17 Commits

Author SHA1 Message Date
Mark Mentovai
952f787f4a doc: Standardize on “macOS” in comments
Use “macOS” as the generic unversioned name of the operating system in
comments. For version-specific references, use Mac OS X through 10.6, OS
X from 10.7 through 10.11, and macOS for 10.12.

Change-Id: I1ebee64fbf79200bc799d4a351725dd73257b54d
Reviewed-on: https://chromium-review.googlesource.com/408269
Reviewed-by: Robert Sesek <rsesek@chromium.org>
2016-11-08 19:21:44 +00:00
Mark Mentovai
c874958fd0 MachMessageServer: eliminate argument redundancy.
MachMessageServer::Run()’s distinct |nonblocking| parameter is removed.
The information it formerly conveyed is now implied by the |timeout_ms|
parameter, which can accept two special values,
kMachMessageTimeoutNonblocking and kMachMessageTimeoutWaitIndefinitely.

TEST=client_test, snapshot_test, util_test
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/777993002
2014-12-10 11:11:21 -05:00
Mark Mentovai
86588c5526 MachMessageServer: scribble over memory allocations in debug mode.
This exposed a bug in the ExcClientVariants test, which was expecting
the memory used for new_state to be initialized with zeroes. In reality,
no guarantee of initialization is made. MIG “out” parameters are
strictly “out” and may contain garbage at function entry.

TEST=util_test
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/779633004
2014-12-03 18:24:27 -05:00
Mark Mentovai
9f520e3fbf MachMessageServer: add some DCHECKs.
These DCHECKs make sure that buffer sizes and message sizes are as
expected.

TEST=util_test MachMessageServer.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/781593003
2014-12-03 18:21:00 -05:00
Mark Mentovai
ef0b7cf6d5 Rewrite MachMessageServer::Run().
This method is now much more straightforward, easy to understand, and
maintainable.

There are no externally-visible changes.

TEST=util_test MachMessageServer.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/723853003
2014-12-03 16:45:48 -05:00
Mark Mentovai
49f170e633 MachMessageServer: handle allocations more reasonably.
MachMessageServer was wasteful with allocations for request and reply
messages. It allocated new memory for each request receive and for each
reply send, and if it needed to resize an allocation for a request, it
would maintain two request allocations simultaneously. The new behavior
allocates memory for a new request only if it needs a different size
than for the previous request, and it never maintains two request
allocations simultaneously. Memory for a reply is allocated once per
method invocation and maintained, since this never needs to be resized.

One pass of the loop is now guaranteed, even if a caller specifies a
very small timeout that expires before attempting to receive a message.

An infinite looping bug that could occur when ignoring large messages
has also been fixed.

TEST=util_test MachMessageServer.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/759023004
2014-12-01 16:13:40 -05:00
Mark Mentovai
50726ac8d0 Undo a68594234262.
The buffer sizing logic was correct to start with. I don’t know why I
misread it. It should say “if this would resize to receive a large
message, use the entire allocation rounded up to full page size,
otherwise, only use the space expected for a message.”

TEST=util_test
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/760573003
2014-12-01 16:12:10 -05:00
Mark Mentovai
0437bc53b6 Pass Mach message trailers to server handler functions.
TEST=util_test ChildPortServer.*:ExcServerVariants.*:MachMessageUtil.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/755313004
2014-12-01 16:06:56 -05:00
Mark Mentovai
a685942342 MachMessageServer: invert the request buffer allocation logic.
The existing implementation used the same logic as is found in
mach_msg_server(), but that logic seems incorrect. When the caller wants
to retry a mach_msg() receive of a too-large message that returns
MACH_RCV_TOO_LARGE, there’s no harm in attempting the receive with a
larger buffer initially. On the other hand, if the caller does not want
to retry such mach_msg() receive attempts, it’s an indication that the
caller is expecting to be intolerant of too-large messages, and there’s
no need to attempt the receive with a buffer any larger than requested.

TEST=util_test
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/753363003
2014-11-25 15:04:31 -05:00
Mark Mentovai
306625dac4 MachMessageServer: don’t deal with MACH_SEND_TRAILER.
As documented, MACH_SEND_TRAILER would allow a sender to provide its own
message trailer instead of having the kernel append its own
kernel-generated trailer. This is a Mach feature that supports a network
of multiple Mach hosts, but even in that environment, the option is
restricted to use by privileged callers. In reality, MACH_SEND_TRAILER
has never been implemented in OS X.

The system’s mach_msg_server() family does consider the value of
MACH_SEND_TRAILER, but this is pointless. Any purported trailer set by a
server function would be ignored.

Maintaining this code gives the illusion that it’s functional, so it’s
being removed.

TEST=util_test MachMessageServer.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/736493007
2014-11-25 15:00:13 -05:00
Mark Mentovai
79b4434c81 Add a ReceiveLarge parameter to MachMessageServer::Run().
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
2014-11-25 14:48:44 -05:00
Mark Mentovai
48b1964d1b Use implicit_cast<> instead of static_cast<> whenever possible.
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
2014-11-06 16:44:38 -05:00
Mark Mentovai
5d74f120fc Convert NULL to nullptr.
This change was generated mechanically by running:

  find . \( -name \*.cc -or -name \*.mm -or -name \*.h \) \
      -and -not -path ./third_party/\* -and -not -path ./out/\* \
      -exec sed -i '' -E -e 's/(^|[^_])NULL/\1nullptr/g' {} +

Further manual fix-ups were applied to remove casts of nullptr to other
pointer types where possible, to preserve the intentional use of NULL
(as a short form of MACH_PORT_NULL) in exception_port_tool, and to fix
80-column violations.

https://groups.google.com/a/chromium.org/d/topic/chromium-dev/4mijeJHzxLg/discussion

TEST=*_test
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/656703002
2014-10-14 11:10:45 -04:00
Mark Mentovai
8decf86db8 Add, test, and use clock utilities.
This includes ClockMonotonicNanoseconds() and SleepNanoseconds().

SleepNanoseconds() is like base::PlatformThread::Sleep(), but
PlatformThread is not in mini_chromium and I’m not keen on adding it
because I’m not sold on the interface. I’m not convinced Sleep() belongs
there, and I don’t want to have to bring all of base::Time* along for
the ride.

TEST=util_test Clock.*:MachMessageServer.*:ServiceManagement.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/597533002
2014-09-24 14:08:48 -04:00
Mark Mentovai
4d35ffa80e Use more-specific typedefs for send rights to task, thread, and
exception handler ports.

task_t, thread_t, and exception_handler_t are typedefs for mach_port_t.
They are more descriptive than mach_port_t, and are already in use in
exc_server_variants.

TEST=util_test
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/577293002
2014-09-18 13:53:43 -04:00
Mark Mentovai
88a681e747 Enhance the MachMessageServer test to cover port right ownership
management.

TEST=util_test MachMessageServer.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/555663002
2014-09-09 09:59:05 -04:00
Mark Mentovai
67082c93b9 Add MachMessageServer and its test.
MachMessageServer is much like mach_msg_server() and
mach_msg_server_once(), but with a C++ interface and with a number of
deficiencies corrected.

TEST=util_test MachMessageServer.*
R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/544393002
2014-09-08 21:06:34 -04:00