boinc/sched/feeder.C

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// The contents of this file are subject to the BOINC Public License
// Version 1.0 (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at
// http://boinc.berkeley.edu/license_1.0.txt
//
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
// License for the specific language governing rights and limitations
// under the License.
//
// The Original Code is the Berkeley Open Infrastructure for Network Computing.
//
// The Initial Developer of the Original Code is the SETI@home project.
// Portions created by the SETI@home project are Copyright (C) 2002
// University of California at Berkeley. All Rights Reserved.
//
// Contributor(s):
//
// feeder [-asynch]
//
// Creates a shared memory segment containing DB info,
// including results/workunits to send.
// This means that the scheduler CGI program doesn't have to
// access the DB to get this info.
//
// -asynch fork and run in a separate process
// TODO:
// - check for wu/results that don't get sent for a long time;
// generate a warning message
// Trigger files:
// The feeder program periodically checks for two trigger files:
//
// stop_server: destroy shmem and exit
// leave trigger file there (for other daemons)
// reread_db: update DB contents in existing shmem
// delete trigger file
// If you get an "Invalid argument" error when trying to run the feeder,
// it is likely that you aren't able to allocate enough shared memory.
// Either increase the maximum shared memory segment size in the kernel
// configuration, or decrease the MAX_PLATFORMS, MAX_APPS
// MAX_APP_VERSIONS, and MAX_WU_RESULTS in sched_shmem.h
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "boinc_db.h"
#include "shmem.h"
#include "util.h"
#include "config.h"
#include "sched_shmem.h"
#include "sched_util.h"
#define RESULTS_PER_ENUM 100
#define REREAD_DB_FILENAME "reread_db"
#define LOCKFILE "feeder.out"
#define PIDFILE "feeder.pid"
CONFIG config;
SCHED_SHMEM* ssp;
void cleanup_shmem()
{
detach_shmem((void*)ssp);
destroy_shmem(config.shmem_key);
}
int check_reread_trigger() {
FILE* f;
f = fopen(REREAD_DB_FILENAME, "r");
if (f) {
fclose(f);
ssp->init();
ssp->scan_tables();
unlink(REREAD_DB_FILENAME);
}
return 0;
}
// Try keep the wu_results array filled.
// This is actually a little tricky.
// We use an enumerator.
// The inner loop scans the wu_result table,
// looking for empty slots and trying to fill them in.
// When the enumerator reaches the end, it is restarted;
// hopefully there will be some new workunits.
// There are two complications:
// - An enumeration may return results already in the array.
// So, for each result, we scan the entire array to make sure
// it's not there already. Can this be streamlined?
// - We must avoid excessive re-enumeration,
// especially when the number of results is less than the array size.
// Crude approach: if a "collision" (as above) occurred on
// a pass through the array, wait a long time (5 sec)
//
void feeder_loop() {
int i, j, nadditions, ncollisions, retval;
DB_RESULT result;
DB_WORKUNIT wu;
bool no_wus, collision, restarted_enum;
char clause[256];
sprintf(clause, "where server_state=%d order by random limit %d",
RESULT_SERVER_STATE_UNSENT, RESULTS_PER_ENUM
);
while (1) {
nadditions = 0;
ncollisions = 0;
no_wus = false;
restarted_enum = false;
for (i=0; i<ssp->nwu_results; i++) {
if (!ssp->wu_results[i].present) {
try_again:
retval = result.enumerate(clause);
if (retval) {
// if we already restarted the enum on this pass,
// there's no point in doing it again.
//
if (restarted_enum) {
log_messages.printf(SchedMessages::DEBUG, "already restarted enum on this pass\n");
break;
}
// restart the enumeration
//
restarted_enum = true;
retval = result.enumerate(clause);
log_messages.printf(SchedMessages::DEBUG, "restarting enumeration\n");
if (retval) {
log_messages.printf(SchedMessages::DEBUG, "enumeration restart returned nothing\n");
no_wus = true;
break;
}
}
// there's a chance this result was sent out
// after the enumeration started.
// So read it from the DB again
//
retval = result.lookup_id(result.id);
if (retval) {
log_messages.printf(SchedMessages::NORMAL, "can't reread result %s\n", result.name);
goto try_again;
}
if (result.server_state != RESULT_SERVER_STATE_UNSENT) {
log_messages.printf(
SchedMessages::NORMAL,
"[%s] RESULT STATE CHANGED\n",
result.name
);
goto try_again;
}
collision = false;
for (j=0; j<ssp->nwu_results; j++) {
if (ssp->wu_results[j].present
&& ssp->wu_results[j].result.id == result.id
) {
ncollisions++;
collision = true;
break;
}
}
if (!collision) {
log_messages.printf(
SchedMessages::NORMAL,
"[%s] adding result in slot %d\n",
result.name, i
);
retval = wu.lookup_id(result.workunitid);
if (retval) {
log_messages.printf(
SchedMessages::CRITICAL,
"[%s] can't read workunit #%d: %d\n",
result.name, result.workunitid, retval
);
continue;
}
ssp->wu_results[i].result = result;
ssp->wu_results[i].workunit = wu;
ssp->wu_results[i].present = true;
nadditions++;
}
}
}
ssp->ready = true;
if (nadditions == 0) {
log_messages.printf(SchedMessages::DEBUG, "No results added; sleeping 1 sec\n");
sleep(1);
} else {
log_messages.printf(SchedMessages::DEBUG, "Added %d results to array\n", nadditions);
}
if (no_wus) {
log_messages.printf(SchedMessages::DEBUG, "No results available; sleeping 5 sec\n");
sleep(5);
}
if (ncollisions) {
log_messages.printf(SchedMessages::DEBUG, "Some results already in array - sleeping 5 sec\n");
sleep(5);
}
fflush(stdout);
check_stop_trigger();
check_reread_trigger();
}
}
int main(int argc, char** argv) {
int i, retval;
bool asynch = false;
void* p;
unlink(REREAD_DB_FILENAME);
retval = config.parse_file();
if (retval) {
log_messages.printf(SchedMessages::CRITICAL, "can't parse config file\n");
exit(1);
}
for (i=1; i<argc; i++) {
if (!strcmp(argv[i], "-asynch")) {
asynch = true;
} else if (!strcmp(argv[i], "-d")) {
log_messages.set_debug_level(atoi(argv[++i]));
}
}
if (asynch) {
if (fork()!=0) {
exit(0);
}
}
// // Call lock_file after fork(), because file locks are not always inherited
// if (lock_file(LOCKFILE)) {
// log_messages.printf(SchedMessages::NORMAL, "Another copy of feeder is already running\n");
// exit(1);
// }
// write_pid_file(PIDFILE);
log_messages.printf(SchedMessages::NORMAL, "Starting\n");
retval = destroy_shmem(config.shmem_key);
if (retval) {
log_messages.printf(SchedMessages::CRITICAL, "can't destroy shmem\n");
exit(1);
}
retval = create_shmem(config.shmem_key, sizeof(SCHED_SHMEM), &p);
if (retval) {
log_messages.printf(SchedMessages::CRITICAL, "can't create shmem\n");
exit(1);
}
ssp = (SCHED_SHMEM*)p;
ssp->init();
atexit(cleanup_shmem);
install_sigint_handler();
retval = boinc_db_open(config.db_name, config.db_passwd);
if (retval) {
log_messages.printf(SchedMessages::CRITICAL, "boinc_db_open: %d\n", retval);
exit(1);
}
ssp->scan_tables();
log_messages.printf(
SchedMessages::NORMAL,
"feeder: read "
"%d platforms, "
"%d apps, "
"%d app_versions\n",
ssp->nplatforms,
ssp->napps,
ssp->napp_versions
);
feeder_loop();
}