| // -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- |
| // Copyright (c) 2005, 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 |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| // --- |
| // Author: Sanjay Ghemawat <opensource@google.com> |
| // |
| // Extra extensions exported by some malloc implementations. These |
| // extensions are accessed through a virtual base class so an |
| // application can link against a malloc that does not implement these |
| // extensions, and it will get default versions that do nothing. |
| // |
| // NOTE FOR C USERS: If you wish to use this functionality from within |
| // a C program, see malloc_extension_c.h. |
| |
| #ifndef BASE_MALLOC_EXTENSION_H_ |
| #define BASE_MALLOC_EXTENSION_H_ |
| |
| #include <stddef.h> |
| // I can't #include config.h in this public API file, but I should |
| // really use configure (and make malloc_extension.h a .in file) to |
| // figure out if the system has stdint.h or not. But I'm lazy, so |
| // for now I'm assuming it's a problem only with MSVC. |
| #ifndef _MSC_VER |
| #include <stdint.h> |
| #endif |
| #include <string> |
| #include <vector> |
| |
| // Annoying stuff for windows -- makes sure clients can import these functions |
| #ifndef PERFTOOLS_DLL_DECL |
| # ifdef _WIN32 |
| # define PERFTOOLS_DLL_DECL __declspec(dllimport) |
| # else |
| # define PERFTOOLS_DLL_DECL |
| # endif |
| #endif |
| |
| static const int kMallocHistogramSize = 64; |
| |
| // One day, we could support other types of writers (perhaps for C?) |
| typedef std::string MallocExtensionWriter; |
| |
| namespace base { |
| struct MallocRange; |
| } |
| |
| // Interface to a pluggable system allocator. |
| class PERFTOOLS_DLL_DECL SysAllocator { |
| public: |
| SysAllocator() { |
| } |
| virtual ~SysAllocator(); |
| |
| // Allocates "size"-byte of memory from system aligned with "alignment". |
| // Returns NULL if failed. Otherwise, the returned pointer p up to and |
| // including (p + actual_size -1) have been allocated. |
| virtual void* Alloc(size_t size, size_t *actual_size, size_t alignment) = 0; |
| }; |
| |
| // The default implementations of the following routines do nothing. |
| // All implementations should be thread-safe; the current one |
| // (TCMallocImplementation) is. |
| class PERFTOOLS_DLL_DECL MallocExtension { |
| public: |
| virtual ~MallocExtension(); |
| |
| // Call this very early in the program execution -- say, in a global |
| // constructor -- to set up parameters and state needed by all |
| // instrumented malloc implemenatations. One example: this routine |
| // sets environemnt variables to tell STL to use libc's malloc() |
| // instead of doing its own memory management. This is safe to call |
| // multiple times, as long as each time is before threads start up. |
| static void Initialize(); |
| |
| // See "verify_memory.h" to see what these routines do |
| virtual bool VerifyAllMemory(); |
| virtual bool VerifyNewMemory(const void* p); |
| virtual bool VerifyArrayNewMemory(const void* p); |
| virtual bool VerifyMallocMemory(const void* p); |
| virtual bool MallocMemoryStats(int* blocks, size_t* total, |
| int histogram[kMallocHistogramSize]); |
| |
| // Get a human readable description of the current state of the malloc |
| // data structures. The state is stored as a null-terminated string |
| // in a prefix of "buffer[0,buffer_length-1]". |
| // REQUIRES: buffer_length > 0. |
| virtual void GetStats(char* buffer, int buffer_length); |
| |
| // Outputs to "writer" a sample of live objects and the stack traces |
| // that allocated these objects. The format of the returned output |
| // is equivalent to the output of the heap profiler and can |
| // therefore be passed to "pprof". This function is equivalent to |
| // ReadStackTraces. The main difference is that this function returns |
| // serialized data appropriately formatted for use by the pprof tool. |
| // NOTE: by default, tcmalloc does not do any heap sampling, and this |
| // function will always return an empty sample. To get useful |
| // data from GetHeapSample, you must also set the environment |
| // variable TCMALLOC_SAMPLE_PARAMETER to a value such as 524288. |
| virtual void GetHeapSample(MallocExtensionWriter* writer); |
| |
| // Outputs to "writer" the stack traces that caused growth in the |
| // address space size. The format of the returned output is |
| // equivalent to the output of the heap profiler and can therefore |
| // be passed to "pprof". This function is equivalent to |
| // ReadHeapGrowthStackTraces. The main difference is that this function |
| // returns serialized data appropriately formatted for use by the |
| // pprof tool. (This does not depend on, or require, |
| // TCMALLOC_SAMPLE_PARAMETER.) |
| virtual void GetHeapGrowthStacks(MallocExtensionWriter* writer); |
| |
| // Invokes func(arg, range) for every controlled memory |
| // range. *range is filled in with information about the range. |
| // |
| // This is a best-effort interface useful only for performance |
| // analysis. The implementation may not call func at all. |
| typedef void (RangeFunction)(void*, const base::MallocRange*); |
| virtual void Ranges(void* arg, RangeFunction func); |
| |
| // ------------------------------------------------------------------- |
| // Control operations for getting and setting malloc implementation |
| // specific parameters. Some currently useful properties: |
| // |
| // generic |
| // ------- |
| // "generic.current_allocated_bytes" |
| // Number of bytes currently allocated by application |
| // This property is not writable. |
| // |
| // "generic.heap_size" |
| // Number of bytes in the heap == |
| // current_allocated_bytes + |
| // fragmentation + |
| // freed memory regions |
| // This property is not writable. |
| // |
| // tcmalloc |
| // -------- |
| // "tcmalloc.max_total_thread_cache_bytes" |
| // Upper limit on total number of bytes stored across all |
| // per-thread caches. Default: 16MB. |
| // |
| // "tcmalloc.current_total_thread_cache_bytes" |
| // Number of bytes used across all thread caches. |
| // This property is not writable. |
| // |
| // "tcmalloc.central_cache_free_bytes" |
| // Number of free bytes in the central cache that have been |
| // assigned to size classes. They always count towards virtual |
| // memory usage, and unless the underlying memory is swapped out |
| // by the OS, they also count towards physical memory usage. |
| // This property is not writable. |
| // |
| // "tcmalloc.transfer_cache_free_bytes" |
| // Number of free bytes that are waiting to be transfered between |
| // the central cache and a thread cache. They always count |
| // towards virtual memory usage, and unless the underlying memory |
| // is swapped out by the OS, they also count towards physical |
| // memory usage. This property is not writable. |
| // |
| // "tcmalloc.thread_cache_free_bytes" |
| // Number of free bytes in thread caches. They always count |
| // towards virtual memory usage, and unless the underlying memory |
| // is swapped out by the OS, they also count towards physical |
| // memory usage. This property is not writable. |
| // |
| // "tcmalloc.pageheap_free_bytes" |
| // Number of bytes in free, mapped pages in page heap. These |
| // bytes can be used to fulfill allocation requests. They |
| // always count towards virtual memory usage, and unless the |
| // underlying memory is swapped out by the OS, they also count |
| // towards physical memory usage. This property is not writable. |
| // |
| // "tcmalloc.pageheap_unmapped_bytes" |
| // Number of bytes in free, unmapped pages in page heap. |
| // These are bytes that have been released back to the OS, |
| // possibly by one of the MallocExtension "Release" calls. |
| // They can be used to fulfill allocation requests, but |
| // typically incur a page fault. They always count towards |
| // virtual memory usage, and depending on the OS, typically |
| // do not count towards physical memory usage. This property |
| // is not writable. |
| // ------------------------------------------------------------------- |
| |
| // Get the named "property"'s value. Returns true if the property |
| // is known. Returns false if the property is not a valid property |
| // name for the current malloc implementation. |
| // REQUIRES: property != NULL; value != NULL |
| virtual bool GetNumericProperty(const char* property, size_t* value); |
| |
| // Set the named "property"'s value. Returns true if the property |
| // is known and writable. Returns false if the property is not a |
| // valid property name for the current malloc implementation, or |
| // is not writable. |
| // REQUIRES: property != NULL |
| virtual bool SetNumericProperty(const char* property, size_t value); |
| |
| // Mark the current thread as "idle". This routine may optionally |
| // be called by threads as a hint to the malloc implementation that |
| // any thread-specific resources should be released. Note: this may |
| // be an expensive routine, so it should not be called too often. |
| // |
| // Also, if the code that calls this routine will go to sleep for |
| // a while, it should take care to not allocate anything between |
| // the call to this routine and the beginning of the sleep. |
| // |
| // Most malloc implementations ignore this routine. |
| virtual void MarkThreadIdle(); |
| |
| // Mark the current thread as "busy". This routine should be |
| // called after MarkThreadIdle() if the thread will now do more |
| // work. If this method is not called, performance may suffer. |
| // |
| // Most malloc implementations ignore this routine. |
| virtual void MarkThreadBusy(); |
| |
| // Gets the system allocator used by the malloc extension instance. Returns |
| // NULL for malloc implementations that do not support pluggable system |
| // allocators. |
| virtual SysAllocator* GetSystemAllocator(); |
| |
| // Sets the system allocator to the specified. |
| // |
| // Users could register their own system allocators for malloc implementation |
| // that supports pluggable system allocators, such as TCMalloc, by doing: |
| // alloc = new MyOwnSysAllocator(); |
| // MallocExtension::instance()->SetSystemAllocator(alloc); |
| // It's up to users whether to fall back (recommended) to the default |
| // system allocator (use GetSystemAllocator() above) or not. The caller is |
| // responsible to any necessary locking. |
| // See tcmalloc/system-alloc.h for the interface and |
| // tcmalloc/memfs_malloc.cc for the examples. |
| // |
| // It's a no-op for malloc implementations that do not support pluggable |
| // system allocators. |
| virtual void SetSystemAllocator(SysAllocator *a); |
| |
| // Try to release num_bytes of free memory back to the operating |
| // system for reuse. Use this extension with caution -- to get this |
| // memory back may require faulting pages back in by the OS, and |
| // that may be slow. (Currently only implemented in tcmalloc.) |
| virtual void ReleaseToSystem(size_t num_bytes); |
| |
| // Same as ReleaseToSystem() but release as much memory as possible. |
| virtual void ReleaseFreeMemory(); |
| |
| // Sets the rate at which we release unused memory to the system. |
| // Zero means we never release memory back to the system. Increase |
| // this flag to return memory faster; decrease it to return memory |
| // slower. Reasonable rates are in the range [0,10]. (Currently |
| // only implemented in tcmalloc). |
| virtual void SetMemoryReleaseRate(double rate); |
| |
| // Gets the release rate. Returns a value < 0 if unknown. |
| virtual double GetMemoryReleaseRate(); |
| |
| // Returns the estimated number of bytes that will be allocated for |
| // a request of "size" bytes. This is an estimate: an allocation of |
| // SIZE bytes may reserve more bytes, but will never reserve less. |
| // (Currently only implemented in tcmalloc, other implementations |
| // always return SIZE.) |
| // This is equivalent to malloc_good_size() in OS X. |
| virtual size_t GetEstimatedAllocatedSize(size_t size); |
| |
| // Returns the actual number N of bytes reserved by tcmalloc for the |
| // pointer p. The client is allowed to use the range of bytes |
| // [p, p+N) in any way it wishes (i.e. N is the "usable size" of this |
| // allocation). This number may be equal to or greater than the number |
| // of bytes requested when p was allocated. |
| // p must have been allocated by this malloc implementation, |
| // must not be an interior pointer -- that is, must be exactly |
| // the pointer returned to by malloc() et al., not some offset |
| // from that -- and should not have been freed yet. p may be NULL. |
| // (Currently only implemented in tcmalloc; other implementations |
| // will return 0.) |
| // This is equivalent to malloc_size() in OS X, malloc_usable_size() |
| // in glibc, and _msize() for windows. |
| virtual size_t GetAllocatedSize(const void* p); |
| |
| // Returns kOwned if this malloc implementation allocated the memory |
| // pointed to by p, or kNotOwned if some other malloc implementation |
| // allocated it or p is NULL. May also return kUnknownOwnership if |
| // the malloc implementation does not keep track of ownership. |
| // REQUIRES: p must be a value returned from a previous call to |
| // malloc(), calloc(), realloc(), memalign(), posix_memalign(), |
| // valloc(), pvalloc(), new, or new[], and must refer to memory that |
| // is currently allocated (so, for instance, you should not pass in |
| // a pointer after having called free() on it). |
| enum Ownership { |
| // NOTE: Enum values MUST be kept in sync with the version in |
| // malloc_extension_c.h |
| kUnknownOwnership = 0, |
| kOwned, |
| kNotOwned |
| }; |
| virtual Ownership GetOwnership(const void* p); |
| |
| // The current malloc implementation. Always non-NULL. |
| static MallocExtension* instance(); |
| |
| // Change the malloc implementation. Typically called by the |
| // malloc implementation during initialization. |
| static void Register(MallocExtension* implementation); |
| |
| // Returns detailed information about malloc's freelists. For each list, |
| // return a FreeListInfo: |
| struct FreeListInfo { |
| size_t min_object_size; |
| size_t max_object_size; |
| size_t total_bytes_free; |
| const char* type; |
| }; |
| // Each item in the vector refers to a different freelist. The lists |
| // are identified by the range of allocations that objects in the |
| // list can satisfy ([min_object_size, max_object_size]) and the |
| // type of freelist (see below). The current size of the list is |
| // returned in total_bytes_free (which count against a processes |
| // resident and virtual size). |
| // |
| // Currently supported types are: |
| // |
| // "tcmalloc.page{_unmapped}" - tcmalloc's page heap. An entry for each size |
| // class in the page heap is returned. Bytes in "page_unmapped" |
| // are no longer backed by physical memory and do not count against |
| // the resident size of a process. |
| // |
| // "tcmalloc.large{_unmapped}" - tcmalloc's list of objects larger |
| // than the largest page heap size class. Only one "large" |
| // entry is returned. There is no upper-bound on the size |
| // of objects in the large free list; this call returns |
| // kint64max for max_object_size. Bytes in |
| // "large_unmapped" are no longer backed by physical memory |
| // and do not count against the resident size of a process. |
| // |
| // "tcmalloc.central" - tcmalloc's central free-list. One entry per |
| // size-class is returned. Never unmapped. |
| // |
| // "debug.free_queue" - free objects queued by the debug allocator |
| // and not returned to tcmalloc. |
| // |
| // "tcmalloc.thread" - tcmalloc's per-thread caches. Never unmapped. |
| virtual void GetFreeListSizes(std::vector<FreeListInfo>* v); |
| |
| // Get a list of stack traces of sampled allocation points. Returns |
| // a pointer to a "new[]-ed" result array, and stores the sample |
| // period in "sample_period". |
| // |
| // The state is stored as a sequence of adjacent entries |
| // in the returned array. Each entry has the following form: |
| // uintptr_t count; // Number of objects with following trace |
| // uintptr_t size; // Total size of objects with following trace |
| // uintptr_t depth; // Number of PC values in stack trace |
| // void* stack[depth]; // PC values that form the stack trace |
| // |
| // The list of entries is terminated by a "count" of 0. |
| // |
| // It is the responsibility of the caller to "delete[]" the returned array. |
| // |
| // May return NULL to indicate no results. |
| // |
| // This is an internal extension. Callers should use the more |
| // convenient "GetHeapSample(string*)" method defined above. |
| virtual void** ReadStackTraces(int* sample_period); |
| |
| // Like ReadStackTraces(), but returns stack traces that caused growth |
| // in the address space size. |
| virtual void** ReadHeapGrowthStackTraces(); |
| }; |
| |
| namespace base { |
| |
| // Information passed per range. More fields may be added later. |
| struct MallocRange { |
| enum Type { |
| INUSE, // Application is using this range |
| FREE, // Range is currently free |
| UNMAPPED, // Backing physical memory has been returned to the OS |
| UNKNOWN |
| // More enum values may be added in the future |
| }; |
| |
| uintptr_t address; // Address of range |
| size_t length; // Byte length of range |
| Type type; // Type of this range |
| double fraction; // Fraction of range that is being used (0 if !INUSE) |
| |
| // Perhaps add the following: |
| // - stack trace if this range was sampled |
| // - heap growth stack trace if applicable to this range |
| // - age when allocated (for inuse) or freed (if not in use) |
| }; |
| |
| } // namespace base |
| |
| #endif // BASE_MALLOC_EXTENSION_H_ |