tree 4ed37024eb41cd46d312018a948cce6e2f6b9434
parent b63ff32f531946a13d80f9340aaa8acf692cf145
author Daniel Colascione <dancol@google.com> 1567543343 -0700
committer Daniel Colascione <dancol@google.com> 1567560477 -0700

Make android_os_Process_readProcFile allocate less

Make android_os_Process_readProcFile read small proc files into a
stack-allocated buffer and fall back to the heap only for larger
files. Avoid pointless zeroing of memory that we're going to use for
read() buffers. Read proc files atomically instead of
piece-by-piece. Use Android RAII helpers instead of explicit
resource management.

Bug: 140439982
Test: booted, works
Change-Id: Ifc02a4bbab0cfd968aff841d7ce0af846db613eb