More than one samples seems enough.

[novacoin.git] / src / ntp.cpp

diff --git a/src/ntp.cpp b/src/ntp.cpp
index b069f39..84f3301 100644 (file)
--- a/src/ntp.cpp
+++ b/src/ntp.cpp
@@ -348,7 +348,7 @@ int64_t DoReq(SOCKET sockfd, socklen_t servlen, struct sockaddr cliaddr) {
     int len=48;
     int retcode = sendto(sockfd, (char *) msg, len, 0, &cliaddr, servlen);
     if (retcode < 0) {
-        printf("sendto() failed: %d", retcode);
+        printf("sendto() failed: %d\n", retcode);
         return -3;
     }
 
@@ -359,7 +359,7 @@ int64_t DoReq(SOCKET sockfd, socklen_t servlen, struct sockaddr cliaddr) {
 
     retcode = select(sockfd + 1, &fdset, NULL, NULL, &timeout);
     if (retcode <= 0) {
-        printf("recvfrom() error");
+        printf("recvfrom() error\n");
         return -4;
     }
 
@@ -424,6 +424,16 @@ void ThreadNtpSamples(void* parg) {
     // Maximum offset is 2 hours.
     const int64_t nMaxOffset = 7200;
 
+    printf("Trying to find NTP server at localhost...\n");
+
+    std::string strLocalHost = "127.0.0.1";
+    if (NtpGetTime(strLocalHost) == GetTime()) {
+        printf("There is NTP server active at localhost,  we don't need NTP thread.\n");
+
+        nNtpOffset = 0;
+        return;
+    }
+
     printf("ThreadNtpSamples started\n");
     vnThreadsRunning[THREAD_NTP]++;
 
@@ -439,14 +449,16 @@ void ThreadNtpSamples(void* parg) {
 
             if (abs64(nClockOffset) < nMaxOffset) {
                 // Everything seems right, remember new trusted offset.
+                printf("ThreadNtpSamples: new offset sample from %s, offset=%" PRId64 ".\n", strTrustedUpstream.c_str(), nClockOffset);
                 nNtpOffset = nClockOffset;
             }
             else {
-                // Something went wrong. Disable trusted offset sampling and wait 600 seconds.
+                // Something went wrong, disable trusted offset sampling.
                 nNtpOffset = INT64_MAX;
                 strTrustedUpstream = "localhost";
 
-                for (int i = 0; i < 600 && !fShutdown; i++) // Sleep for 5 minutes
+                int nSleepMinutes = 1 + GetRandInt(9); // Sleep for 1-10 minutes.
+                for (int i = 0; i < nSleepMinutes * 60 && !fShutdown; i++)
                     Sleep(1000);
 
                 continue;
@@ -461,17 +473,19 @@ void ThreadNtpSamples(void* parg) {
                 int64_t nClockOffset = NtpGetTime(ip) - GetTime();
 
                 if (abs64(nClockOffset) < nMaxOffset) { // Skip the deliberately wrong timestamps
+                    printf("ThreadNtpSamples: new offset sample from %s, offset=%" PRId64 ".\n", ip.ToString().c_str(), nClockOffset);
                     vTimeOffsets.input(nClockOffset);
                 }
             }
 
-            if (vTimeOffsets.size() > 2) {
+            if (vTimeOffsets.size() > 1) {
                 nNtpOffset = vTimeOffsets.median();
             }
             else {
-                // Not enough offsets yet, try again 300 seconds later.
+                // Not enough offsets yet, try to collect additional samples later.
                 nNtpOffset = INT64_MAX;
-                for (int i = 0; i < 300 && !fShutdown; i++) 
+                int nSleepMinutes = 1 + GetRandInt(4); // Sleep for 1-5 minutes.
+                for (int i = 0; i < nSleepMinutes * 60 && !fShutdown; i++) 
                     Sleep(1000);
                 continue;
             }
@@ -479,7 +493,8 @@ void ThreadNtpSamples(void* parg) {
 
         printf("nNtpOffset = %+" PRId64 "  (%+" PRId64 " minutes)\n", nNtpOffset, nNtpOffset/60);
 
-        for (int i = 0; i < 43200 && !fShutdown; i++) // Sleep for 12 hours
+        int nSleepHours = 1 + GetRandInt(5); // Sleep for 1-6 hours.
+        for (int i = 0; i < nSleepHours * 3600 && !fShutdown; i++)
             Sleep(1000);
     }