From 89028b1701faa4207fceaf015971c48a9e521feb Mon Sep 17 00:00:00 2001
From: Bruce Allen <bruce.allen@aei.mpg.de>
Date: Wed, 12 Jan 2005 21:04:25 +0000
Subject: [PATCH] Fixed two bugs, one trivial, the other nasty. Trivial bug,
 FPE on n % 0 when host has no files. Hard bug, in the deterministic search to
 find a new result that can be sent, the upwards search on name must be done
 not by comparing RESULT name to FILENAME, but instead by comparing result
 name to the maximal lexical resultname that can be constructed from the
 filename, which is filename_ZZZ...Z where Z==0xff.

svn path=/trunk/boinc/; revision=5085
---
 sched/sched_locality.C | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/sched/sched_locality.C b/sched/sched_locality.C
index f9162583a9..61d679cda5 100644
--- a/sched/sched_locality.C
+++ b/sched/sched_locality.C
@@ -261,9 +261,14 @@ static int send_results_for_file(
         if (retval) return retval;
     }
 
+
     nsent = 0;
     for (i=0; i<100; i++) {     // avoid infinite loop
         if (!wreq.work_needed(reply)) break;
+    
+        log_messages.printf(SCHED_MSG_LOG::DEBUG,
+            "in_send_results_for_file(%s) maxid=%d prev_result.id=%d\n", filename, maxid, prev_result.id
+        );
 
         // Use a transaction so that if we get a result,
         // someone else doesn't send it before we do
@@ -295,12 +300,19 @@ static int send_results_for_file(
             boinc_db.commit_transaction();
             if (!work_generator_invoked && config.locality_scheduling_wait_period) {
                 retval = make_more_work_for_file(filename);
+                log_messages.printf(SCHED_MSG_LOG::DEBUG,
+                    "make_more_work_for_file(%s, %d)=%d\n", filename, i, retval
+                );
+
                 if (retval) break;
                 work_generator_invoked = true;
             } else {
                 if (in_working_set) {
 		    if (work_generation_over(filename)) {
                         flag_for_possible_removal(filename);
+                        log_messages.printf(SCHED_MSG_LOG::DEBUG,
+                            "No remaining work for file %s, flagging for removal\n", filename
+                        );
 		    } else {
 		    //  DAVID: if work generation is NOT over then we
 		    //  should invoke make_more_work_for_file(),
@@ -359,19 +371,27 @@ static int send_new_file_work_deterministic(
 
     strcpy(min_filename, "");
     while (1) {
+        int len;
         sprintf(query,
             "where server_state=%d and name>'%s' order by name limit 1",
             RESULT_SERVER_STATE_UNSENT, min_filename
         );
         retval = result.lookup(query);
-        if (retval) break;
+        if (retval) break; // no more unsent results, return -1
         retval = extract_filename(result.name, filename);
-        if (retval) return retval;
+        if (retval) return retval; // not locality scheduled, now what???
         retval = send_results_for_file(
             filename, nsent, sreq, reply, platform, wreq, ss, false
         );
-        if (nsent>0) break;
-        strcpy(min_filename, filename);
+        if (nsent>0) break; // agreed
+        strcpy(min_filename, filename); // logic bug here is that RESULT name and FILENAME are not same!
+	// construct the lexically maximum result name corresponding to given filename
+        strcat(min_filename,"__");
+        for (len=strlen(min_filename) ; len<255; len++)
+            min_filename[len]=0xff;  // DAVID: IS THIS MYSQL SORT ORDER FOR VARCHAR??. Probably
+                                     // 'Z' is safe, the question is, what's the 'max' mysql char?
+        min_filename[255]='\0';      // Also for varchar(254) do I want strlen()==254 or 255?
+
     }
     return 0;
 }
@@ -463,6 +483,8 @@ void send_work_locality(
     int nsent, nfiles, j, k;
 
     nfiles = (int) sreq.file_infos.size();
+    if (!nfiles)
+        nfiles=1;
     j = rand()%nfiles;
 
     // send old work if there is any