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Diffstat (limited to 'src/pkg/runtime/malloc.h')
| -rw-r--r-- | src/pkg/runtime/malloc.h | 412 |
1 files changed, 0 insertions, 412 deletions
diff --git a/src/pkg/runtime/malloc.h b/src/pkg/runtime/malloc.h deleted file mode 100644 index 4e2794570..000000000 --- a/src/pkg/runtime/malloc.h +++ /dev/null @@ -1,412 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Memory allocator, based on tcmalloc. -// http://goog-perftools.sourceforge.net/doc/tcmalloc.html - -// The main allocator works in runs of pages. -// Small allocation sizes (up to and including 32 kB) are -// rounded to one of about 100 size classes, each of which -// has its own free list of objects of exactly that size. -// Any free page of memory can be split into a set of objects -// of one size class, which are then managed using free list -// allocators. -// -// The allocator's data structures are: -// -// FixAlloc: a free-list allocator for fixed-size objects, -// used to manage storage used by the allocator. -// MHeap: the malloc heap, managed at page (4096-byte) granularity. -// MSpan: a run of pages managed by the MHeap. -// MCentral: a shared free list for a given size class. -// MCache: a per-thread (in Go, per-M) cache for small objects. -// MStats: allocation statistics. -// -// Allocating a small object proceeds up a hierarchy of caches: -// -// 1. Round the size up to one of the small size classes -// and look in the corresponding MCache free list. -// If the list is not empty, allocate an object from it. -// This can all be done without acquiring a lock. -// -// 2. If the MCache free list is empty, replenish it by -// taking a bunch of objects from the MCentral free list. -// Moving a bunch amortizes the cost of acquiring the MCentral lock. -// -// 3. If the MCentral free list is empty, replenish it by -// allocating a run of pages from the MHeap and then -// chopping that memory into a objects of the given size. -// Allocating many objects amortizes the cost of locking -// the heap. -// -// 4. If the MHeap is empty or has no page runs large enough, -// allocate a new group of pages (at least 1MB) from the -// operating system. Allocating a large run of pages -// amortizes the cost of talking to the operating system. -// -// Freeing a small object proceeds up the same hierarchy: -// -// 1. Look up the size class for the object and add it to -// the MCache free list. -// -// 2. If the MCache free list is too long or the MCache has -// too much memory, return some to the MCentral free lists. -// -// 3. If all the objects in a given span have returned to -// the MCentral list, return that span to the page heap. -// -// 4. If the heap has too much memory, return some to the -// operating system. -// -// TODO(rsc): Step 4 is not implemented. -// -// Allocating and freeing a large object uses the page heap -// directly, bypassing the MCache and MCentral free lists. -// -// The small objects on the MCache and MCentral free lists -// may or may not be zeroed. They are zeroed if and only if -// the second word of the object is zero. The spans in the -// page heap are always zeroed. When a span full of objects -// is returned to the page heap, the objects that need to be -// are zeroed first. There are two main benefits to delaying the -// zeroing this way: -// -// 1. stack frames allocated from the small object lists -// can avoid zeroing altogether. -// 2. the cost of zeroing when reusing a small object is -// charged to the mutator, not the garbage collector. -// -// This C code was written with an eye toward translating to Go -// in the future. Methods have the form Type_Method(Type *t, ...). - -typedef struct FixAlloc FixAlloc; -typedef struct MCentral MCentral; -typedef struct MHeap MHeap; -typedef struct MSpan MSpan; -typedef struct MStats MStats; -typedef struct MLink MLink; - -enum -{ - PageShift = 12, - PageSize = 1<<PageShift, - PageMask = PageSize - 1, -}; -typedef uintptr PageID; // address >> PageShift - -enum -{ - // Computed constant. The definition of MaxSmallSize and the - // algorithm in msize.c produce some number of different allocation - // size classes. NumSizeClasses is that number. It's needed here - // because there are static arrays of this length; when msize runs its - // size choosing algorithm it double-checks that NumSizeClasses agrees. - NumSizeClasses = 61, - - // Tunable constants. - MaxSmallSize = 32<<10, - - FixAllocChunk = 128<<10, // Chunk size for FixAlloc - MaxMCacheListLen = 256, // Maximum objects on MCacheList - MaxMCacheSize = 2<<20, // Maximum bytes in one MCache - MaxMHeapList = 1<<(20 - PageShift), // Maximum page length for fixed-size list in MHeap. - HeapAllocChunk = 1<<20, // Chunk size for heap growth - - // Number of bits in page to span calculations (4k pages). - // On 64-bit, we limit the arena to 16G, so 22 bits suffices. - // On 32-bit, we don't bother limiting anything: 20 bits for 4G. -#ifdef _64BIT - MHeapMap_Bits = 22, -#else - MHeapMap_Bits = 20, -#endif -}; - -// A generic linked list of blocks. (Typically the block is bigger than sizeof(MLink).) -struct MLink -{ - MLink *next; -}; - -// SysAlloc obtains a large chunk of zeroed memory from the -// operating system, typically on the order of a hundred kilobytes -// or a megabyte. If the pointer argument is non-nil, the caller -// wants a mapping there or nowhere. -// -// SysUnused notifies the operating system that the contents -// of the memory region are no longer needed and can be reused -// for other purposes. The program reserves the right to start -// accessing those pages in the future. -// -// SysFree returns it unconditionally; this is only used if -// an out-of-memory error has been detected midway through -// an allocation. It is okay if SysFree is a no-op. -// -// SysReserve reserves address space without allocating memory. -// If the pointer passed to it is non-nil, the caller wants the -// reservation there, but SysReserve can still choose another -// location if that one is unavailable. -// -// SysMap maps previously reserved address space for use. - -void* runtime·SysAlloc(uintptr nbytes); -void runtime·SysFree(void *v, uintptr nbytes); -void runtime·SysUnused(void *v, uintptr nbytes); -void runtime·SysMap(void *v, uintptr nbytes); -void* runtime·SysReserve(void *v, uintptr nbytes); - -// FixAlloc is a simple free-list allocator for fixed size objects. -// Malloc uses a FixAlloc wrapped around SysAlloc to manages its -// MCache and MSpan objects. -// -// Memory returned by FixAlloc_Alloc is not zeroed. -// The caller is responsible for locking around FixAlloc calls. -// Callers can keep state in the object but the first word is -// smashed by freeing and reallocating. -struct FixAlloc -{ - uintptr size; - void *(*alloc)(uintptr); - void (*first)(void *arg, byte *p); // called first time p is returned - void *arg; - MLink *list; - byte *chunk; - uint32 nchunk; - uintptr inuse; // in-use bytes now - uintptr sys; // bytes obtained from system -}; - -void runtime·FixAlloc_Init(FixAlloc *f, uintptr size, void *(*alloc)(uintptr), void (*first)(void*, byte*), void *arg); -void* runtime·FixAlloc_Alloc(FixAlloc *f); -void runtime·FixAlloc_Free(FixAlloc *f, void *p); - - -// Statistics. -// Shared with Go: if you edit this structure, also edit extern.go. -struct MStats -{ - // General statistics. No locking; approximate. - uint64 alloc; // bytes allocated and still in use - uint64 total_alloc; // bytes allocated (even if freed) - uint64 sys; // bytes obtained from system (should be sum of xxx_sys below) - uint64 nlookup; // number of pointer lookups - uint64 nmalloc; // number of mallocs - uint64 nfree; // number of frees - - // Statistics about malloc heap. - // protected by mheap.Lock - uint64 heap_alloc; // bytes allocated and still in use - uint64 heap_sys; // bytes obtained from system - uint64 heap_idle; // bytes in idle spans - uint64 heap_inuse; // bytes in non-idle spans - uint64 heap_objects; // total number of allocated objects - - // Statistics about allocation of low-level fixed-size structures. - // Protected by FixAlloc locks. - uint64 stacks_inuse; // bootstrap stacks - uint64 stacks_sys; - uint64 mspan_inuse; // MSpan structures - uint64 mspan_sys; - uint64 mcache_inuse; // MCache structures - uint64 mcache_sys; - uint64 buckhash_sys; // profiling bucket hash table - - // Statistics about garbage collector. - // Protected by stopping the world during GC. - uint64 next_gc; // next GC (in heap_alloc time) - uint64 pause_total_ns; - uint64 pause_ns[256]; - uint32 numgc; - bool enablegc; - bool debuggc; - - // Statistics about allocation size classes. - // No locking; approximate. - struct { - uint32 size; - uint64 nmalloc; - uint64 nfree; - } by_size[NumSizeClasses]; -}; - -#define mstats runtime·MemStats /* name shared with Go */ -extern MStats mstats; - - -// Size classes. Computed and initialized by InitSizes. -// -// SizeToClass(0 <= n <= MaxSmallSize) returns the size class, -// 1 <= sizeclass < NumSizeClasses, for n. -// Size class 0 is reserved to mean "not small". -// -// class_to_size[i] = largest size in class i -// class_to_allocnpages[i] = number of pages to allocate when -// making new objects in class i -// class_to_transfercount[i] = number of objects to move when -// taking a bunch of objects out of the central lists -// and putting them in the thread free list. - -int32 runtime·SizeToClass(int32); -extern int32 runtime·class_to_size[NumSizeClasses]; -extern int32 runtime·class_to_allocnpages[NumSizeClasses]; -extern int32 runtime·class_to_transfercount[NumSizeClasses]; -extern void runtime·InitSizes(void); - - -// Per-thread (in Go, per-M) cache for small objects. -// No locking needed because it is per-thread (per-M). -typedef struct MCacheList MCacheList; -struct MCacheList -{ - MLink *list; - uint32 nlist; - uint32 nlistmin; -}; - -struct MCache -{ - MCacheList list[NumSizeClasses]; - uint64 size; - int64 local_alloc; // bytes allocated (or freed) since last lock of heap - int64 local_objects; // objects allocated (or freed) since last lock of heap - int32 next_sample; // trigger heap sample after allocating this many bytes -}; - -void* runtime·MCache_Alloc(MCache *c, int32 sizeclass, uintptr size, int32 zeroed); -void runtime·MCache_Free(MCache *c, void *p, int32 sizeclass, uintptr size); -void runtime·MCache_ReleaseAll(MCache *c); - -// An MSpan is a run of pages. -enum -{ - MSpanInUse = 0, - MSpanFree, - MSpanListHead, - MSpanDead, -}; -struct MSpan -{ - MSpan *next; // in a span linked list - MSpan *prev; // in a span linked list - MSpan *allnext; // in the list of all spans - PageID start; // starting page number - uintptr npages; // number of pages in span - MLink *freelist; // list of free objects - uint32 ref; // number of allocated objects in this span - uint32 sizeclass; // size class - uint32 state; // MSpanInUse etc - byte *limit; // end of data in span -}; - -void runtime·MSpan_Init(MSpan *span, PageID start, uintptr npages); - -// Every MSpan is in one doubly-linked list, -// either one of the MHeap's free lists or one of the -// MCentral's span lists. We use empty MSpan structures as list heads. -void runtime·MSpanList_Init(MSpan *list); -bool runtime·MSpanList_IsEmpty(MSpan *list); -void runtime·MSpanList_Insert(MSpan *list, MSpan *span); -void runtime·MSpanList_Remove(MSpan *span); // from whatever list it is in - - -// Central list of free objects of a given size. -struct MCentral -{ - Lock; - int32 sizeclass; - MSpan nonempty; - MSpan empty; - int32 nfree; -}; - -void runtime·MCentral_Init(MCentral *c, int32 sizeclass); -int32 runtime·MCentral_AllocList(MCentral *c, int32 n, MLink **first); -void runtime·MCentral_FreeList(MCentral *c, int32 n, MLink *first); - -// Main malloc heap. -// The heap itself is the "free[]" and "large" arrays, -// but all the other global data is here too. -struct MHeap -{ - Lock; - MSpan free[MaxMHeapList]; // free lists of given length - MSpan large; // free lists length >= MaxMHeapList - MSpan *allspans; - - // span lookup - MSpan *map[1<<MHeapMap_Bits]; - - // range of addresses we might see in the heap - byte *bitmap; - uintptr bitmap_mapped; - byte *arena_start; - byte *arena_used; - byte *arena_end; - - // central free lists for small size classes. - // the union makes sure that the MCentrals are - // spaced 64 bytes apart, so that each MCentral.Lock - // gets its own cache line. - union { - MCentral; - byte pad[64]; - } central[NumSizeClasses]; - - FixAlloc spanalloc; // allocator for Span* - FixAlloc cachealloc; // allocator for MCache* -}; -extern MHeap runtime·mheap; - -void runtime·MHeap_Init(MHeap *h, void *(*allocator)(uintptr)); -MSpan* runtime·MHeap_Alloc(MHeap *h, uintptr npage, int32 sizeclass, int32 acct); -void runtime·MHeap_Free(MHeap *h, MSpan *s, int32 acct); -MSpan* runtime·MHeap_Lookup(MHeap *h, void *v); -MSpan* runtime·MHeap_LookupMaybe(MHeap *h, void *v); -void runtime·MGetSizeClassInfo(int32 sizeclass, uintptr *size, int32 *npages, int32 *nobj); -void* runtime·MHeap_SysAlloc(MHeap *h, uintptr n); -void runtime·MHeap_MapBits(MHeap *h); - -void* runtime·mallocgc(uintptr size, uint32 flag, int32 dogc, int32 zeroed); -int32 runtime·mlookup(void *v, byte **base, uintptr *size, MSpan **s); -void runtime·gc(int32 force); -void runtime·markallocated(void *v, uintptr n, bool noptr); -void runtime·checkallocated(void *v, uintptr n); -void runtime·markfreed(void *v, uintptr n); -void runtime·checkfreed(void *v, uintptr n); -int32 runtime·checking; -void runtime·markspan(void *v, uintptr size, uintptr n, bool leftover); -void runtime·unmarkspan(void *v, uintptr size); -bool runtime·blockspecial(void*); -void runtime·setblockspecial(void*); - -enum -{ - // flags to malloc - FlagNoPointers = 1<<0, // no pointers here - FlagNoProfiling = 1<<1, // must not profile - FlagNoGC = 1<<2, // must not free or scan for pointers -}; - -void runtime·MProf_Malloc(void*, uintptr); -void runtime·MProf_Free(void*, uintptr); - -// Malloc profiling settings. -// Must match definition in extern.go. -enum { - MProf_None = 0, - MProf_Sample = 1, - MProf_All = 2, -}; -extern int32 runtime·malloc_profile; - -typedef struct Finalizer Finalizer; -struct Finalizer -{ - Finalizer *next; // for use by caller of getfinalizer - void (*fn)(void*); - void *arg; - int32 nret; -}; - -Finalizer* runtime·getfinalizer(void*, bool); |