Set Android/V8 memory limits from dalvik.vm.heapsize.

webkit/glue/webkitplatformsupport_impl.cc

Index: webkit/glue/webkitplatformsupport_impl.cc
diff --git a/webkit/glue/webkitplatformsupport_impl.cc b/webkit/glue/webkitplatformsupport_impl.cc
index 7b7ab157875b2f29e8c8bed55605ed95fdf579c7..0ff7d8006c9888c43154d25bd06ff55f0070ecc8 100644
--- a/webkit/glue/webkitplatformsupport_impl.cc
+++ b/webkit/glue/webkitplatformsupport_impl.cc
@@ -24,6 +24,7 @@
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/synchronization/lock.h"
+#include "base/sys_info.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "grit/webkit_chromium_resources.h"
@@ -620,8 +621,8 @@ WebKit::WebString WebKitPlatformSupportImpl::signedPublicKeyAndChallengeString(
   return WebKit::WebString("");
 }
 
-#if defined(OS_LINUX)
-static size_t memoryUsageMBLinux() {
+#if defined(OS_LINUX) || defined(OS_ANDROID)
+static size_t memoryUsageMB() {
   struct mallinfo minfo = mallinfo();
   uint64_t mem_usage =
 #if defined(USE_TCMALLOC)
@@ -635,10 +636,8 @@ static size_t memoryUsageMBLinux() {
   v8::V8::GetHeapStatistics(&stat);
   return mem_usage + (static_cast<uint64_t>(stat.total_heap_size()) >> 20);
 }
-#endif
-
-#if defined(OS_MACOSX)
-static size_t memoryUsageMBMac() {
+#elif defined(OS_MACOSX)
+static size_t memoryUsageMB() {
   using base::ProcessMetrics;
   static ProcessMetrics* process_metrics =
       // The default port provider is sufficient to get data for the current
@@ -648,10 +647,8 @@ static size_t memoryUsageMBMac() {
   DCHECK(process_metrics);
   return process_metrics->GetWorkingSetSize() >> 20;
 }
-#endif
-
-#if !defined(OS_LINUX) && !defined(OS_MACOSX)
-static size_t memoryUsageMBGeneric() {
+#else
+static size_t memoryUsageMB() {
   using base::ProcessMetrics;
   static ProcessMetrics* process_metrics =
       ProcessMetrics::CreateProcessMetrics(base::GetCurrentProcessHandle());
@@ -667,14 +664,7 @@ static size_t getMemoryUsageMB(bool bypass_cache) {
       mem_usage_cache_singleton->IsCachedValueValid(&current_mem_usage))
     return current_mem_usage;
 
-  current_mem_usage =
-#if defined(OS_LINUX)
-      memoryUsageMBLinux();
-#elif defined(OS_MACOSX)
-      memoryUsageMBMac();
-#else
-      memoryUsageMBGeneric();
-#endif
+  current_mem_usage = memoryUsageMB();
   mem_usage_cache_singleton->SetMemoryValue(current_mem_usage);
   return current_mem_usage;
 }
@@ -687,6 +677,27 @@ size_t WebKitPlatformSupportImpl::actualMemoryUsageMB() {
   return getMemoryUsageMB(true);
 }
 
+#if defined(OS_ANDROID)
+size_t WebKitPlatformSupportImpl::lowMemoryUsageMB() {
+  // If memory usage is below this threshold, do not bother forcing GC.
+  // Allow us to use up to our memory class value before V8's GC kicks in.
+  // These values have been determined by experimentation.
+  return base::SysInfo::DalvikHeapSizeMB() / 2;
+}
+
+size_t WebKitPlatformSupportImpl::highMemoryUsageMB() {
+  // If memory usage is above this threshold, force GC more aggressively.
+  return base::SysInfo::DalvikHeapSizeMB() * 3 / 4;
+}
+
+size_t WebKitPlatformSupportImpl::highUsageDeltaMB() {
+  // Threshold of delta of memory usage growth (vs. last working set estimate)
+  // to force GC when memory usage is high.
+  // Avoid constant V8 GC when memory usage equals to working set estimate.

[Satish, 2012/05/16 11:23:51]

Can you mention here that this should be sufficiently higher than the memory
used by v8 internal data structures (8M?) so any changes to this in future would
be done with that in mind?

[ulan, 2012/05/16 11:46:40]

Done.

+  return base::SysInfo::DalvikHeapSizeMB() / 8;
+}
+#endif
+
 void WebKitPlatformSupportImpl::SuspendSharedTimer() {
   ++shared_timer_suspended_;
 }