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Test that GetPerformanceCounter() increments

This commit is contained in:
Pieter Wuille 2017-05-05 11:32:06 -07:00
parent f544094d5e
commit 33f853d8d8
1 changed files with 11 additions and 1 deletions
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12
src/random.cpp
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@ -17,6 +17,7 @@
#include <stdlib.h>
#include <limits>
#include <chrono>
#include <thread>
#ifndef WIN32
#include <sys/time.h>
@ -262,6 +263,8 @@ FastRandomContext::FastRandomContext(const uint256& seed) : requires_seed(false)
bool Random_SanityCheck()
{
uint64_t start = GetPerformanceCounter();
/* This does not measure the quality of randomness, but it does test that
* OSRandom() overwrites all 32 bytes of the output given a maximum
* number of tries.
@ -288,7 +291,14 @@ bool Random_SanityCheck()
tries += 1;
} while (num_overwritten < NUM_OS_RANDOM_BYTES && tries < MAX_TRIES);
return (num_overwritten == NUM_OS_RANDOM_BYTES); /* If this failed, bailed out after too many tries */
if (num_overwritten != NUM_OS_RANDOM_BYTES) return false; /* If this failed, bailed out after too many tries */
// Check that GetPerformanceCounter increases at least during a GetOSRand() call + 1ms sleep.
std::this_thread::sleep_for(std::chrono::milliseconds(1));
uint64_t stop = GetPerformanceCounter();
if (stop == start) return false;
return true;
}
FastRandomContext::FastRandomContext(bool fDeterministic) : requires_seed(!fDeterministic), bytebuf_size(0), bitbuf_size(0)