summaryrefslogtreecommitdiff
path: root/db2/mp/mp_sync.c
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>1997-11-12 00:06:02 +0000
committerUlrich Drepper <drepper@redhat.com>1997-11-12 00:06:02 +0000
commitcc3fa755128c70f8afc2d604936f33e4d7d652d8 (patch)
tree0c68c1298140e1524078e8bfdf5154fb6129b680 /db2/mp/mp_sync.c
parent86187531d302de284b67ac162cf76c60c86bd7da (diff)
downloadglibc-cc3fa755128c70f8afc2d604936f33e4d7d652d8.tar.gz
1997-11-11 21:30 Ulrich Drepper <drepper@cygnus.com> * include/sys/stat.h: Define stat, fstat, lstat and *64 variants as macros so the the library compiles correctly even without optimization. * io/fstat.c: Undef fstat. * io/fstat64.c: Undef fstat64 * io/lstat.c: Undef lstat. * io/lstat64.c: Undef lstat64 * io/stat.c: Undef stat. * io/stat64.c: Undef stat64 * io/fts.c: Include <include/sys/stat.h> to get macro definitions. * io/ftw.c: Likewise. * io/getdirname.c: Likewise. * Makefile (install): Run test-installation.pl if possible. * db2/Makefile: Update from db-2.3.12. * db2/db.h: Likewise. * db2/db_int.h: Likewise. * db2/btree/bt_cursor.c: Likewise. * db2/btree/bt_delete.c: Likewise. * db2/btree/bt_open.c: Likewise. * db2/btree/bt_put.c: Likewise. * db2/btree/bt_rec.c: Likewise. * db2/btree/bt_recno.c: Likewise. * db2/btree/bt_search.c: Likewise. * db2/btree/bt_split.c: Likewise. * db2/btree/bt_stat.c: Likewise. * db2/btree/btree.src: Likewise. * db2/btree/btree_auto.c: Likewise. * db2/btree/bt_cursor.c: Likewise. * db2/btree/bt_delete.c: Likewise. * db2/btree/bt_open.c: Likewise. * db2/btree/bt_put.c: Likewise. * db2/btree/bt_rec.c: Likewise. * db2/btree/bt_recno.c: Likewise. * db2/btree/bt_search.c: Likewise. * db2/btree/bt_split.c: Likewise. * db2/btree/bt_stat.c: Likewise. * db2/btree/btree.src: Likewise. * db2/btree/btree_auto.c: Likewise. * db2/common/db_appinit.c: Likewise. * db2/common/db_apprec.c: Likewise. * db2/common/db_byteorder.c: Likewise. * db2/common/db_region.c: Likewise. * db2/db/db.c: Likewise * db2/db/db.src: Likewise * db2/db/db_auto.c: Likewise * db2/db/db_dispatch.c: Likewise * db2/db/db_dup.c: Likewise * db2/db/db_overflow.c: Likewise * db2/db/db_pr.c: Likewise * db2/db/db_rec.c: Likewise * db2/db/db_ret.c: Likewise * db2/db/db_thread.c: Likewise * db2/db185/db185.c: Likewise. * db2/hash/hash.c: Likewise. * db2/hash/hash.src: Likewise. * db2/hash/hash_auto.c: Likewise. * db2/hash/hash_dup.c: Likewise. * db2/hash/hash_page.c: Likewise. * db2/hash/hash_rec.c: Likewise. * db2/include/btree_auto.h: Likewise. * db2/include/btree_ext.h: Likewise. * db2/include/clib_ext.h: Likewise. * db2/include/common_ext.h: Likewise. * db2/include/db.h.src: Likewise. * db2/include/db_am.h: Likewise. * db2/include/db_auto.h: Likewise. * db2/include/db_cxx.h: Likewise. * db2/include/db_ext.h: Likewise. * db2/include/db_int.h.src: Likewise. * db2/include/hash.h: Likewise. * db2/include/hash_auto.h: Likewise. * db2/include/hash_ext.h: Likewise. * db2/include/lock.h: Likewise. * db2/include/lock_ext.h: Likewise. * db2/include/log.h: Likewise. * db2/include/log_ext.h: Likewise. * db2/include/mp.h: Likewise. * db2/include/mp_ext.h: Likewise. * db2/include/mutex_ext.h: Likewise. * db2/include/os_ext.h: Likewise. * db2/include/os_func.h: Likewise. * db2/include/txn.h: Likewise. * db2/include/txn_ext.h: Likewise. * db2/lock/lock.c: Likewise. * db2/lock/lock_deadlock.c: Likewise. * db2/log/log.c: Likewise. * db2/log/log_archive.c: Likewise. * db2/log/log_auto.c: Likewise. * db2/log/log_findckp.c: Likewise. * db2/log/log_get.c: Likewise. * db2/log/log_put.c: Likewise. * db2/log/log_rec.c: Likewise. * db2/log/log_register.c: Likewise. * db2/mp/mp_bh.c: Likewise. * db2/mp/mp_fget.c: Likewise. * db2/mp/mp_fopen.c: Likewise. * db2/mp/mp_fput.c: Likewise. * db2/mp/mp_fset.c: Likewise. * db2/mp/mp_open.c: Likewise. * db2/mp/mp_pr.c: Likewise. * db2/mp/mp_region.c: Likewise. * db2/mp/mp_sync.c: Likewise. * db2/mutex/mutex.c: Likewise. * db2/os/os_abs.c: Likewise. * db2/os/os_dir.c: Likewise. * db2/os/os_fid.c: Likewise. * db2/os/os_fsync.c: Likewise. * db2/os/os_func.c: Likewise. * db2/os/os_map.c: Likewise. * db2/os/os_oflags.c: Likewise. * db2/os/os_open.c: Likewise. * db2/os/os_rpath.c: Likewise. * db2/os/os_rw.c: Likewise. * db2/os/os_seek.c: Likewise. * db2/os/os_sleep.c: Likewise. * db2/os/os_stat.c: Likewise. * db2/os/os_unlink.c: Likewise. * db2/progs/db_deadlock/db_deadlock.c: Likewise. * db2/progs/db_dump/db_dump.c: Likewise. * db2/progs/db_load/db_load.c: Likewise. * db2/progs/db_recover/db_recover.c: Likewise. * db2/progs/db_stat/db_stat.c: Likewise. * db2/txn/txn.c: Likewise. * db2/txn/txn_auto.c: Likewise. * db2/txn/txn_rec.c: Likewise. * db2/os/db_os_abs.c: Removed. * db2/os/db_os_dir.c: Removed. * db2/os/db_os_fid.c: Removed. * db2/os/db_os_lseek.c: Removed. * db2/os/db_os_mmap.c: Removed. * db2/os/db_os_open.c: Removed. * db2/os/db_os_rw.c: Removed. * db2/os/db_os_sleep.c: Removed. * db2/os/db_os_stat.c: Removed. * db2/os/db_os_unlink.c: Removed. * libio/stdio.h (fopen): Add __restrict to parameters. * manual/process.texi (system): Describe behaviour for NULL argument. * stdio-common/printf-parse.h: Parse hh modifier. * stdio-common/vfprintf.c: Handle hh modifier. * stdio-common/vfscanf.c: Likewise. * manual/stdio.texi: Describe hh modifier for scanf/printf. * math/complex.h: Don't define _Imaginary_I, but instead _Complex_I. gcc does no yet know the `imaginary' keyword. * math/test-math.c: Add little test for know gcc bug. * math/tgmath.h: Make complex versions of log10() only available if __USE_GNU. * stdlib/test-canon.c: Fix typo. * sysdeps/generic/setenv.c: Avoid compilation warnings. Reported by Jim Meyering. * sysdeps/generic/bits/errno.h: EILSEQ is an ISO C error number. * sysdeps/mach/hurd/bits/errno.h: Likewise. * sysdeps/standalone/bits/errno.h: Likewise. * sysdeps/unix/sysv/linux/bits/errno.h: Likewise. * sysdeps/i386/i586/memcpy.S: New file. * sysdeps/i386/i586/mempcpy.S: New file. * sysdeps/i386/i586/memset.S: Fix typo. * sysdeps/posix/getcwd.c: Define HAVE_MEMPCPY for _LIBC. Add casts. * sysdeps/posix/system.c: Add comment to explain code. * sysdeps/wordsize-32/inttypes.h: Include <stddef.h> for wchar_t. Define PTRDIFF_{MIN,MAX}, SIG_ATOMIC_{MIN,MAX}, SIZE_MAX, WCHAR_{MIN,MAX}, WINT_{MIN,MAX}. Define wcstoimax, wcstoumax. * sysdeps/wordsize-64/inttypes.h: Likewise. * wcsmbs/wchar.h: Define WCHAR_{MIN,MAX} if not already defined. Declare __wcsto{l,ul,ll,ull}_internal only if not already done. * time/Makefile (routines): Add strfxtime. * time/strftime.c: Implement %F and %f format. * time/strfxtime.c: New file. * time/time.h: Define new types and symbols from ISO C 9X. * time/mktime.c: Little comment correction. 1997-11-10 Andreas Jaeger <aj@arthur.rhein-neckar.de> * sysdeps/libm-ieee754/s_sincosl.c: Fix typo. * sysdeps/libm-ieee754/s_tanl.c: Fix typo. * sysdeps/libm-ieee754/s_floorl.c: Correct typos. * sysdeps/libm-ieee754/e_remainderl.c: Replace EXTRACT_LDOUBLE_WORDS by GET_LDOUBLE_WORDS. * sysdeps/libm-ieee754/e_atan2l.c: Replace EXTRACT_LDOUBLE_WORDS by GET_LDOUBLE_WORDS. * sysdeps/libm-ieee754/s_scalbnl.c: Replace ";" by "," for correct variable declaration. * sysdeps/libm-ieee754/s_scalblnl.c: Likewise. * sysdeps/libm-ieee754/s_lrint.c (__lrint): Correct function. * math/libm-test.c (sqrt_test): Add test for sqrt (0.25). (asin_test): Add more test. 1997-11-10 23:34 Ulrich Drepper <drepper@cygnus.com> * sysdeps/libm-ieee754/e_asin.c: Add braces to make code clearer and to not confuse the poor compiler. * sysdeps/libm-ieee754/e_asinf.c: Likewise. Reported by vertex@cagent.com. 1997-11-09 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * elf/dl-lookup.c (do_lookup): Don't accept the base version if we require a specific one. * libio/oldfreopen.c: Bind old symbols to version GLIBC_2.0. * libio/oldiofopen.c: Likewise. * libio/oldstdfiles.c: Likewise. * libc.map: Export them. 1997-11-10 07:40 H.J. Lu <hjl@gnu.ai.mit.edu> * stdlib/exit.c (exit): Handle recursive calls to exit (). 1997-11-09 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/m68k/fpu/s_llrint.c: Fixed to take double argument instead of long double. * sysdeps/m68k/fpu/s_llrintf.c: New file. * sysdeps/m68k/fpu/s_llrintl.c: New file. * sysdeps/libm-ieee754/s_llrint.c: Make compilable and fix overflow condition. * sysdeps/libm-ieee754/s_llrintf.c: Fix overflow condition. * sysdeps/libm-ieee754/s_llrintl.c: Likewise. * sysdeps/libm-ieee754/s_llround.c: Likewise. * sysdeps/libm-ieee754/s_llroundf.c: Likewise. * sysdeps/libm-ieee754/s_llroundl.c: Likewise. * sysdeps/libm-ieee754/s_lrint.c: Likewise. * sysdeps/libm-ieee754/s_lrintf.c: Likewise. * sysdeps/libm-ieee754/s_lrintl.c: Likewise. * sysdeps/libm-ieee754/s_lround.c: Likewise. * sysdeps/libm-ieee754/s_lroundf.c: Likewise. * sysdeps/libm-ieee754/s_lroundl.c: Likewise. * math/libm-test.c: Test all three variants of lrint and llrint. Fix typos in lround and llround tests. Add tests for boundary cases for lrint and llround. 1997-11-08 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * manual/arith.texi: Misc doc fixes. * manual/ctype.texi: Likewise. * manual/pattern.texi: Likewise. * manual/terminal.texi: Likewise. 1997-11-08 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/unix/sysv/linux/xstatconv.c: Use struct assignment instead of memcpy to let the compiler use whatever it regards as optimal. * sysdeps/unix/sysv/linux/alpha/xstatconv.c: Likewise. 1997-11-08 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/unix/sysv/linux/Makefile (sysdep_headers) [$(subdir)=misc]: Add sys/prctl.h. * sysdeps/unix/sysv/linux/Dist: Distribute it. 1997-11-08 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * io/ftwtest-sh: Don't use the unknown which command, instead try pwd as /bin/pwd and /usr/bin/pwd. 1997-11-08 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * manual/maint.texi (Tools for Installation): Don't recommend broken version 3.76.1 of make. (Porting): Fix wording. 1997-11-06 06:13 H.J. Lu <hjl@gnu.ai.mit.edu> * config.make.in (build-pic-default): New, defined with pic_default. * configure.in (pic_default): New, set to yes if PIC is default. * Makeconfig (CPPFLAGS-.o, CPPFLAGS-.op, CPPFLAGS-.og, CPPFLAGS-.ob): Add -DPIC if $(build-pic-default) is yes. 1997-11-09 18:15 Ulrich Drepper <drepper@cygnus.com> * Makerules (libc.so): Fix typo. * csu/Makefile (CFLAGS-initfini.s): Correctly fix moving function definition. Patch by Zack Weinberg <zack@rabi.phys.columbia.edu>. * stdlib/strtod.c: Handle numbers like 0.0e10000 correctly which produce ±0.0. Reported by Joe Keane <jgk@jgk.org>. * sysdeps/libm-ieee754/s_ceill.c: Fix typos. * sysdeps/libm-ieee754/s_llrint.c: Correct code, it never worked. 1997-11-06 07:00 H.J. Lu <hjl@gnu.ai.mit.edu> * sysdeps/unix/sysv/i386/i686/time.S: Removed. 1997-11-08 14:07 Thorsten Kukuk <kukuk@vt.uni-paderborn.de> * nis/libnsl.map: Add __do_niscall2 for nis_cachemgr. * nis/nis_call.c: Set UDP resend timeout correct. * nis/nss_compat/compat-grp.c: Rewritten to make it faster. * nis/nss_compat/compat-pwd.c: Likewise. * nis/nss_compat/compat-spwd.c: Likewise. * nis/ypclnt.c: Fix UDP resend timeout, fix yp_bind/do_ypcall interaction. * inet/protocols/routed.h: Include sys/socket.h. * inet/protocols/talkd.h: Likewise. * inet/protocols/timed.h: Include rpc/types.h. * sunrpc/rpc/pmap_clnt.h: Include rpc/clnt.h. 1997-11-06 01:39 Ulrich Drepper <drepper@cygnus.com> * Makerules (libc.so): Add missing closing brace. 1997-11-05 Brendan Kehoe <brendan@lisa.cygnus.com> * libio.h (__P): Name its arg `p' instead of `params'. This was added solely to work around problems with the definition of __P in the Solaris math.h header.
Diffstat (limited to 'db2/mp/mp_sync.c')
-rw-r--r--db2/mp/mp_sync.c393
1 files changed, 320 insertions, 73 deletions
diff --git a/db2/mp/mp_sync.c b/db2/mp/mp_sync.c
index 65b2a18267..2f042df9e1 100644
--- a/db2/mp/mp_sync.c
+++ b/db2/mp/mp_sync.c
@@ -7,13 +7,14 @@
#include "config.h"
#ifndef lint
-static const char sccsid[] = "@(#)mp_sync.c 10.9 (Sleepycat) 8/29/97";
+static const char sccsid[] = "@(#)mp_sync.c 10.15 (Sleepycat) 11/1/97";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
+#include <stdlib.h>
#include <string.h>
#endif
@@ -23,6 +24,8 @@ static const char sccsid[] = "@(#)mp_sync.c 10.9 (Sleepycat) 8/29/97";
#include "mp.h"
#include "common_ext.h"
+static int __bhcmp __P((const void *, const void *));
+
/*
* memp_sync --
* Mpool sync function.
@@ -32,27 +35,40 @@ memp_sync(dbmp, lsnp)
DB_MPOOL *dbmp;
DB_LSN *lsnp;
{
- BH *bhp;
+ BH *bhp, **bharray;
DB_ENV *dbenv;
MPOOL *mp;
MPOOLFILE *mfp;
- int can_write, wrote, lsn_cnt, restart, ret;
+ int ar_cnt, cnt, nalloc, next, notused, ret, wrote;
dbenv = dbmp->dbenv;
- if (dbmp->dbenv->lg_info == NULL) {
- __db_err(dbenv, "memp_sync requires logging");
+ if (dbenv->lg_info == NULL) {
+ __db_err(dbenv, "memp_sync: requires logging");
return (EINVAL);
}
+ /*
+ * We try and write the buffers in page order so that the underlying
+ * filesystem doesn't have to seek and can write contiguous blocks,
+ * plus, we don't want to hold the region lock while we write the
+ * buffers. Get memory to hold the buffer pointers. Get a good-size
+ * block, too, because we realloc while holding the region lock if we
+ * run out.
+ */
+ if ((bharray =
+ (BH **)__db_malloc((nalloc = 1024) * sizeof(BH *))) == NULL)
+ return (ENOMEM);
+
LOCKREGION(dbmp);
/*
- * If the application is asking about a previous call, and we haven't
- * found any buffers that the application holding the pin couldn't
- * write, return yes or no based on the current count. Note, if the
- * application is asking about a LSN *smaller* than one we've already
- * handled, then we return based on the count for that LSN.
+ * If the application is asking about a previous call to memp_sync(),
+ * and we haven't found any buffers that the application holding the
+ * pin couldn't write, return yes or no based on the current count.
+ * Note, if the application is asking about a LSN *smaller* than one
+ * we've already handled or are currently handling, then we return a
+ * result based on the count for the larger LSN.
*/
mp = dbmp->mp;
if (!F_ISSET(mp, MP_LSN_RETRY) && log_compare(lsnp, &mp->lsn) <= 0) {
@@ -61,9 +77,7 @@ memp_sync(dbmp, lsnp)
ret = 0;
} else
ret = DB_INCOMPLETE;
-
- UNLOCKREGION(dbmp);
- return (ret);
+ goto done;
}
/* Else, it's a new checkpoint. */
@@ -74,7 +88,7 @@ memp_sync(dbmp, lsnp)
* for which we were already doing a checkpoint. (BTW, I don't expect
* to see multiple LSN's from the same or multiple processes, but You
* Just Never Know. Responding as if they all called with the largest
- * of the LSNs specified makes everything work.
+ * of the LSNs specified makes everything work.)
*
* We don't currently use the LSN we save. We could potentially save
* the last-written LSN in each buffer header and use it to determine
@@ -93,64 +107,127 @@ memp_sync(dbmp, lsnp)
/*
* Walk the list of buffers and mark all dirty buffers to be written
- * and all pinned buffers to be potentially written. We do this in
- * single fell swoop while holding the region locked so that processes
- * can't make new buffers dirty, causing us to never finish. Since
- * the application may have restarted the sync, clear any BH_WRITE
- * flags that appear to be left over.
+ * and all pinned buffers to be potentially written (we can't know if
+ * we'll need to write them until the holding process returns them to
+ * the cache). We do this in one pass while holding the region locked
+ * so that processes can't make new buffers dirty, causing us to never
+ * finish. Since the application may have restarted the sync, clear
+ * any BH_WRITE flags that appear to be left over from previous calls.
+ *
+ * Keep a count of the total number of buffers we need to write in
+ * MPOOL->lsn_cnt, and for each file, in MPOOLFILE->lsn_count.
*/
- can_write = lsn_cnt = 0;
- for (lsn_cnt = 0, bhp = SH_TAILQ_FIRST(&mp->bhq, __bh);
+ ar_cnt = 0;
+ for (bhp = SH_TAILQ_FIRST(&mp->bhq, __bh);
bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, q, __bh))
if (F_ISSET(bhp, BH_DIRTY) || bhp->ref != 0) {
F_SET(bhp, BH_WRITE);
- if (bhp->ref == 0)
- can_write = 1;
+ ++mp->lsn_cnt;
- mfp = ADDR(dbmp, bhp->mf_offset);
+ mfp = R_ADDR(dbmp, bhp->mf_offset);
++mfp->lsn_cnt;
- ++lsn_cnt;
+ /*
+ * If the buffer isn't in use, we should be able to
+ * write it immediately, so save a reference to it.
+ */
+ if (bhp->ref == 0) {
+ if (ar_cnt == nalloc) {
+ nalloc *= 2;
+ if ((bharray =
+ (BH **)__db_realloc(bharray,
+ nalloc * sizeof(BH *))) == NULL) {
+ ret = ENOMEM;
+ goto err;
+ }
+ }
+ bharray[ar_cnt++] = bhp;
+ }
} else
F_CLR(bhp, BH_WRITE);
- mp->lsn_cnt = lsn_cnt;
-
- /* If there no buffers we can write, we're done. */
- if (!can_write) {
- UNLOCKREGION(dbmp);
- return (mp->lsn_cnt ? DB_INCOMPLETE : 0);
+ /* If there no buffers we can write immediately, we're done. */
+ if (ar_cnt == 0) {
+ ret = mp->lsn_cnt ? DB_INCOMPLETE : 0;
+ goto done;
}
- /*
- * Write any buffers that we can. Restart the walk after each write,
- * __memp_pgwrite() discards and reacquires the region lock during I/O.
- */
-retry: for (bhp = SH_TAILQ_FIRST(&mp->bhq, __bh);
- bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, q, __bh)) {
- /* Ignore pinned or locked buffers. */
- if (!F_ISSET(bhp, BH_WRITE) ||
- bhp->ref != 0 || F_ISSET(bhp, BH_LOCKED))
- continue;
+ /* Lock down the buffers and their contents. */
+ for (cnt = 0; cnt < ar_cnt; ++cnt)
+ ++bharray[cnt]->ref;
- mfp = ADDR(dbmp, bhp->mf_offset);
- if ((ret =
- __memp_bhwrite(dbmp, mfp, bhp, &restart, &wrote)) != 0)
- goto err;
- if (wrote) {
- if (restart)
- goto retry;
+ UNLOCKREGION(dbmp);
+
+ /* Sort the buffers we're going to write. */
+ qsort(bharray, ar_cnt, sizeof(BH *), __bhcmp);
+
+ LOCKREGION(dbmp);
+
+ /* Walk the array, writing buffers. */
+ for (next = 0; next < ar_cnt; ++next) {
+ /*
+ * It's possible for a thread to have gotten the buffer since
+ * we listed it for writing. If the reference count is still
+ * 1, we're the only ones using the buffer, go ahead and write.
+ * If it's >1, then skip the buffer and assume that it will be
+ * written when it's returned to the cache.
+ */
+ if (bharray[next]->ref > 1) {
+ --bharray[next]->ref;
continue;
}
- __db_err(dbenv, "%s: unable to flush page: %lu",
- ADDR(dbmp, mfp->path_off), (u_long)bhp->pgno);
- ret = EPERM;
- goto err;
+
+ /* Write the buffer. */
+ mfp = R_ADDR(dbmp, bharray[next]->mf_offset);
+ ret =
+ __memp_bhwrite(dbmp, mfp, bharray[next], &notused, &wrote);
+
+ /* Release the buffer. */
+ --bharray[next]->ref;
+
+ /* If there's an error, release the rest of the buffers. */
+ if (ret != 0 || !wrote) {
+ while (++next < ar_cnt)
+ --bharray[next]->ref;
+
+ if (ret != 0)
+ goto err;
+
+ /*
+ * Any process syncing the shared memory buffer pool
+ * had better be able to write to any underlying file.
+ * Be understanding, but firm, on this point.
+ */
+ if (!wrote) {
+ __db_err(dbenv, "%s: unable to flush page: %lu",
+ R_ADDR(dbmp, mfp->path_off),
+ (u_long)bharray[next]->pgno);
+ ret = EPERM;
+ goto err;
+ }
+ }
}
ret = mp->lsn_cnt ? DB_INCOMPLETE : 0;
-err: UNLOCKREGION(dbmp);
+done:
+ if (0) {
+err: /*
+ * On error, clear:
+ * MPOOL->lsn_cnt (the total sync count)
+ * MPOOLFILE->lsn_cnt (the per-file sync count)
+ * BH_WRITE flag (the scheduled for writing flag)
+ */
+ mp->lsn_cnt = 0;
+ for (mfp = SH_TAILQ_FIRST(&dbmp->mp->mpfq, __mpoolfile);
+ mfp != NULL; mfp = SH_TAILQ_NEXT(mfp, q, __mpoolfile))
+ mfp->lsn_cnt = 0;
+ for (bhp = SH_TAILQ_FIRST(&mp->bhq, __bh);
+ bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, q, __bh))
+ F_CLR(bhp, BH_WRITE);
+ }
+ UNLOCKREGION(dbmp);
+ __db_free(bharray);
return (ret);
}
@@ -162,10 +239,10 @@ int
memp_fsync(dbmfp)
DB_MPOOLFILE *dbmfp;
{
- BH *bhp;
+ BH *bhp, **bharray;
DB_MPOOL *dbmp;
size_t mf_offset;
- int pincnt, restart, ret, wrote;
+ int ar_cnt, cnt, nalloc, next, pincnt, notused, ret, wrote;
/*
* If this handle doesn't have a file descriptor that's open for
@@ -175,35 +252,205 @@ memp_fsync(dbmfp)
if (F_ISSET(dbmfp, MP_READONLY | MP_PATH_TEMP))
return (0);
- dbmp = dbmfp->dbmp;
ret = 0;
+ dbmp = dbmfp->dbmp;
+ mf_offset = R_OFFSET(dbmp, dbmfp->mfp);
- mf_offset = OFFSET(dbmp, dbmfp->mfp);
+ /*
+ * We try and write the buffers in page order so that the underlying
+ * filesystem doesn't have to seek and can write contiguous blocks,
+ * plus, we don't want to hold the region lock while we write the
+ * buffers. Get memory to hold the buffer pointers. Get a good-size
+ * block, too, because we realloc while holding the region lock if we
+ * run out.
+ */
+ nalloc = 1024;
+ if ((bharray =
+ (BH **)__db_malloc((size_t)nalloc * sizeof(BH *))) == NULL)
+ return (ENOMEM);
LOCKREGION(dbmp);
/*
- * Walk the list of buffer headers for the MPOOLFILE, and write out any
- * dirty buffers that we can.
+ * Walk the LRU list of buffer headers, and get a list of buffers to
+ * write for this MPOOLFILE.
*/
-retry: pincnt = 0;
+ ar_cnt = pincnt = 0;
for (bhp = SH_TAILQ_FIRST(&dbmp->mp->bhq, __bh);
- bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, q, __bh))
- if (F_ISSET(bhp, BH_DIRTY) && bhp->mf_offset == mf_offset) {
- if (bhp->ref != 0 || F_ISSET(bhp, BH_LOCKED)) {
- ++pincnt;
- continue;
- }
- if ((ret =
- __memp_pgwrite(dbmfp, bhp, &restart, &wrote)) != 0)
+ bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, q, __bh)) {
+ if (!F_ISSET(bhp, BH_DIRTY) || bhp->mf_offset != mf_offset)
+ continue;
+ if (bhp->ref != 0 || F_ISSET(bhp, BH_LOCKED)) {
+ ++pincnt;
+ continue;
+ }
+
+ if (ar_cnt == nalloc) {
+ nalloc *= 2;
+ if ((bharray = (BH **)__db_realloc(bharray,
+ nalloc * sizeof(BH *))) == NULL) {
+ ret = ENOMEM;
goto err;
- if (!wrote)
- ++pincnt;
- if (restart)
- goto retry;
+ }
+ }
+
+ bharray[ar_cnt++] = bhp;
+ }
+
+ /* Lock down the buffers and their contents. */
+ for (cnt = 0; cnt < ar_cnt; ++cnt)
+ ++bharray[cnt]->ref;
+
+ UNLOCKREGION(dbmp);
+
+ /* Sort the buffers we're going to write. */
+ qsort(bharray, ar_cnt, sizeof(BH *), __bhcmp);
+
+ LOCKREGION(dbmp);
+
+ /* Walk the array, writing buffers. */
+ for (next = 0; next < ar_cnt; ++next) {
+ /*
+ * It's possible for a thread to have gotten the buffer since
+ * we listed it for writing. If the reference count is still
+ * 1, we're the only ones using the buffer, go ahead and write.
+ * If it's >1, then skip the buffer and assume that it will be
+ * written when it's returned to the cache.
+ */
+ if (bharray[next]->ref > 1) {
+ ++pincnt;
+
+ --bharray[next]->ref;
+ continue;
}
+ /* Write the buffer. */
+ ret = __memp_pgwrite(dbmfp, bharray[next], &notused, &wrote);
+
+ /* Release the buffer. */
+ --bharray[next]->ref;
+
+ /* If there's an error, release the rest of the buffers. */
+ if (ret != 0) {
+ while (++next < ar_cnt)
+ --bharray[next]->ref;
+ goto err;
+ }
+ if (!wrote)
+ ++pincnt;
+ }
+
+err: UNLOCKREGION(dbmp);
+
+ __db_free(bharray);
+
+ /*
+ * Sync the underlying file as the last thing we do, so that the OS
+ * has maximal opportunity to flush buffers before we request it.
+ *
+ * XXX:
+ * Don't lock the region around the sync, fsync(2) has no atomicity
+ * issues.
+ */
+ if (ret == 0)
+ return (pincnt == 0 ? __db_fsync(dbmfp->fd) : DB_INCOMPLETE);
+ return (ret);
+
+}
+
+/*
+ * memp_trickle --
+ * Keep a specified percentage of the buffers clean.
+ */
+int
+memp_trickle(dbmp, pct, nwrotep)
+ DB_MPOOL *dbmp;
+ int pct, *nwrotep;
+{
+ BH *bhp;
+ MPOOL *mp;
+ MPOOLFILE *mfp;
+ u_long total;
+ int notused, ret, wrote;
+
+ mp = dbmp->mp;
+ if (nwrotep != NULL)
+ *nwrotep = 0;
+
+ if (pct < 1 || pct > 100)
+ return (EINVAL);
+
+ LOCKREGION(dbmp);
+
+ /*
+ * If there are sufficient clean buffers, or no buffers or no dirty
+ * buffers, we're done.
+ *
+ * XXX
+ * Using st_page_clean and st_page_dirty is our only choice at the
+ * moment, but it's not as correct as we might like in the presence
+ * of pools with more than one buffer size, as a free 512-byte buffer
+ * isn't the same as a free 8K buffer.
+ */
+loop: total = mp->stat.st_page_clean + mp->stat.st_page_dirty;
+ if (total == 0 || mp->stat.st_page_dirty == 0 ||
+ (mp->stat.st_page_clean * 100) / total >= (u_long)pct) {
+ UNLOCKREGION(dbmp);
+ return (0);
+ }
+
+ /* Loop until we write a buffer. */
+ for (bhp = SH_TAILQ_FIRST(&mp->bhq, __bh);
+ bhp != NULL; bhp = SH_TAILQ_NEXT(bhp, q, __bh)) {
+ if (bhp->ref != 0 ||
+ !F_ISSET(bhp, BH_DIRTY) || F_ISSET(bhp, BH_LOCKED))
+ continue;
+
+ mfp = R_ADDR(dbmp, bhp->mf_offset);
+ if ((ret =
+ __memp_bhwrite(dbmp, mfp, bhp, &notused, &wrote)) != 0)
+ goto err;
+
+ /*
+ * Any process syncing the shared memory buffer pool
+ * had better be able to write to any underlying file.
+ * Be understanding, but firm, on this point.
+ */
+ if (!wrote) {
+ __db_err(dbmp->dbenv, "%s: unable to flush page: %lu",
+ R_ADDR(dbmp, mfp->path_off), (u_long)bhp->pgno);
+ ret = EPERM;
+ goto err;
+ }
+
+ ++mp->stat.st_page_trickle;
+ if (nwrotep != NULL)
+ ++*nwrotep;
+ goto loop;
+ }
+
+ /* No more buffers to write. */
+ return (0);
+
err: UNLOCKREGION(dbmp);
+ return (ret);
+}
+
+static int
+__bhcmp(p1, p2)
+ const void *p1, *p2;
+{
+ BH *bhp1, *bhp2;
+
+ bhp1 = *(BH **)p1;
+ bhp2 = *(BH **)p2;
+
+ /* Sort by file (shared memory pool offset). */
+ if (bhp1->mf_offset < bhp2->mf_offset)
+ return (-1);
+ if (bhp1->mf_offset > bhp2->mf_offset)
+ return (1);
- return (ret == 0 ? (pincnt ? DB_INCOMPLETE : 0) : ret);
+ /* Sort by page in file. */
+ return (bhp1->pgno < bhp2->pgno ? -1 : 1);
}