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llvm-project/llvm/lib/Support/Unix
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Rui Ueyama 7c8fc8142e MemoryBlock: Do not automatically extend a given size to a multiple of page size. 
Previously, MemoryBlock automatically extends a requested buffer size to a
multiple of page size because (I believe) doing it was thought to be harmless
and with that you could get more memory (on average 2KiB on 4KiB-page systems)
"for free".

That programming interface turned out to be error-prone. If you request N
bytes, you usually expect that a resulting object returns N for `size()`.
That's not the case for MemoryBlock.

Looks like there is only one place where we take the advantage of
allocating more memory than the requested size. So, with this patch, I
simply removed the automatic size expansion feature from MemoryBlock
and do it on the caller side when needed. MemoryBlock now always
returns a buffer whose size is equal to the requested size.

Differential Revision: https://reviews.llvm.org/D56941

llvm-svn: 351916
 		2019-01-23 02:03:26 +00:00
..
COM.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
DynamicLibrary.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Host.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Memory.inc MemoryBlock: Do not automatically extend a given size to a multiple of page size. 2019-01-23 02:03:26 +00:00
Mutex.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Path.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Process.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Program.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
README.txt
…
RWMutex.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Signals.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
ThreadLocal.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Threading.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Unix.h Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
Watchdog.inc Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00

README.txt 

llvm/lib/Support/Unix README
===========================

This directory provides implementations of the lib/System classes that
are common to two or more variants of UNIX. For example, the directory
structure underneath this directory could look like this:

Unix           - only code that is truly generic to all UNIX platforms
  Posix        - code that is specific to Posix variants of UNIX
  SUS          - code that is specific to the Single Unix Specification
  SysV         - code that is specific to System V variants of UNIX

As a rule, only those directories actually needing to be created should be
created. Also, further subdirectories could be created to reflect versions of
the various standards. For example, under SUS there could be v1, v2, and v3
subdirectories to reflect the three major versions of SUS.