[Android] Add ps_ext tool for tools-friendly cpu/mem/proc stats.

ps_ext is a simple ps-like tool, which generates a JSON dump containing
OS and processes stats. It is intended to be used by other tools, in
particular by the new memory_inspector (see related bug).

BUG=340294
R=pliard@chromium.org

Review URL: https://codereview.chromium.org/146803007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249686 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 217 insertions, 0 deletions

diff --git a/tools/android/ps_ext/ps_ext.c b/tools/android/ps_ext/ps_ext.c
new file mode 100644
index 0000000..caf6d88
--- /dev/null
+++ b/tools/android/ps_ext/ps_ext.c
@@ -0,0 +1,189 @@
+/*
+ * Copyright 2014 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <dirent.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+/*
+ * This tool is essentially an extended version of ps with JSON output.
+ * Its output is meant consumed by scripts / tools for gathering OS/ps stats.
+ * Output units:
+ *   All times are expressed in ticks.
+ *   All memory counters are expressed in Kb.
+ */
+
+#define CONV_PAGES_TO_KB(x) (x << (PAGE_SHIFT - 10))
+
+static void dump_time(void) {
+  struct timespec tm = {0, 0};
+  const long rate = sysconf(_SC_CLK_TCK);
+  clock_gettime(CLOCK_MONOTONIC, &tm);
+  const long ticks = rate * (tm.tv_sec * 1000L + tm.tv_nsec / 1000000) / 1000;
+  printf("  \"time\": { \"ticks\": %d, \"rate\": %d}", ticks, rate);
+}
+
+static void dump_cpu_stats(void) {
+  FILE *f = fopen("/proc/stat", "r");
+  if (!f)
+    return;
+  printf("  \"cpu\":\n  [\n");
+
+  bool terminate_prev_line = false;
+  while (!feof(f)) {
+    char line[256];
+    char cpu[8];
+    long unsigned t_usr = 0;
+    long unsigned t_nice = 0;
+    long unsigned t_sys = 0;
+    long unsigned t_idle = 0;
+    fgets(line, sizeof(line), f);
+
+    /* Skip the total 'cpu ' line and the other irrelevant ones. */
+    if (strncmp(line, "cpu", 3) != 0 || line[3] == ' ')
+      continue;
+    if (sscanf(line, "%s %lu %lu %lu %lu",
+               cpu, &t_usr, &t_nice, &t_sys, &t_idle) != 5) {
+      continue;
+    }
+
+    if (terminate_prev_line)
+      printf(",\n");
+    terminate_prev_line = true;
+    printf("    {\"usr\": %lu, \"sys\": %lu, \"idle\": %lu}",
+           t_usr + t_nice, t_sys, t_idle);
+  }
+  fclose(f);
+  printf("\n  ]");
+}
+
+static void dump_mem_stats(void) {
+  FILE *f = fopen("/proc/meminfo", "r");
+  if (!f)
+    return;
+  printf("  \"mem\":\n  {\n");
+
+  bool terminate_prev_line = false;
+  while (!feof(f)) {
+    char line[256];
+    char key[32];
+    long value = 0;
+
+    fgets(line, sizeof(line), f);
+    if (sscanf(line, "%s %lu %*s", key, &value) < 2)
+      continue;
+
+    if (terminate_prev_line)
+      printf(",\n");
+    terminate_prev_line = true;
+    printf("    \"%s\": %lu", key, value);
+  }
+  fclose(f);
+  printf("\n  }");
+}
+
+static void dump_proc_stats(void) {
+  struct dirent *de;
+  DIR *d = opendir("/proc");
+  if (!d)
+    return;
+
+  bool terminate_prev_line = false;
+  printf("  \"processes\":\n  [\n");
+  while ((de = readdir(d))) {
+    if (!isdigit(de->d_name[0]))
+      continue;
+    const int pid = atoi(de->d_name);
+
+    /* Don't print out ourselves (how civilized). */
+    if (pid == getpid())
+      continue;
+
+    char cmdline[64];
+    char fpath[32];
+    FILE *f;
+
+    /* Read full process path / package from cmdline. */
+    sprintf(fpath, "/proc/%d/cmdline", pid);
+    f = fopen(fpath, "r");
+    if (!f)
+      continue;
+    cmdline[0] = '\0';
+    fgets(cmdline, sizeof(cmdline), f);
+    fclose(f);
+
+    /* Read cpu/io/mem stats. */
+    char proc_name[256];
+    long num_threads = 0;
+    long unsigned min_faults = 0;
+    long unsigned maj_faults = 0;
+    long unsigned utime = 0;
+    long unsigned ktime = 0;
+    long unsigned vm_rss = 0;
+    long long unsigned start_time = 0;
+
+    sprintf(fpath, "/proc/%d/stat", pid);
+    f = fopen(fpath, "r");
+    if (!f)
+      continue;
+    fscanf(f, "%*d %s %*c %*d %*d %*d %*d %*d %*u %lu %*lu %lu %*lu %lu %lu "
+           "%*ld %*ld %*ld %*ld %ld %*ld %llu %*lu %ld", proc_name, &min_faults,
+           &maj_faults, &utime, &ktime, &num_threads, &start_time, &vm_rss);
+    fclose(f);
+
+    /* Prefer the cmdline when available, since it contains the package name. */
+    char const * const cmd = (strlen(cmdline) > 0) ? cmdline : proc_name;
+
+    if (terminate_prev_line)
+      printf(",\n");
+    terminate_prev_line = true;
+    printf("    {"
+           "\"pid\": %d, "
+           "\"name\": \"%s\", "
+           "\"n_threads\": %ld, "
+           "\"start_time\": %llu, "
+           "\"user_time\": %lu, "
+           "\"sys_time\": %lu, "
+           "\"min_faults\": %lu, "
+           "\"maj_faults\": %lu, "
+           "\"vm_rss\": %lu"
+           "}",
+           pid,
+           cmd,
+           num_threads,
+           start_time,
+           utime,
+           ktime,
+           min_faults,
+           maj_faults,
+           CONV_PAGES_TO_KB(vm_rss));
+  }
+  closedir(d);
+  printf("\n  ]");
+}
+
+int main()
+{
+  printf("{\n");
+
+  dump_time();
+  printf(",\n");
+
+  dump_mem_stats();
+  printf(",\n");
+
+  dump_cpu_stats();
+  printf(",\n");
+
+  dump_proc_stats();
+  printf("\n}\n");
+
+  return 0;
+}
diff --git a/tools/android/ps_ext/ps_ext.gyp b/tools/android/ps_ext/ps_ext.gyp
new file mode 100644
index 0000000..f1a24fe
--- /dev/null
+++ b/tools/android/ps_ext/ps_ext.gyp
@@ -0,0 +1,28 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'targets': [
+    {
+      'target_name': 'ps_ext',
+      'type': 'executable',
+      'conditions': [
+        # Warning: A PIE tool cannot run on ICS 4.0.4, so only
+        #          build it as position-independent when ASAN
+        #          is activated. See b/6587214 for details.
+        [ 'asan==1', {
+          'cflags': [
+            '-fPIE',
+          ],
+          'ldflags': [
+            '-pie',
+          ],
+        }],
+      ],
+      'sources': [
+        'ps_ext.c',
+      ],
+    },
+  ],
+}