Windows: [3/3] Used os::random.

Review: https://reviews.apache.org/r/47053/

src/executor/executor.cpp

@@ -485,7 +485,7 @@ class MesosProcess : public ProtobufProcess<MesosProcess>
 
     // Linearly backoff by picking a random duration between 0 and
     // `maxBackoff`.
-    Duration backoff = maxBackoff.get() * ((double) ::random() / RAND_MAX);
+    Duration backoff = maxBackoff.get() * ((double) os::random() / RAND_MAX);
 
     VLOG(1) << "Will retry connecting with the agent again in " << backoff;
 

src/log/consensus.cpp

@@ -27,6 +27,7 @@
 #include <stout/check.hpp>
 #include <stout/duration.hpp>
 #include <stout/lambda.hpp>
+#include <stout/os.hpp>
 #include <stout/nothing.hpp>
 #include <stout/foreach.hpp>
 
@@ -771,7 +772,7 @@ class FillProcess : public Process<FillProcess>
     // one proposer usually times out and wins before others wake up.
     // On the other hand, we want T to be as small as possible such
     // that we can reduce the wait time.
-    Duration d = T * (1.0 + (double) ::random() / RAND_MAX);
+    Duration d = T * (1.0 + (double) os::random() / RAND_MAX);
     delay(d, self(), &Self::runPromisePhase);
   }
 

src/log/recover.cpp

@@ -33,6 +33,7 @@
 #include <stout/lambda.hpp>
 #include <stout/none.hpp>
 #include <stout/option.hpp>
+#include <stout/os.hpp>
 
 #include "log/catchup.hpp"
 #include "log/recover.hpp"
@@ -332,7 +333,7 @@ class RecoverProtocolProcess : public Process<RecoverProtocolProcess>
       // likelihood of conflicts (i.e., a replica receives a recover
       // request while it is changing its status).
       static const Duration T = Milliseconds(500);
-      Duration d = T * (1.0 + (double) ::random() / RAND_MAX);
+      Duration d = T * (1.0 + (double) os::random() / RAND_MAX);
       VLOG(2) << "Didn't receive enough responses for recovery, retrying "
               << "in " << stringify(d);
 

src/log/tool/benchmark.cpp

@@ -31,6 +31,7 @@
 #include <stout/bytes.hpp>
 #include <stout/error.hpp>
 #include <stout/foreach.hpp>
+#include <stout/os.hpp>
 #include <stout/stopwatch.hpp>
 #include <stout/strings.hpp>
 #include <stout/os/read.hpp>
@@ -216,7 +217,7 @@ Try<Nothing> Benchmark::execute(int argc, char** argv)
     if (flags.type == "one") {
       data.push_back(string(sizes[i].bytes(), static_cast<char>(0xff)));
     } else if (flags.type == "random") {
-      data.push_back(string(sizes[i].bytes(), ::random() % 256));
+      data.push_back(string(sizes[i].bytes(), os::random() % 256));
     } else {
       data.push_back(string(sizes[i].bytes(), 0));
     }

src/sched/sched.cpp

@@ -811,7 +811,7 @@ class SchedulerProcess : public ProtobufProcess<SchedulerProcess>
     // Determine the delay for next attempt by picking a random
     // duration between 0 and 'maxBackoff'.
     // TODO(vinod): Use random numbers from <random> header.
-    Duration delay = maxBackoff * ((double) ::random() / RAND_MAX);
+    Duration delay = maxBackoff * ((double) os::random() / RAND_MAX);
 
     VLOG(1) << "Will retry registration in " << delay << " if necessary";
 

src/slave/slave.cpp

@@ -953,7 +953,7 @@ void Slave::detected(const Future<Option<MasterInfo>>& _master)
     // Wait for a random amount of time before authentication or
     // registration.
     Duration duration =
-      flags.registration_backoff_factor * ((double) ::random() / RAND_MAX);
+      flags.registration_backoff_factor * ((double) os::random() / RAND_MAX);
 
     if (credential.isSome()) {
       // Authenticate with the master.
@@ -1480,7 +1480,7 @@ void Slave::doReliableRegistration(Duration maxBackoff)
 
   // Determine the delay for next attempt by picking a random
   // duration between 0 and 'maxBackoff'.
-  Duration delay = maxBackoff * ((double) ::random() / RAND_MAX);
+  Duration delay = maxBackoff * ((double) os::random() / RAND_MAX);
 
   VLOG(1) << "Will retry registration in " << delay << " if necessary";