Merge lp:~epics-core/epics-base/dbscan-update into lp:~epics-core/epics-base/3.16

[mdavidsaver]

Some misc. changes to dbScan API looking forward to parallel scanning. Adds two new API functions scanOnce3() and scanIoImmediate().

scanOnce3() allows a once scan w/ completion callback. dbCa is changed to use this, which fixes lp:1362362.

scanIoImmediate() allows external drivers to use the I/O Intr infrastructure while doing scanning on internal threads instead of the shared callback threads.

Also a minor changed to eventNameToHandle to avoid a cantProceed().

[mdavidsaver (mdavidsaver)]

I've included a test case for scanOnce3(). I have one for scanIoImmediate(), but this is dependent on a re-write of scanIoTest.c. I'm unsure about including that in this branch as it is much larger than the other changes.

[Ralph Lange (ralph-lange)]

I like the changes.

scanIoImmediate() needs to be documented.

So - now we have two options for IO scan processing:
1. Request processing on shared background thread created by iocCore
2. Direct processing on current thread

My original idea of "request progressing on private non-shared thread created by iocCore" is still missing, but I will postpone that (and the complexity that would come with it) until I have a valid use case.

review: Needs Fixing

[mdavidsaver (mdavidsaver)]

Documentation in:

lp:~epics-documenters/epics-appdev/dbscan-update

[Andrew Johnson (anj)]

My only objection to this is the name scanOnce3() which doesn't match the style of the other routine names in the IOC. Something like scanOnceCallback() might be more in keeping, see dbCa.h for several examples using that suffix, but feel free to suggest any alternative you prefer. Just adding a number to indicate extra parameters is not a naming style I particularly like.

review: Needs Fixing

[lp:~epics-core/epics-base/dbscan-update]

12629. By mdavidsaver on 2015-02-17

dbScan: rename scanOnce3 to scanOnceCallback

[mdavidsaver (mdavidsaver)]

Renamed scanOnce3 to scanOnceCallback in code and documentation.

review: Needs Resubmitting

=== modified file 'src/ioc/db/dbCa.c'
--- src/ioc/db/dbCa.c	2014-10-06 23:04:33 +0000
+++ src/ioc/db/dbCa.c	2015-02-17 16:31:52 +0000
@@ -629,6 +629,31 @@
     return gotAttributes ? 0 : -1;
 }
 
+static void scanComplete(void *raw, dbCommon *prec)
+{
+    caLink *pca = raw;
+    epicsMutexMustLock(pca->lock);
+    if(pca->scanningOnce==0)
+        errlogPrintf("dbCa.c complete callback w/ scanningOnce==0\n");
+    else if(--pca->scanningOnce){
+        /* another scan is queued */
+        if(scanOnceCallback(prec, scanComplete, raw)) {
+            errlogPrintf("dbCa.c failed to re-queue scanOnce\n");
+        }
+    }
+    epicsMutexUnlock(pca->lock);
+}
+
+/* must be called with pca->lock held */
+static void scanLinkOnce(dbCommon *prec, caLink *pca) {
+    if(pca->scanningOnce==0 && scanOnceCallback(prec, scanComplete, pca)) {
+        errlogPrintf("dbCa.c failed to queue scanOnce\n");
+    }
+    if(pca->scanningOnce<5)
+        pca->scanningOnce++;
+    /* else too many scans queued */
+}
+
 static void connectionCallback(struct connection_handler_args arg)
 {
     caLink *pca;
@@ -649,7 +674,7 @@
         if (precord &&
             ((ppv_link->pvlMask & pvlOptCP) ||
              ((ppv_link->pvlMask & pvlOptCPP) && precord->scan == 0)))
-            scanOnce(precord);
+            scanLinkOnce(precord, pca);
         goto done;
     }
     pca->hasReadAccess = ca_read_access(arg.chid);
@@ -762,7 +787,7 @@
 
         if ((ppv_link->pvlMask & pvlOptCP) ||
             ((ppv_link->pvlMask & pvlOptCPP) && precord->scan == 0))
-        scanOnce(precord);
+        scanLinkOnce(precord, pca);
     }
 done:
     epicsMutexUnlock(pca->lock);
@@ -835,7 +860,7 @@
     if (precord &&
         ((ppv_link->pvlMask & pvlOptCP) ||
          ((ppv_link->pvlMask & pvlOptCPP) && precord->scan == 0)))
-        scanOnce(precord);
+        scanLinkOnce(precord, pca);
 done:
     epicsMutexUnlock(pca->lock);
 }

=== modified file 'src/ioc/db/dbCaPvt.h'
--- src/ioc/db/dbCaPvt.h	2014-10-06 05:57:02 +0000
+++ src/ioc/db/dbCaPvt.h	2015-02-17 16:31:52 +0000
@@ -38,56 +38,57 @@
 

 typedef struct caLink
 {
-	ELLNODE		node;
-	epicsMutexId	lock;
-	struct link	*plink;
-        char		*pvname;
-	chid 		chid;
-	short		link_action;
-        /* The following have new values after each data event*/
-	epicsEnum16	sevr;
-	epicsEnum16	stat;
-	epicsTimeStamp	timeStamp;
-        /* The following have values after connection*/
-	short		dbrType;
-	long		nelements;
-        char		hasReadAccess;
-        char		hasWriteAccess;
-        char            isConnected;
-	char		gotFirstConnection;
-        /* The following are for dbCaAddLinkCallback */
-        dbCaCallback    connect;
-        dbCaCallback    monitor;
-        void            *userPvt;
-        /* The following are for write request */
-        short           putType;
-        dbCaCallback    putCallback;
-        void            *putUserPvt;
-        struct link     *plinkPutCallback;
-        /* The following are for access to additional attributes*/
-        char            gotAttributes;
-        dbCaCallback	getAttributes;
-        void            *getAttributesPvt;
-        /* The following have values after getAttribEventCallback*/
-        double          controlLimits[2];
-        double          displayLimits[2];
-        double          alarmLimits[4];
-        short           precision;
-        char            units[MAX_UNITS_SIZE];  /* units of value */
-        /* The following are for handling data*/
-	void 		*pgetNative;
-	char		*pgetString;
-	void		*pputNative;
-	char		*pputString;
-	char		gotInNative;
-	char		gotInString;
-	char		gotOutNative;
-	char		gotOutString;
-	char		newOutNative;
-	char		newOutString;
-        /* The following are for dbcar*/
-	unsigned long	nDisconnect;
-	unsigned long	nNoWrite; /*only modified by dbCaPutLink*/
+    ELLNODE		node;
+    epicsMutexId	lock;
+    struct link	*plink;
+    char		*pvname;
+    chid 		chid;
+    short		link_action;
+    /* The following have new values after each data event*/
+    epicsEnum16	sevr;
+    epicsEnum16	stat;
+    epicsTimeStamp	timeStamp;
+    /* The following have values after connection*/
+    short		dbrType;
+    long		nelements;
+    char		hasReadAccess;
+    char		hasWriteAccess;
+    char            isConnected;
+    char		gotFirstConnection;
+    /* The following are for dbCaAddLinkCallback */
+    dbCaCallback    connect;
+    dbCaCallback    monitor;
+    void            *userPvt;
+    /* The following are for write request */
+    short           putType;
+    dbCaCallback    putCallback;
+    void            *putUserPvt;
+    struct link     *plinkPutCallback;
+    /* The following are for access to additional attributes*/
+    char            gotAttributes;
+    dbCaCallback	getAttributes;
+    void            *getAttributesPvt;
+    /* The following have values after getAttribEventCallback*/
+    double          controlLimits[2];
+    double          displayLimits[2];
+    double          alarmLimits[4];
+    short           precision;
+    char            units[MAX_UNITS_SIZE];  /* units of value */
+    /* The following are for handling data*/
+    void 		*pgetNative;
+    char		*pgetString;
+    void		*pputNative;
+    char		*pputString;
+    char		gotInNative;
+    char		gotInString;
+    char		gotOutNative;
+    char		gotOutString;
+    char		newOutNative;
+    char		newOutString;
+    unsigned char scanningOnce;
+    /* The following are for dbcar*/
+    unsigned long	nDisconnect;
+    unsigned long	nNoWrite; /*only modified by dbCaPutLink*/
 }caLink;
 
 #endif /* INC_dbCaPvt_H */

=== modified file 'src/ioc/db/dbScan.c'
--- src/ioc/db/dbScan.c	2014-12-02 17:30:37 +0000
+++ src/ioc/db/dbScan.c	2015-02-17 16:31:52 +0000
@@ -26,10 +26,9 @@
 #include "ellLib.h"
 #include "epicsEvent.h"
 #include "epicsExit.h"
-#include "epicsInterrupt.h"
 #include "epicsMutex.h"
 #include "epicsPrint.h"
-#include "epicsRingPointer.h"
+#include "epicsRingBytes.h"
 #include "epicsStdio.h"
 #include "epicsStdlib.h"
 #include "epicsString.h"
@@ -64,7 +63,7 @@
 
 static int onceQueueSize = 1000;
 static epicsEventId onceSem;
-static epicsRingPointerId onceQ;
+static epicsRingBytesId onceQ;
 static epicsThreadId onceTaskId;
 static void *exitOnce;
 
@@ -172,7 +171,7 @@
     deletePeriodic();
     ioscanDestroy();
 
-    epicsRingPointerDelete(onceQ);
+    epicsRingBytesDelete(onceQ);
 
     epicsEventDestroy(startStopEvent);
     epicsEventDestroy(onceSem);
@@ -456,7 +455,9 @@
         if (strcmp(pel->event_name, eventname) == 0) break;
     }
     if (pel == NULL) {
-        pel = dbCalloc(1, sizeof(event_list));
+        pel = calloc(1, sizeof(event_list));
+        if (!pel)
+            goto done;
         strcpy(pel->event_name, eventname);
         for (prio = 0; prio < NUM_CALLBACK_PRIORITIES; prio++) {
             callbackSetUser(&pel->scan_list[prio], &pel->callback[prio]);
@@ -474,6 +475,7 @@
                 pevent_list[e] = pel;
         }
     }
+done:
     epicsMutexUnlock(event_lock);
     return pel;
 }
@@ -580,6 +582,28 @@
     return queued;
 }
 
+unsigned int scanIoImmediate(IOSCANPVT piosh, int prio)
+{
+    io_scan_list *piosl;
+
+    if (prio<0 || prio>=NUM_CALLBACK_PRIORITIES)
+        return S_db_errArg;
+    else if (scanCtl != ctlRun)
+        return 0;
+
+    piosl = &piosh->iosl[prio];
+
+    if (ellCount(&piosl->scan_list.list) == 0)
+        return 0;
+
+    scanList(&piosl->scan_list);
+
+    if (piosh->cb)
+        piosh->cb(piosh->arg, piosh, prio);
+
+    return 1 << prio;
+}
+
 /* May not be called while a scan request is queued or running */
 void scanIoSetComplete(IOSCANPVT piosh, io_scan_complete cb, void *arg)
 {
@@ -587,15 +611,27 @@
     piosh->arg = arg;
 }
 
-void scanOnce(struct dbCommon *precord)
+int scanOnce(struct dbCommon *precord) {
+    return scanOnceCallback(precord, NULL, NULL);
+}
+
+typedef struct {
+    struct dbCommon *prec;
+    once_complete cb;
+    void *usr;
+} onceEntry;
+
+int scanOnceCallback(struct dbCommon *precord, once_complete cb, void *usr)
 {
     static int newOverflow = TRUE;
-    int lockKey;
+    onceEntry ent;
     int pushOK;
 
-    lockKey = epicsInterruptLock();
-    pushOK = epicsRingPointerPush(onceQ, precord);
-    epicsInterruptUnlock(lockKey);
+    ent.prec = precord;
+    ent.cb = cb;
+    ent.usr = usr;
+
+    pushOK = epicsRingBytesPut(onceQ, (void*)&ent, sizeof(ent));
 
     if (!pushOK) {
         if (newOverflow) errlogPrintf("scanOnce: Ring buffer overflow\n");
@@ -604,6 +640,8 @@
         newOverflow = TRUE;
     }
     epicsEventSignal(onceSem);
+
+    return !pushOK;
 }
 
 static void onceTask(void *arg)
@@ -612,14 +650,24 @@
     epicsEventSignal(startStopEvent);
 
     while (TRUE) {
-        void *precord;
 
         epicsEventMustWait(onceSem);
-        while ((precord = epicsRingPointerPop(onceQ))) {
-            if (precord == &exitOnce) goto shutdown;
-            dbScanLock(precord);
-            dbProcess(precord);
-            dbScanUnlock(precord);
+        while(1) {
+            onceEntry ent;
+            int bytes = epicsRingBytesGet(onceQ, (void*)&ent, sizeof(ent));
+            if(bytes==0)
+                break;
+            if(bytes!=sizeof(ent)) {
+                errlogPrintf("onceTask: received incomplete %d of %u\n",
+                             bytes, (unsigned)sizeof(ent));
+                continue; /* what to do? */
+            } else if (ent.prec == (void*)&exitOnce) goto shutdown;
+
+            dbScanLock(ent.prec);
+            dbProcess(ent.prec);
+            dbScanUnlock(ent.prec);
+            if(ent.cb)
+                ent.cb(ent.usr, ent.prec);
         }
     }
 
@@ -636,7 +684,7 @@
 
 static void initOnce(void)
 {
-    if ((onceQ = epicsRingPointerCreate(onceQueueSize)) == NULL) {
+    if ((onceQ = epicsRingBytesLockedCreate(sizeof(onceEntry)*onceQueueSize)) == NULL) {
         cantProceed("initOnce: Ring buffer create failed\n");
     }
     onceSem = epicsEventMustCreate(epicsEventEmpty);

=== modified file 'src/ioc/db/dbScan.h'
--- src/ioc/db/dbScan.h	2014-09-30 21:22:03 +0000
+++ src/ioc/db/dbScan.h	2015-02-17 16:31:52 +0000
@@ -39,9 +39,10 @@
 typedef struct ioscan_head *IOSCANPVT;
 typedef struct event_list *EVENTPVT;
 
+struct dbCommon;
+
 typedef void (*io_scan_complete)(void *usr, IOSCANPVT, int prio);
-
-struct dbCommon;
+typedef void (*once_complete)(void *usr, struct dbCommon*);
 
 epicsShareFunc long scanInit(void);
 epicsShareFunc void scanRun(void);
@@ -54,7 +55,8 @@
 epicsShareFunc void scanAdd(struct dbCommon *);
 epicsShareFunc void scanDelete(struct dbCommon *);
 epicsShareFunc double scanPeriod(int scan);
-epicsShareFunc void scanOnce(struct dbCommon *);
+epicsShareFunc int scanOnce(struct dbCommon *);
+epicsShareFunc int scanOnceCallback(struct dbCommon *, once_complete cb, void *usr);
 epicsShareFunc int scanOnceSetQueueSize(int size);
 
 /*print periodic lists*/
@@ -68,6 +70,7 @@
 
 epicsShareFunc void scanIoInit(IOSCANPVT *ppios);
 epicsShareFunc unsigned int scanIoRequest(IOSCANPVT pios);
+epicsShareFunc unsigned int scanIoImmediate(IOSCANPVT pios, int prio);
 epicsShareFunc void scanIoSetComplete(IOSCANPVT, io_scan_complete, void *usr);
 
 #ifdef __cplusplus

=== modified file 'src/ioc/db/test/Makefile'
--- src/ioc/db/test/Makefile	2014-11-19 14:08:48 +0000
+++ src/ioc/db/test/Makefile	2015-02-17 16:31:52 +0000
@@ -28,6 +28,12 @@
 
 PROD_LIBS = dbTestIoc dbCore ca Com
 
+TESTPROD_HOST += dbScanTest
+dbScanTest_SRCS += dbScanTest.c
+dbScanTest_SRCS += dbTestIoc_registerRecordDeviceDriver.cpp
+testHarness_SRCS += dbScanTest.c
+TESTS += dbScanTest
+
 TESTPROD_HOST += dbShutdownTest
 dbShutdownTest_SRCS += dbShutdownTest.c
 dbShutdownTest_SRCS += dbTestIoc_registerRecordDeviceDriver.cpp

=== added file 'src/ioc/db/test/dbScanTest.c'
--- src/ioc/db/test/dbScanTest.c	1970-01-01 00:00:00 +0000
+++ src/ioc/db/test/dbScanTest.c	2015-02-17 16:31:52 +0000
@@ -0,0 +1,73 @@
+/*************************************************************************\
+* Copyright (c) 2015 Brookhaven Science Assoc. as operator of Brookhaven
+*               National Laboratory.
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+ \*************************************************************************/
+
+/*
+ *  Author: Michael Davidsaver <[e-mail]>
+ */
+
+#include <string.h>
+
+#include "dbScan.h"
+#include "epicsEvent.h"
+
+#include "dbUnitTest.h"
+#include "testMain.h"
+
+#include "dbAccess.h"
+#include "errlog.h"
+
+void dbTestIoc_registerRecordDeviceDriver(struct dbBase *);
+
+static epicsEventId waiter;
+static int called;
+static dbCommon *prec;
+
+static void onceComp(void *junk, dbCommon *prec)
+{
+    testOk1(junk==(void*)&waiter);
+    testOk1(strcmp(prec->name, "reca")==0);
+    called = 1;
+    epicsEventMustTrigger(waiter);
+}
+
+static void testOnce(void)
+{
+    testDiag("check scanOnceCallback() callback");
+    waiter = epicsEventMustCreate(epicsEventError);
+
+    testdbPrepare();
+
+    testdbReadDatabase("dbTestIoc.dbd", NULL, NULL);
+    dbTestIoc_registerRecordDeviceDriver(pdbbase);
+    testdbReadDatabase("dbLockTest.db", NULL, NULL);
+
+    eltc(0);
+    testIocInitOk();
+    eltc(1);
+
+    prec = testdbRecordPtr("reca");
+
+    testDiag("scanOnce %s", prec->name);
+    scanOnceCallback(prec, onceComp, &waiter);
+    testDiag("Waiting");
+    epicsEventMustWait(waiter);
+    testOk1(called==1);
+    if(!called)
+        testSkip(2, "callback failed to run");
+
+    testIocShutdownOk();
+
+    testdbCleanup();
+    epicsEventDestroy(waiter);
+}
+
+MAIN(dbScanTest)
+{
+    testPlan(3);
+    testOnce();
+    return testDone();
+}

=== modified file 'src/ioc/db/test/epicsRunDbTests.c'
--- src/ioc/db/test/epicsRunDbTests.c	2014-11-19 16:22:39 +0000
+++ src/ioc/db/test/epicsRunDbTests.c	2015-02-17 16:31:52 +0000
@@ -22,6 +22,7 @@
 int dbStateTest(void);
 int dbCaStatsTest(void);
 int dbShutdownTest(void);
+int dbScanTest(void);
 int scanIoTest(void);
 int dbLockTest(void);
 int dbPutLinkTest(void);
@@ -40,6 +41,7 @@
     runTest(dbStateTest);
     runTest(dbCaStatsTest);
     runTest(dbShutdownTest);
+    runTest(dbScanTest);
     runTest(scanIoTest);
     runTest(dbLockTest);
     runTest(dbPutLinkTest);