1662564 - Use RAII classes in base::SharedMemory

Status: RESOLVED FIXED

(Core :: IPC, enhancement)

Description

[Jed Davis [:jld] (on leave until 08-31)]

I have some cleanups for base::SharedMemory in my topic branch for bug 1440203 that I'm breaking out into a separate bug:

1. Using mozilla::UniqueFileHandle instead of raw ints/HANDLEs. This makes it easier to avoid fd/handle leaks or double closes, which is useful given how freezing and memfd both increase the complexity of this code, and slightly reduces the per-platform code here.

2. Changing the mapped memory to a UniquePtr instance, with a stateful deleter on POSIX platforms. This encapsulates some things that have caused problems in the past. More usefully, combined with the above change, this allows = defaulting the default and move constructors; in the past it's been too easy to forget to handle a new or changed field in one of them.

Comment 1

[Jed Davis [:jld] (on leave until 08-31)]

Attachment: Bug 1662564 - Change IPC base::SharedMemory to use RAII for file descriptors/handles.

Comment 2

[Jed Davis [:jld] (on leave until 08-31)]

Attachment: Bug 1662564 - Use RAII for the memory mapping in IPC base::SharedMemory, and default its constructors.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3a2941fa7d4b
Change IPC base::SharedMemory to use RAII for file descriptors/handles. r=nika
https://hg.mozilla.org/integration/autoland/rev/f6527a1d0f14
Use RAII for the memory mapping in IPC base::SharedMemory, and default its constructors. r=nika

Comment 4

[Razvan Maries]

Backed out for Valgrind bustages.

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&selectedTaskRun=RO-jBvxyQjCie-3N8Gcqow.0&resultStatus=pending%2Crunning%2Csuccess%2Ctestfailed%2Cbusted%2Cexception&searchStr=linux%2Cx64%2Copt%2Cvalgrind-linux64-valgrind%2Fopt%2Cv&revision=9366b15ee97cfe97ab9e00dbad6dd4a981fe965b

Log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=317836923&repo=autoland&lineNumber=64229

Backout: https://hg.mozilla.org/integration/autoland/rev/007e30d27d93106dac27d9ca988cc58d2fd53863

Comment 5

[Jed Davis [:jld] (on leave until 08-31)]

See bug 1440203 comment #19.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/08a6fb2b9100
Change IPC base::SharedMemory to use RAII for file descriptors/handles. r=nika
https://hg.mozilla.org/integration/autoland/rev/ad1bd0312bcd
Use RAII for the memory mapping in IPC base::SharedMemory, and default its constructors. r=nika

Comment 7

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/08a6fb2b9100
https://hg.mozilla.org/mozilla-central/rev/ad1bd0312bcd