author Andrew McCreight <continuation@gmail.com>
Mon, 22 Apr 2019 16:34:51 +0000
changeset 470376 3073770e06f157040f4c64951b7e8425e1ad7bbe
parent 430717 ff3a0784588f2cb5aaa84e8d6a2a3677a5e52930
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: https://phabricator.services.mozilla.com/D27981

# .lldbinit file for debugging Mozilla

# -----------------------------------------------------------------------------
# For documentation on all of the commands and type summaries defined here and
# in the accompanying Python scripts, see third_party/python/lldbutils/README.txt.
# -----------------------------------------------------------------------------

# Import the module that defines complex Gecko debugging commands.  This assumes
# you are either running lldb from the top level source directory, the objdir,
# or the dist/bin directory.  (.lldbinit files in the objdir and dist/bin set
# topsrcdir appropriately.)
script topsrcdir = topsrcdir if locals().has_key("topsrcdir") else os.getcwd(); sys.path.append(os.path.join(topsrcdir, "third_party/python/lldbutils")); import lldbutils; lldbutils.init()

# Mozilla's use of UNIFIED_SOURCES to include multiple source files into a
# single compiled file breaks lldb breakpoint setting. This works around that.
# See http://lldb.llvm.org/troubleshooting.html for more info.
settings set target.inline-breakpoint-strategy always

# Show the dynamic type of an object when using "expr".  This, for example,
# will show a variable declared as "nsIFrame *" that points to an nsBlockFrame
# object as being of type "nsBlockFrame *" rather than "nsIFrame *".
settings set target.prefer-dynamic-value run-target

# Show the value of text nodes.
type summary add nsTextNode --summary-string "${var.mText}"

# Dump the current JS stack.
command alias js expr DumpJSStack()