[tracing] Implement polling in MemoryDumpManager

base/trace_event/memory_dump_scheduler.cc

Index: base/trace_event/memory_dump_scheduler.cc
diff --git a/base/trace_event/memory_dump_scheduler.cc b/base/trace_event/memory_dump_scheduler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9b9933b1c986c976dcb107d70e17d118bd63c13b
--- /dev/null
+++ b/base/trace_event/memory_dump_scheduler.cc
@@ -0,0 +1,222 @@
+// Copyright 2017 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 "base/trace_event/memory_dump_scheduler.h"
+
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/trace_event/memory_dump_manager.h"
+#include "build/build_config.h"
+
+namespace base {
+namespace trace_event {
+
+namespace {
+// Threshold on increase in memory from last dump beyond which a new dump must
+// be triggered.
+int64_t kMemoryIncreaseThreshold = 50 * 1024 * 1024;  // 50MiB
+const uint32_t kMemoryTotalsPollingInterval = 25;
+uint32_t g_polling_interval_ms_for_testing = 0;
+}  // namespace
+
+MemoryDumpScheduler::MemoryDumpScheduler(
+    MemoryDumpManager* mdm,
+    scoped_refptr<SingleThreadTaskRunner> polling_task_runner)
+    : mdm_(mdm), polling_state_(polling_task_runner) {}
+
+MemoryDumpScheduler::~MemoryDumpScheduler() {}
+
+void MemoryDumpScheduler::AddTrigger(MemoryDumpType trigger_type,
+                                     MemoryDumpLevelOfDetail level_of_detail,
+                                     uint32_t min_time_between_dumps_ms) {
+  if (trigger_type == MemoryDumpType::PEAK_MEMORY_USAGE) {
+    DCHECK(!periodic_state_.is_configured);
+    DCHECK(!polling_state_.is_configured);
+    DCHECK_NE(0u, min_time_between_dumps_ms);
+
+    polling_state_.level_of_detail = level_of_detail;
+    polling_state_.min_polls_between_dumps =
+        (min_time_between_dumps_ms + polling_state_.polling_interval_ms - 1) /
+        polling_state_.polling_interval_ms;
+    polling_state_.is_configured = true;
+  } else if (trigger_type == MemoryDumpType::PERIODIC_INTERVAL) {
+    DCHECK(!polling_state_.is_configured);
+    periodic_state_.is_configured = true;
+    DCHECK_NE(0u, min_time_between_dumps_ms);
+    switch (level_of_detail) {
+      case MemoryDumpLevelOfDetail::BACKGROUND:
+        break;
+      case MemoryDumpLevelOfDetail::LIGHT:
+        DCHECK_EQ(0u, periodic_state_.light_dump_period_ms);
+        periodic_state_.light_dump_period_ms = min_time_between_dumps_ms;
+        break;
+      case MemoryDumpLevelOfDetail::DETAILED:
+        DCHECK_EQ(0u, periodic_state_.heavy_dump_period_ms);
+        periodic_state_.heavy_dump_period_ms = min_time_between_dumps_ms;
+        break;
+    }
+
+    periodic_state_.min_timer_period_ms = std::min(
+        periodic_state_.min_timer_period_ms, min_time_between_dumps_ms);
+    DCHECK_EQ(0u, periodic_state_.light_dump_period_ms %
+                      periodic_state_.min_timer_period_ms);
+    DCHECK_EQ(0u, periodic_state_.heavy_dump_period_ms %
+                      periodic_state_.min_timer_period_ms);
+  }
+}
+
+void MemoryDumpScheduler::NotifyPeriodicTriggerSupported() {
+  if (!periodic_state_.is_configured || periodic_state_.timer.IsRunning())
+    return;
+  periodic_state_.light_dumps_rate = periodic_state_.light_dump_period_ms /
+                                     periodic_state_.min_timer_period_ms;
+  periodic_state_.heavy_dumps_rate = periodic_state_.heavy_dump_period_ms /
+                                     periodic_state_.min_timer_period_ms;
+
+  periodic_state_.dump_count = 0;
+  periodic_state_.timer.Start(
+      FROM_HERE,
+      TimeDelta::FromMilliseconds(periodic_state_.min_timer_period_ms),
+      Bind(&MemoryDumpScheduler::RequestPeriodicGlobalDump, Unretained(this)));
+}
+
+void MemoryDumpScheduler::NotifyPollingSupported() {
+  if (!polling_state_.is_configured || polling_state_.is_polling_enabled)
+    return;
+  polling_state_.is_polling_enabled = true;
+  polling_state_.num_polls_from_last_dump = 0;
+  polling_state_.last_dump_memory_total = 0;
+  polling_state_.polling_task_runner->PostTask(
+      FROM_HERE,
+      Bind(&MemoryDumpScheduler::PollMemoryOnPollingThread, Unretained(this)));
+}
+
+void MemoryDumpScheduler::DisableAllTriggers() {
+  if (periodic_state_.timer.IsRunning())
+    periodic_state_.timer.Stop();
+  DisablePolling();
+}
+
+void MemoryDumpScheduler::DisablePolling() {
+  if (ThreadTaskRunnerHandle::Get() != polling_state_.polling_task_runner) {
+    if (polling_state_.polling_task_runner->PostTask(
+            FROM_HERE,
+            Bind(&MemoryDumpScheduler::DisablePolling, Unretained(this))))
+      return;
+  }
+  polling_state_.is_polling_enabled = false;
+  polling_state_.is_configured = false;
+  polling_state_.polling_task_runner = nullptr;
+}
+
+// static
+void MemoryDumpScheduler::SetPollingIntervalForTesting(uint32_t interval) {
+  g_polling_interval_ms_for_testing = interval;
+}
+
+bool MemoryDumpScheduler::IsPeriodicTimerRunningForTesting() {
+  return periodic_state_.timer.IsRunning();
+}
+
+void MemoryDumpScheduler::RequestPeriodicGlobalDump() {
+  MemoryDumpLevelOfDetail level_of_detail = MemoryDumpLevelOfDetail::BACKGROUND;
+  if (periodic_state_.light_dumps_rate > 0 &&
+      periodic_state_.dump_count % periodic_state_.light_dumps_rate == 0)
+    level_of_detail = MemoryDumpLevelOfDetail::LIGHT;
+  if (periodic_state_.heavy_dumps_rate > 0 &&
+      periodic_state_.dump_count % periodic_state_.heavy_dumps_rate == 0)
+    level_of_detail = MemoryDumpLevelOfDetail::DETAILED;
+  ++periodic_state_.dump_count;
+
+  mdm_->RequestGlobalDump(MemoryDumpType::PERIODIC_INTERVAL, level_of_detail);
+}
+
+void MemoryDumpScheduler::PollMemoryOnPollingThread() {
+  if (!polling_state_.is_configured)
+    return;
+
+  uint64_t polled_memory = 0;
+  bool res = mdm_->PollFastMemoryTotal(&polled_memory);
+  DCHECK(res);
+  if (polling_state_.level_of_detail == MemoryDumpLevelOfDetail::DETAILED) {
+    TRACE_COUNTER1(MemoryDumpManager::kTraceCategory, "PolledMemoryMB",
+                   polled_memory / 1024 / 1024);
+  }
+
+  if (ShouldTriggerDump(polled_memory)) {
+    TRACE_EVENT_INSTANT1(MemoryDumpManager::kTraceCategory,
+                         "Peak memory dump Triggered",
+                         TRACE_EVENT_SCOPE_PROCESS, "total_usage_MB",
+                         polled_memory / 1024 / 1024);
+
+    mdm_->RequestGlobalDump(MemoryDumpType::PEAK_MEMORY_USAGE,
+                            polling_state_.level_of_detail);
+  }
+
+  // TODO(ssid): Use RequestSchedulerCallback, crbug.com/607533.
+  ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE,
+      Bind(&MemoryDumpScheduler::PollMemoryOnPollingThread, Unretained(this)),
+      TimeDelta::FromMilliseconds(polling_state_.polling_interval_ms));
+}
+
+bool MemoryDumpScheduler::ShouldTriggerDump(uint64_t current_memory_total) {
+  // This function tries to detect peak memory usage as discussed in
+  // https://goo.gl/0kOU4A.
+
+  if (current_memory_total == 0)
+    return false;
+
+  bool should_dump = false;
+  ++polling_state_.num_polls_from_last_dump;
+  if (polling_state_.last_dump_memory_total == 0) {
+    // If it's first sample then trigger memory dump.
+    should_dump = true;
+  } else if (polling_state_.min_polls_between_dumps >
+             polling_state_.num_polls_from_last_dump) {
+    return false;
+  }
+
+  int64_t increase_from_last_dump =
+      current_memory_total - polling_state_.last_dump_memory_total;
+  should_dump |= increase_from_last_dump > kMemoryIncreaseThreshold;
+  if (should_dump) {
+    polling_state_.last_dump_memory_total = current_memory_total;
+    polling_state_.num_polls_from_last_dump = 0;
+  }
+  return should_dump;
+}
+
+MemoryDumpScheduler::PeriodicTriggerState::PeriodicTriggerState()
+    : is_configured(false),
+      dump_count(0),
+      min_timer_period_ms(std::numeric_limits<uint32_t>::max()),
+      light_dumps_rate(0),
+      heavy_dumps_rate(0),
+      light_dump_period_ms(0),
+      heavy_dump_period_ms(0) {}
+
+MemoryDumpScheduler::PeriodicTriggerState::~PeriodicTriggerState() {
+  DCHECK(!timer.IsRunning());
+}
+
+MemoryDumpScheduler::PollingTriggerState::PollingTriggerState(
+    scoped_refptr<SingleThreadTaskRunner> polling_task_runner)
+    : is_configured(false),
+      is_polling_enabled(false),
+      level_of_detail(MemoryDumpLevelOfDetail::FIRST),
+      polling_task_runner(polling_task_runner),
+      polling_interval_ms(g_polling_interval_ms_for_testing
+                              ? g_polling_interval_ms_for_testing
+                              : kMemoryTotalsPollingInterval),
+      min_polls_between_dumps(0),
+      num_polls_from_last_dump(0),
+      last_dump_memory_total(0) {}
+
+MemoryDumpScheduler::PollingTriggerState::~PollingTriggerState() {
+  DCHECK(!polling_task_runner);
+}
+
+}  // namespace trace_event
+}  // namespace base