openldap/servers/slurpd/fm.c
1998-08-13 19:32:43 +00:00

285 lines
7.0 KiB
C

/*
* Copyright (c) 1996 Regents of the University of Michigan.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of Michigan at Ann Arbor. The name of the University
* may not be used to endorse or promote products derived from this
* software without specific prior written permission. This software
* is provided ``as is'' without express or implied warranty.
*/
/*
* fm.c - file management routines.
*/
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include "slurp.h"
#include "globals.h"
extern void do_admin();
static void set_shutdown();
void do_nothing();
/*
* Externs
*/
#ifdef NEEDPROTOS
extern int file_nonempty( char * );
extern int acquire_lock(char *, FILE **, FILE ** );
extern int relinquish_lock(char *, FILE *, FILE * );
#else /* NEEDPROTOS */
extern int file_nonempty();
extern int acquire_lock();
extern int relinquish_lock();
#endif /* NEEDPROTOS */
/*
* Forward references
*/
#ifdef NEEDPROTOS
static char *get_record( FILE * );
static void populate_queue( char *f );
static void set_shutdown();
void do_nothing();
#else /* NEEDPROTOS */
static char *get_record();
static void populate_queue();
static void set_shutdown();
void do_nothing();
#endif /* NEEDPROTOS */
#ifndef SYSERRLIST_IN_STDIO
extern char *sys_errlist[];
#endif /* SYSERRLIST_IN_STDIO */
/*
* Main file manager routine. Watches for new data to be appended to the
* slapd replication log. When new data is appended, fm does the following:
* - appends the data to slurpd's private copy of the replication log.
* - truncates the slapd replog
* - adds items to the internal queue of replication work to do
* - signals the replication threads to let them know new work has arrived.
*/
void
fm(
void *arg
)
{
int rc;
/* Set up our signal handlers:
* SIG{TERM,INT,HUP} causes a shutdown
* SIG(STKFLT|USR1) - does nothing, used to wake up sleeping threads.
* SIG(UNUSED|USR2) - causes slurpd to read its administrative interface file.
* (not yet implemented).
*/
#ifdef SIGSTKFLT
(void) SIGNAL( SIGSTKFLT, (void *) do_nothing );
#else
(void) SIGNAL( SIGUSR1, (void *) do_nothing );
#endif
#ifdef SIGUNUSED
(void) SIGNAL( SIGUNUSED, (void *) do_admin );
#else
(void) SIGNAL( SIGUSR2, (void *) do_admin );
#endif
(void) SIGNAL( SIGTERM, (void *) set_shutdown );
(void) SIGNAL( SIGINT, (void *) set_shutdown );
(void) SIGNAL( SIGHUP, (void *) set_shutdown );
if ( sglob->one_shot_mode ) {
if ( file_nonempty( sglob->slapd_replogfile )) {
populate_queue( sglob->slapd_replogfile );
}
printf( "Processing in one-shot mode:\n" );
printf( "%d total replication records in file,\n",
sglob->rq->rq_getcount( sglob->rq, RQ_COUNT_ALL ));
printf( "%d replication records to process.\n",
sglob->rq->rq_getcount( sglob->rq, RQ_COUNT_NZRC ));
return;
}
/*
* There may be some leftover replication records in our own
* copy of the replication log. If any exist, add them to the
* queue.
*/
if ( file_nonempty( sglob->slurpd_replogfile )) {
populate_queue( sglob->slurpd_replogfile );
}
while ( !sglob->slurpd_shutdown ) {
if ( file_nonempty( sglob->slapd_replogfile )) {
/* New work found - copy to slurpd replog file */
Debug( LDAP_DEBUG_ARGS, "new work in %s\n",
sglob->slapd_replogfile, 0, 0 );
if (( rc = copy_replog( sglob->slapd_replogfile,
sglob->slurpd_replogfile )) == 0 ) {
populate_queue( sglob->slurpd_replogfile );
} else {
if ( rc < 0 ) {
Debug( LDAP_DEBUG_ANY,
"Fatal error while copying replication log\n",
0, 0, 0 );
sglob->slurpd_shutdown = 1;
}
}
} else {
tsleep( sglob->no_work_interval );
}
/* Garbage-collect queue */
sglob->rq->rq_gc( sglob->rq );
/* Trim replication log file, if needed */
if ( sglob->rq->rq_needtrim( sglob->rq )) {
FILE *fp, *lfp;
if (( rc = acquire_lock( sglob->slurpd_replogfile, &fp,
&lfp )) < 0 ) {
Debug( LDAP_DEBUG_ANY,
"Error: cannot acquire lock on \"%s\" for trimming\n",
sglob->slurpd_replogfile, 0, 0 );
} else {
sglob->rq->rq_write( sglob->rq, fp );
(void) relinquish_lock( sglob->slurpd_replogfile, fp, lfp );
}
}
}
Debug( LDAP_DEBUG_ARGS, "fm: exiting\n", 0, 0, 0 );
}
/*
* Set a global flag which signals that we're shutting down.
*/
static void
set_shutdown()
{
int i;
sglob->slurpd_shutdown = 1; /* set flag */
#ifdef SIGSTKFLT
pthread_kill( sglob->fm_tid, SIGSTKFLT ); /* wake up file mgr */
#else
pthread_kill( sglob->fm_tid, SIGUSR1 ); /* wake up file mgr */
#endif
sglob->rq->rq_lock( sglob->rq ); /* lock queue */
pthread_cond_broadcast( &(sglob->rq->rq_more) ); /* wake repl threads */
for ( i = 0; i < sglob->num_replicas; i++ ) {
(sglob->replicas[ i ])->ri_wake( sglob->replicas[ i ]);
}
sglob->rq->rq_unlock( sglob->rq ); /* unlock queue */
(void) SIGNAL( SIGTERM, (void *) set_shutdown ); /* reinstall handlers */
(void) SIGNAL( SIGINT, (void *) set_shutdown );
(void) SIGNAL( SIGHUP, (void *) set_shutdown );
}
/*
* A do-nothing signal handler.
*/
void
do_nothing()
{
#ifdef SIGSTKFLT
(void) SIGNAL( SIGSTKFLT, (void *) do_nothing );
#else
(void) SIGNAL( SIGUSR1, (void *) do_nothing );
#endif
}
/*
* Open the slurpd replication log, seek to our last known position, and
* process any pending replication entries.
*/
static void
populate_queue(
char *f
)
{
FILE *fp, *lfp;
Rq *rq = sglob->rq;
char *p;
if ( acquire_lock( f, &fp, &lfp ) < 0 ) {
Debug( LDAP_DEBUG_ANY,
"error: can't lock file \"%s\": %s\n",
f, sys_errlist[ errno ], 0 );
return;
}
/*
* Read replication records from fp and append them the
* the queue.
*/
if ( fseek( fp, sglob->srpos, 0 ) < 0 ) {
Debug( LDAP_DEBUG_ANY,
"error: can't seek to offset %ld in file \"%s\"\n",
sglob->srpos, f, 0 );
return;
}
while (( p = get_record( fp )) != NULL ) {
if ( sglob->rq->rq_add( sglob->rq, p ) < 0 ) {
char *t;
/* Print an error message. Only print first line. */
if (( t = strchr( p, '\n' )) != NULL ) {
*t = '\0';
}
Debug( LDAP_DEBUG_ANY,
"error: malformed replog entry (begins with \"%s\")\n",
p, 0, 0 );
}
free( p );
pthread_yield();
}
sglob->srpos = ftell( fp );
(void) relinquish_lock( f, fp, lfp );
}
/*
* Get the next "record" from the file pointed to by fp. A "record"
* is delimited by two consecutive newlines. Returns NULL on EOF.
*/
static char *
get_record(
FILE *fp
)
{
int len;
static char line[BUFSIZ];
char *buf = NULL;
static int lcur, lmax;
lcur = lmax = 0;
while (( fgets( line, sizeof(line), fp ) != NULL ) &&
(( len = strlen( line )) > 1 )) {
while ( lcur + len + 1 > lmax ) {
lmax += BUFSIZ;
buf = (char *) ch_realloc( buf, lmax );
}
strcpy( buf + lcur, line );
lcur += len;
}
return( buf );
}