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Code Issues Releases Wiki Activity

1. Cleanup (no more FreeFd - unuseful; others). 

2. FreeFile() has to do nothing with nfile (# of files opened
   by VFD manager).
This commit is contained in:
Vadim B. Mikheev 1997-05-22 16:51:19 +00:00
parent 12d9a12eda
commit ff8ce5230d
1 changed files with 57 additions and 82 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

139
src/backend/storage/file/fd.c
View File

@ -6,7 +6,7 @@
* Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Id: fd.c,v 1.16 1997/02/20 22:54:18 scrappy Exp $
* $Id: fd.c,v 1.17 1997/05/22 16:51:19 vadim Exp $
*
* NOTES:
*
@ -119,11 +119,6 @@ typedef struct vfd {
static Vfd *VfdCache;
static Size SizeVfdCache = 0;
/*
* Minimum number of file descriptors known to be free.
*/
static int FreeFd = 0;
/*
* Number of file descriptors known to be open.
*/
@ -215,15 +210,17 @@ _dump_lru()
{
int mru = VfdCache[0].lruLessRecently;
Vfd *vfdP = &VfdCache[mru];
char buf[2048];
printf("MOST %d ", mru);
sprintf(buf, "LRU: MOST %d ", mru);
while (mru != 0)
{
mru = vfdP->lruLessRecently;
vfdP = &VfdCache[mru];
printf("%d ", mru);
}
printf("LEAST\n");
{
mru = vfdP->lruLessRecently;
vfdP = &VfdCache[mru];
sprintf (buf + strlen(buf), "%d ", mru);
}
sprintf(buf + strlen(buf), "LEAST");
elog (DEBUG, buf);
}
#endif /* FDDEBUG */
@ -232,7 +229,7 @@ Delete(File file)
{
Vfd *fileP;
DO_DB(printf("DEBUG: Delete %d (%s)\n",
DO_DB(elog (DEBUG, "Delete %d (%s)",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
@ -254,7 +251,7 @@ LruDelete(File file)
Vfd *fileP;
int returnValue;
DO_DB(printf("DEBUG: LruDelete %d (%s)\n",
DO_DB(elog (DEBUG, "LruDelete %d (%s)",
file, VfdCache[file].fileName));
Assert(file != 0);
@ -281,9 +278,7 @@ LruDelete(File file)
--nfile;
fileP->fd = VFD_CLOSED;
/* note that there is now one more free real file descriptor */
FreeFd++;
}
static void
@ -291,7 +286,7 @@ Insert(File file)
{
Vfd *vfdP;
DO_DB(printf("DEBUG: Insert %d (%s)\n",
DO_DB(elog(DEBUG, "Insert %d (%s)",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
@ -311,13 +306,16 @@ LruInsert (File file)
Vfd *vfdP;
int returnValue;
DO_DB(printf("DEBUG: LruInsert %d (%s)\n",
DO_DB(elog(DEBUG, "LruInsert %d (%s)",
file, VfdCache[file].fileName));
vfdP = &VfdCache[file];
if (FileIsNotOpen(file)) {
int tmpfd;
if ( nfile >= pg_nofile() )
AssertLruRoom();
/*
* Note, we check to see if there's a free file descriptor
@ -329,7 +327,6 @@ LruInsert (File file)
tryAgain:
tmpfd = open(Nulldev, O_CREAT|O_RDWR, 0666);
if (tmpfd < 0) {
FreeFd = 0;
errno = 0;
AssertLruRoom();
goto tryAgain;
@ -339,11 +336,11 @@ LruInsert (File file)
vfdP->fd = open(vfdP->fileName,vfdP->fileFlags,vfdP->fileMode);
if (vfdP->fd < 0) {
DO_DB(printf("RE_OPEN FAILED: %d\n",
DO_DB(elog(DEBUG, "RE_OPEN FAILED: %d",
errno));
return (vfdP->fd);
} else {
DO_DB(printf("RE_OPEN SUCCESS\n"));
DO_DB(elog (DEBUG, "RE_OPEN SUCCESS"));
++nfile;
}
@ -357,9 +354,6 @@ LruInsert (File file)
/* init state on open */
vfdP->fdstate = 0x0;
/* note that a file descriptor has been used up */
if (FreeFd > 0)
FreeFd--;
}
/*
@ -374,16 +368,16 @@ LruInsert (File file)
static void
AssertLruRoom()
{
DO_DB(printf("DEBUG: AssertLruRoom (FreeFd = %d)\n",
FreeFd));
DO_DB(elog(DEBUG, "AssertLruRoom. Opened %d", nfile));
if (FreeFd <= 0 || nfile >= pg_nofile()) {
/* We supposedly are using more vfds than we want to be. First
assert that there is at least one used vfd in the ring.
*/
Assert(VfdCache[0].lruMoreRecently != 0);
LruDelete(VfdCache[0].lruMoreRecently);
}
if ( nfile <= 0 )
elog (FATAL, "AssertLruRoom: No opened files - no one can be closed");
/*
* There are opened files and so there should be at least one used vfd
* in the ring.
*/
Assert(VfdCache[0].lruMoreRecently != 0);
LruDelete(VfdCache[0].lruMoreRecently);
}
static File
@ -392,13 +386,12 @@ AllocateVfd()
Index i;
File file;
DO_DB(printf("DEBUG: AllocateVfd\n"));
DO_DB(elog(DEBUG, "AllocateVfd. Size %d", SizeVfdCache));
if (SizeVfdCache == 0) {
/* initialize */
VfdCache = (Vfd *)malloc(sizeof(Vfd));
VfdCache->nextFree = 0;
VfdCache->lruMoreRecently = 0;
VfdCache->lruLessRecently = 0;
@ -408,8 +401,8 @@ AllocateVfd()
SizeVfdCache = 1;
}
if (VfdCache[0].nextFree == 0) {
if (VfdCache[0].nextFree == 0)
{
/*
* The free list is empty so it is time to increase the
* size of the array
@ -417,7 +410,7 @@ AllocateVfd()
VfdCache =(Vfd *)realloc(VfdCache, sizeof(Vfd)*SizeVfdCache*2);
Assert(VfdCache != NULL);
/*
* Set up the free list for the new entries
*/
@ -452,7 +445,7 @@ AllocateVfd()
static void
FreeVfd(File file)
{
DO_DB(printf("DB: FreeVfd: %d (%s)\n",
DO_DB(elog(DEBUG, "FreeVfd: %d (%s)",
file, VfdCache[file].fileName));
VfdCache[file].nextFree = VfdCache[0].nextFree;
@ -488,7 +481,7 @@ FileAccess(File file)
{
int returnValue;
DO_DB(printf("DB: FileAccess %d (%s)\n",
DO_DB(elog(DEBUG, "FileAccess %d (%s)",
file, VfdCache[file].fileName));
/*
@ -498,8 +491,6 @@ FileAccess(File file)
if (FileIsNotOpen(file)) {
AssertLruRoom();
returnValue = LruInsert(file);
if (returnValue != 0)
return returnValue;
@ -537,29 +528,25 @@ fileNameOpenFile(FileName fileName,
int fileFlags,
int fileMode)
{
static int osRanOut = 0;
File file;
Vfd *vfdP;
int tmpfd;
DO_DB(printf("DEBUG: FileNameOpenFile: %s %x %o\n",
DO_DB(elog(DEBUG, "fileNameOpenFile: %s %x %o",
fileName, fileFlags, fileMode));
file = AllocateVfd();
vfdP = &VfdCache[file];
if (nfile >= pg_nofile() || (FreeFd == 0 && osRanOut)) {
if ( nfile >= pg_nofile() )
AssertLruRoom();
}
tryAgain:
tmpfd = open(Nulldev, O_CREAT|O_RDWR, 0666);
if (tmpfd < 0) {
DO_DB(printf("DB: not enough descs, retry, er= %d\n",
DO_DB(elog(DEBUG, "fileNameOpenFile: not enough descs, retry, er= %d",
errno));
errno = 0;
FreeFd = 0;
osRanOut = 1;
AssertLruRoom();
goto tryAgain;
} else {
@ -574,17 +561,17 @@ fileNameOpenFile(FileName fileName,
return -1;
}
++nfile;
DO_DB(printf("DB: FNOF success %d\n",
DO_DB(elog(DEBUG, "fileNameOpenFile: success %d",
vfdP->fd));
(void)LruInsert(file);
Insert(file);
if (fileName==NULL) {
elog(WARN, "fileNameOpenFile: NULL fname");
}
vfdP->fileName = malloc(strlen(fileName)+1);
strcpy(vfdP->fileName,fileName);
vfdP->fileFlags = fileFlags & ~(O_TRUNC|O_EXCL);
vfdP->fileMode = fileMode;
vfdP->seekPos = 0;
@ -621,7 +608,7 @@ FileClose(File file)
{
int returnValue;
DO_DB(printf("DEBUG: FileClose: %d (%s)\n",
DO_DB(elog(DEBUG, "FileClose: %d (%s)",
file, VfdCache[file].fileName));
if (!FileIsNotOpen(file)) {
@ -629,9 +616,6 @@ FileClose(File file)
/* remove the file from the lru ring */
Delete(file);
/* record the new free operating system file descriptor */
FreeFd++;
/* if we did any writes, sync the file before closing */
if (VfdCache[file].fdstate & FD_DIRTY) {
returnValue = fsync(VfdCache[file].fd);
@ -661,7 +645,7 @@ FileUnlink(File file)
{
int returnValue;
DO_DB(printf("DB: FileClose: %d (%s)\n",
DO_DB(elog(DEBUG, "FileUnlink: %d (%s)",
file, VfdCache[file].fileName));
if (!FileIsNotOpen(file)) {
@ -669,9 +653,6 @@ FileUnlink(File file)
/* remove the file from the lru ring */
Delete(file);
/* record the new free operating system file descriptor */
FreeFd++;
/* if we did any writes, sync the file before closing */
if (VfdCache[file].fdstate & FD_DIRTY) {
returnValue = fsync(VfdCache[file].fd);
@ -699,7 +680,7 @@ FileRead(File file, char *buffer, int amount)
{
int returnCode;
DO_DB(printf("DEBUG: FileRead: %d (%s) %d 0x%x\n",
DO_DB(elog(DEBUG, "FileRead: %d (%s) %d %p",
file, VfdCache[file].fileName, amount, buffer));
FileAccess(file);
@ -716,7 +697,7 @@ FileWrite(File file, char *buffer, int amount)
{
int returnCode;
DO_DB(printf("DB: FileWrite: %d (%s) %d 0x%lx\n",
DO_DB(elog(DEBUG, "FileWrite: %d (%s) %d %p",
file, VfdCache[file].fileName, amount, buffer));
FileAccess(file);
@ -736,7 +717,7 @@ FileSeek(File file, long offset, int whence)
{
int returnCode;
DO_DB(printf("DEBUG: FileSeek: %d (%s) %d %d\n",
DO_DB(elog (DEBUG, "FileSeek: %d (%s) %ld %d",
file, VfdCache[file].fileName, offset, whence));
if (FileIsNotOpen(file)) {
@ -771,7 +752,7 @@ FileSeek(File file, long offset, int whence)
long
FileTell(File file)
{
DO_DB(printf("DEBUG: FileTell %d (%s)\n",
DO_DB(elog(DEBUG, "FileTell %d (%s)",
file, VfdCache[file].fileName));
return VfdCache[file].seekPos;
}
@ -781,7 +762,7 @@ FileTruncate(File file, int offset)
{
int returnCode;
DO_DB(printf("DEBUG: FileTruncate %d (%s)\n",
DO_DB(elog(DEBUG, "FileTruncate %d (%s)",
file, VfdCache[file].fileName));
(void) FileSync(file);
@ -840,26 +821,25 @@ AllocateFile()
{
int fd;
int fdleft;
DO_DB(elog(DEBUG, "AllocateFile: Allocated %d.", allocatedFiles));
while ((fd = open(Nulldev,O_WRONLY,0)) < 0) {
if (errno == EMFILE) {
errno = 0;
FreeFd = 0;
AssertLruRoom();
} else {
elog(WARN,"Open: %s in %s line %d, %s\n", Nulldev,
elog(WARN,"Open: %s in %s line %d, %s", Nulldev,
__FILE__, __LINE__, strerror(errno));
}
}
close(fd);
++allocatedFiles;
fdleft = pg_nofile() - allocatedFiles;
fdleft = pg_nofile() - allocatedFiles - nfile;
if (fdleft < 6) {
elog(DEBUG,"warning: few usable file descriptors left (%d)", fdleft);
elog(NOTICE,"warning: few usable file descriptors left (%d)", fdleft);
}
DO_DB(printf("DEBUG: AllocatedFile. FreeFd = %d\n",
FreeFd));
}
/*
@ -869,10 +849,8 @@ AllocateFile()
void
FreeFile()
{
DO_DB(printf("DEBUG: FreeFile. FreeFd now %d\n",
FreeFd));
FreeFd++;
nfile++; /* dangerous */
DO_DB(elog(DEBUG, "FreeFile: Allocated %d.", allocatedFiles));
Assert(allocatedFiles > 0);
--allocatedFiles;
}
@ -894,11 +872,8 @@ closeOneVfd()
int tmpfd;
tmpfd = open(Nulldev, O_CREAT | O_RDWR, 0666);
if (tmpfd < 0) {
FreeFd = 0;
if (tmpfd < 0)
AssertLruRoom();
FreeFd = 0;
}
else
close(tmpfd);
}