bpo-32798: Add restriction on the offset parameter for mmap.flush in the docs (GH...

Add restriction on the offset parameter for mmap.flush.

Explain that ALLOCATIONGRANULARITY is the same as PAGESIZE in Unix.
(cherry picked from commit 027664a3d5ebad575aafe5fcc572e3b05f7f24e5)

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>

diff --git a/Doc/library/mmap.rst b/Doc/library/mmap.rst
index d965fa36b47aea050b52e72311484347d1b5855a..6c0f9a0d1255d51d42dfdb9d10f9c4cffe655e68 100644 (file)
--- a/Doc/library/mmap.rst
+++ b/Doc/library/mmap.rst
@@ -61,7 +61,7 @@ To map anonymous memory, -1 should be passed as the fileno along with the length
 
    *offset* may be specified as a non-negative integer offset. mmap references
    will be relative to the offset from the beginning of the file. *offset*
-   defaults to 0.  *offset* must be a multiple of the ALLOCATIONGRANULARITY.
+   defaults to 0.  *offset* must be a multiple of the :const:`ALLOCATIONGRANULARITY`.
 
 
 .. class:: mmap(fileno, length, flags=MAP_SHARED, prot=PROT_WRITE|PROT_READ, access=ACCESS_DEFAULT[, offset])
@@ -90,8 +90,8 @@ To map anonymous memory, -1 should be passed as the fileno along with the length
 
    *offset* may be specified as a non-negative integer offset. mmap references
    will be relative to the offset from the beginning of the file. *offset*
-   defaults to 0.  *offset* must be a multiple of the PAGESIZE or
-   ALLOCATIONGRANULARITY.
+   defaults to 0. *offset* must be a multiple of :const:`ALLOCATIONGRANULARITY`
+   which is equal to :const:`PAGESIZE` on Unix systems.
 
    To ensure validity of the created memory mapping the file specified
    by the descriptor *fileno* is internally automatically synchronized
@@ -185,7 +185,8 @@ To map anonymous memory, -1 should be passed as the fileno along with the length
       use of this call there is no guarantee that changes are written back before
       the object is destroyed.  If *offset* and *size* are specified, only
       changes to the given range of bytes will be flushed to disk; otherwise, the
-      whole extent of the mapping is flushed.
+      whole extent of the mapping is flushed.  *offset* must be a multiple of the
+      :const:`PAGESIZE` or :const:`ALLOCATIONGRANULARITY`.
 
       **(Windows version)** A nonzero value returned indicates success; zero
       indicates failure.