diff options
Diffstat (limited to 'lib/system/memalloc.nim')
| -rw-r--r-- | lib/system/memalloc.nim | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/lib/system/memalloc.nim b/lib/system/memalloc.nim new file mode 100644 index 000000000..a94d0995c --- /dev/null +++ b/lib/system/memalloc.nim @@ -0,0 +1,449 @@ +when notJSnotNims: + proc zeroMem*(p: pointer, size: Natural) {.inline, noSideEffect, + tags: [], raises: [].} + ## Overwrites the contents of the memory at `p` with the value 0. + ## + ## Exactly `size` bytes will be overwritten. Like any procedure + ## dealing with raw memory this is **unsafe**. + + proc copyMem*(dest, source: pointer, size: Natural) {.inline, benign, + tags: [], raises: [].} + ## Copies the contents from the memory at `source` to the memory + ## at `dest`. + ## Exactly `size` bytes will be copied. The memory + ## regions may not overlap. Like any procedure dealing with raw + ## memory this is **unsafe**. + + proc moveMem*(dest, source: pointer, size: Natural) {.inline, benign, + tags: [], raises: [].} + ## Copies the contents from the memory at `source` to the memory + ## at `dest`. + ## + ## Exactly `size` bytes will be copied. The memory + ## regions may overlap, `moveMem` handles this case appropriately + ## and is thus somewhat more safe than `copyMem`. Like any procedure + ## dealing with raw memory this is still **unsafe**, though. + + proc equalMem*(a, b: pointer, size: Natural): bool {.inline, noSideEffect, + tags: [], raises: [].} + ## Compares the memory blocks `a` and `b`. `size` bytes will + ## be compared. + ## + ## If the blocks are equal, `true` is returned, `false` + ## otherwise. Like any procedure dealing with raw memory this is + ## **unsafe**. + + proc cmpMem*(a, b: pointer, size: Natural): int {.inline, noSideEffect, + tags: [], raises: [].} + ## Compares the memory blocks `a` and `b`. `size` bytes will + ## be compared. + ## + ## Returns: + ## * a value less than zero, if `a < b` + ## * a value greater than zero, if `a > b` + ## * zero, if `a == b` + ## + ## Like any procedure dealing with raw memory this is + ## **unsafe**. + +when hasAlloc and not defined(js): + + proc allocImpl*(size: Natural): pointer {.noconv, rtl, tags: [], benign, raises: [].} + proc alloc0Impl*(size: Natural): pointer {.noconv, rtl, tags: [], benign, raises: [].} + proc deallocImpl*(p: pointer) {.noconv, rtl, tags: [], benign, raises: [].} + proc reallocImpl*(p: pointer, newSize: Natural): pointer {.noconv, rtl, tags: [], benign, raises: [].} + proc realloc0Impl*(p: pointer, oldSize, newSize: Natural): pointer {.noconv, rtl, tags: [], benign, raises: [].} + + proc allocSharedImpl*(size: Natural): pointer {.noconv, compilerproc, rtl, benign, raises: [], tags: [].} + proc allocShared0Impl*(size: Natural): pointer {.noconv, rtl, benign, raises: [], tags: [].} + proc deallocSharedImpl*(p: pointer) {.noconv, rtl, benign, raises: [], tags: [].} + proc reallocSharedImpl*(p: pointer, newSize: Natural): pointer {.noconv, rtl, tags: [], benign, raises: [].} + proc reallocShared0Impl*(p: pointer, oldSize, newSize: Natural): pointer {.noconv, rtl, tags: [], benign, raises: [].} + + # Allocator statistics for memory leak tests + + {.push stackTrace: off.} + + type AllocStats* = object + allocCount: int + deallocCount: int + + proc `-`*(a, b: AllocStats): AllocStats = + result.allocCount = a.allocCount - b.allocCount + result.deallocCount = a.deallocCount - b.deallocCount + + template dumpAllocstats*(code: untyped) = + let stats1 = getAllocStats() + code + let stats2 = getAllocStats() + echo $(stats2 - stats1) + + when defined(nimAllocStats): + var stats: AllocStats + template incStat(what: untyped) = atomicInc stats.what + proc getAllocStats*(): AllocStats = stats + + else: + template incStat(what: untyped) = discard + proc getAllocStats*(): AllocStats = discard + + template alloc*(size: Natural): pointer = + ## Allocates a new memory block with at least `size` bytes. + ## + ## The block has to be freed with `realloc(block, 0) <#realloc.t,pointer,Natural>`_ + ## or `dealloc(block) <#dealloc,pointer>`_. + ## The block is not initialized, so reading + ## from it before writing to it is undefined behaviour! + ## + ## The allocated memory belongs to its allocating thread! + ## Use `allocShared <#allocShared.t,Natural>`_ to allocate from a shared heap. + ## + ## See also: + ## * `alloc0 <#alloc0.t,Natural>`_ + incStat(allocCount) + allocImpl(size) + + proc createU*(T: typedesc, size = 1.Positive): ptr T {.inline, benign, raises: [].} = + ## Allocates a new memory block with at least `T.sizeof * size` bytes. + ## + ## The block has to be freed with `resize(block, 0) <#resize,ptr.T,Natural>`_ + ## or `dealloc(block) <#dealloc,pointer>`_. + ## The block is not initialized, so reading + ## from it before writing to it is undefined behaviour! + ## + ## The allocated memory belongs to its allocating thread! + ## Use `createSharedU <#createSharedU,typedesc>`_ to allocate from a shared heap. + ## + ## See also: + ## * `create <#create,typedesc>`_ + cast[ptr T](alloc(T.sizeof * size)) + + template alloc0*(size: Natural): pointer = + ## Allocates a new memory block with at least `size` bytes. + ## + ## The block has to be freed with `realloc(block, 0) <#realloc.t,pointer,Natural>`_ + ## or `dealloc(block) <#dealloc,pointer>`_. + ## The block is initialized with all bytes containing zero, so it is + ## somewhat safer than `alloc <#alloc.t,Natural>`_. + ## + ## The allocated memory belongs to its allocating thread! + ## Use `allocShared0 <#allocShared0.t,Natural>`_ to allocate from a shared heap. + incStat(allocCount) + alloc0Impl(size) + + proc create*(T: typedesc, size = 1.Positive): ptr T {.inline, benign, raises: [].} = + ## Allocates a new memory block with at least `T.sizeof * size` bytes. + ## + ## The block has to be freed with `resize(block, 0) <#resize,ptr.T,Natural>`_ + ## or `dealloc(block) <#dealloc,pointer>`_. + ## The block is initialized with all bytes containing zero, so it is + ## somewhat safer than `createU <#createU,typedesc>`_. + ## + ## The allocated memory belongs to its allocating thread! + ## Use `createShared <#createShared,typedesc>`_ to allocate from a shared heap. + cast[ptr T](alloc0(sizeof(T) * size)) + + template realloc*(p: pointer, newSize: Natural): pointer = + ## Grows or shrinks a given memory block. + ## + ## If `p` is **nil** then a new memory block is returned. + ## In either way the block has at least `newSize` bytes. + ## If `newSize == 0` and `p` is not **nil** `realloc` calls `dealloc(p)`. + ## In other cases the block has to be freed with + ## `dealloc(block) <#dealloc,pointer>`_. + ## + ## The allocated memory belongs to its allocating thread! + ## Use `reallocShared <#reallocShared.t,pointer,Natural>`_ to reallocate + ## from a shared heap. + reallocImpl(p, newSize) + + template realloc0*(p: pointer, oldSize, newSize: Natural): pointer = + ## Grows or shrinks a given memory block. + ## + ## If `p` is **nil** then a new memory block is returned. + ## In either way the block has at least `newSize` bytes. + ## If `newSize == 0` and `p` is not **nil** `realloc` calls `dealloc(p)`. + ## In other cases the block has to be freed with + ## `dealloc(block) <#dealloc,pointer>`_. + ## + ## The block is initialized with all bytes containing zero, so it is + ## somewhat safer then realloc + ## + ## The allocated memory belongs to its allocating thread! + ## Use `reallocShared <#reallocShared.t,pointer,Natural>`_ to reallocate + ## from a shared heap. + realloc0Impl(p, oldSize, newSize) + + proc resize*[T](p: ptr T, newSize: Natural): ptr T {.inline, benign, raises: [].} = + ## Grows or shrinks a given memory block. + ## + ## If `p` is **nil** then a new memory block is returned. + ## In either way the block has at least `T.sizeof * newSize` bytes. + ## If `newSize == 0` and `p` is not **nil** `resize` calls `dealloc(p)`. + ## In other cases the block has to be freed with `free`. + ## + ## The allocated memory belongs to its allocating thread! + ## Use `resizeShared <#resizeShared,ptr.T,Natural>`_ to reallocate + ## from a shared heap. + cast[ptr T](realloc(p, T.sizeof * newSize)) + + proc dealloc*(p: pointer) {.noconv, compilerproc, rtl, benign, raises: [], tags: [].} = + ## Frees the memory allocated with `alloc`, `alloc0`, + ## `realloc`, `create` or `createU`. + ## + ## **This procedure is dangerous!** + ## If one forgets to free the memory a leak occurs; if one tries to + ## access freed memory (or just freeing it twice!) a core dump may happen + ## or other memory may be corrupted. + ## + ## The freed memory must belong to its allocating thread! + ## Use `deallocShared <#deallocShared,pointer>`_ to deallocate from a shared heap. + incStat(deallocCount) + deallocImpl(p) + + template allocShared*(size: Natural): pointer = + ## Allocates a new memory block on the shared heap with at + ## least `size` bytes. + ## + ## The block has to be freed with + ## `reallocShared(block, 0) <#reallocShared.t,pointer,Natural>`_ + ## or `deallocShared(block) <#deallocShared,pointer>`_. + ## + ## The block is not initialized, so reading from it before writing + ## to it is undefined behaviour! + ## + ## See also: + ## * `allocShared0 <#allocShared0.t,Natural>`_. + incStat(allocCount) + allocSharedImpl(size) + + proc createSharedU*(T: typedesc, size = 1.Positive): ptr T {.inline, tags: [], + benign, raises: [].} = + ## Allocates a new memory block on the shared heap with at + ## least `T.sizeof * size` bytes. + ## + ## The block has to be freed with + ## `resizeShared(block, 0) <#resizeShared,ptr.T,Natural>`_ or + ## `freeShared(block) <#freeShared,ptr.T>`_. + ## + ## The block is not initialized, so reading from it before writing + ## to it is undefined behaviour! + ## + ## See also: + ## * `createShared <#createShared,typedesc>`_ + cast[ptr T](allocShared(T.sizeof * size)) + + template allocShared0*(size: Natural): pointer = + ## Allocates a new memory block on the shared heap with at + ## least `size` bytes. + ## + ## The block has to be freed with + ## `reallocShared(block, 0) <#reallocShared.t,pointer,Natural>`_ + ## or `deallocShared(block) <#deallocShared,pointer>`_. + ## + ## The block is initialized with all bytes + ## containing zero, so it is somewhat safer than + ## `allocShared <#allocShared.t,Natural>`_. + incStat(allocCount) + allocShared0Impl(size) + + proc createShared*(T: typedesc, size = 1.Positive): ptr T {.inline.} = + ## Allocates a new memory block on the shared heap with at + ## least `T.sizeof * size` bytes. + ## + ## The block has to be freed with + ## `resizeShared(block, 0) <#resizeShared,ptr.T,Natural>`_ or + ## `freeShared(block) <#freeShared,ptr.T>`_. + ## + ## The block is initialized with all bytes + ## containing zero, so it is somewhat safer than + ## `createSharedU <#createSharedU,typedesc>`_. + cast[ptr T](allocShared0(T.sizeof * size)) + + template reallocShared*(p: pointer, newSize: Natural): pointer = + ## Grows or shrinks a given memory block on the heap. + ## + ## If `p` is **nil** then a new memory block is returned. + ## In either way the block has at least `newSize` bytes. + ## If `newSize == 0` and `p` is not **nil** `reallocShared` calls + ## `deallocShared(p)`. + ## In other cases the block has to be freed with + ## `deallocShared <#deallocShared,pointer>`_. + reallocSharedImpl(p, newSize) + + template reallocShared0*(p: pointer, oldSize, newSize: Natural): pointer = + ## Grows or shrinks a given memory block on the heap. + ## + ## When growing, the new bytes of the block is initialized with all bytes + ## containing zero, so it is somewhat safer then reallocShared + ## + ## If `p` is **nil** then a new memory block is returned. + ## In either way the block has at least `newSize` bytes. + ## If `newSize == 0` and `p` is not **nil** `reallocShared` calls + ## `deallocShared(p)`. + ## In other cases the block has to be freed with + ## `deallocShared <#deallocShared,pointer>`_. + reallocShared0Impl(p, oldSize, newSize) + + proc resizeShared*[T](p: ptr T, newSize: Natural): ptr T {.inline, raises: [].} = + ## Grows or shrinks a given memory block on the heap. + ## + ## If `p` is **nil** then a new memory block is returned. + ## In either way the block has at least `T.sizeof * newSize` bytes. + ## If `newSize == 0` and `p` is not **nil** `resizeShared` calls + ## `freeShared(p)`. + ## In other cases the block has to be freed with + ## `freeShared <#freeShared,ptr.T>`_. + cast[ptr T](reallocShared(p, T.sizeof * newSize)) + + proc deallocShared*(p: pointer) {.noconv, compilerproc, rtl, benign, raises: [], tags: [].} = + ## Frees the memory allocated with `allocShared`, `allocShared0` or + ## `reallocShared`. + ## + ## **This procedure is dangerous!** + ## If one forgets to free the memory a leak occurs; if one tries to + ## access freed memory (or just freeing it twice!) a core dump may happen + ## or other memory may be corrupted. + incStat(deallocCount) + deallocSharedImpl(p) + + proc freeShared*[T](p: ptr T) {.inline, benign, raises: [].} = + ## Frees the memory allocated with `createShared`, `createSharedU` or + ## `resizeShared`. + ## + ## **This procedure is dangerous!** + ## If one forgets to free the memory a leak occurs; if one tries to + ## access freed memory (or just freeing it twice!) a core dump may happen + ## or other memory may be corrupted. + deallocShared(p) + + include bitmasks + + template `+!`(p: pointer, s: SomeInteger): pointer = + cast[pointer](cast[int](p) +% int(s)) + + template `-!`(p: pointer, s: SomeInteger): pointer = + cast[pointer](cast[int](p) -% int(s)) + + proc alignedAlloc(size, align: Natural): pointer = + if align <= MemAlign: + when compileOption("threads"): + result = allocShared(size) + else: + result = alloc(size) + else: + # allocate (size + align - 1) necessary for alignment, + # plus 2 bytes to store offset + when compileOption("threads"): + let base = allocShared(size + align - 1 + sizeof(uint16)) + else: + let base = alloc(size + align - 1 + sizeof(uint16)) + # memory layout: padding + offset (2 bytes) + user_data + # in order to deallocate: read offset at user_data - 2 bytes, + # then deallocate user_data - offset + let offset = align - (cast[int](base) and (align - 1)) + cast[ptr uint16](base +! (offset - sizeof(uint16)))[] = uint16(offset) + result = base +! offset + + proc alignedAlloc0(size, align: Natural): pointer = + if align <= MemAlign: + when compileOption("threads"): + result = allocShared0(size) + else: + result = alloc0(size) + else: + # see comments for alignedAlloc + when compileOption("threads"): + let base = allocShared0(size + align - 1 + sizeof(uint16)) + else: + let base = alloc0(size + align - 1 + sizeof(uint16)) + let offset = align - (cast[int](base) and (align - 1)) + cast[ptr uint16](base +! (offset - sizeof(uint16)))[] = uint16(offset) + result = base +! offset + + proc alignedDealloc(p: pointer, align: int) {.compilerproc.} = + if align <= MemAlign: + when compileOption("threads"): + deallocShared(p) + else: + dealloc(p) + else: + # read offset at p - 2 bytes, then deallocate (p - offset) pointer + let offset = cast[ptr uint16](p -! sizeof(uint16))[] + when compileOption("threads"): + deallocShared(p -! offset) + else: + dealloc(p -! offset) + + proc alignedRealloc(p: pointer, oldSize, newSize, align: Natural): pointer = + if align <= MemAlign: + when compileOption("threads"): + result = reallocShared(p, newSize) + else: + result = realloc(p, newSize) + else: + result = alignedAlloc(newSize, align) + copyMem(result, p, oldSize) + alignedDealloc(p, align) + + proc alignedRealloc0(p: pointer, oldSize, newSize, align: Natural): pointer = + if align <= MemAlign: + when compileOption("threads"): + result = reallocShared0(p, oldSize, newSize) + else: + result = realloc0(p, oldSize, newSize) + else: + result = alignedAlloc(newSize, align) + copyMem(result, p, oldSize) + zeroMem(result +! oldSize, newSize - oldSize) + alignedDealloc(p, align) + + {.pop.} + +# GC interface: + +when hasAlloc: + proc getOccupiedMem*(): int {.rtl.} + ## Returns the number of bytes that are owned by the process and hold data. + + proc getFreeMem*(): int {.rtl.} + ## Returns the number of bytes that are owned by the process, but do not + ## hold any meaningful data. + + proc getTotalMem*(): int {.rtl.} + ## Returns the number of bytes that are owned by the process. + + +when defined(js): + # Stubs: + proc getOccupiedMem(): int = return -1 + proc getFreeMem(): int = return -1 + proc getTotalMem(): int = return -1 + + proc dealloc(p: pointer) = discard + proc alloc(size: Natural): pointer = discard + proc alloc0(size: Natural): pointer = discard + proc realloc(p: pointer, newsize: Natural): pointer = discard + proc realloc0(p: pointer, oldsize, newsize: Natural): pointer = discard + + proc allocShared(size: Natural): pointer = discard + proc allocShared0(size: Natural): pointer = discard + proc deallocShared(p: pointer) = discard + proc reallocShared(p: pointer, newsize: Natural): pointer = discard + proc reallocShared0(p: pointer, oldsize, newsize: Natural): pointer = discard + + +when hasAlloc and hasThreadSupport and not defined(useMalloc): + proc getOccupiedSharedMem*(): int {.rtl.} + ## Returns the number of bytes that are owned by the process + ## on the shared heap and hold data. This is only available when + ## threads are enabled. + + proc getFreeSharedMem*(): int {.rtl.} + ## Returns the number of bytes that are owned by the + ## process on the shared heap, but do not hold any meaningful data. + ## This is only available when threads are enabled. + + proc getTotalSharedMem*(): int {.rtl.} + ## Returns the number of bytes on the shared heap that are owned by the + ## process. This is only available when threads are enabled. |