Additional field name changes and commit fixes associated with shared-memory

locking in the unix VFS, to improve maintainability.  No logic changes.

FossilOrigin-Name: 9280774a4bbc665d70f346d258768cbcca3e0e77791473aecfd7d0e87810ab31

manifest

@@ -1,5 +1,5 @@
-C Fix\scomments\sand\srefactor\ssome\snames\sassociated\swith\sshared-memory\slocking\nin\sthe\sUnix\sVFS.\s\sNo\slogical\schanges.
-D 2018-10-02T19:36:40.212
+C Additional\sfield\sname\schanges\sand\scommit\sfixes\sassociated\swith\sshared-memory\nlocking\sin\sthe\sunix\sVFS,\sto\simprove\smaintainability.\s\sNo\slogic\schanges.
+D 2018-10-02T19:58:08.325
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 01e95208a78b57d056131382c493c963518f36da4c42b12a97eb324401b3a334
@@ -487,7 +487,7 @@ F src/os.c 8aeb0b0f40f8f5b0da03fe49706695adaf42d2f516ab95abc72e86c245e119de
 F src/os.h 48388821692e87da174ea198bf96b1b2d9d83be5dfc908f673ee21fafbe0d432
 F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85
 F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
-F src/os_unix.c 3acd41af1334d7d2af8ca8ce684ccc73eeab7fe907ddab630963fd54102b4be4
+F src/os_unix.c fd755a51cc621b14c6b5816912e8e103ccc28c46d64f8173f22ba992ddbe9fd3
 F src/os_win.c 070cdbb400097c6cda54aa005356095afdc2f3ee691d17192c54724ef146a971
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c a0d8f686ef64549ad5b356fd30429bd9ee7a06dd42b4d6faa096352ff26b1c5b
@@ -1770,7 +1770,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P defa0515b8fd50ed9be699542f8c6695dd4a60c02f310665db6657ec5b6b67d0
-R 9097a8d83ca39760ec0a01128c0dade1
+P 3e9f1635271c92dce5324728b4ee1cc1a1856ec3c60b1b512a652c21e010e63e
+R 4c540d033fc87107981e8569f09af526
 U drh
-Z 3fc014f602248e5c82ae5fe3e9828c74
+Z d5d2b74c6598d9bd4b46abde946440e8

manifest.uuid

@@ -1 +1 @@
-3e9f1635271c92dce5324728b4ee1cc1a1856ec3c60b1b512a652c21e010e63e
+9280774a4bbc665d70f346d258768cbcca3e0e77791473aecfd7d0e87810ab31

src/os_unix.c

@@ -4215,10 +4215,10 @@ static int unixGetpagesize(void){
 **
 ** The following fields are read-only after the object is created:
 ** 
-**      fid
+**      hShm
 **      zFilename
 **
-** Either unixShmNode.mutex must be held or unixShmNode.nRef==0 and
+** Either unixShmNode.pShmMutex must be held or unixShmNode.nRef==0 and
 ** unixMutexHeld() is true when reading or writing any other field
 ** in this structure.
 */
@@ -4226,7 +4226,7 @@ struct unixShmNode {
   unixInodeInfo *pInode;     /* unixInodeInfo that owns this SHM node */
   sqlite3_mutex *pShmMutex;  /* Mutex to access this object */
   char *zFilename;           /* Name of the mmapped file */
-  int h;                     /* Open file descriptor */
+  int hShm;                  /* Open file descriptor */
   int szRegion;              /* Size of shared-memory regions */
   u16 nRegion;               /* Size of array apRegion */
   u8 isReadonly;             /* True if read-only */
@@ -4295,13 +4295,13 @@ static int unixShmSystemLock(
   /* Locks are within range */
   assert( n>=1 && n<=SQLITE_SHM_NLOCK );
 
-  if( pShmNode->h>=0 ){
+  if( pShmNode->hShm>=0 ){
     /* Initialize the locking parameters */
     f.l_type = lockType;
     f.l_whence = SEEK_SET;
     f.l_start = ofst;
     f.l_len = n;
-    rc = osSetPosixAdvisoryLock(pShmNode->h, &f, pFile);
+    rc = osSetPosixAdvisoryLock(pShmNode->hShm, &f, pFile);
     rc = (rc!=(-1)) ? SQLITE_OK : SQLITE_BUSY;
   }
 
@@ -4375,16 +4375,16 @@ static void unixShmPurge(unixFile *pFd){
     assert( p->pInode==pFd->pInode );
     sqlite3_mutex_free(p->pShmMutex);
     for(i=0; i<p->nRegion; i+=nShmPerMap){
-      if( p->h>=0 ){
+      if( p->hShm>=0 ){
         osMunmap(p->apRegion[i], p->szRegion);
       }else{
         sqlite3_free(p->apRegion[i]);
       }
     }
     sqlite3_free(p->apRegion);
-    if( p->h>=0 ){
-      robust_close(pFd, p->h, __LINE__);
-      p->h = -1;
+    if( p->hShm>=0 ){
+      robust_close(pFd, p->hShm, __LINE__);
+      p->hShm = -1;
     }
     p->pInode->pShmNode = 0;
     sqlite3_free(p);
@@ -4426,7 +4426,7 @@ static int unixLockSharedMemory(unixFile *pDbFd, unixShmNode *pShmNode){
   lock.l_start = UNIX_SHM_DMS;
   lock.l_len = 1;
   lock.l_type = F_WRLCK;
-  if( osFcntl(pShmNode->h, F_GETLK, &lock)!=0 ) {
+  if( osFcntl(pShmNode->hShm, F_GETLK, &lock)!=0 ) {
     rc = SQLITE_IOERR_LOCK;
   }else if( lock.l_type==F_UNLCK ){
     if( pShmNode->isReadonly ){
@@ -4434,7 +4434,7 @@ static int unixLockSharedMemory(unixFile *pDbFd, unixShmNode *pShmNode){
       rc = SQLITE_READONLY_CANTINIT;
     }else{
       rc = unixShmSystemLock(pDbFd, F_WRLCK, UNIX_SHM_DMS, 1);
-      if( rc==SQLITE_OK && robust_ftruncate(pShmNode->h, 0) ){
+      if( rc==SQLITE_OK && robust_ftruncate(pShmNode->hShm, 0) ){
         rc = unixLogError(SQLITE_IOERR_SHMOPEN,"ftruncate",pShmNode->zFilename);
       }
     }
@@ -4540,7 +4540,7 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
     sqlite3_snprintf(nShmFilename, zShm, "%s-shm", zBasePath);
     sqlite3FileSuffix3(pDbFd->zPath, zShm);
 #endif
-    pShmNode->h = -1;
+    pShmNode->hShm = -1;
     pDbFd->pInode->pShmNode = pShmNode;
     pShmNode->pInode = pDbFd->pInode;
     if( sqlite3GlobalConfig.bCoreMutex ){
@@ -4553,11 +4553,11 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
 
     if( pInode->bProcessLock==0 ){
       if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
-        pShmNode->h = robust_open(zShm, O_RDWR|O_CREAT, (sStat.st_mode&0777));
+        pShmNode->hShm = robust_open(zShm, O_RDWR|O_CREAT,(sStat.st_mode&0777));
       }
-      if( pShmNode->h<0 ){
-        pShmNode->h = robust_open(zShm, O_RDONLY, (sStat.st_mode&0777));
-        if( pShmNode->h<0 ){
+      if( pShmNode->hShm<0 ){
+        pShmNode->hShm = robust_open(zShm, O_RDONLY, (sStat.st_mode&0777));
+        if( pShmNode->hShm<0 ){
           rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShm);
           goto shm_open_err;
         }
@@ -4568,7 +4568,7 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
       ** is owned by the same user that owns the original database.  Otherwise,
       ** the original owner will not be able to connect.
       */
-      robustFchown(pShmNode->h, sStat.st_uid, sStat.st_gid);
+      robustFchown(pShmNode->hShm, sStat.st_uid, sStat.st_gid);
 
       rc = unixLockSharedMemory(pDbFd, pShmNode);
       if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;
@@ -4654,8 +4654,8 @@ static int unixShmMap(
   }
   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
   assert( pShmNode->pInode==pDbFd->pInode );
-  assert( pShmNode->h>=0 || pDbFd->pInode->bProcessLock==1 );
-  assert( pShmNode->h<0 || pDbFd->pInode->bProcessLock==0 );
+  assert( pShmNode->hShm>=0 || pDbFd->pInode->bProcessLock==1 );
+  assert( pShmNode->hShm<0 || pDbFd->pInode->bProcessLock==0 );
 
   /* Minimum number of regions required to be mapped. */
   nReqRegion = ((iRegion+nShmPerMap) / nShmPerMap) * nShmPerMap;
@@ -4667,12 +4667,12 @@ static int unixShmMap(
 
     pShmNode->szRegion = szRegion;
 
-    if( pShmNode->h>=0 ){
+    if( pShmNode->hShm>=0 ){
       /* The requested region is not mapped into this processes address space.
       ** Check to see if it has been allocated (i.e. if the wal-index file is
       ** large enough to contain the requested region).
       */
-      if( osFstat(pShmNode->h, &sStat) ){
+      if( osFstat(pShmNode->hShm, &sStat) ){
         rc = SQLITE_IOERR_SHMSIZE;
         goto shmpage_out;
       }
@@ -4700,7 +4700,7 @@ static int unixShmMap(
           assert( (nByte % pgsz)==0 );
           for(iPg=(sStat.st_size/pgsz); iPg<(nByte/pgsz); iPg++){
             int x = 0;
-            if( seekAndWriteFd(pShmNode->h, iPg*pgsz + pgsz-1, "", 1, &x)!=1 ){
+            if( seekAndWriteFd(pShmNode->hShm, iPg*pgsz + pgsz-1,"",1,&x)!=1 ){
               const char *zFile = pShmNode->zFilename;
               rc = unixLogError(SQLITE_IOERR_SHMSIZE, "write", zFile);
               goto shmpage_out;
@@ -4723,10 +4723,10 @@ static int unixShmMap(
       int nMap = szRegion*nShmPerMap;
       int i;
       void *pMem;
-      if( pShmNode->h>=0 ){
+      if( pShmNode->hShm>=0 ){
         pMem = osMmap(0, nMap,
             pShmNode->isReadonly ? PROT_READ : PROT_READ|PROT_WRITE, 
-            MAP_SHARED, pShmNode->h, szRegion*(i64)pShmNode->nRegion
+            MAP_SHARED, pShmNode->hShm, szRegion*(i64)pShmNode->nRegion
         );
         if( pMem==MAP_FAILED ){
           rc = unixLogError(SQLITE_IOERR_SHMMAP, "mmap", pShmNode->zFilename);
@@ -4789,8 +4789,8 @@ static int unixShmLock(
        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)
        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );
   assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );
-  assert( pShmNode->h>=0 || pDbFd->pInode->bProcessLock==1 );
-  assert( pShmNode->h<0 || pDbFd->pInode->bProcessLock==0 );
+  assert( pShmNode->hShm>=0 || pDbFd->pInode->bProcessLock==1 );
+  assert( pShmNode->hShm<0 || pDbFd->pInode->bProcessLock==0 );
 
   mask = (1<<(ofst+n)) - (1<<ofst);
   assert( n>1 || mask==(1<<ofst) );
@@ -4933,7 +4933,7 @@ static int unixShmUnmap(
   assert( pShmNode->nRef>0 );
   pShmNode->nRef--;
   if( pShmNode->nRef==0 ){
-    if( deleteFlag && pShmNode->h>=0 ){
+    if( deleteFlag && pShmNode->hShm>=0 ){
       osUnlink(pShmNode->zFilename);
     }
     unixShmPurge(pDbFd);