From 2a35666bfa88e8260add9b48b71762308a3710d2 Mon Sep 17 00:00:00 2001
From: Davi de Castro Reis <davi.reis@gmail.com>
Date: Mon, 24 Jan 2011 10:29:22 -0200
Subject: [PATCH] Add benchmarking code.

---
 src/Makefile.am      |   1 +
 src/cmph_benchmark.c | 103 +++++++++++++++++++++++++++++++++++++++++++
 src/cmph_benchmark.h |  20 +++++++++
 3 files changed, 124 insertions(+)
 create mode 100644 src/cmph_benchmark.c
 create mode 100644 src/cmph_benchmark.h

diff --git a/src/Makefile.am b/src/Makefile.am
index 40734e4..c44d832 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -23,6 +23,7 @@ libcmph_la_SOURCES =  hash.h hash.c \
 		      select.h select.c select_lookup_tables.h \
 		      compressed_seq.h compressed_seq.c \
 		      compressed_rank.h compressed_rank.c \
+		      cmph_benchmark.h cmph_benchmark.cc \
 		      cmph_time.h
 
 libcmph_la_LDFLAGS = -version-info 0:0:0
diff --git a/src/cmph_benchmark.c b/src/cmph_benchmark.c
new file mode 100644
index 0000000..9d7c9da
--- /dev/null
+++ b/src/cmph_benchmark.c
@@ -0,0 +1,103 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "cmph_benchmark.h"
+
+typedef struct {
+  const char* name;
+  void (*func)(int);
+  struct rusage begin;
+  struct rusage end;
+} benchmark_t;
+
+static benchmark_t* global_benchmarks = NULL;
+
+/* Subtract the `struct timeval' values X and Y,
+   storing the result in RESULT.
+   Return 1 if the difference is negative, otherwise 0.  */
+
+int timeval_subtract ( 
+    struct timeval *result, struct timeval *x, struct timeval* y) {
+  /* Perform the carry for the later subtraction by updating y. */
+  if (x->tv_usec < y->tv_usec) {
+    int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
+    y->tv_usec -= 1000000 * nsec;
+    y->tv_sec += nsec;
+  }
+  if (x->tv_usec - y->tv_usec > 1000000) {
+    int nsec = (x->tv_usec - y->tv_usec) / 1000000;
+    y->tv_usec += 1000000 * nsec;
+    y->tv_sec -= nsec;
+  }
+
+  /* Compute the time remaining to wait.
+     tv_usec is certainly positive. */
+  result->tv_sec = x->tv_sec - y->tv_sec;
+  result->tv_usec = x->tv_usec - y->tv_usec;
+
+  /* Return 1 if result is negative. */
+  return x->tv_sec < y->tv_sec;
+}
+
+benchmark_t* find_benchmark(const char* name) {
+  benchmark_t* benchmark = global_benchmarks;
+  while (benchmark->name != NULL) if (strcmp(benchmark->name, name) != 0) break;
+  if (!benchmark->name) return NULL;
+  return benchmark;
+}
+
+int global_benchmarks_length() {
+  benchmark_t* benchmark;
+  int length = 0;
+  if (global_benchmarks == 0) return 0;
+  benchmark = global_benchmarks;
+  while (benchmark->name != NULL) ++length;
+  return length;
+}
+
+void bm_register(const char* name, void (*func)(int), int iters) {
+  benchmark_t benchmark;
+  int length = global_benchmarks_length();
+  benchmark.name = name;
+  benchmark.func = func;
+  assert(!find_benchmark(name));
+  global_benchmarks = realloc(global_benchmarks, length + 1);
+  global_benchmarks[length] = benchmark;
+}
+
+void bm_start(const char* name) {
+  benchmark_t* benchmark;
+  struct rusage rs;
+
+  benchmark = find_benchmark(name);
+  int ret = getrusage(RUSAGE_SELF, &rs);  
+  if (ret != 0) {
+    perror("rusage failed");    
+    exit(-1);
+  }
+  benchmark->begin = rs;
+  (*benchmark->func)(1);
+}
+
+void bm_end(const char* name) { 
+  benchmark_t* benchmark;
+  struct rusage rs;
+
+  int ret = getrusage(RUSAGE_SELF, &rs);  
+  if (ret != 0) {
+    perror("rusage failed");    
+    exit(-1);
+  }
+
+  benchmark = find_benchmark(name);
+  benchmark->end = rs;
+
+  struct timeval utime;
+  timeval_subtract(&utime, &benchmark->end.ru_utime, &benchmark->begin.ru_utime);
+  struct timeval stime;
+  timeval_subtract(&stime, &benchmark->end.ru_stime, &benchmark->begin.ru_stime);
+  
+  printf("User cpu time used: %ld.%6ld\n", utime.tv_sec, utime.tv_usec);
+  printf("System cpu time used: %ld.%6ld\n", stime.tv_sec, stime.tv_usec);
+}
diff --git a/src/cmph_benchmark.h b/src/cmph_benchmark.h
new file mode 100644
index 0000000..f987ce1
--- /dev/null
+++ b/src/cmph_benchmark.h
@@ -0,0 +1,20 @@
+#ifndef __CMPH_BENCHMARK_H__
+#define __CMPH_BENCHMARK_H__
+
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+  
+#define BM_REGISTER(func, iters) bm_register(##func, func, iters);
+void bm_register(const char* name, void (*func)(int), int iters);
+void run_benchmarks(int argc, char** argv);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // __CMPH_BENCHMARK_H__