int util_check_lock_file(const char *lockFileName) {
int result = 0;
FILE *fp = safe_fopen_wrapper_follow( lockFileName, "r" );
if ( fp == NULL ) {
debug_printf( DEBUG_QUIET,
"ERROR: could not open lock file %s for reading.\n",
lockFileName );
result = -1;
}
ProcessId *procId = NULL;
if ( result != -1 ) {
int status;
procId = new ProcessId( fp, status );
if ( status != ProcessId::SUCCESS ) {
debug_printf( DEBUG_QUIET, "ERROR: unable to create ProcessId "
"object from lock file %s\n", lockFileName );
result = -1;
}
}
if ( result != -1 ) {
int status;
int aliveResult = ProcAPI::isAlive( *procId, status );
if ( aliveResult != PROCAPI_SUCCESS ) {
debug_printf( DEBUG_QUIET, "ERROR: failed to determine "
"whether DAGMan that wrote lock file is alive\n" );
result = -1;
} else {
if ( status == PROCAPI_ALIVE ) {
debug_printf( DEBUG_NORMAL,
"Duplicate DAGMan PID %d is alive; this DAGMan "
"should abort.\n", procId->getPid() );
result = 1;
} else if ( status == PROCAPI_DEAD ) {
debug_printf( DEBUG_NORMAL,
"Duplicate DAGMan PID %d is no longer alive; "
"this DAGMan should continue.\n",
procId->getPid() );
result = 0;
} else if ( status == PROCAPI_UNCERTAIN ) {
debug_printf( DEBUG_NORMAL,
"Duplicate DAGMan PID %d *may* be alive; this "
"DAGMan is continuing, but this will cause "
"problems if the duplicate DAGMan is alive.\n",
procId->getPid() );
result = 0;
} else {
EXCEPT( "Illegal ProcAPI::isAlive() status value: %d",
status );
}
}
}
delete procId;
if ( fp != NULL ) {
if ( fclose( fp ) != 0 ) {
debug_printf( DEBUG_QUIET, "ERROR: closing lock "
"file failed with errno %d (%s)\n", errno,
strerror( errno ) );
}
}
return result;
}
