randr: use explicit case statement instead of SProcRandrVector table

No need to go indirectly through a vector table, since everything's fixed
anyways. It's not a pretty robust programming style: any changes need great
care, in order to not mix up things.

Replacing this by direct switch/case statement, which is using the defines
from the xrandr protocol headers. Also adding a little bit more protection
against subtle programming errors and reducing cognitive load (source size)
on understanding the code by using a tiny macro for deducing define name and
function name from the request's name.

This approach actually uncovered some subtle bug that had been waiting in
the dark for over 15 years.

As collateral benefit, getting a tiny bit better performance.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1794>
This commit is contained in:
Enrico Weigelt, metux IT consult 2024-07-29 15:03:35 +02:00 committed by Marge Bot
parent 42677ae1e3
commit 058815bed1
3 changed files with 68 additions and 71 deletions

View File

@ -50,8 +50,6 @@ static int RRNScreens;
real->mem = priv->mem; \
}
static int SProcRRDispatch(ClientPtr pClient);
int RREventBase;
int RRErrorBase;
RESTYPE RRClientType, RREventType; /* resource types for event masks */
@ -736,13 +734,3 @@ RRVerticalRefresh(xRRModeInfo * mode)
refresh = 0xffff;
return (CARD16) refresh;
}
static int _X_COLD
SProcRRDispatch(ClientPtr client)
{
REQUEST(xReq);
if (stuff->data >= RRNumberRequests || !SProcRandrVector[stuff->data])
return BadRequest;
UpdateCurrentTimeIf();
return (*SProcRandrVector[stuff->data]) (client);
}

View File

@ -33,8 +33,6 @@
extern int RREventBase, RRErrorBase;
extern int (*SProcRandrVector[RRNumberRequests]) (ClientPtr);
extern RESTYPE RRClientType, RREventType; /* resource types for event masks */
extern DevPrivateKeyRec RRClientPrivateKeyRec;
@ -141,4 +139,6 @@ int ProcRRSelectInput(ClientPtr client);
int ProcRRDispatch(ClientPtr client);
int SProcRRDispatch(ClientPtr client);
#endif /* _XSERVER_RANDRSTR_PRIV_H_ */

View File

@ -603,60 +603,69 @@ SProcRRFreeLease(ClientPtr client) {
return ProcRRFreeLease(client);
}
int (*SProcRandrVector[RRNumberRequests]) (ClientPtr) = {
SProcRRQueryVersion, /* 0 */
/* we skip 1 to make old clients fail pretty immediately */
NULL, /* 1 SProcRandrOldGetScreenInfo */
/* V1.0 apps share the same set screen config request id */
SProcRRSetScreenConfig, /* 2 */
NULL, /* 3 SProcRandrOldScreenChangeSelectInput */
/* 3 used to be ScreenChangeSelectInput; deprecated */
SProcRRSelectInput, /* 4 */
SProcRRGetScreenInfo, /* 5 */
/* V1.2 additions */
SProcRRGetScreenSizeRange, /* 6 */
SProcRRSetScreenSize, /* 7 */
SProcRRGetScreenResources, /* 8 */
SProcRRGetOutputInfo, /* 9 */
SProcRRListOutputProperties, /* 10 */
SProcRRQueryOutputProperty, /* 11 */
SProcRRConfigureOutputProperty, /* 12 */
SProcRRChangeOutputProperty, /* 13 */
SProcRRDeleteOutputProperty, /* 14 */
SProcRRGetOutputProperty, /* 15 */
SProcRRCreateMode, /* 16 */
SProcRRDestroyMode, /* 17 */
SProcRRAddOutputMode, /* 18 */
SProcRRDeleteOutputMode, /* 19 */
SProcRRGetCrtcInfo, /* 20 */
SProcRRSetCrtcConfig, /* 21 */
SProcRRGetCrtcGammaSize, /* 22 */
SProcRRGetCrtcGamma, /* 23 */
SProcRRSetCrtcGamma, /* 24 */
/* V1.3 additions */
SProcRRGetScreenResourcesCurrent, /* 25 */
SProcRRSetCrtcTransform, /* 26 */
SProcRRGetCrtcTransform, /* 27 */
SProcRRGetPanning, /* 28 */
SProcRRSetPanning, /* 29 */
SProcRRSetOutputPrimary, /* 30 */
SProcRRGetOutputPrimary, /* 31 */
/* V1.4 additions */
SProcRRGetProviders, /* 32 */
SProcRRGetProviderInfo, /* 33 */
SProcRRSetProviderOffloadSink, /* 34 */
SProcRRSetProviderOutputSource, /* 35 */
SProcRRListProviderProperties, /* 36 */
SProcRRQueryProviderProperty, /* 37 */
SProcRRConfigureProviderProperty, /* 38 */
SProcRRChangeProviderProperty, /* 39 */
SProcRRDeleteProviderProperty, /* 40 */
SProcRRGetProviderProperty, /* 41 */
/* V1.5 additions */
SProcRRGetMonitors, /* 42 */
SProcRRSetMonitor, /* 43 */
SProcRRDeleteMonitor, /* 44 */
/* V1.6 additions */
SProcRRCreateLease, /* 45 */
SProcRRFreeLease, /* 46 */
};
int
SProcRRDispatch(ClientPtr client)
{
REQUEST(xReq);
UpdateCurrentTimeIf();
switch (stuff->data) {
case X_RRQueryVersion: return SProcRRQueryVersion(client);
case X_RRSetScreenConfig: return SProcRRSetScreenConfig(client);
case X_RRSelectInput: return SProcRRSelectInput(client);
case X_RRGetScreenInfo: return SProcRRGetScreenInfo(client);
/* V1.2 additions */
case X_RRGetScreenSizeRange: return SProcRRGetScreenSizeRange(client);
case X_RRSetScreenSize: return SProcRRSetScreenSize(client);
case X_RRGetScreenResources: return SProcRRGetScreenResources(client);
case X_RRGetOutputInfo: return SProcRRGetOutputInfo(client);
case X_RRListOutputProperties: return SProcRRListOutputProperties(client);
case X_RRQueryOutputProperty: return SProcRRQueryOutputProperty(client);
case X_RRConfigureOutputProperty: return SProcRRConfigureOutputProperty(client);
case X_RRChangeOutputProperty: return SProcRRChangeOutputProperty(client);
case X_RRDeleteOutputProperty: return SProcRRDeleteOutputProperty(client);
case X_RRGetOutputProperty: return SProcRRGetOutputProperty(client);
case X_RRCreateMode: return SProcRRCreateMode(client);
case X_RRDestroyMode: return SProcRRDestroyMode(client);
case X_RRAddOutputMode: return SProcRRAddOutputMode(client);
case X_RRDeleteOutputMode: return SProcRRDeleteOutputMode(client);
case X_RRGetCrtcInfo: return SProcRRGetCrtcInfo(client);
case X_RRSetCrtcConfig: return SProcRRSetCrtcConfig(client);
case X_RRGetCrtcGammaSize: return SProcRRGetCrtcGammaSize(client);
case X_RRGetCrtcGamma: return SProcRRGetCrtcGamma(client);
case X_RRSetCrtcGamma: return SProcRRSetCrtcGamma(client);
/* V1.3 additions */
case X_RRGetScreenResourcesCurrent: return SProcRRGetScreenResourcesCurrent(client);
case X_RRSetCrtcTransform: return SProcRRSetCrtcTransform(client);
case X_RRGetCrtcTransform: return SProcRRGetCrtcTransform(client);
case X_RRGetPanning: return SProcRRGetPanning(client);
case X_RRSetPanning: return SProcRRSetPanning(client);
case X_RRSetOutputPrimary: return SProcRRSetOutputPrimary(client);
case X_RRGetOutputPrimary: return SProcRRGetOutputPrimary(client);
/* V1.4 additions */
case X_RRGetProviders: return SProcRRGetProviders(client);
case X_RRGetProviderInfo: return SProcRRGetProviderInfo(client);
case X_RRSetProviderOffloadSink: return SProcRRSetProviderOffloadSink(client);
case X_RRSetProviderOutputSource: return SProcRRSetProviderOutputSource(client);
case X_RRListProviderProperties: return SProcRRListProviderProperties(client);
case X_RRQueryProviderProperty: return SProcRRQueryProviderProperty(client);
case X_RRConfigureProviderProperty: return SProcRRConfigureProviderProperty(client);
case X_RRChangeProviderProperty: return SProcRRChangeProviderProperty(client);
case X_RRDeleteProviderProperty: return SProcRRDeleteProviderProperty(client);
case X_RRGetProviderProperty: return SProcRRGetProviderProperty(client);
/* V1.5 additions */
case X_RRGetMonitors: return SProcRRGetMonitors(client);
case X_RRSetMonitor: return SProcRRSetMonitor(client);
case X_RRDeleteMonitor: return SProcRRDeleteMonitor(client);
/* V1.6 additions */
case X_RRCreateLease: return SProcRRCreateLease(client);
case X_RRFreeLease: return SProcRRFreeLease(client);
}
return BadRequest;
}