From b99194f5fac913d745f9af3b9b7c24ad6a032c1a Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Wed, 24 May 2017 18:12:14 +0200
Subject: Some more TFTP upload robustness work

---
 bbot/agent.cli           |  4 ++--
 bbot/agent.cxx           | 48 +++++++++++++++++++++++++++---------------------
 bbot/bbot-agent@.service |  2 +-
 3 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/bbot/agent.cli b/bbot/agent.cli
index b55379c..2f5ad65 100644
--- a/bbot/agent.cli
+++ b/bbot/agent.cli
@@ -106,11 +106,11 @@ namespace bbot
        by adding the toolchain number \c{--toolchain-num} to this value."
     }
 
-    size_t --bootstrap-timeout = 600
+    size_t --bootstrap-timeout = 900
     {
       "<sec>",
       "Maximum number of seconds to wait for machine bootstrap completion,
-       600 (10 minutes) by default."
+       900 (15 minutes) by default."
     }
 
     size_t --bootstrap-retries = 2
diff --git a/bbot/agent.cxx b/bbot/agent.cxx
index ac4905d..234763f 100644
--- a/bbot/agent.cxx
+++ b/bbot/agent.cxx
@@ -8,7 +8,7 @@
 #include <limits.h> // PATH_MAX
 #include <signal.h> // signal()
 #include <stdlib.h> // rand_r()
-#include <unistd.h> // sleep(), realink(), getuid()
+#include <unistd.h> // sleep(), realink(), getuid(), fsync()
 
 #include <net/if.h>     // ifreq
 #include <netinet/in.h> // sockaddr_in
@@ -53,6 +53,14 @@ namespace bbot
   string uname;
 }
 
+static void
+file_sync (const path& f)
+{
+  auto_fd fd (fdopen (f, fdopen_mode::in));
+  if (fsync (fd.get ()) != 0)
+    throw_system_error (errno);
+}
+
 // The btrfs tool likes to print informational messages, like "Created
 // snapshot such and such". Luckily, it writes them to stdout while proper
 // diagnostics to stderr.
@@ -211,20 +219,21 @@ bootstrap_machine (const dir_path& md,
         // our side we serve TFTP requests while periodically checking for the
         // manifest file.
         //
-        for (to = bootstrap_to;
-             to != 0 && (!file_exists (mf) || file_empty (mf));
-             tftpd.serve (to)) ;
+        for (to = bootstrap_to; to != 0; tftpd.serve (to))
+        {
+          if (file_exists (mf))
+          {
+            file_sync (mf);
+            if (!file_empty (mf))
+              break;
+          }
+        }
 
         if (to == 0)
           return soft_fail ("bootstrap timeout");
 
         l3 ([&]{trace << "completed bootstrap in " << bootstrap_to - to << "s";});
 
-        // The file may have been created but not yet (completely) uploaded.
-        // So we wait for a one second window without any TFTP activity.
-        //
-        while (tftpd.serve ((to = 1))) ;
-
         // Shut the machine down cleanly.
         //
         if (!m->shutdown ((to = shutdown_to)))
@@ -693,24 +702,21 @@ try
         // So on our side we serve TFTP requests while checking for the
         // manifest file.
         //
-        // There are seem to be some "anomalies" in the Windows network stack
-        // in that we get an empty file and then the upload process gets stuck
-        // for no apparent reason.
-        //
-        for (to = build_to;
-             to != 0 && (!file_exists (rf) || file_empty (rf));
-             tftpd.serve (to)) ;
+        for (to = build_to; to != 0; tftpd.serve (to))
+        {
+          if (file_exists (rf))
+          {
+            file_sync (rf);
+            if (!file_empty (rf))
+              break;
+          }
+        }
 
         if (to == 0)
           return soft_fail ("build timeout");
 
         l3 ([&]{trace << "completed build in " << build_to - to << "s";});
 
-        // The file may have been created but not yet (completely) uploaded.
-        // So we wait for a one second window without any TFTP activity.
-        //
-        while (tftpd.serve ((to = 1))) ;
-
         // Parse the result manifest.
         //
         try
diff --git a/bbot/bbot-agent@.service b/bbot/bbot-agent@.service
index 66d46f4..7d8c250 100644
--- a/bbot/bbot-agent@.service
+++ b/bbot/bbot-agent@.service
@@ -10,7 +10,7 @@ Environment=VERBOSE=3
 Environment=CPU=1
 Environment=RAM=1048576
 
-Environment=BOOTSTRAP_TIMEOUT=600
+Environment=BOOTSTRAP_TIMEOUT=900
 Environment=BOOTSTRAP_RETRIES=2
 Environment=BUILD_TIMEOUT=1800
 Environment=BUILD_RETRIES=2
-- 
cgit v1.1