (I don't, but we could be breaking
> someone's control flow).  Should qapi_enum_parse be taught to be
> case-insensitive?  Or perhaps we answer related questions first: Do we
> have any QAPI enums that have values differing only in case? Do we
> prevent such QAPI definitions, to give us the potential of making the
> parsing insensitive?

Case-sensitive everywhere is fine.  Case-insensitive everywhere also
fine, just not my personal preference.  What's not fine is "guess
whether this part of the interface is case-sensitive or not".

QMP is case-sensitive.  Let's keep it that way.

The -watchdog-action option has a case-insensitive argument.  The
obvious way to remain misfeature-^Wbackwards compatible is converting
the argument to lower case before handing it off to qapi_enum_parse.  I
doubt it matters, but just doing it is less work than debating how far
exactly we want to bend over backwards.

g_ascii_strdown() should do.  It only converts ASCII characters, but
anything else is going to fail in qapi_enum_parse() anyway.
Michal Privoznik Sept. 7, 2017, 7:56 a.m. UTC | #3
On 09/06/2017 07:25 PM, Markus Armbruster wrote:
> Eric Blake <eblake@redhat.com> writes:
> 
>> On 09/06/2017 06:24 AM, Michal Privoznik wrote:
>>> We already have enum that enumerates all the action that a
>>
>> s/action/actions/
>>
>>> watchdog can take when hitting its timeout: WatchdogAction.
>>> Use that instead of inventing our own.
>>>
>>> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
>>> ---
>>
>>> @@ -77,27 +77,16 @@ int select_watchdog(const char *p)
>>>  
>>>  int select_watchdog_action(const char *p)
>>>  {
>>> -    if (strcasecmp(p, "reset") == 0)
>>> -        watchdog_action = WDT_RESET;
>>
>> The old code was case-insensitive,
>>
>>> +    action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL);
>>
>> the new code is not.  Do we care?  (I don't, but we could be breaking
>> someone's control flow).  Should qapi_enum_parse be taught to be
>> case-insensitive?  Or perhaps we answer related questions first: Do we
>> have any QAPI enums that have values differing only in case? Do we
>> prevent such QAPI definitions, to give us the potential of making the
>> parsing insensitive?
> 
> Case-sensitive everywhere is fine.  Case-insensitive everywhere also
> fine, just not my personal preference.  What's not fine is "guess
> whether this part of the interface is case-sensitive or not".
> 
> QMP is case-sensitive.  Let's keep it that way.
> 
> The -watchdog-action option has a case-insensitive argument.  The
> obvious way to remain misfeature-^Wbackwards compatible is converting
> the argument to lower case before handing it off to qapi_enum_parse.  I
> doubt it matters, but just doing it is less work than debating how far
> exactly we want to bend over backwards.
> 
> g_ascii_strdown() should do.  It only converts ASCII characters, but
> anything else is going to fail in qapi_enum_parse() anyway.
> 

On the other hand, the documentation enumerates the accepted values in
lowercase. So one can argue that upper- or mixed-case is just a misuse
of a bug in the code. But getting the code in is more important to me so
I'll do the strdown() conversion and sent yet another version.

Michal
Markus Armbruster Sept. 7, 2017, 9:02 a.m. UTC | #4
Michal Privoznik <mprivozn@redhat.com> writes:

> On 09/06/2017 07:25 PM, Markus Armbruster wrote:
>> Eric Blake <eblake@redhat.com> writes:
>> 
>>> On 09/06/2017 06:24 AM, Michal Privoznik wrote:
>>>> We already have enum that enumerates all the action that a
>>>
>>> s/action/actions/
>>>
>>>> watchdog can take when hitting its timeout: WatchdogAction.
>>>> Use that instead of inventing our own.
>>>>
>>>> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
>>>> ---
>>>
>>>> @@ -77,27 +77,16 @@ int select_watchdog(const char *p)
>>>>  
>>>>  int select_watchdog_action(const char *p)
>>>>  {
>>>> -    if (strcasecmp(p, "reset") == 0)
>>>> -        watchdog_action = WDT_RESET;
>>>
>>> The old code was case-insensitive,
>>>
>>>> +    action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL);
>>>
>>> the new code is not.  Do we care?  (I don't, but we could be breaking
>>> someone's control flow).  Should qapi_enum_parse be taught to be
>>> case-insensitive?  Or perhaps we answer related questions first: Do we
>>> have any QAPI enums that have values differing only in case? Do we
>>> prevent such QAPI definitions, to give us the potential of making the
>>> parsing insensitive?
>> 
>> Case-sensitive everywhere is fine.  Case-insensitive everywhere also
>> fine, just not my personal preference.  What's not fine is "guess
>> whether this part of the interface is case-sensitive or not".
>> 
>> QMP is case-sensitive.  Let's keep it that way.
>> 
>> The -watchdog-action option has a case-insensitive argument.  The
>> obvious way to remain misfeature-^Wbackwards compatible is converting
>> the argument to lower case before handing it off to qapi_enum_parse.  I
>> doubt it matters, but just doing it is less work than debating how far
>> exactly we want to bend over backwards.
>> 
>> g_ascii_strdown() should do.  It only converts ASCII characters, but
>> anything else is going to fail in qapi_enum_parse() anyway.
>> 
>
> On the other hand, the documentation enumerates the accepted values in
> lowercase. So one can argue that upper- or mixed-case is just a misuse
> of a bug in the code.

I quite agree, but...

>                       But getting the code in is more important to me so
> I'll do the strdown() conversion and sent yet another version.

... like you, I have to pick my battles.  A respin adding the stupid
case conversion seems safer for both of us than risking a debate on how
far we need to go for backward compatibility.
diff mbox

Patch

diff --git a/hw/watchdog/watchdog.c b/hw/watchdog/watchdog.c
index 358d79804d..547a49a1e4 100644
--- a/hw/watchdog/watchdog.c
+++ b/hw/watchdog/watchdog.c
@@ -30,7 +30,7 @@ 
 #include "hw/nmi.h"
 #include "qemu/help_option.h"
 
-static int watchdog_action = WDT_RESET;
+static WatchdogAction watchdog_action = WATCHDOG_ACTION_RESET;
 static QLIST_HEAD(watchdog_list, WatchdogTimerModel) watchdog_list;
 
 void watchdog_add_model(WatchdogTimerModel *model)
@@ -77,27 +77,16 @@  int select_watchdog(const char *p)
 
 int select_watchdog_action(const char *p)
 {
-    if (strcasecmp(p, "reset") == 0)
-        watchdog_action = WDT_RESET;
-    else if (strcasecmp(p, "shutdown") == 0)
-        watchdog_action = WDT_SHUTDOWN;
-    else if (strcasecmp(p, "poweroff") == 0)
-        watchdog_action = WDT_POWEROFF;
-    else if (strcasecmp(p, "pause") == 0)
-        watchdog_action = WDT_PAUSE;
-    else if (strcasecmp(p, "debug") == 0)
-        watchdog_action = WDT_DEBUG;
-    else if (strcasecmp(p, "none") == 0)
-        watchdog_action = WDT_NONE;
-    else if (strcasecmp(p, "inject-nmi") == 0)
-        watchdog_action = WDT_NMI;
-    else
-        return -1;
+    int action;
 
+    action = qapi_enum_parse(&WatchdogAction_lookup, p, -1, NULL);
+    if (action < 0)
+        return -1;
+    watchdog_action = action;
     return 0;
 }
 
-int get_watchdog_action(void)
+WatchdogAction get_watchdog_action(void)
 {
     return watchdog_action;
 }
@@ -108,21 +97,21 @@  int get_watchdog_action(void)
 void watchdog_perform_action(void)
 {
     switch (watchdog_action) {
-    case WDT_RESET:             /* same as 'system_reset' in monitor */
+    case WATCHDOG_ACTION_RESET:     /* same as 'system_reset' in monitor */
         qapi_event_send_watchdog(WATCHDOG_ACTION_RESET, &error_abort);
         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
         break;
 
-    case WDT_SHUTDOWN:          /* same as 'system_powerdown' in monitor */
+    case WATCHDOG_ACTION_SHUTDOWN:  /* same as 'system_powerdown' in monitor */
         qapi_event_send_watchdog(WATCHDOG_ACTION_SHUTDOWN, &error_abort);
         qemu_system_powerdown_request();
         break;
 
-    case WDT_POWEROFF:          /* same as 'quit' command in monitor */
+    case WATCHDOG_ACTION_POWEROFF:  /* same as 'quit' command in monitor */
         qapi_event_send_watchdog(WATCHDOG_ACTION_POWEROFF, &error_abort);
         exit(0);
 
-    case WDT_PAUSE:             /* same as 'stop' command in monitor */
+    case WATCHDOG_ACTION_PAUSE:     /* same as 'stop' command in monitor */
         /* In a timer callback, when vm_stop calls qemu_clock_enable
          * you would get a deadlock.  Bypass the problem.
          */
@@ -131,19 +120,22 @@  void watchdog_perform_action(void)
         qemu_system_vmstop_request(RUN_STATE_WATCHDOG);
         break;
 
-    case WDT_DEBUG:
+    case WATCHDOG_ACTION_DEBUG:
         qapi_event_send_watchdog(WATCHDOG_ACTION_DEBUG, &error_abort);
         fprintf(stderr, "watchdog: timer fired\n");
         break;
 
-    case WDT_NONE:
+    case WATCHDOG_ACTION_NONE:
         qapi_event_send_watchdog(WATCHDOG_ACTION_NONE, &error_abort);
         break;
 
-    case WDT_NMI:
+    case WATCHDOG_ACTION_INJECT_NMI:
         qapi_event_send_watchdog(WATCHDOG_ACTION_INJECT_NMI,
                                  &error_abort);
         nmi_monitor_handle(0, NULL);
         break;
+
+    default:
+        assert(0);
     }
 }
diff --git a/hw/watchdog/wdt_diag288.c b/hw/watchdog/wdt_diag288.c
index 47f289216a..1475743527 100644
--- a/hw/watchdog/wdt_diag288.c
+++ b/hw/watchdog/wdt_diag288.c
@@ -57,9 +57,9 @@  static void diag288_timer_expired(void *dev)
      * the BQL; reset before triggering the action to avoid races with
      * diag288 instructions. */
     switch (get_watchdog_action()) {
-    case WDT_DEBUG:
-    case WDT_NONE:
-    case WDT_PAUSE:
+    case WATCHDOG_ACTION_DEBUG:
+    case WATCHDOG_ACTION_NONE:
+    case WATCHDOG_ACTION_PAUSE:
         break;
     default:
         wdt_diag288_reset(dev);
diff --git a/include/sysemu/watchdog.h b/include/sysemu/watchdog.h
index 72a4da07a6..677ace3945 100644
--- a/include/sysemu/watchdog.h
+++ b/include/sysemu/watchdog.h
@@ -23,15 +23,7 @@ 
 #define QEMU_WATCHDOG_H
 
 #include "qemu/queue.h"
-
-/* Possible values for action parameter. */
-#define WDT_RESET        1      /* Hard reset. */
-#define WDT_SHUTDOWN     2      /* Shutdown. */
-#define WDT_POWEROFF     3      /* Quit. */
-#define WDT_PAUSE        4      /* Pause. */
-#define WDT_DEBUG        5      /* Prints a message and continues running. */
-#define WDT_NONE         6      /* Do nothing. */
-#define WDT_NMI          7      /* Inject nmi into the guest. */
+#include "qapi-types.h"
 
 struct WatchdogTimerModel {
     QLIST_ENTRY(WatchdogTimerModel) entry;
@@ -46,7 +38,7 @@  typedef struct WatchdogTimerModel WatchdogTimerModel;
 /* in hw/watchdog.c */
 int select_watchdog(const char *p);
 int select_watchdog_action(const char *action);
-int get_watchdog_action(void);
+WatchdogAction get_watchdog_action(void);
 void watchdog_add_model(WatchdogTimerModel *model);
 void watchdog_perform_action(void);