Previously, MachMessageServer::Run() only provided two strategies for
dealing with large messages, indicated by mach_msg() returning
MACH_RCV_TOO_LARGE: the receive buffer could be reallocated and the
message received, or the entire function could return MACH_RCV_TOO_LARGE
to the caller. There are situations where an intermediate behavior might
be desirable. This intermediate behavior would allow the function to
continue waiting for another message without returning an error to the
caller or attempting to receive the large message. This is desirable
when dealing with fixed-sized messages and a receiver that might be sent
messages by unknown, possibly-malicious callers. This can happen when
the corresponding send right is published with the bootstrap server, for
example.
Existing users continue to request their existing behavior, typically
receiving an error when encountering a large message.
catch_exception_tool will use the new “ignore” behavior when running in
persistent mode.
TEST=util_test MachMessageServer.*
R=rsesek@chromium.org
Review URL: https://codereview.chromium.org/756803002
implicit_cast<> only performs a cast in cases where an implicit
conversion would be possible. It’s even safer than static_cast<> It’s an
“explicit implicit” cast, which is not normally necsesary, but is
frequently required when working with the ?: operator, functions like
std::min() and std::max(), and logging and testing macros.
The public style guide does not mention implicit_cast<> only because it
is not part of the standard library, but would otherwise require it in
these situations. Since base does provide implicit_cast<>, it should be
used whenever possible.
The only uses of static_cast<> not converted to implicit_cast<> are
those that require static_cast<>, such as those that assign an integer
constant to a variable of an enum type.
R=rsesek@chromium.org
Review URL: https://codereview.chromium.org/700383007
