Consolidate the non-canonical epoch timers, like cpuid and Win32's

QueryPerformanceCounter, into an entropy source hres_timer. Its
results, if any, do not count as contributing entropy to the poll.

Convert the other (monotonic/fixed epoch) timers to a single function
get_nanoseconds_clock(), living in time.h, which statically chooses
the 'best' timer type (clock_gettime, gettimeofday, std::clock, in
that order depending on what is available). Add feature test macros
for clock_gettime and gettimeofday.

Remove the Timer class and timer.h. Remove the Timer& argument to the
algorithm benchmark function.

3 files changed, 21 insertions, 48 deletions

diff --git a/src/benchmark/benchmark.cpp b/src/benchmark/benchmark.cpp
index 41c9cd10c..69d3a40ec 100644
--- a/src/benchmark/benchmark.cpp
+++ b/src/benchmark/benchmark.cpp
@@ -11,6 +11,7 @@
 #include <botan/stream_cipher.h>
 #include <botan/hash.h>
 #include <botan/mac.h>
+#include <botan/time.h>
 #include <memory>
 
 namespace Botan {
@@ -21,19 +22,19 @@ namespace {
 * Benchmark BufferedComputation (hash or MAC)
 */
 std::pair<u64bit, u64bit> bench_buf_comp(BufferedComputation* buf_comp,
-                                         Timer& timer,
                                          u64bit nanoseconds_max,
                                          const byte buf[], u32bit buf_len)
    {
-   const u64bit start = timer.clock();
-   u64bit nanoseconds_used = 0;
    u64bit reps = 0;
 
+   const u64bit start = get_nanoseconds_clock();
+   u64bit nanoseconds_used = 0;
+
    while(nanoseconds_used < nanoseconds_max)
       {
       buf_comp->update(buf, buf_len);
       ++reps;
-      nanoseconds_used = timer.clock() - start;
+      nanoseconds_used = get_nanoseconds_clock() - start;
       }
 
    return std::make_pair(reps * buf_len, nanoseconds_used);
@@ -44,15 +45,15 @@ std::pair<u64bit, u64bit> bench_buf_comp(BufferedComputation* buf_comp,
 */
 std::pair<u64bit, u64bit>
 bench_block_cipher(BlockCipher* block_cipher,
-                   Timer& timer,
                    u64bit nanoseconds_max,
                    byte buf[], u32bit buf_len)
    {
-   const u64bit start = timer.clock();
-   u64bit nanoseconds_used = 0;
+   const u32bit in_blocks = buf_len / block_cipher->BLOCK_SIZE;
+
    u64bit reps = 0;
 
-   const u32bit in_blocks = buf_len / block_cipher->BLOCK_SIZE;
+   const u64bit start = get_nanoseconds_clock();
+   u64bit nanoseconds_used = 0;
 
    block_cipher->set_key(buf, block_cipher->MAXIMUM_KEYLENGTH);
 
@@ -61,7 +62,7 @@ bench_block_cipher(BlockCipher* block_cipher,
       block_cipher->encrypt_n(buf, buf, in_blocks);
 
       ++reps;
-      nanoseconds_used = timer.clock() - start;
+      nanoseconds_used = get_nanoseconds_clock() - start;
       }
 
    return std::make_pair(reps * in_blocks * block_cipher->BLOCK_SIZE,
@@ -73,21 +74,21 @@ bench_block_cipher(BlockCipher* block_cipher,
 */
 std::pair<u64bit, u64bit>
 bench_stream_cipher(StreamCipher* stream_cipher,
-                    Timer& timer,
                     u64bit nanoseconds_max,
                     byte buf[], u32bit buf_len)
    {
-   const u64bit start = timer.clock();
-   u64bit nanoseconds_used = 0;
    u64bit reps = 0;
 
+   const u64bit start = get_nanoseconds_clock();
+   u64bit nanoseconds_used = 0;
+
    stream_cipher->set_key(buf, stream_cipher->MAXIMUM_KEYLENGTH);
 
    while(nanoseconds_used < nanoseconds_max)
       {
       stream_cipher->cipher1(buf, buf_len);
       ++reps;
-      nanoseconds_used = timer.clock() - start;
+      nanoseconds_used = get_nanoseconds_clock() - start;
       }
 
    return std::make_pair(reps * buf_len, nanoseconds_used);
@@ -97,11 +98,11 @@ bench_stream_cipher(StreamCipher* stream_cipher,
 * Benchmark hash
 */
 std::pair<u64bit, u64bit>
-bench_hash(HashFunction* hash, Timer& timer,
+bench_hash(HashFunction* hash,
            u64bit nanoseconds_max,
            const byte buf[], u32bit buf_len)
    {
-   return bench_buf_comp(hash, timer, nanoseconds_max, buf, buf_len);
+   return bench_buf_comp(hash, nanoseconds_max, buf, buf_len);
    }
 
 /**
@@ -109,12 +110,11 @@ bench_hash(HashFunction* hash, Timer& timer,
 */
 std::pair<u64bit, u64bit>
 bench_mac(MessageAuthenticationCode* mac,
-          Timer& timer,
           u64bit nanoseconds_max,
           const byte buf[], u32bit buf_len)
    {
    mac->set_key(buf, mac->MAXIMUM_KEYLENGTH);
-   return bench_buf_comp(mac, timer, nanoseconds_max, buf, buf_len);
+   return bench_buf_comp(mac, nanoseconds_max, buf, buf_len);
    }
 
 }
@@ -122,7 +122,6 @@ bench_mac(MessageAuthenticationCode* mac,
 std::map<std::string, double>
 algorithm_benchmark(const std::string& name,
                     u32bit milliseconds,
-                    Timer& timer,
                     RandomNumberGenerator& rng,
                     Algorithm_Factory& af)
    {
@@ -148,7 +147,7 @@ algorithm_benchmark(const std::string& name,
             af.prototype_block_cipher(name, provider))
          {
          std::auto_ptr<BlockCipher> block_cipher(proto->clone());
-         results = bench_block_cipher(block_cipher.get(), timer,
+         results = bench_block_cipher(block_cipher.get(),
                                       ns_per_provider,
                                       &buf[0], buf.size());
          }
@@ -156,7 +155,7 @@ algorithm_benchmark(const std::string& name,
                  af.prototype_stream_cipher(name, provider))
          {
          std::auto_ptr<StreamCipher> stream_cipher(proto->clone());
-         results = bench_stream_cipher(stream_cipher.get(), timer,
+         results = bench_stream_cipher(stream_cipher.get(),
                                        ns_per_provider,
                                        &buf[0], buf.size());
          }
@@ -164,14 +163,14 @@ algorithm_benchmark(const std::string& name,
                  af.prototype_hash_function(name, provider))
          {
          std::auto_ptr<HashFunction> hash(proto->clone());
-         results = bench_hash(hash.get(), timer, ns_per_provider,
+         results = bench_hash(hash.get(), ns_per_provider,
                               &buf[0], buf.size());
          }
       else if(const MessageAuthenticationCode* proto =
                  af.prototype_mac(name, provider))
          {
          std::auto_ptr<MessageAuthenticationCode> mac(proto->clone());
-         results = bench_mac(mac.get(), timer, ns_per_provider,
+         results = bench_mac(mac.get(), ns_per_provider,
                              &buf[0], buf.size());
          }
 
diff --git a/src/benchmark/benchmark.h b/src/benchmark/benchmark.h
index 1b2730105..9c4e410f1 100644
--- a/src/benchmark/benchmark.h
+++ b/src/benchmark/benchmark.h
@@ -9,40 +9,16 @@
 #define BOTAN_RUNTIME_BENCHMARK_H__
 
 #include <botan/algo_factory.h>
-#include <botan/timer.h>
 #include <botan/rng.h>
 #include <map>
 #include <string>
 
-/**
-* Choose some sort of default timer implementation to use, since some
-* (like hardware tick counters and current Win32 timer) are not
-* reliable for benchmarking.
-*/
-#if defined(BOTAN_HAS_TIMER_POSIX)
-  #include <botan/tm_posix.h>
-#elif defined(BOTAN_HAS_TIMER_UNIX)
-  #include <botan/tm_unix.h>
-#endif
-
 namespace Botan {
 
-#if defined(BOTAN_HAS_TIMER_POSIX)
-  typedef POSIX_Timer Default_Benchmark_Timer;
-#elif defined(BOTAN_HAS_TIMER_UNIX)
-  typedef Unix_Timer Default_Benchmark_Timer;
-#else
-   /* I have not had good success using clock(), the results seem
-    * pretty bogus, but as a last resort it works.
-    */
-  typedef ANSI_Clock_Timer Default_Benchmark_Timer;
-#endif
-
 /**
 * Algorithm benchmark
 * @param name the name of the algorithm to test (cipher, hash, or MAC)
 * @param milliseconds total time for the benchmark to run
-* @param timer the timer to use
 * @param rng the rng to use to generate random inputs
 * @param af the algorithm factory used to create objects
 * @return results a map from provider to speed in mebibytes per second
@@ -50,7 +26,6 @@ namespace Botan {
 std::map<std::string, double>
 BOTAN_DLL algorithm_benchmark(const std::string& name,
                               u32bit milliseconds,
-                              Timer& timer,
                               RandomNumberGenerator& rng,
                               Algorithm_Factory& af);
 
diff --git a/src/benchmark/info.txt b/src/benchmark/info.txt
index f148ae5ce..0210971f7 100644
--- a/src/benchmark/info.txt
+++ b/src/benchmark/info.txt
@@ -15,5 +15,4 @@ hash
 mac
 rng
 stream
-timer
 </requires>