memory-infra: Switch to MemoryPeakDetector and simplify MemoryDumpScheduler

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
index 91d70b78f9b7d3f79c6e8516faa1ec50850c87ff..17921959d38fe7275a37c73341569a8ba1622548 100644
--- a/base/trace_event/memory_dump_scheduler.cc
+++ b/base/trace_event/memory_dump_scheduler.cc
@@ -4,326 +4,109 @@
 
 #include "base/trace_event/memory_dump_scheduler.h"
 
-#include "base/process/process_metrics.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"
+#include <algorithm>
+#include <limits>
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/threading/sequenced_task_runner_handle.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 kDefaultMemoryIncreaseThreshold = 50 * 1024 * 1024;  // 50MiB
-const uint32_t kMemoryTotalsPollingInterval = 25;
-uint32_t g_polling_interval_ms_for_testing = 0;
-}  // namespace
-
 // static
 MemoryDumpScheduler* MemoryDumpScheduler::GetInstance() {
   static MemoryDumpScheduler* instance = new MemoryDumpScheduler();
   return instance;
 }
 
-MemoryDumpScheduler::MemoryDumpScheduler() : mdm_(nullptr), is_setup_(false) {}
-MemoryDumpScheduler::~MemoryDumpScheduler() {}
-
-void MemoryDumpScheduler::Setup(
-    MemoryDumpManager* mdm,
-    scoped_refptr<SingleThreadTaskRunner> polling_task_runner) {
-  mdm_ = mdm;
-  polling_task_runner_ = polling_task_runner;
-  periodic_state_.reset(new PeriodicTriggerState);
-  polling_state_.reset(new PollingTriggerState);
-  is_setup_ = true;
+MemoryDumpScheduler::MemoryDumpScheduler() : period_ms_(0), generation_(0) {}
+MemoryDumpScheduler::~MemoryDumpScheduler() {
+  // Hit only in tests. Check that tests don't leave without stopping.
+  DCHECK(!is_enabled_for_testing());
 }
 
-void MemoryDumpScheduler::AddTrigger(MemoryDumpType trigger_type,
-                                     MemoryDumpLevelOfDetail level_of_detail,
-                                     uint32_t min_time_between_dumps_ms) {
-  DCHECK(is_setup_);
-  if (trigger_type == MemoryDumpType::PEAK_MEMORY_USAGE) {
-    DCHECK(!periodic_state_->is_configured);
-    DCHECK_EQ(PollingTriggerState::DISABLED, polling_state_->current_state);
-    DCHECK_NE(0u, min_time_between_dumps_ms);
+void MemoryDumpScheduler::Start(
+    MemoryDumpScheduler::Config config,
+    scoped_refptr<SequencedTaskRunner> task_runner) {
+  DCHECK(!task_runner_);
+  task_runner_ = task_runner;
+  task_runner->PostTask(FROM_HERE, BindOnce(&MemoryDumpScheduler::StartInternal,
+                                            Unretained(this), config));
+}
 
-    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_->current_state = PollingTriggerState::CONFIGURED;
-  } else if (trigger_type == MemoryDumpType::PERIODIC_INTERVAL) {
-    DCHECK_EQ(PollingTriggerState::DISABLED, polling_state_->current_state);
-    periodic_state_->is_configured = true;
-    DCHECK_NE(0u, min_time_between_dumps_ms);
-    switch (level_of_detail) {
+void MemoryDumpScheduler::Stop() {
+  if (!task_runner_)
+    return;
+  task_runner_->PostTask(FROM_HERE, BindOnce(&MemoryDumpScheduler::StopInternal,
+                                             Unretained(this)));
+  task_runner_ = nullptr;
+}
+
+void MemoryDumpScheduler::StartInternal(MemoryDumpScheduler::Config config) {
+  uint32_t light_dump_period_ms = 0;
+  uint32_t heavy_dump_period_ms = 0;
+  uint32_t min_period_ms = std::numeric_limits<uint32_t>::max();
+  for (const Config::Trigger& trigger : config.triggers) {
+    DCHECK_GT(trigger.period_ms, 0u);
+    switch (trigger.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;
+        DCHECK_EQ(0u, light_dump_period_ms);
+        light_dump_period_ms = trigger.period_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;
+        DCHECK_EQ(0u, heavy_dump_period_ms);
+        heavy_dump_period_ms = trigger.period_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);
+    min_period_ms = std::min(min_period_ms, trigger.period_ms);
   }
-}
-
-void MemoryDumpScheduler::EnablePeriodicTriggerIfNeeded() {
-  DCHECK(is_setup_);
-  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(
+  DCHECK_EQ(0u, light_dump_period_ms % min_period_ms);
+  DCHECK_EQ(0u, heavy_dump_period_ms % min_period_ms);
+  DCHECK(!config.callback.is_null());
+  callback_ = config.callback;
+  period_ms_ = min_period_ms;
+  tick_count_ = 0;
+  light_dump_rate_ = light_dump_period_ms / min_period_ms;
+  heavy_dump_rate_ = heavy_dump_period_ms / min_period_ms;
+  SequencedTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
-      TimeDelta::FromMilliseconds(periodic_state_->min_timer_period_ms),
-      Bind(&MemoryDumpScheduler::RequestPeriodicGlobalDump, Unretained(this)));
+      BindOnce(&MemoryDumpScheduler::Tick, Unretained(this), ++generation_));
 }
 
-void MemoryDumpScheduler::EnablePollingIfNeeded() {
-  DCHECK(is_setup_);
-  if (polling_state_->current_state != PollingTriggerState::CONFIGURED)
-    return;
-
-  polling_state_->current_state = PollingTriggerState::ENABLED;
-  polling_state_->ResetTotals();
-
-  polling_task_runner_->PostTask(
-      FROM_HERE, BindOnce(&MemoryDumpScheduler::PollMemoryOnPollingThread,
-                          Unretained(this)));
+void MemoryDumpScheduler::StopInternal() {
+  period_ms_ = 0;
+  generation_++;
+  callback_.Reset();
 }
 
-void MemoryDumpScheduler::NotifyDumpTriggered() {
-  if (polling_task_runner_ &&
-      !polling_task_runner_->RunsTasksOnCurrentThread()) {
-    polling_task_runner_->PostTask(
-        FROM_HERE,
-        BindOnce(&MemoryDumpScheduler::NotifyDumpTriggered, Unretained(this)));
-    return;
-  }
-
-  if (!polling_state_ ||
-      polling_state_->current_state != PollingTriggerState::ENABLED) {
+void MemoryDumpScheduler::Tick(uint32_t expected_generation) {
+  if (period_ms_ == 0 || generation_ != expected_generation)
     return;
-  }
 
-  polling_state_->ResetTotals();
-}
-
-void MemoryDumpScheduler::DisableAllTriggers() {
-  if (periodic_state_) {
-    if (periodic_state_->timer.IsRunning())
-      periodic_state_->timer.Stop();
-    periodic_state_.reset();
-  }
-
-  if (polling_task_runner_) {
-    DCHECK(polling_state_);
-    polling_task_runner_->PostTask(
-        FROM_HERE, BindOnce(&MemoryDumpScheduler::DisablePollingOnPollingThread,
-                            Unretained(this)));
-    polling_task_runner_ = nullptr;
-  }
-  is_setup_ = false;
-}
-
-void MemoryDumpScheduler::DisablePollingOnPollingThread() {
-  polling_state_->current_state = PollingTriggerState::DISABLED;
-  polling_state_.reset();
-}
-
-// static
-void MemoryDumpScheduler::SetPollingIntervalForTesting(uint32_t interval) {
-  g_polling_interval_ms_for_testing = interval;
-}
-
-bool MemoryDumpScheduler::IsPeriodicTimerRunningForTesting() {
-  return periodic_state_->timer.IsRunning();
-}
+  SequencedTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE,
+      BindOnce(&MemoryDumpScheduler::Tick, Unretained(this),
+               expected_generation),
+      TimeDelta::FromMilliseconds(period_ms_));
 
-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)
+  if (light_dump_rate_ > 0 && tick_count_ % light_dump_rate_ == 0)
     level_of_detail = MemoryDumpLevelOfDetail::LIGHT;
-  if (periodic_state_->heavy_dumps_rate > 0 &&
-      periodic_state_->dump_count % periodic_state_->heavy_dumps_rate == 0)
+  if (heavy_dump_rate_ > 0 && tick_count_ % heavy_dump_rate_ == 0)
     level_of_detail = MemoryDumpLevelOfDetail::DETAILED;
-  ++periodic_state_->dump_count;
+  tick_count_++;
 
-  mdm_->RequestGlobalDump(MemoryDumpType::PERIODIC_INTERVAL, level_of_detail);
+  callback_.Run(level_of_detail);
 }
 
-void MemoryDumpScheduler::PollMemoryOnPollingThread() {
-  if (!polling_state_)
-    return;
-
-  DCHECK_EQ(PollingTriggerState::ENABLED, polling_state_->current_state);
-
-  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,
-      BindOnce(&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 > polling_state_->memory_increase_threshold;
-  should_dump |= IsCurrentSamplePeak(current_memory_total);
-  if (should_dump)
-    polling_state_->ResetTotals();
-  return should_dump;
-}
-
-bool MemoryDumpScheduler::IsCurrentSamplePeak(
-    uint64_t current_memory_total_bytes) {
-  uint64_t current_memory_total_kb = current_memory_total_bytes / 1024;
-  polling_state_->last_memory_totals_kb_index =
-      (polling_state_->last_memory_totals_kb_index + 1) %
-      PollingTriggerState::kMaxNumMemorySamples;
-  uint64_t mean = 0;
-  for (uint32_t i = 0; i < PollingTriggerState::kMaxNumMemorySamples; ++i) {
-    if (polling_state_->last_memory_totals_kb[i] == 0) {
-      // Not enough samples to detect peaks.
-      polling_state_
-          ->last_memory_totals_kb[polling_state_->last_memory_totals_kb_index] =
-          current_memory_total_kb;
-      return false;
-    }
-    mean += polling_state_->last_memory_totals_kb[i];
-  }
-  mean = mean / PollingTriggerState::kMaxNumMemorySamples;
-  uint64_t variance = 0;
-  for (uint32_t i = 0; i < PollingTriggerState::kMaxNumMemorySamples; ++i) {
-    variance += (polling_state_->last_memory_totals_kb[i] - mean) *
-                (polling_state_->last_memory_totals_kb[i] - mean);
-  }
-  variance = variance / PollingTriggerState::kMaxNumMemorySamples;
-
-  polling_state_
-      ->last_memory_totals_kb[polling_state_->last_memory_totals_kb_index] =
-      current_memory_total_kb;
-
-  // If stddev is less than 0.2% then we consider that the process is inactive.
-  bool is_stddev_low = variance < mean / 500 * mean / 500;
-  if (is_stddev_low)
-    return false;
-
-  // (mean + 3.69 * stddev) corresponds to a value that is higher than current
-  // sample with 99.99% probability.
-  return (current_memory_total_kb - mean) * (current_memory_total_kb - mean) >
-         (3.69 * 3.69 * variance);
-}
-
-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()
-    : current_state(DISABLED),
-      level_of_detail(MemoryDumpLevelOfDetail::FIRST),
-      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(-1),
-      last_dump_memory_total(0),
-      memory_increase_threshold(0),
-      last_memory_totals_kb_index(0) {}
-
-MemoryDumpScheduler::PollingTriggerState::~PollingTriggerState() {}
-
-void MemoryDumpScheduler::PollingTriggerState::ResetTotals() {
-  if (!memory_increase_threshold) {
-    memory_increase_threshold = kDefaultMemoryIncreaseThreshold;
-#if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX) || \
-    defined(OS_ANDROID)
-    // Set threshold to 1% of total system memory.
-    SystemMemoryInfoKB meminfo;
-    bool res = GetSystemMemoryInfo(&meminfo);
-    if (res) {
-      memory_increase_threshold =
-          (static_cast<int64_t>(meminfo.total) / 100) * 1024;
-    }
-    DCHECK_GT(memory_increase_threshold, 0u);
-#endif
-  }
-
-  // Update the |last_dump_memory_total|'s value from the totals if it's not
-  // first poll.
-  if (num_polls_from_last_dump >= 0 &&
-      last_memory_totals_kb[last_memory_totals_kb_index]) {
-    last_dump_memory_total =
-        last_memory_totals_kb[last_memory_totals_kb_index] * 1024;
-  }
-  num_polls_from_last_dump = 0;
-  for (uint32_t i = 0; i < kMaxNumMemorySamples; ++i)
-    last_memory_totals_kb[i] = 0;
-  last_memory_totals_kb_index = 0;
-}
+MemoryDumpScheduler::Config::Config() {}
+MemoryDumpScheduler::Config::~Config() {}
+MemoryDumpScheduler::Config::Config(const MemoryDumpScheduler::Config&) =
+    default;
 
 }  // namespace trace_event
 }  // namespace base