Add pssbench tool for benchmarking memory statisics collection.

Test: builds
Change-Id: Iced8c4d23d75adb3c3c69ae50252f7c376de56d4

2 files changed, 104 insertions, 0 deletions

diff --git a/pssbench/Android.mk b/pssbench/Android.mk
new file mode 100644
index 00000000..45bab557
--- /dev/null
+++ b/pssbench/Android.mk
@@ -0,0 +1,16 @@
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
+LOCAL_MODULE_PATH := $(TARGET_OUT_DATA)/local/tmp
+LOCAL_MODULE:= pssbench
+LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_CLASS := EXECUTABLES
+
+LOCAL_SRC_FILES += \
+	main.cpp \
+
+LOCAL_SHARED_LIBRARIES := \
+	libutils \
+	liblog \
+
+include $(BUILD_EXECUTABLE)
diff --git a/pssbench/main.cpp b/pssbench/main.cpp
new file mode 100644
index 00000000..160bf6cb
--- /dev/null
+++ b/pssbench/main.cpp
@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <string.h>
+#include <errno.h>
+
+const char* smaps_file = "smaps";
+bool verbose = false;
+int iterations = 1;
+int bufsz = -1;
+
+int64_t
+get_pss(int pid)
+{
+  char filename[64];
+  snprintf(filename, sizeof(filename), "/proc/%" PRId32 "/%s", pid,
+           smaps_file);
+  if (verbose)
+    fprintf(stderr, "smaps:[%s]\n", filename);
+
+  FILE * file = fopen(filename, "r");
+  if (!file) {
+    return (int64_t) -1;
+  }
+
+  if (bufsz >= 0) {
+    if (setvbuf(file, NULL, _IOFBF, bufsz)) {
+      fprintf(stderr, "setvbuf failed: %s\n", strerror(errno));
+      exit(1);
+    }
+  }
+
+  // Tally up all of the Pss from the various maps
+  char line[256];
+  int64_t pss = 0;
+  while (fgets(line, sizeof(line), file)) {
+    int64_t v;
+    if (sscanf(line, "Pss: %" SCNd64 " kB", &v) == 1) {
+      if (verbose)
+        fprintf(stderr, "pss line: %llu\n", (unsigned long long) v);
+      pss += v;
+    }
+  }
+
+  fclose(file);
+
+  // Return the Pss value in bytes, not kilobytes
+  return pss * 1024;
+}
+
+int
+main(int argc, char** argv)
+{
+  int c;
+  while ((c = getopt(argc, argv, "n:rvb:")) != -1) {
+    switch (c) {
+      case 'r':
+        smaps_file = "smaps_rollup";
+        break;
+      case 'v':
+        verbose = true;
+        break;
+      case 'n':
+        iterations = atoi(optarg);
+        break;
+      case 'b':
+        bufsz = atoi(optarg);
+        break;
+      default:
+        return 1;
+    }
+  }
+
+  if (argv[optind] == NULL) {
+    fprintf(stderr, "pssbench: no PID given\n");
+    return 1;
+  }
+  int pid = atoi(argv[optind]);
+  int64_t pss = 0;
+  for (int i = 0; i < iterations; ++i)
+    pss = get_pss(pid);
+  fflush(NULL);
+
+  printf("iterations:%d pid:%d pss:%lld\n", iterations, pid, (long long)pss);
+  return 0;
+}