Move pg_test_timing from contrib/ to src/bin/

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

3 files changed, 216 insertions, 0 deletions

diff --git a/src/bin/pg_test_timing/.gitignore b/src/bin/pg_test_timing/.gitignore
new file mode 100644
index 00000000000..f6c664c7657
--- /dev/null
+++ b/src/bin/pg_test_timing/.gitignore
@@ -0,0 +1 @@
+/pg_test_timing
diff --git a/src/bin/pg_test_timing/Makefile b/src/bin/pg_test_timing/Makefile
new file mode 100644
index 00000000000..d1f35954f0f
--- /dev/null
+++ b/src/bin/pg_test_timing/Makefile
@@ -0,0 +1,27 @@
+# src/bin/pg_test_timing/Makefile
+
+PGFILEDESC = "pg_test_timing - test timing overhead"
+PGAPPICON = win32
+
+subdir = src/bin/pg_test_timing
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+
+OBJS = pg_test_timing.o $(WIN32RES)
+
+all: pg_test_timing
+
+pg_test_timing: $(OBJS) | submake-libpgport
+	$(CC) $(CFLAGS) $^ $(LDFLAGS) $(LDFLAGS_EX) $(LIBS) -o $@$(X)
+
+install: all installdirs
+	$(INSTALL_PROGRAM) pg_test_timing$(X) '$(DESTDIR)$(bindir)/pg_test_timing$(X)'
+
+installdirs:
+	$(MKDIR_P) '$(DESTDIR)$(bindir)'
+
+uninstall:
+	rm -f '$(DESTDIR)$(bindir)/pg_test_timing$(X)'
+
+clean distclean maintainer-clean:
+	rm -f pg_test_timing$(X) $(OBJS)
diff --git a/src/bin/pg_test_timing/pg_test_timing.c b/src/bin/pg_test_timing/pg_test_timing.c
new file mode 100644
index 00000000000..e5c11de6bb4
--- /dev/null
+++ b/src/bin/pg_test_timing/pg_test_timing.c
@@ -0,0 +1,188 @@
+/*
+ *	pg_test_timing.c
+ *		tests overhead of timing calls and their monotonicity:	that
+ *		they always move forward
+ */
+
+#include "postgres_fe.h"
+
+#include "getopt_long.h"
+#include "portability/instr_time.h"
+
+static const char *progname;
+
+static int32 test_duration = 3;
+
+static void handle_args(int argc, char *argv[]);
+static uint64 test_timing(int32);
+static void output(uint64 loop_count);
+
+/* record duration in powers of 2 microseconds */
+int64		histogram[32];
+
+int
+main(int argc, char *argv[])
+{
+	uint64		loop_count;
+
+	progname = get_progname(argv[0]);
+
+	handle_args(argc, argv);
+
+	loop_count = test_timing(test_duration);
+
+	output(loop_count);
+
+	return 0;
+}
+
+static void
+handle_args(int argc, char *argv[])
+{
+	static struct option long_options[] = {
+		{"duration", required_argument, NULL, 'd'},
+		{NULL, 0, NULL, 0}
+	};
+
+	int			option;			/* Command line option */
+	int			optindex = 0;	/* used by getopt_long */
+
+	if (argc > 1)
+	{
+		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
+		{
+			printf("Usage: %s [-d DURATION]\n", progname);
+			exit(0);
+		}
+		if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
+		{
+			puts("pg_test_timing (PostgreSQL) " PG_VERSION);
+			exit(0);
+		}
+	}
+
+	while ((option = getopt_long(argc, argv, "d:",
+								 long_options, &optindex)) != -1)
+	{
+		switch (option)
+		{
+			case 'd':
+				test_duration = atoi(optarg);
+				break;
+
+			default:
+				fprintf(stderr, "Try \"%s --help\" for more information.\n",
+						progname);
+				exit(1);
+				break;
+		}
+	}
+
+	if (argc > optind)
+	{
+		fprintf(stderr,
+				"%s: too many command-line arguments (first is \"%s\")\n",
+				progname, argv[optind]);
+		fprintf(stderr, "Try \"%s --help\" for more information.\n",
+				progname);
+		exit(1);
+	}
+
+	if (test_duration > 0)
+	{
+		printf("Testing timing overhead for %d seconds.\n", test_duration);
+	}
+	else
+	{
+		fprintf(stderr,
+			"%s: duration must be a positive integer (duration is \"%d\")\n",
+				progname, test_duration);
+		fprintf(stderr, "Try \"%s --help\" for more information.\n",
+				progname);
+		exit(1);
+	}
+}
+
+static uint64
+test_timing(int32 duration)
+{
+	uint64		total_time;
+	int64		time_elapsed = 0;
+	uint64		loop_count = 0;
+	uint64		prev,
+				cur;
+	instr_time	start_time,
+				end_time,
+				temp;
+
+	total_time = duration > 0 ? duration * INT64CONST(1000000) : 0;
+
+	INSTR_TIME_SET_CURRENT(start_time);
+	cur = INSTR_TIME_GET_MICROSEC(start_time);
+
+	while (time_elapsed < total_time)
+	{
+		int32		diff,
+					bits = 0;
+
+		prev = cur;
+		INSTR_TIME_SET_CURRENT(temp);
+		cur = INSTR_TIME_GET_MICROSEC(temp);
+		diff = cur - prev;
+
+		/* Did time go backwards? */
+		if (diff < 0)
+		{
+			printf("Detected clock going backwards in time.\n");
+			printf("Time warp: %d microseconds\n", diff);
+			exit(1);
+		}
+
+		/* What is the highest bit in the time diff? */
+		while (diff)
+		{
+			diff >>= 1;
+			bits++;
+		}
+
+		/* Update appropriate duration bucket */
+		histogram[bits]++;
+
+		loop_count++;
+		INSTR_TIME_SUBTRACT(temp, start_time);
+		time_elapsed = INSTR_TIME_GET_MICROSEC(temp);
+	}
+
+	INSTR_TIME_SET_CURRENT(end_time);
+
+	INSTR_TIME_SUBTRACT(end_time, start_time);
+
+	printf("Per loop time including overhead: %0.2f nsec\n",
+		   INSTR_TIME_GET_DOUBLE(end_time) * 1e9 / loop_count);
+
+	return loop_count;
+}
+
+static void
+output(uint64 loop_count)
+{
+	int64		max_bit = 31,
+				i;
+
+	/* find highest bit value */
+	while (max_bit > 0 && histogram[max_bit] == 0)
+		max_bit--;
+
+	printf("Histogram of timing durations:\n");
+	printf("%6s   %10s %10s\n", "< usec", "% of total", "count");
+
+	for (i = 0; i <= max_bit; i++)
+	{
+		char		buf[100];
+
+		/* lame hack to work around INT64_FORMAT deficiencies */
+		snprintf(buf, sizeof(buf), INT64_FORMAT, histogram[i]);
+		printf("%6ld    %9.5f %10s\n", 1l << i,
+			   (double) histogram[i] * 100 / loop_count, buf);
+	}
+}