PartitionAlloc: API changes to support new partitionPurgeMemoryGeneric() mode.

Source/wtf/PartitionAlloc.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 333 matching lines @@
 
 // Struct used to retrieve memory statistics about a partition bucket. Used by
 // PartitionStatsDumper implementation.
 struct PartitionBucketMemoryStats {
     bool isValid; // Used to check if the stats is valid.
     bool isDirectMap; // True if this is a direct mapping; size will not be unique.
     uint32_t bucketSlotSize; // The size of the slot in bytes.
     uint32_t allocatedPageSize; // Total size the partition page allocated from the system.
     uint32_t activeBytes; // Total active bytes used in the bucket.
     uint32_t residentBytes; // Total bytes provisioned in the bucket.
-    uint32_t freeableBytes; // Total bytes that could be decommitted.
+    uint32_t decommittableBytes; // Total bytes that could be decommitted.
+    uint32_t discardableBytes; // Total bytes that could be discarded.
     uint32_t numFullPages; // Number of pages with all slots allocated.
     uint32_t numActivePages; // Number of pages that have at least one provisioned slot.
     uint32_t numEmptyPages; // Number of pages that are empty but not decommitted.
     uint32_t numDecommittedPages; // Number of pages that are empty and decommitted.
 };
 
 // Interface that is passed to partitionDumpStats and
 // partitionDumpStatsGeneric for using the memory statistics.
 class WTF_EXPORT PartitionStatsDumper {
 public:
     virtual void partitionsDumpBucketStats(const char* partitionName, const PartitionBucketMemoryStats*) = 0;
 };
 
 WTF_EXPORT void partitionAllocInit(PartitionRoot*, size_t numBuckets, size_t maxAllocation);
 WTF_EXPORT bool partitionAllocShutdown(PartitionRoot*);
 WTF_EXPORT void partitionAllocGenericInit(PartitionRootGeneric*);
 WTF_EXPORT bool partitionAllocGenericShutdown(PartitionRootGeneric*);
-WTF_EXPORT void partitionPurgeMemory(PartitionRoot*);
-WTF_EXPORT void partitionPurgeMemoryGeneric(PartitionRootGeneric*);
+
+enum PartitionPurgeFlags {
+    // Decommitting the ring list of empty pages is reasonably fast.
+    PartitionPurgeDecommitEmptyPages = 1 << 0,
+};
+
+WTF_EXPORT void partitionPurgeMemory(PartitionRoot*, int);
+WTF_EXPORT void partitionPurgeMemoryGeneric(PartitionRootGeneric*, int);
 
 WTF_EXPORT NEVER_INLINE void* partitionAllocSlowPath(PartitionRootBase*, int, size_t, PartitionBucket*);
 WTF_EXPORT NEVER_INLINE void partitionFreeSlowPath(PartitionPage*);
 WTF_EXPORT NEVER_INLINE void* partitionReallocGeneric(PartitionRootGeneric*, void*, size_t);
 
 WTF_EXPORT void partitionDumpStats(PartitionRoot*, const char* partitionName, PartitionStatsDumper*);
 WTF_EXPORT void partitionDumpStatsGeneric(PartitionRootGeneric*, const char* partitionName, PartitionStatsDumper*);
 
 ALWAYS_INLINE PartitionFreelistEntry* partitionFreelistMask(PartitionFreelistEntry* ptr)
 {
@@ skipping 347 matching lines @@
 using WTF::partitionAlloc;
 using WTF::partitionFree;
 using WTF::partitionAllocGeneric;
 using WTF::partitionFreeGeneric;
 using WTF::partitionReallocGeneric;
 using WTF::partitionAllocActualSize;
 using WTF::partitionAllocSupportsGetSize;
 using WTF::partitionAllocGetSize;
 
 #endif // WTF_PartitionAlloc_h