Merge pull request #979 from EXetoC/alloc-overloads

More updates to the allocation interface

lib/system.nim

@@ -1164,13 +1164,13 @@ when not defined(nimrodVM):
       ## from it before writing to it is undefined behaviour!
       ## The allocated memory belongs to its allocating thread!
       ## Use `allocShared` to allocate from a shared heap.
-    proc alloc*(T: typedesc, size = 1): ptr T {.inline.} =
+    proc createU*(T: typedesc, size = 1.Positive): ptr T {.inline.} =
       ## allocates a new memory block with at least ``T.sizeof * size``
-      ## bytes. The block has to be freed with ``realloc(block, 0)`` or
-      ## ``dealloc(block)``. The block is not initialized, so reading
+      ## bytes. The block has to be freed with ``resize(block, 0)`` or
+      ## ``free(block)``. 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` to allocate from a shared heap.
+      ## Use `createSharedU` to allocate from a shared heap.
       cast[ptr T](alloc(T.sizeof * size))
     proc alloc0*(size: int): pointer {.noconv, rtl, tags: [].}
       ## allocates a new memory block with at least ``size`` bytes. The
@@ -1179,13 +1179,13 @@ when not defined(nimrodVM):
       ## containing zero, so it is somewhat safer than ``alloc``.
       ## The allocated memory belongs to its allocating thread!
       ## Use `allocShared0` to allocate from a shared heap.
-    proc alloc0*(T: typedesc, size = 1): ptr T {.inline.} =
+    proc create*(T: typedesc, size = 1.Positive): ptr T {.inline.} =
       ## allocates a new memory block with at least ``T.sizeof * size``
-      ## bytes. The block has to be freed with ``realloc(block, 0)`` or
-      ## ``dealloc(block)``. The block is initialized with all bytes
-      ## containing zero, so it is somewhat safer than ``alloc``.
+      ## bytes. The block has to be freed with ``resize(block, 0)`` or
+      ## ``free(block)``. The block is initialized with all bytes
+      ## containing zero, so it is somewhat safer than ``createU``.
       ## The allocated memory belongs to its allocating thread!
-      ## Use `allocShared0` to allocate from a shared heap.
+      ## Use `createShared` to allocate from a shared heap.
       cast[ptr T](alloc0(T.sizeof * size))
     proc realloc*(p: pointer, newSize: int): pointer {.noconv, rtl, tags: [].}
       ## grows or shrinks a given memory block. If p is **nil** then a new
@@ -1195,14 +1195,14 @@ when not defined(nimrodVM):
       ## be freed with ``dealloc``.
       ## The allocated memory belongs to its allocating thread!
       ## Use `reallocShared` to reallocate from a shared heap.
-    proc reallocType*[T](p: ptr T, newSize: int): ptr T {.inline.} =
+    proc resize*[T](p: ptr T, newSize: Natural): ptr T {.inline.} =
       ## 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** ``realloc`` calls ``dealloc(p)``. In other cases the block
-      ## has to be freed with ``dealloc``. The allocated memory belongs to
+      ## **nil** ``resize`` calls ``free(p)``. In other cases the block
+      ## has to be freed with ``free``. The allocated memory belongs to
       ## its allocating thread!
-      ## Use `reallocShared` to reallocate from a shared heap.
+      ## Use `resizeShared` to reallocate from a shared heap.
       cast[ptr T](realloc(p, T.sizeof * newSize))
     proc dealloc*(p: pointer) {.noconv, rtl, tags: [].}
       ## frees the memory allocated with ``alloc``, ``alloc0`` or
@@ -1212,16 +1212,18 @@ when not defined(nimrodVM):
       ## or other memory may be corrupted. 
       ## The freed memory must belong to its allocating thread!
       ## Use `deallocShared` to deallocate from a shared heap.
+    proc free*[T](p: ptr T) {.inline.} =
+      dealloc(p)
     proc allocShared*(size: int): pointer {.noconv, rtl.}
       ## allocates a new memory block on the shared heap with at
       ## least ``size`` bytes. The block has to be freed with
       ## ``reallocShared(block, 0)`` or ``deallocShared(block)``. The block
       ## is not initialized, so reading from it before writing to it is 
       ## undefined behaviour!
-    proc allocShared*(T: typedesc, size: int): ptr T {.inline.} =
+    proc createSharedU*(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
-      ## ``reallocShared(block, 0)`` or ``deallocShared(block)``. The block
+      ## ``resizeShared(block, 0)`` or ``freeShared(block)``. The block
       ## is not initialized, so reading from it before writing to it is 
       ## undefined behaviour!
       cast[ptr T](allocShared(T.sizeof * size))
@@ -1231,25 +1233,25 @@ when not defined(nimrodVM):
       ## ``reallocShared(block, 0)`` or ``deallocShared(block)``.
       ## The block is initialized with all bytes
       ## containing zero, so it is somewhat safer than ``allocShared``.
-    proc allocShared0*(T: typedesc, size: int): ptr T {.inline.} =
+    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
-      ## ``reallocShared(block, 0)`` or ``deallocShared(block)``.
+      ## ``resizeShared(block, 0)`` or ``freeShared(block)``.
       ## The block is initialized with all bytes
-      ## containing zero, so it is somewhat safer than ``allocShared``.
-      cast[ptr T](allocShared(T.sizeof * size))
+      ## containing zero, so it is somewhat safer than ``createSharedU``.
+      cast[ptr T](allocShared0(T.sizeof * size))
     proc reallocShared*(p: pointer, newSize: int): pointer {.noconv, rtl.}
       ## 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``.
-    proc reallocSharedType*[T](p: ptr T, newSize: int): ptr T {.inline.} =
+    proc resizeShared*[T](p: ptr T, newSize: Natural): ptr T {.inline.} =
       ## 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** ``reallocShared`` calls ``deallocShared(p)``. In other
-      ## cases the block has to be freed with ``deallocShared``.
+      ## not **nil** ``resizeShared`` calls ``freeShared(p)``. In other
+      ## cases the block has to be freed with ``freeShared``.
       cast[ptr T](reallocShared(p, T.sizeof * newSize))
     proc deallocShared*(p: pointer) {.noconv, rtl.}
       ## frees the memory allocated with ``allocShared``, ``allocShared0`` or
@@ -1257,6 +1259,13 @@ when not defined(nimrodVM):
       ## 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.
+    proc freeShared*[T](p: ptr T) {.inline.} =
+      ## 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)
 
 proc swap*[T](a, b: var T) {.magic: "Swap", noSideEffect.}
   ## swaps the values `a` and `b`. This is often more efficient than

tests/system/alloc.nim

@@ -2,44 +2,51 @@ var x: ptr int
 
 x = cast[ptr int](alloc(7))
 assert x != nil
-
-x = alloc(int, 3)
+x = cast[ptr int](x.realloc(2))
 assert x != nil
 x.dealloc()
 
-x = alloc0(int, 4)
+x = createU(int, 3)
+assert x != nil
+x.free()
+
+x = create(int, 4)
 assert cast[ptr array[4, int]](x)[0] == 0
 assert cast[ptr array[4, int]](x)[1] == 0
 assert cast[ptr array[4, int]](x)[2] == 0
 assert cast[ptr array[4, int]](x)[3] == 0
 
-x = cast[ptr int](x.realloc(2))
+x = x.resize(4)
 assert x != nil
-
-x = x.reallocType(4)
-assert x != nil
-x.dealloc()
+x.free()
 
 x = cast[ptr int](allocShared(100))
 assert x != nil
 deallocShared(x)
 
-x = allocShared(int, 3)
+x = createSharedU(int, 3)
 assert x != nil
-x.deallocShared()
+x.freeShared()
 
-x = allocShared0(int, 3)
+x = createShared(int, 3)
 assert x != nil
 assert cast[ptr array[3, int]](x)[0] == 0
 assert cast[ptr array[3, int]](x)[1] == 0
 assert cast[ptr array[3, int]](x)[2] == 0
 
-x = cast[ptr int](reallocShared(x, 2))
 assert x != nil
+x = cast[ptr int](x.resizeShared(2))
+assert x != nil
+x.freeShared()
 
-x = reallocType(x, 12)
+x = create(int, 10)
 assert x != nil
+x = x.resize(12)
+assert x != nil
+x.dealloc()
 
-x = reallocSharedType(x, 1)
+x = createShared(int, 1)
 assert x != nil
-x.deallocShared()
+x = x.resizeShared(1)
+assert x != nil
+x.freeShared()