Fix public issue #29: Write CPU timing code for Windows, based on GetProcessTimes()

instead of getursage().

I thought I'd already committed this patch, so that the 1.0.1 release already
would have a Windows-compatible snappy_unittest, but I'd seemingly deleted it
instead, so this is a reconstruction.

R=csilvers
DELTA=43  (39 added, 3 deleted, 1 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=1295


git-svn-id: https://snappy.googlecode.com/svn/trunk@28 03e5f5b5-db94-4691-08a0-1a8bf15f6143

configure.ac

@@ -18,7 +18,7 @@ AC_SUBST([LIBTOOL_DEPS])
 AC_PROG_CXX
 AC_LANG([C++])
 AC_C_BIGENDIAN
-AC_CHECK_HEADERS([stdint.h stddef.h sys/mman.h])
+AC_CHECK_HEADERS([stdint.h stddef.h sys/mman.h sys/resource.h windows.h])
 
 # Don't use AC_FUNC_MMAP, as it checks for mappings of already-mapped memory,
 # which we don't need (and does not exist on Windows).

snappy-test.cc

@@ -30,6 +30,10 @@
 
 #include "snappy-test.h"
 
+#ifdef HAVE_WINDOWS_H
+#include <windows.h>
+#endif
+
 #include <algorithm>
 
 DEFINE_bool(run_microbenchmarks, true,
@@ -64,20 +68,31 @@ int64 benchmark_cpu_time_us = 0;
 string *benchmark_label = NULL;
 int64 benchmark_bytes_processed = 0;
 
-struct timeval benchmark_start_real;
-struct rusage benchmark_start_cpu;
-
 void ResetBenchmarkTiming() {
   benchmark_real_time_us = 0;
   benchmark_cpu_time_us = 0;
 }
 
+struct timeval benchmark_start_real;
+
+#ifdef WIN32
+FILETIME benchmark_start_cpu;
+#else  // WIN32
+struct rusage benchmark_start_cpu;
+#endif  // WIN32
+
 void StartBenchmarkTiming() {
   gettimeofday(&benchmark_start_real, NULL);
+#ifdef WIN32
+  FILETIME dummy;
+  CHECK(GetProcessTimes(
+      GetCurrentProcess(), &dummy, &dummy, &dummy, &benchmark_start_cpu));
+#else
   if (getrusage(RUSAGE_SELF, &benchmark_start_cpu) == -1) {
     perror("getrusage(RUSAGE_SELF)");
     exit(1);
   }
+#endif
   benchmark_running = true;
 }
 
@@ -92,6 +107,22 @@ void StopBenchmarkTiming() {
   benchmark_real_time_us +=
       (benchmark_stop_real.tv_usec - benchmark_start_real.tv_usec);
 
+#ifdef WIN32
+  FILETIME benchmark_stop_cpu, dummy;
+  CHECK(GetProcessTimes(
+      GetCurrentProcess(), &dummy, &dummy, &dummy, &benchmark_stop_cpu));
+
+  ULARGE_INTEGER start_ulargeint;
+  start_ulargeint.LowPart = benchmark_start_cpu.dwLowDateTime;
+  start_ulargeint.HighPart = benchmark_start_cpu.dwHighDateTime;
+
+  ULARGE_INTEGER stop_ulargeint;
+  stop_ulargeint.LowPart = benchmark_stop_cpu.dwLowDateTime;
+  stop_ulargeint.HighPart = benchmark_stop_cpu.dwHighDateTime;
+
+  benchmark_cpu_time_us +=
+      (stop_ulargeint.QuadPart - start_ulargeint.QuadPart + 5) / 10;
+#else  // WIN32
   struct rusage benchmark_stop_cpu;
   if (getrusage(RUSAGE_SELF, &benchmark_stop_cpu) == -1) {
     perror("getrusage(RUSAGE_SELF)");
@@ -101,6 +132,8 @@ void StopBenchmarkTiming() {
                                       benchmark_start_cpu.ru_utime.tv_sec);
   benchmark_cpu_time_us += (benchmark_stop_cpu.ru_utime.tv_usec -
                             benchmark_start_cpu.ru_utime.tv_usec);
+#endif  // WIN32
+
   benchmark_running = false;
 }
 

snappy-test.h

@@ -40,7 +40,10 @@
 #include <sys/mman.h>
 #endif
 
+#ifdef HAVE_SYS_RESOURCE_H
 #include <sys/resource.h>
+#endif
+
 #include <sys/time.h>
 
 #include <string>