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-rw-r--r--src/random.cpp17
-rw-r--r--src/random.h7
-rw-r--r--src/scheduler.cpp6
3 files changed, 30 insertions, 0 deletions
diff --git a/src/random.cpp b/src/random.cpp
index 3c856ecfa6..de7553c825 100644
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -203,6 +203,23 @@ void GetRandBytes(unsigned char* buf, int num)
}
}
+static void AddDataToRng(void* data, size_t len);
+
+void RandAddSeedSleep()
+{
+ int64_t nPerfCounter1 = GetPerformanceCounter();
+ std::this_thread::sleep_for(std::chrono::milliseconds(1));
+ int64_t nPerfCounter2 = GetPerformanceCounter();
+
+ // Combine with and update state
+ AddDataToRng(&nPerfCounter1, sizeof(nPerfCounter1));
+ AddDataToRng(&nPerfCounter2, sizeof(nPerfCounter2));
+
+ memory_cleanse(&nPerfCounter1, sizeof(nPerfCounter1));
+ memory_cleanse(&nPerfCounter2, sizeof(nPerfCounter2));
+}
+
+
static std::mutex cs_rng_state;
static unsigned char rng_state[32] = {0};
static uint64_t rng_counter = 0;
diff --git a/src/random.h b/src/random.h
index 9551e1c461..6a63d57429 100644
--- a/src/random.h
+++ b/src/random.h
@@ -24,6 +24,13 @@ int GetRandInt(int nMax);
uint256 GetRandHash();
/**
+ * Add a little bit of randomness to the output of GetStrongRangBytes.
+ * This sleeps for a millisecond, so should only be called when there is
+ * no other work to be done.
+ */
+void RandAddSeedSleep();
+
+/**
* Function to gather random data from multiple sources, failing whenever any
* of those source fail to provide a result.
*/
diff --git a/src/scheduler.cpp b/src/scheduler.cpp
index 0c1cfa2718..923ba2c231 100644
--- a/src/scheduler.cpp
+++ b/src/scheduler.cpp
@@ -4,6 +4,7 @@
#include "scheduler.h"
+#include "random.h"
#include "reverselock.h"
#include <assert.h>
@@ -39,6 +40,11 @@ void CScheduler::serviceQueue()
// is called.
while (!shouldStop()) {
try {
+ if (!shouldStop() && taskQueue.empty()) {
+ reverse_lock<boost::unique_lock<boost::mutex> > rlock(lock);
+ // Use this chance to get a tiny bit more entropy
+ RandAddSeedSleep();
+ }
while (!shouldStop() && taskQueue.empty()) {
// Wait until there is something to do.
newTaskScheduled.wait(lock);