TODO: add some notes for future work.

[loba.git] / process.cpp

diff --git a/process.cpp b/process.cpp
index d1576cef6f6330589d79edaec9d2e7a396045163..e77217686c25ac7ff6961282fac698c8008d9263 100644 (file)
--- a/process.cpp
+++ b/process.cpp
@@ -1,111 +1,501 @@
 #include <algorithm>
 #include <algorithm>

+#include <cmath>

 #include <functional>
 #include <iterator>
 #include <functional>
 #include <iterator>

+#include <numeric>

 #include <stdexcept>
 #include <sstream>
 #include <xbt/log.h>
 #include <stdexcept>
 #include <sstream>
 #include <xbt/log.h>

+#include <xbt/time.h>
+
+XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(proc);
+

 #include "misc.h"
 #include "options.h"
 #include "misc.h"
 #include "options.h"

+#include "tracing.h"
+

 #include "process.h"
 
 #include "process.h"
 

-XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simu);
+double process::total_load_init = 0.0;
+double process::total_load_running = 0.0;
+double process::total_load_exit = 0.0;
+
+int process::process_counter = 0;
+double process::total_load_average;
+double process::load_diff_threshold;

 
 

-struct message {
-    double measure;
-    double transfer;
-};
+namespace {
+
+    void sleep_until_date(double& date, double duration)
+    {
+        double sleep_duration = date - MSG_get_clock();
+        if (sleep_duration > 0.0)
+            MSG_process_sleep(sleep_duration);
+        date = MSG_get_clock() + duration;
+    }
+
+}

 
 

-process::process(int argc, char *argv[])
+process::process(int argc, char* argv[])

 {
 {

-    if (argc < 2 || !(std::istringstream(argv[1]) >> load))
-        throw std::invalid_argument("bad or missing initial load");
+    if (argc < 2 || !(std::istringstream(argv[1]) >> real_load))
+        throw std::invalid_argument("bad or missing initial load parameter");
+
+    double iload = std::trunc(real_load);
+    if (opt::integer_transfer && real_load != iload) {
+        XBT_WARN("Initial load %g is not an integer.  Truncate it.",
+                 real_load);
+        real_load = iload;
+    }
+

     neigh.assign(argv + 2, argv + argc);
     neigh.assign(argv + 2, argv + argc);

+
+    pneigh.reserve(neigh.size());
+    for (unsigned i = 0 ; i < neigh.size() ; i++) {
+        neighbor* ptr = &neigh[i];
+        m_host_t host = MSG_get_host_by_name(ptr->get_name());
+        pneigh.push_back(ptr);
+        rev_neigh.insert(std::make_pair(host, ptr));
+    }
+
+    // Note: there should not be race condition with the current
+    // version of Simgrid, when updating the global variables.
+
+    prev_load_broadcast = -1;   // force sending of load on first send_all()
+    expected_load = real_load;
+    total_load_running += real_load;
+    total_load_init += real_load;
+    received_load = 0.0;
+
+    convergence = -1.0;
+
+    process_counter++;
+    total_load_average = total_load_running / process_counter;
+    load_diff_threshold = (opt::load_ratio_threshold +
+                           opt::avg_load_ratio * total_load_average) / 100.0;
+
+    ctrl_close_pending = data_close_pending = neigh.size();
+    close_received = false;
+    finalizing = false;
+
+    all_comp_iter = comp_iter = lb_iter = 0;
+
+    lb_thread = new_msg_thread("loba",
+                               std::bind(&process::load_balance_loop, this));
+

     e_xbt_log_priority_t logp = xbt_log_priority_verbose;
     if (!LOG_ISENABLED(logp))
         return;
     e_xbt_log_priority_t logp = xbt_log_priority_verbose;
     if (!LOG_ISENABLED(logp))
         return;

-    LOG1(logp, "My initial load is: %g", load);

     std::ostringstream oss;
     oss << neigh.size() << " neighbor";
     if (!neigh.empty()) {
     std::ostringstream oss;
     oss << neigh.size() << " neighbor";
     if (!neigh.empty()) {

-        oss << (neigh.size() > 1 ? "s: " : ": ");
+        oss << ESSE(neigh.size()) << ": ";

         std::transform(neigh.begin(), neigh.end() - 1,
         std::transform(neigh.begin(), neigh.end() - 1,

-                       std::ostream_iterator<std::string>(oss, ", "),
-                       std::mem_fun_ref(&neighbor::getName));
-        oss << neigh.back().getName();
+                       std::ostream_iterator<const char*>(oss, ", "),
+                       std::mem_fn(&neighbor::get_name));
+        oss << neigh.back().get_name();

     }
     }

-    LOG1(logp, "Got %s.", oss.str().c_str());
-    print_loads(logp);
+    XBT_LOG(logp, "Got %s.", oss.str().c_str());
+    print_loads(false, logp);
+}
+
+process::~process()
+{
+    delete lb_thread;
+    total_load_exit += real_load;
+    xbt_assert(received_load == 0.0,
+               "received_load is %g, but should be 0.0 !", received_load);
+    if (opt::log_rate < 0)
+        return;
+    XBT_INFO("Final load after %d:%d:%d iterations: %g",
+             lb_iter, comp_iter, all_comp_iter, real_load);
+    if (convergence >= 0.0)
+        XBT_INFO("Convergence within %g%% was achieved at time %g",
+                 opt::avg_load_ratio, convergence);
+    else
+        XBT_INFO("Convergence within %g%% was not achieved",
+                 opt::avg_load_ratio);
+    XBT_VERB("Expected load was: %g", expected_load);
+    XBT_VERB("Total computation for this process: %g", get_comp_amount());
+    print_loads(true, xbt_log_priority_debug);

 }
 
 int process::run()
 {
 }
 
 int process::run()
 {

-    INFO0("Coucou !");
+    if (opt::log_rate >= 0) {
+        XBT_INFO("Initial load: %g", real_load);
+        XBT_VERB("Initial expected load: %g", expected_load);
+    }
+    XBT_VERB("Starting...");
+    mutex.acquire();
+    lb_thread->start();
+    while (lb_iter <= opt::comp_iter_delay)
+        cond.wait(mutex);
+    mutex.release();
+    double sleep_duration = opt::comp_time_delay - MSG_get_clock();
+    if (sleep_duration > 0.0)
+        MSG_process_sleep(sleep_duration);
+    compute_loop();
+    lb_thread->wait();
+    XBT_VERB("Done.");
+    return 0;
+}
+
+void process::load_balance_loop()
+{
+    using std::placeholders::_1;

 
 

-    int n = 100;
-    while (n--) {
-        compute();
-        receive();
+    double next_iter_after_date = MSG_get_clock() + opt::min_lb_iter_duration;
+    while (still_running()) {
+        if (lb_iter == opt::comp_iter_delay) {
+            mutex.acquire();
+            ++lb_iter;
+            cond.signal();
+            mutex.release();
+        } else {
+            ++lb_iter;
+        }
+
+        ctrl_receive(0.0);
+
+        mutex.acquire();
+        if (!opt::bookkeeping)
+            expected_load = real_load - get_sum_of_to_send();
+        // nothing to do with opt::bookkeeping
+
+        if (opt::log_rate && lb_iter % opt::log_rate == 0) {
+            XBT_INFO("(%u:%u:%u) current load: %g",
+                     lb_iter, comp_iter, all_comp_iter, real_load);
+            XBT_VERB("... expected load: %g", expected_load);
+        }
+
+        if (expected_load > 0.0)
+            load_balance();
+
+        print_loads(true, xbt_log_priority_debug);
+
+        // send
+        comm.ctrl_flush(false);
+        std::for_each(neigh.begin(), neigh.end(),
+                      std::bind(&process::ctrl_send, this, _1));
+        prev_load_broadcast = expected_load;
+        mutex.release();
+
+        sleep_until_date(next_iter_after_date, opt::min_lb_iter_duration);

     }
     }

-    //    MSG_process_sleep(100.0);   // xxx
-    /* xxx:
-     * while (there is something to do) {
-     *    compute some task;
-     *    get received tasks;
-     *    compute load balancing;
-     *    send tasks to neighbors;
-     * }
-     */

 
 

-    /* Open Questions :
-     * - definition of load on heterogeneous hosts ?
-     * - how to detect convergence ?
-     * - how to manage link failures ?
-     */
+    XBT_VERB("Going to finalize for %s...", __func__);
+    XBT_DEBUG("send CTRL_CLOSE to %zu neighbor%s",
+              neigh.size(), ESSE(neigh.size()));
+    std::for_each(neigh.begin(), neigh.end(),
+                  std::bind(&process::ctrl_close, this, _1));
+    while (ctrl_close_pending) {
+        comm.ctrl_flush(false);
+        XBT_DEBUG("waiting for %d CTRL_CLOSE", ctrl_close_pending);
+        ctrl_receive(-1.0);
+    }
+    comm.ctrl_flush(true);
+}
+
+void process::compute_loop()
+{
+    using std::placeholders::_1;

 
 

-    // xxx: shall we retrieve pending tasks?
+    double next_iter_after_date = MSG_get_clock() + opt::min_comp_iter_duration;
+    while (still_running()) {
+        // receive (do not block if there is something to compute)
+        data_receive(real_load > 0.0 ? 0.0 : opt::min_comp_iter_duration);

 
 

-    return 0;
+        // send
+        comm.data_flush(false);
+        mutex.acquire();
+        real_load += received_load;
+        received_load = 0.0;
+        std::for_each(neigh.begin(), neigh.end(),
+                      std::bind(&process::data_send, this, _1));
+        mutex.release();
+
+        ++all_comp_iter;
+        if (real_load == 0.0)
+            continue;
+
+        convergence_check();
+
+        // compute
+        ++comp_iter;
+        double flops = opt::comp_cost(real_load);
+        m_task_t task = MSG_task_create("computation", flops, 0.0, NULL);
+        TRACE_msg_set_task_category(task, TRACE_CAT_COMP);
+        XBT_DEBUG("compute %g flop%s", flops, ESSE(flops));
+        MSG_task_execute(task);
+        add_comp_amount(flops);
+        MSG_task_destroy(task);
+
+        sleep_until_date(next_iter_after_date, opt::min_comp_iter_duration);
+    }
+
+    XBT_VERB("Going to finalize for %s...", __func__);
+    finalizing = true;
+    XBT_DEBUG("send DATA_CLOSE to %zu neighbor%s",
+              neigh.size(), ESSE(neigh.size()));
+    std::for_each(neigh.begin(), neigh.end(),
+                  std::bind(&process::data_close, this, _1));
+    while (data_close_pending) {
+        comm.data_flush(false);
+        XBT_DEBUG("waiting for %d DATA_CLOSE", data_close_pending);
+        data_receive(-1.0);
+    }
+    real_load += received_load;
+    received_load = 0.0;
+    total_load_running -= real_load;
+    convergence_check();
+    comm.data_flush(true);

 }
 
 }
 

-void process::receive()
+void process::convergence_check()

 {
 {

-    m_task_t task;
-    while ((task = comm.recv())) {
-        message *msg = (message *)MSG_task_get_data(task);
-        DEBUG3("Received load: %g, info: %g from %s",
-               msg->transfer, msg->measure,
-               MSG_host_get_name(MSG_task_get_source(task)));
-        load += msg->transfer;
-        // fixme: what is xxx ???
-        // neigh[xxx].setLoad(msg->measure);
+    double load_diff = std::fabs(real_load - total_load_average);
+    bool converged = load_diff <= load_diff_threshold;
+
+    if (convergence >= 0.0) {
+        if (!converged) {
+            XBT_VERB("current load has diverged: %g (%.4g%%)",
+                     real_load, 100.0 * load_diff / total_load_average);
+            convergence = -1.0;
+        }
+    } else {
+        if (converged) {
+            XBT_VERB("current load has converged: %g (%.4g%%)",
+                     real_load,  100.0 * load_diff / total_load_average);
+            convergence = MSG_get_clock();
+        }

     }
 }
 
     }
 }
 

-void process::compute()
+bool process::still_running()

 {
 {

-    double duration = opt::comp_cost(load);
-    m_task_t task = MSG_task_create("computation", duration, 0.0, NULL);
-    DEBUG2("Compute %g flop%s.", duration, duration > 1 ? "s" : "");
-    MSG_task_execute(task);
-    MSG_task_destroy(task);
+    static bool last_status = true;
+
+    if (!last_status) {
+        /* nop */
+
+    } else if (opt::exit_request) {
+        XBT_VERB("Global exit requested");
+        last_status = false;
+
+    } else if (opt::time_limit && MSG_get_clock() >= opt::time_limit) {
+        XBT_VERB("Reached time limit: %g/%g", MSG_get_clock(), opt::time_limit);
+        last_status = false;
+
+    } else if (opt::lb_maxiter && lb_iter >= opt::lb_maxiter) {
+        XBT_VERB("Reached lb_maxiter: %d/%d", lb_iter, opt::lb_maxiter);
+        last_status = false;
+
+    } else if (opt::comp_maxiter && comp_iter >= opt::comp_maxiter) {
+        XBT_VERB("Reached comp_maxiter: %d/%d", comp_iter, opt::comp_maxiter);
+        last_status = false;
+
+    } else if (opt::exit_on_close && close_received) {
+        XBT_VERB("Close received");
+        last_status = false;
+
+    } else if (real_load == 0.0 && !data_close_pending) {
+        XBT_VERB("I'm a poor lonesome process, and I have no load...");
+        last_status = false;
+
+    } else if (100.0 * total_load_running / total_load_init <=
+               opt::load_ratio_threshold) {
+        // fixme: this check should be implemented with a distributed
+        // algorithm, and not a shared global variable!
+        XBT_VERB("No more load to balance in system.");
+        last_status = false;
+    }
+
+    return last_status;

 }
 
 }
 

-void process::print_loads(e_xbt_log_priority_t logp)
+double process::get_sum_of_to_send() const

 {
 {

-    if (!LOG_ISENABLED(logp))
-        return;
-    std::ostringstream oss;
-    if (neigh.empty()) {
-        oss << "no neighbor!";
-    } else {
-        std::transform(neigh.begin(), neigh.end() - 1,
-                       std::ostream_iterator<double>(oss, ", "),
-                       std::mem_fun_ref(&neighbor::getLoad));
-        oss << neigh.back().getLoad();
+    using std::placeholders::_1;
+    using std::placeholders::_2;
+
+    return std::accumulate(neigh.begin(), neigh.end(), 0.0,
+                           std::bind(std::plus<double>(), _1,
+                                     std::bind(&neighbor::get_to_send, _2)));
+}
+
+void process::load_balance()
+{
+    if (lb_iter == 1)           // warn only once
+        XBT_WARN("process::load_balance() is a no-op!");
+}
+
+void process::send(neighbor& nb, double amount)
+{
+    expected_load -= amount;
+    nb.set_to_send(nb.get_to_send() + amount);
+    nb.set_load(nb.get_load() + amount);
+}
+
+void process::ctrl_send(neighbor& nb)
+{
+    double info_to_send = expected_load;
+    double debt_to_send;
+    if (opt::bookkeeping) {     // bookkeeping
+        debt_to_send = nb.get_to_send();
+        if (debt_to_send > 0.0) {
+            nb.set_to_send(0.0);
+            nb.set_debt(nb.get_debt() + debt_to_send);
+        }
+    } else {                    // !bookkeeping
+        debt_to_send = 0.0;
+    }
+    if (info_to_send != prev_load_broadcast || debt_to_send > 0.0) {
+        message* msg = new message(message::CTRL, info_to_send, debt_to_send);
+        add_ctrl_send_mesg(msg->get_size());
+        comm.ctrl_send(nb.get_ctrl_mbox(), msg);
+    }
+}
+
+double process::compute_load_to_send(double desired)
+{
+    if (opt::integer_transfer)
+        desired = std::floor(desired);
+    return desired >= opt::min_transfer_amount ? desired : 0.0;
+}
+
+void process::data_send(neighbor& nb)
+{
+    double load_to_send;
+    if (opt::bookkeeping) {     // bookkeeping
+        double excess_load;     // load amount we are able to send
+        if (opt::egocentric)
+            excess_load = std::max(0.0, real_load - expected_load);
+        else
+            excess_load = real_load;
+
+        double balance = nb.get_debt() - nb.get_credit();
+        load_to_send = std::min(excess_load,
+                                std::max(0.0, balance));
+
+        // adjust load to send (rounding, truncation, etc.)
+        load_to_send = compute_load_to_send(load_to_send);
+        if (load_to_send > 0.0)
+            nb.set_debt(nb.get_debt() - load_to_send);
+    } else {                    // !bookkeeping
+        load_to_send = compute_load_to_send(nb.get_to_send());
+        if (load_to_send > 0.0)
+            nb.set_to_send(nb.get_to_send() - load_to_send);
+    }
+    real_load -= load_to_send;
+    while (load_to_send > 0.0) {
+        double amount;
+        if (opt::max_transfer_amount)
+            amount = std::min(load_to_send, opt::max_transfer_amount);
+        else
+            amount = load_to_send;
+        message* msg = new message(message::DATA, amount);
+        add_data_send_mesg(msg->get_size());
+        comm.data_send(nb.get_data_mbox(), msg);
+        load_to_send -= amount;
+    }
+}
+
+void process::ctrl_close(neighbor& nb)
+{
+    comm.ctrl_send(nb.get_ctrl_mbox(), new message(message::CTRL_CLOSE, 0.0));
+}
+
+void process::data_close(neighbor& nb)
+{
+    comm.data_send(nb.get_data_mbox(), new message(message::DATA_CLOSE, 0.0));
+}
+
+void process::ctrl_receive(double timeout)
+{
+    message* msg;
+    m_host_t from;
+
+    XBT_DEBUG("%sblocking receive on ctrl (%g)", "\0non-" + !timeout, timeout);
+    while (ctrl_close_pending && comm.ctrl_recv(msg, from, timeout)) {
+        if (msg->get_type() != message::CTRL_CLOSE)
+            add_ctrl_recv_mesg(msg->get_size());
+        handle_message(msg, from);
+        timeout = 0.0;
+    }
+}
+
+void process::data_receive(double timeout)
+{
+    message* msg;
+    m_host_t from;
+
+    XBT_DEBUG("%sblocking receive on data (%g)", "\0non-" + !timeout, timeout);
+    while (data_close_pending && comm.data_recv(msg, from, timeout)) {
+        if (msg->get_type() != message::DATA_CLOSE)
+            add_data_recv_mesg(msg->get_size());
+        handle_message(msg, from);
+        timeout = 0.0;

     }
     }

-    LOG1(logp, "Neighbor loads: %s", oss.str().c_str());

 }
 
 }
 

+void process::handle_message(message* msg, m_host_t from)
+{
+    switch (msg->get_type()) {
+    case message::CTRL: {
+        neighbor* n = rev_neigh[from];
+        n->set_load(msg->get_amount() + n->get_to_send());
+        if (opt::bookkeeping) {
+            double credit = msg->get_credit();
+            expected_load += credit;
+            n->set_credit(n->get_credit() + credit);
+        }
+        break;
+    }
+    case message::DATA: {
+        neighbor* n = rev_neigh[from];
+        double ld = msg->get_amount();
+        received_load += ld;
+        n->set_credit(n->get_credit() - ld);
+        break;
+    }
+    case message::CTRL_CLOSE:
+        ctrl_close_pending--;
+        close_received = true;
+        break;
+    case message::DATA_CLOSE:
+        data_close_pending--;
+        close_received = true;
+        break;
+    }
+    delete msg;
+}
+
+#define print_loads_generic(vec, verbose, logp, cat)                    \
+    if (_XBT_LOG_ISENABLEDV((*cat), logp)) {                            \
+        using std::placeholders::_1;                                    \
+        XBT_XCLOG(cat, logp, "My load: %g (real); %g (expected).  "     \
+                  "Neighbor loads:", real_load, expected_load);         \
+        std::for_each(vec.begin(), vec.end(),                           \
+                      std::bind(&neighbor::print, _1, verbose, logp, cat)); \
+    } else ((void)0)
+
+void process::print_loads(bool verbose,
+                          e_xbt_log_priority_t logp,
+                          xbt_log_category_t cat) const
+{
+    print_loads_generic(neigh, verbose, logp, cat);
+}
+
+void process::print_loads_p(bool verbose,
+                            e_xbt_log_priority_t logp,
+                            xbt_log_category_t cat) const
+{
+    print_loads_generic(pneigh, verbose, logp, cat);
+}
+
+#undef print_loads_generic
+

 // Local variables:
 // mode: c++
 // End:
 // Local variables:
 // mode: c++
 // End: