robouser_t::static_init(&sked, arg_filename,
arg_clientBandwidth, 0.8 * arg_clientBandwidth, 1500,
arg_hostname, 21, arg_username, arg_password);
/* Start the first user */
robouser_t::static_startUser();
and then sits in an infinite loop that looks like this:
for (;;) {
/* Let the scheduler run the robots that need it */
sked->runAll(now);
/* Find out what sockets need attention */
nfds = robouser_t::prePoll(&pfds[0]);
poll(pfds, nfds, 50);
/* Give them the attention they deserve. */
for (i=0; i<nfds; i++) {
if (!pfds[i].revents)
continue;
robouser_t::handle_io(pfds[i].fd, pfds[i].revents);
}
}
The fetching of files is initiated the call to robouser_t::static_startUser(),
which starts the robouser's state machine going by scheduling a first call to
robouser_t::ftpCmdDone(). The state machine calls ftp_client_pipe_t::get() to
start the file transfer. Whenever poll() says a packet is ready, main() calls
robouser_t::static_handle_io(), which calls ftp_client_pipe_t::handle_io(),
which reads data from the network, hands it to ftp_client_proto_t::giveInput(),
gets output from the protocol module by calling ftp_client_proto_t::getOutput(),
and sends it to the network. Whenever the ftp client library finishes a command,
it calls robouser_t::ftpCmdDone(), which starts the next ftp command.
To see the flow of control in action, run the program in verbose mode, and note the class and method names at the beginning of each line. Here's an excerpt from the command
/bench -n1 -hkrunch -uspanky -pXXXXXX -ftest.dat -t2 -vshowing the events from the start of the test up to the end of the first file transfer. (Repetitive sections are omitted, and line numbers have been added.)
1 Option values: 2 -hkrunch host name of ftp server 3 -P21 port number of ftp server 4 -n1 number of users 5 -t2 length of run (in seconds) 6 -b3600 desired bandwidth (in bytes per second) 7 -usparky user name 8 -pXXXXXX user password 9 -ftest.dat file to fetch 10 -m1500 bytes per 'packet' 11 -v1 verbose mode 12 Sked::init: Allocating 2048 bytes. 13 robouser_t::static_init: 14 robouser0::start: 15 ftp_client_proto_t::setState: line 135: m_state was 0, now 1 16 ftp_client_pipe_t::init(0x806c260, 0xbffff9b0, 3600): bytes_per_tick 36 17 Sked::addClient(0x806c264, 3257788) 18 Sked::pop: clearing skc 0x806c264 ->skedIndex 19 robouser0::ftpCmdDone: m_state 1 20 ftp_client_pipe_t::connect(krunch, 21, 0) 21 ftp_client_proto_t::setState: line 135: m_state was 0, now 1 22 ftp_client_pipe_t::init(0x806c260, 0xbffff9b0, 3600): bytes_per_tick 36 23 ftp_client_pipe_t::init: Waiting for connect to finish, m_cfd 3 24 robouser0::watchfd 3 25 fdmap_t::add(fd 3, userid 0) 26 ftp_client_pipe_t::login(sparky, XXXXXX) 27 ftp_client_proto_t::login(sparky,XXXXXX) 28 ftp_client_pipe_t::handle_io(fd 3, ffff8004): state 0 29 ftp_client_proto_t::getOutput: Sending 'USER sparky' 30 ftp_client_pipe_t::handle_io fd 3 put 'USER sparky' 31 robouser0::gotoState: old state 1 cad 1 0 0; new state 2 cad 1 0 0 32 robouser_t::static_prePoll: user 0, ndfs 1 33 main:handling j 0 fd 3 revents 4 34 fdmap_t::fd2user(fd 3) 35 robouser0::static_handle_io(fd 3, revents 4): 36 ftp_client_pipe_t::handle_io(fd 3, 4): state 0 37 ftp_client_pipe_t::handle_io: Connect cfd 3 succeeded 38 robouser_t::static_prePoll: user 0, ndfs 1 39 main:handling j 0 fd 3 revents 1 40 fdmap_t::fd2user(fd 3) 41 robouser0::static_handle_io(fd 3, revents 1): 42 ftp_client_pipe_t::handle_io(fd 3, 1): state 0 43 ftp_client_pipe_t::handle_io fd 3 got '220 krunch FTP server (Version wu-2.4.2-VR17(1) Mon Apr 19 09:21:53 EDT 1999) ready.' 44 ftp_client_proto_t::giveInput: state: 1 oReady 0 status 220, ibuf: '220 krunch FTP server (Version wu-2.4.2-VR17(1) Mon Apr 19 09:21:53 EDT 1999) ready.' 45 ftp_client_proto_t::giveInput: server ok, 220 krunch FTP server (Version wu-2.4.2-VR17(1) Mon Apr 19 09:21:53 EDT 1999) ready. 46 ftp_client_proto_t::setState: line 179: m_state was 1, now 3 47 ftp_client_pipe_t::handle_io fd 3 got '331 Password required for sparky.' 48 ftp_client_proto_t::giveInput: state: 3 oReady 0 status 331, ibuf: '331 Password required for sparky.' 49 ftp_client_proto_t::setState: line 201: m_state was 3, now 4 50 ftp_client_proto_t::getOutput: Sending 'PASS XXXXXX' 51 ftp_client_pipe_t::handle_io fd 3 put 'PASS XXXXXX' 52 robouser_t::static_prePoll: user 0, ndfs 1 53 main:handling j 0 fd 3 revents 4 54 fdmap_t::fd2user(fd 3) 55 robouser0::static_handle_io(fd 3, revents 4): 56 ftp_client_pipe_t::handle_io(fd 3, 4): state 0 57 robouser_t::static_prePoll: user 0, ndfs 1 58 main:handling j 0 fd 3 revents 1 59 fdmap_t::fd2user(fd 3) 60 robouser0::static_handle_io(fd 3, revents 1): 61 ftp_client_pipe_t::handle_io(fd 3, 1): state 0 62 ftp_client_pipe_t::handle_io fd 3 got '230-Please read the file README' 63 ftp_client_proto_t::giveInput: state: 4 oReady 0 status 230, ibuf: '230-Please read the file README' 64 ftp_client_proto_t::giveInput: multiline reply begins: '230-Please read the file README' 65 ftp_client_proto_t::giveInput::PASS ok, 230-Please read the file README 66 ftp_client_proto_t::setState: line 211: m_state was 4, now 5 67 ftp_client_pipe_t::handle_io:notify_app: status 230, dfd_conn 0, dfd -1 68 ftp_client_pipe_t::handle_io:notify_app: calling ftpCmdDone(0, 230) 69 robouser0::ftpCmdDone: m_state 2 70 robouser0::ftpCmdDone:CONNECTING: connect succeeded, jumping to state 3 71 robouser0::gotoState: old state 2 cad 1 0 0; new state 3 cad 0 1 0 72 robouser0::ftpCmdDone: m_state 3 73 robouser0::ftpCmdDone:GET: fetching file test.dat 74 ftp_client_pipe_t::get(test.dat,1) 75 ftp_client_proto_t::get(test.dat,): requesting port from server 76 ftp_client_proto_t::callState: line 496: m_state was 5, now 8 77 ftp_client_pipe_t::handle_io(fd 3, ffff8004): state 1 78 ftp_client_proto_t::getOutput: Sending 'PASV' 79 ftp_client_pipe_t::handle_io fd 3 put 'PASV' 80 robouser0::gotoState: old state 3 cad 0 1 0; new state 4 cad 0 1 0 81 1 users 82 robouser_t::static_prePoll: user 0, ndfs 1 83 main:handling j 0 fd 3 revents 1 84 fdmap_t::fd2user(fd 3) 85 robouser0::static_handle_io(fd 3, revents 1): 86 ftp_client_pipe_t::handle_io(fd 3, 1): state 1 87 ftp_client_pipe_t::handle_io fd 3 got '230- it was last modified on Wed Nov 10 23:21:37 1999 - 53 days ago' 88 ftp_client_proto_t::giveInput: state: 8 oReady 0 status 230, ibuf: '230- it was last modified on Wed Nov 10 23:21:37 1999 - 53 days ago' 89 ftp_client_proto_t::giveInput: multiline reply continues: '230- it was last modified on Wed Nov 10 23:21:37 1999 - 53 days ago' 90 ftp_client_pipe_t::handle_io fd 3 got '230 User sparky logged in.' 91 ftp_client_proto_t::giveInput: state: 8 oReady 0 status 230, ibuf: '230 User sparky logged in.' 92 ftp_client_proto_t::giveInput: multiline reply ends: '230 User sparky logged in.' 93 robouser_t::static_prePoll: user 0, ndfs 1 94 main:handling j 0 fd 3 revents 1 95 fdmap_t::fd2user(fd 3) 96 robouser0::static_handle_io(fd 3, revents 1): 97 ftp_client_pipe_t::handle_io(fd 3, 1): state 1 98 ftp_client_pipe_t::handle_io fd 3 got '227 Entering Passive Mode (127,0,0,1,58,93)' 99 ftp_client_proto_t::giveInput: state: 8 oReady 0 status 227, ibuf: '227 Entering Passive Mode (127,0,0,1,58,93)' 100 ftp_client_proto_t::giveInput::PASV ok, 227 Entering Passive Mode (127,0,0,1,58,93) 101 ftp_client_proto_t::returnState: m_state was 8, now 9 102 ftp_client_proto_t::giveInput::PASV: sending RETR 103 ftp_client_proto_t::getOutput: Sending 'RETR test.dat' 104 ftp_client_pipe_t::handle_io fd 3 put 'RETR test.dat' 105 ftp_client_pipe_t::handle_io: isPortReady TRUE, address 127.0.0.1:23866 106 robouser0::watchfd 4 107 fdmap_t::add(fd 4, userid 0) 108 ftp_client_pipe_t::handle_io: socket returns dfd 4 109 robouser_t::static_prePoll: user 0, ndfs 2 110 main:handling j 0 fd 3 revents 4 111 fdmap_t::fd2user(fd 3) 112 robouser0::static_handle_io(fd 3, revents 4): 113 ftp_client_pipe_t::handle_io(fd 3, 4): state 1 114 ftp_client_pipe_t::handle_io: Connect dfd 4 succeeded 115 robouser_t::static_prePoll: user 0, ndfs 2 116 main:handling j 0 fd 3 revents 1 117 fdmap_t::fd2user(fd 3) 118 robouser0::static_handle_io(fd 3, revents 1): 119 ftp_client_pipe_t::handle_io(fd 3, 1): state 1 120 ftp_client_pipe_t::handle_io fd 3 got '150 Opening ASCII mode data connection for test.dat (2135 bytes).' 121 ftp_client_proto_t::giveInput: state: 9 oReady 0 status 150, ibuf: '150 Opening ASCII mode data connection for test.dat (2135 bytes).' 122 ftp_client_proto_t::giveInput::RETR in progress 123 robouser_t::static_prePoll: user 0, ndfs 2 124 main:handling j 1 fd 4 revents 1 125 fdmap_t::fd2user(fd 4) 126 robouser0::static_handle_io(fd 4, revents 1): 127 ftp_client_pipe_t::handle_io(fd 4, 1): state 1 128 ftp_client_pipe_t::handle_io: calling subclass 129 robouser0::handle_data_io: fd 4, revents 1; read 1500 bytes 130 ftp_client_pipe_t::handle_io: dfd 4 read 1500 bytes, won't read again for 41 ticks 131 robouser_t::static_prePoll: user 0, ndfs 2 132 main:handling j 1 fd 4 revents 1 133 fdmap_t::fd2user(fd 4) 134 robouser0::static_handle_io(fd 4, revents 1): 135 ftp_client_pipe_t::handle_io(fd 4, 1): state 1 136 ftp_client_pipe_t::handle_io: dfd 4 still needs to snooze for 41 ticks 137 Sked::addClient(0x806c284, 3257851) 138 ftp_client_pipe_t::handle_io: dfd 4 asleep; revents 1, m_dfd_events 1 139 robouser_t::static_prePoll: user 0, ndfs 2 140 main:handling j 0 fd 3 revents 1 141 fdmap_t::fd2user(fd 3) 142 robouser0::static_handle_io(fd 3, revents 1): 143 ftp_client_pipe_t::handle_io(fd 3, 1): state 2 144 ftp_client_pipe_t::handle_io fd 3 got '226 Transfer complete.' 145 ftp_client_proto_t::giveInput: state: 9 oReady 0 status 226, ibuf: '226 Transfer complete.' 146 ftp_client_proto_t::giveInput::RETR server finished, 226 Transfer complete. 147 ftp_client_proto_t::setState: line 286: m_state was 9, now 5 148 ftp_client_pipe_t::handle_io:notify_app: status 226, dfd_conn 0, dfd 4 149 ftp_client_pipe_t::handle_io:notify_app: status 226, connecting 0, dfd 4, so no notification yet 150 robouser_t::static_prePoll: user 0, ndfs 2 151 Sked::pop: clearing skc 0x806c284 ->skedIndex 152 ftp_client_pipe_t::handle_io(fd 4, 1): state 1 153 ftp_client_pipe_t::handle_io: calling subclass 154 robouser0::handle_data_io: fd 4, revents 1; read 690 bytes 155 ftp_client_pipe_t::handle_io: dfd 4 read 714 bytes, won't read again for 19 ticks 156 robouser_t::static_prePoll: user 0, ndfs 2 157 main:handling j 1 fd 4 revents 10 158 fdmap_t::fd2user(fd 4) 159 robouser0::static_handle_io(fd 4, revents 10): 160 ftp_client_pipe_t::handle_io(fd 4, 10): state 1 161 ftp_client_pipe_t::handle_io: closing dfd 4 162 Sked::delClient: index 0, m_used 0 163 robouser0::unwatchfd 4 164 fdmap_t::del(fd 4) 165 ftp_client_pipe_t::handle_io:notify_app: status 226, dfd_conn 0, dfd -1 166 ftp_client_pipe_t::handle_io:notify_app: calling ftpCmdDone(0, 226) 167 robouser0::ftpCmdDone: m_state 4 168 User0: fetching 2190 bytes took 0.430000 seconds, 5093 bytes per secondEventually, this page will provide a line-by-line analysis of the above trace. At the moment, you'll have to wade through it yourself, referring to the source code to see what printed out each line.