author Andrew McCreight <>
Mon, 22 Apr 2019 16:34:51 +0000
changeset 470376 3073770e06f157040f4c64951b7e8425e1ad7bbe
parent 469492 ef00d4a58102a86d99a48a350d51941500b133cd
child 471064 df4c4083aff8d84ff17010249d08e7b6dc6f9beb
permissions -rw-r--r--
Bug 1535403 - Take indirection into account for the CC optimizations for the outer window wrapper. r=peterv Most wrapper cached C++ objects are held alive by their wrapper. The cycle collector takes advantage of this in many classes and ignores the C++ object if the wrapper is marked black. However, this is not true for the outer window's wrapper. Instead, the outer window's wrapper keeps the inner window alive. The inner window usually keeps its outer window alive, but not after it has been unlinked. For reasons I do not yet understand, the outer window's wrapper can be kept alive after the inner window it is a proxy for is unlinked. This patch fixes the cycle collector optimization for the outer window by only applying it if the outer window still has a weak reference to the inner window, which it will until the inner no longer holds the outer alive. This in turn fixes, or at least helps fix, window leaks seen intermittently when the lifetime of outer windows and docshells are tied together. The code comment is based on a review comment by peterv. Differential Revision:


# These are the "root" crates, which we build and test as top-level targets.
# Their transitive dependencies and dev-dependencies are included automatically
# and do not need to be listed here. Their external dependencies are vendored
# into `third_party/rust` by `mach vendor rust`.
members = [
  "js/src/frontend/binast", # Code generator.

# Excluded crates may be built as dependencies, but won't be considered members
# of the workspace and their dev-dependencies won't be included.
exclude = [
  # Exclude third-party code vendored into mozilla-central.

  # Excluded because these crates have their own Cargo workspaces so they can't
  # be included in the top-level one.

  # Excluded because they are used only as dependencies, not top-level targets,
  # so we don't need to vendor their dev-dependencies.

# Explicitly specify what our profiles use.  The opt-level setting here is
# a total fiction; see the setup of MOZ_RUST_DEFAULT_FLAGS for what the
# opt-level setting will be as a result of various other configure flags.
opt-level = 1
rpath = false
lto = false
debug-assertions = true
panic = "abort"

opt-level = 2
rpath = false
debug-assertions = false
panic = "abort"
codegen-units = 1

libudev-sys = { path = "dom/webauthn/libudev-sys" }
serde_derive = { git = "", branch = "deserialize_from_enums10" }
winapi = { git = "", branch = "aarch64" }
packed_simd = { git = "", branch = "rust_1_32" }
cranelift-codegen = { git = "", rev = "542d799dd7a3b2cc15b91eefdcd85cace8fe5cee" }
cranelift-wasm = { git = "", rev = "542d799dd7a3b2cc15b91eefdcd85cace8fe5cee" }