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      1 // Copyright (c) 2008, Google Inc.
      2 // All rights reserved.
      3 //
      4 // Redistribution and use in source and binary forms, with or without
      5 // modification, are permitted provided that the following conditions are
      6 // met:
      7 //
      8 //     * Redistributions of source code must retain the above copyright
      9 // notice, this list of conditions and the following disclaimer.
     10 //     * Redistributions in binary form must reproduce the above
     11 // copyright notice, this list of conditions and the following disclaimer
     12 // in the documentation and/or other materials provided with the
     13 // distribution.
     14 //     * Neither the name of Google Inc. nor the names of its
     15 // contributors may be used to endorse or promote products derived from
     16 // this software without specific prior written permission.
     17 //
     18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29 
     30 // ---
     31 // Author: Ken Ashcraft <opensource (at) google.com>
     32 //
     33 // Static variables shared by multiple classes.
     34 
     35 #ifndef TCMALLOC_STATIC_VARS_H_
     36 #define TCMALLOC_STATIC_VARS_H_
     37 
     38 #include <config.h>
     39 #include "base/spinlock.h"
     40 #include "central_freelist.h"
     41 #include "common.h"
     42 #include "page_heap.h"
     43 #include "page_heap_allocator.h"
     44 #include "span.h"
     45 #include "stack_trace_table.h"
     46 
     47 namespace tcmalloc {
     48 
     49 class Static {
     50  public:
     51   // Linker initialized, so this lock can be accessed at any time.
     52   static SpinLock* pageheap_lock() { return &pageheap_lock_; }
     53 
     54   // Must be called before calling any of the accessors below.
     55   static void InitStaticVars();
     56 
     57   // Central cache -- an array of free-lists, one per size-class.
     58   // We have a separate lock per free-list to reduce contention.
     59   static CentralFreeListPadded* central_cache() { return central_cache_; }
     60 
     61   static SizeMap* sizemap() { return &sizemap_; }
     62 
     63   //////////////////////////////////////////////////////////////////////
     64   // In addition to the explicit initialization comment, the variables below
     65   // must be protected by pageheap_lock.
     66 
     67   // Page-level allocator.
     68   static PageHeap* pageheap() { return pageheap_; }
     69 
     70   static PageHeapAllocator<Span>* span_allocator() { return &span_allocator_; }
     71 
     72   static PageHeapAllocator<StackTrace>* stacktrace_allocator() {
     73     return &stacktrace_allocator_;
     74   }
     75 
     76   static StackTrace* growth_stacks() { return growth_stacks_; }
     77   static void set_growth_stacks(StackTrace* s) { growth_stacks_ = s; }
     78 
     79   // State kept for sampled allocations (/pprof/heap support)
     80   static Span* sampled_objects() { return &sampled_objects_; }
     81   static PageHeapAllocator<StackTraceTable::Bucket>* bucket_allocator() {
     82     return &bucket_allocator_;
     83   }
     84 
     85  private:
     86   static SpinLock pageheap_lock_;
     87 
     88   // These static variables require explicit initialization.  We cannot
     89   // count on their constructors to do any initialization because other
     90   // static variables may try to allocate memory before these variables
     91   // can run their constructors.
     92 
     93   static SizeMap sizemap_;
     94   static CentralFreeListPadded central_cache_[kNumClasses];
     95   static PageHeapAllocator<Span> span_allocator_;
     96   static PageHeapAllocator<StackTrace> stacktrace_allocator_;
     97   static Span sampled_objects_;
     98   static PageHeapAllocator<StackTraceTable::Bucket> bucket_allocator_;
     99 
    100   // Linked list of stack traces recorded every time we allocated memory
    101   // from the system.  Useful for finding allocation sites that cause
    102   // increase in the footprint of the system.  The linked list pointer
    103   // is stored in trace->stack[kMaxStackDepth-1].
    104   static StackTrace* growth_stacks_;
    105 
    106   static PageHeap* pageheap_;
    107 };
    108 
    109 }  // namespace tcmalloc
    110 
    111 #endif  // TCMALLOC_STATIC_VARS_H_
    112