SendContinuePacketAndWaitForResponse was huge function with very complex interactions with
several other functions (SendAsyncSignal, SendInterrupt, SendPacket). This meant that making any
changes to how packet sending functions and threads interact was very difficult and error-prone.
This change does not add any functionality yet, it merely paves the way for future changes. In a
follow-up, I plan to add the ability to have multiple query packets in flight (i.e.,
request,request,response,response instead of the usual request,response sequences) and use that
to speed up qModuleInfo packet processing.
Here, I introduce two special kinds of locks: ContinueLock, which is used by the continue thread,
and Lock, which is used by everyone else. ContinueLock (atomically) sends a continue packet, and
blocks any other async threads from accessing the connection. Other threads create an instance of
the Lock object when they want to access the connection. This object, while in scope prevents the
continue from being send. Optionally, it can also interrupt the process to gain access to the
connection for async processing.
Most of the syncrhonization logic is encapsulated within these two classes. Some of it still
had to bleed over into the SendContinuePacketAndWaitForResponse, but the function is still much
more manageable than before -- partly because of most of the work is done in the ContinueLock
class, and partly because I have factored out a lot of the packet processing code separate
functions (this also makes the functionality more easily testable). Most importantly, there is
none of syncrhonization code in the async thread users -- as far as they are concerned, they just
need to declare a Lock object, and they are good to go (SendPacketAndWaitForResponse is now a
very thin wrapper around the NoLock version of the function, whereas previously it had over 100
lines of synchronization code). This will make my follow up changes there easy.
I have written a number of unit tests for the new code and I have ran the test suite on linux and
osx with no regressions.
Subscribers: tberghammer
Differential Revision: https://reviews.llvm.org/D22629
llvm-svn: 277139
This finally removes the use of the Mutex and Condition classes. This is an
intricate patch as the Mutex and Condition classes were tied together.
Furthermore, many places had slightly differing uses of time values. Convert
timeout values to relative everywhere to permit the use of
std::chrono::duration, which is required for the use of
std::condition_variable's timeout. Adjust all Condition and related Mutex
classes over to std::{,recursive_}mutex and std::condition_variable.
This change primarily comes at the cost of breaking the TracingMutex which was
based around the Mutex class. It would be possible to write a wrapper to
provide similar functionality, but that is beyond the scope of this change.
llvm-svn: 277011
debugserver jGetSharedCacheInfo packet instead of reading
the dyld internal data structures directly. This code is
(currently) only used for ios native lldb's - I should really
move this ObjectFileMachO::GetProcessSharedCacheUUID method
somewhere else, it makes less and less sense being in the
file reader.
<rdar://problem/25251243>
llvm-svn: 276369
This is a pretty straightforward first pass over removing a number of uses of
Mutex in favor of std::mutex or std::recursive_mutex. The problem is that there
are interfaces which take Mutex::Locker & to lock internal locks. This patch
cleans up most of the easy cases. The only non-trivial change is in
CommandObjectTarget.cpp where a Mutex::Locker was split into two.
llvm-svn: 269877
Summary:
eRegisterKindProcessPlugin is used to store the register
indices used by the remote, and eRegisterKindLLDB is used
to store the internal lldb register indices. However, we're currently
using the lldb indices instead of the process plugin indices
when sending p/P packets. This will break if the remote uses
non-contiguous register indices.
Reviewers: jasonmolenda, clayborg
Subscribers: lldb-commits, sas
Differential Revision: http://reviews.llvm.org/D19305
llvm-svn: 267466
This is a packet which allows the remote gdb stub to ask for the address
of a symbol in the process. lldb sends the packet (offering to provide
addresses for symbol names) after every solib loaded. I changed lldb so
that once the stub has indicated that it doesn't need any more symbol
addresses, lldb will stop sending the qSymbol:: packet on new solib loads.
This can yield a performance benefit over slower communication links when
there are many solibs involved.
<rdar://problem/23310049>
llvm-svn: 257569
Summary:
Some debug servers don't support it so there's no point in spamming
this.
Reviewers: clayborg
Subscribers: fjricci, lldb-commits
Differential Revision: http://reviews.llvm.org/D15972
llvm-svn: 257116
The standard remote debugging workflow with gdb is to start the
application on the remote host under gdbserver (e.g.: gdbserver :5039
a.out) and then connect to it with gdb.
The same workflow is supported by debugserver/lldb-gdbserver with a very
similar syntax but to access all features of lldb we need to be
connected also to an lldb-platform instance running on the target.
Before this change this had to be done manually with starting a separate
lldb-platform on the target machine and then connecting to it with lldb
before connecting to the process.
This change modifies the behavior of "platform connect" with
automatically connecting to the process instance if it was started by
the remote platform. With this command replacing gdbserver in a gdb
based worflow is usually as simple as replacing the command to execute
gdbserver with executing lldb-platform.
Differential revision: http://reviews.llvm.org/D14952
llvm-svn: 255016
SUMMARY:
The patch supports TAAwatch:addr packet. The patch also sets m_watchpoints_trigger_after_instruction
to eLazyBoolNo when qHostInfo or qWatchpointSupportInfo is not supported by the target.
Reviewers: jingham, clayborg
Subscribers: nitesh.jain, mohit.bhakkad, sagar, bhushan and lldb-commits
Differential Revision: http://reviews.llvm.org/D11747
llvm-svn: 244865
jGetLoadedDynamicLibrariesInfos. This packet is similar to
qXfer:libraries:read except that lldb supplies the number of solibs
that should be reported about, and the start address for the list
of them. At the initial process launch we'll read the full list
of solibs linked by the process -- at this point we could be using
qXfer:libraries:read -- but on subsequence solib-loaded notifications,
we'll be fetching a smaller number of solibs, often only one or two.
A typical Mac/iOS GUI app may have a couple hundred different
solibs loaded - doing all of the loads via memory reads takes
a couple of megabytes of traffic between lldb and debugserver.
Having debugserver summarize the load addresses of all the solibs
and sending it in JSON requires a couple of hundred kilobytes
of traffic. It's a significant performance improvement when
communicating over a slower channel.
This patch leaves all of the logic for loading the libraries
in DynamicLoaderMacOSXDYLD -- it only call over ot ProcesGDBRemote
to get the JSON result.
If the jGetLoadedDynamicLibrariesInfos packet is not implemented,
the normal technique of using memory read packets to get all of
the details from the target will be used.
<rdar://problem/21007465>
llvm-svn: 241964
- Avoid sending the qfThreadInfo, qsThreadInfo packets if we have a stop reply packet with the threads already (save 2 round trip packets)
- Include the qname, qserial and qkind in the JSON info
- Report the qname, qserial and qkind to the thread so it can cache it to avoid many packets on MacOSX and iOS
- Don't clear all discoverable settings when we exec, just the ones we need to saves 1-5 packets for each exec.
llvm-svn: 240988
A few extras were fixed
- Symbol::GetAddress() now returns an Address object, not a reference. There were places where people were accessing the address of a symbol when the symbol's value wasn't an address symbol. On MacOSX, undefined symbols have a value zero and some places where using the symbol's address and getting an absolute address of zero (since an Address object with no section and an m_offset whose value isn't LLDB_INVALID_ADDRESS is considered an absolute address). So fixing this required some changes to make sure people were getting what they expected.
- Since some places want to access the address as a reference, I added a few new functions to symbol:
Address &Symbol::GetAddressRef();
const Address &Symbol::GetAddressRef() const;
Linux test suite passes just fine now.
<rdar://problem/21494354>
llvm-svn: 240702
A "qSymbol::" is sent when shared libraries have been loaded by hooking into the Process::ModulesDidLoad() function from within ProcessGDBRemote. This function was made virtual so that the ProcessGDBRemote version is called, which then first calls the Process::ModulesDidLoad(), and then it queries for any symbol lookups that the remote GDB server might want to do.
This allows debugserver to request the "dispatch_queue_offsets" symbol so that it can read the queue name, queue kind and queue serial number and include this data as part of the stop reply packet. Previously each thread would have to do 3 memory reads in order to read the queue name.
This is part of reducing the number of packets that are sent between LLDB and the remote GDB server.
<rdar://problem/21494354>
llvm-svn: 240466
This patch adds a listener to the AynscThread in ProcessGDBRemote, specifically for dealing with any async notification packets.
From the broadcast our listener receives we can process the notify packet from the event data. A handler function then sets the thread stop info from this packet, and updates lldb by setting the process private state to stopped. Allowing the async thread to go back to sleep and getting the main thread to handle the implications of a state change.
When sending a vCont in nonstop mode we also get a different reply from all-stop mode, an OK response as opposed to a stop reply. So a condition is added to handle this and set the process state without the stop-reply data.
Reviewers: clayborg
Subscribers: lldb-commits, labath, ted, aidan.dodds, deepak2427
Differential Revision: http://reviews.llvm.org/D10544
llvm-svn: 240397
We have been working on reducing the packet count that is sent between LLDB and the debugserver on MacOSX and iOS. Our approach to this was to reduce the packets required when debugging multiple threads. We currently make one qThreadStopInfoXXXX call (where XXXX is the thread ID in hex) per thread except the thread that stopped with a stop reply packet. In order to implement multiple thread infos in a single reply, we need to use structured data, which means JSON. The new jThreadsInfo packet will attempt to retrieve all thread infos in a single packet. The data is very similar to the stop reply packets, but packaged in JSON and uses JSON arrays where applicable. The JSON output looks like:
[
{ "tid":1580681,
"metype":6,
"medata":[2,0],
"reason":"exception",
"qaddr":140735118423168,
"registers": {
"0":"8000000000000000",
"1":"0000000000000000",
"2":"20fabf5fff7f0000",
"3":"e8f8bf5fff7f0000",
"4":"0100000000000000",
"5":"d8f8bf5fff7f0000",
"6":"b0f8bf5fff7f0000",
"7":"20f4bf5fff7f0000",
"8":"8000000000000000",
"9":"61a8db78a61500db",
"10":"3200000000000000",
"11":"4602000000000000",
"12":"0000000000000000",
"13":"0000000000000000",
"14":"0000000000000000",
"15":"0000000000000000",
"16":"960b000001000000",
"17":"0202000000000000",
"18":"2b00000000000000",
"19":"0000000000000000",
"20":"0000000000000000"},
"memory":[
{"address":140734799804592,"bytes":"c8f8bf5fff7f0000c9a59e8cff7f0000"},
{"address":140734799804616,"bytes":"00000000000000000100000000000000"}
]
}
]
It contains an array of dicitionaries with all of the key value pairs that are normally in the stop reply packet. Including the expedited registers. Notice that is also contains expedited memory in the "memory" key. Any values in this memory will get included in a new L1 cache in lldb_private::Process where if a memory read request is made and that memory request fits into one of the L1 memory cache blocks, it will use that memory data. If a memory request fails in the L1 cache, it will fall back to the L2 cache which is the same block sized caching we were using before these changes. This allows a process to expedite memory that you are likely to use and it reduces packet count. On MacOSX with debugserver, we expedite the frame pointer backchain for a thread (up to 256 entries) by reading 2 pointers worth of bytes at the frame pointer (for the previous FP and PC), and follow the backchain. Most backtraces on MacOSX and iOS now don't require us to read any memory!
We will try these packets out and if successful, we should port these to lldb-server in the near future.
<rdar://problem/21494354>
llvm-svn: 240354
For some communication channels, sending large packets can be very
slow. In those cases, it may be faster to compress the contents of
the packet on the target device and decompress it on the debug host
system. For instance, communicating with a device using something
like Bluetooth may be an environment where this tradeoff is a good one.
This patch adds a new field to the response to the "qSupported" packet
(which returns a "qXfer:features:" response) -- SupportedCompressions
and DefaultCompressionMinSize. These tell you what the remote
stub can support.
lldb, if it wants to enable compression and can handle one of those
algorithms, it can send a QEnableCompression packet specifying the
algorithm and optionally the minimum packet size to use compression
on. lldb may have better knowledge about the best tradeoff for
a given communication channel.
I added support to debugserver an lldb to use the zlib APIs
(if -DHAVE_LIBZ=1 is in CFLAGS and -lz is in LDFLAGS) and the
libcompression APIs on Mac OS X 10.11 and later
(if -DHAVE_LIBCOMPRESSION=1). libz "zlib-deflate" compression.
libcompression can support deflate, lz4, lzma, and a proprietary
lzfse algorithm. libcompression has been hand-tuned for Apple
hardware so it should be preferred if available.
debugserver currently only adds the SupportedCompressions when
it is being run on an Apple watch (TARGET_OS_WATCH). Comment
that #if out from RNBRemote.cpp if you want to enable it to
see how it works. I haven't tested this on a native system
configuration but surely it will be slower to compress & decompress
the packets in a same-system debug session.
I haven't had a chance to add support for this to
GDBRemoteCommunciationServer.cpp yet.
<rdar://problem/21090180>
llvm-svn: 240066
Summary:
This should solve the issue of sending denormalized paths over gdb-remote
if we stick to GetPath(false) in GDBRemoteCommunicationClient, and let the
server handle any denormalization.
Reviewers: ovyalov, zturner, vharron, clayborg
Reviewed By: clayborg
Subscribers: tberghammer, emaste, lldb-commits
Differential Revision: http://reviews.llvm.org/D9728
llvm-svn: 238604
qEcho:%s
where '%s' is any valid string. The response to this packet is the exact packet itself with no changes, just reply with what you received!
This will help us to recover from packets timing out much more gracefully. Currently if a packet times out, LLDB quickly will hose up the debug session. For example, if we send a "abc" packet and we expect "ABC" back in response, but the "abc" command takes longer than the current timeout value this will happen:
--> "abc"
<-- <<<error: timeout>>>
Now we want to send "def" and get "DEF" back:
--> "def"
<-- "ABC"
We got the wrong response for the "def" packet because we didn't sync up with the server to clear any current responses from previously issues commands.
The fix is to modify GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock() so that when it gets a timeout, it syncs itself up with the client by sending a "qEcho:%u" where %u is an increasing integer, one for each time we timeout. We then wait for 3 timeout periods to sync back up. So the above "abc" session would look like:
--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
<-- "abc"
<-- "qEcho:1"
The first timeout is from trying to get the response, then we know we timed out and we send the "qEcho:1" packet and wait for 3 timeout periods to get back in sync knowing that we might actually get the response for the "abc" packet in the mean time...
In this case we would actually succeed in getting the response for "abc". But lets say the remote GDB server is deadlocked and will never response, it would look like:
--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
We then disconnect and say we lost connection.
We might also have a bad GDB server that just dropped the "abc" packet on the floor. We can still recover in this case and it would look like:
--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- "qEcho:1"
Then we know our remote GDB server is still alive and well, and it just dropped the "abc" response on the floor and we can continue to debug.
<rdar://problem/21082939>
llvm-svn: 238530
Summary:
This patch is the beginnings of support for Non-stop mode in the remote protocol. Letting a user examine stopped threads, while other threads execute freely.
Non-stop mode is enabled using the setting target.non-stop-mode, which sends a QNonStop packet when establishing the remote connection.
Changes are also made to treat the '?' stop reply packet differently in non-stop mode, according to spec https://sourceware.org/gdb/current/onlinedocs/gdb/Remote-Non_002dStop.html#Remote-Non_002dStop.
A setting for querying the remote for default thread on setup is also included.
Handling of '%' async notification packets will be added next.
Reviewers: clayborg
Subscribers: lldb-commits, ADodds, ted, deepak2427
Differential Revision: http://reviews.llvm.org/D9656
llvm-svn: 237239
Previously the remote module sepcification was fetched only from the
remote platform. With this CL if we have a remote process then we ask it
if it have any information from a given module. It is required because
on android the dynamic linker only reports the name of the SO file and
the platform can't always find it without a full path (the process can
do it based on /proc/<pid>/maps).
Differential revision: http://reviews.llvm.org/D8547
llvm-svn: 233061
Processes running on a remote target can already send $O messages
to send stdout but there is no way to send stdin to a remote
inferior.
This allows processes using the API to pump stdin into a remote
inferior process.
It fixes a hang in TestProcessIO.py when running against a remote
target.
llvm-svn: 228419
lldb support. I'll be doing more testing & cleanup but I wanted to
get the initial checkin done.
This adds a new SBExpressionOptions::SetLanguage API for selecting a
language of an expression.
I added adds a new SBThread::GetInfoItemByPathString for retriving
information about a thread from that thread's StructuredData.
I added a new StructuredData class for representing
key-value/array/dictionary information (e.g. JSON formatted data).
Helper functions to read JSON and create a StructuredData object,
and to print a StructuredData object in JSON format are included.
A few Cocoa / Cocoa Touch data formatters were updated by Enrico
to track changes in iOS 8 / Yosemite.
Before we query a thread's extended information, the system runtime may
provide hints to the remote debug stub that it will use to retrieve values
out of runtime structures. I added a new SystemRuntime method
AddThreadExtendedInfoPacketHints which allows the SystemRuntime to add
key-value type data to the initial request that we send to the remote stub.
The thread-format formatter string can now retrieve values out of a thread's
extended info structured data. The default thread-format string picks up
two of these - thread.info.activity.name and thread.info.trace_messages.
I added a new "jThreadExtendedInfo" packet in debugserver; I will
add documentation to the lldb-gdb-remote.txt doc soon. It accepts
JSON formatted arguments (most importantly, "thread":threadnum) and
it returns a variety of information regarding the thread to lldb
in JSON format. This JSON return is scanned into a StructuredData
object that is associated with the thread; UI layers can query the
thread's StructuredData to see if key-values are present, and if
so, show them to the user. These key-values are likely to be
specific to different targets with some commonality among many
targets. For instance, many targets will be able to advertise the
pthread_t value for a thread.
I added an initial rough cut of "thread info" command which will print
the information about a thread from the jThreadExtendedInfo result.
I need to do more work to make this format reasonably.
Han Ming added calls into the pmenergy and pmsample libraries if
debugserver is run on Mac OS X Yosemite to get information about the
inferior's power use.
I added support to debugserver for gathering the Genealogy information
about threads, if it exists, and returning it in the jThreadExtendedInfo
JSON result.
llvm-svn: 210874
$qC from debugserver now returns the current thread's thread-id (and, like $?, will set a current thread if one is not already selected). Previously it was returning the current process id.
lldb will now query $qProcessInfo to retrieve the process id. The process id is now cached lazily and reset like other cached values. Retrieval of the process id will fall back to the old $qC method for vendor==Apple and os==iOS if the qProcessInfo retrieval fails.
Added a gdb remote protocol-level test to verify that $qProcessInfo reports a valid process id after launching a process, while the process is in the initial stopped state. Verifies the given process id is a currently valid process on host OSes for which we know how to check (MacOSX, Linux, {Free/Net}BSD). Ignores the live process check for OSes where we don't know how to do this. (I saw no portable way to do this in stock Python without pulling in other libs).
llvm-svn: 208241
These changes were written by Greg Clayton, Jim Ingham, Jason Molenda.
It builds cleanly against TOT llvm with xcodebuild. I updated the
cmake files by visual inspection but did not try a build. I haven't
built these sources on any non-Mac platforms - I don't think this
patch adds any code that requires darwin, but please let me know if
I missed something.
In debugserver, MachProcess.cpp and MachTask.cpp were renamed to
MachProcess.mm and MachTask.mm as they picked up some new Objective-C
code needed to launch processes when running on iOS.
llvm-svn: 205113
ProcessGDBRemote::GetAuxvData obtains the auxv from a remote gdbserver (via a binary-data packet), and returns the data as a DataBufferSP.
The patch includes a small fix to GDBRemoteCommunicationClient::SendPacketsAndConcatenateResponses() to support binary file format packet returns (by not assuming each binary packet is a null-terminated string when concatenating them).
llvm-svn: 202907
There are a couple of pieces:
* some lazy-evaluation members that store info listed in a qSupported response
* new method SendPacketsAndConcatenateResponses which is used for
fetching fixed-size objects from the remote gdbserver by using multiple
packets if necessary (first use will be to fetch shared-library XML files).
llvm-svn: 200072
<rdar://problem/15600045>
Due to other recent changes, all connections to GDB servers that didn't support the "QStartNoAckMode" packet would cause us to fail to attach to the remote GDB server.
The problem was that SendPacket* and WaitForResponse* packets would return a size_t indicating the number of bytes sent/received. The other issue was WaitForResponse* packets would strip the leading '$' and the trailing "#CC" (checksum) bytes, so the unimplemented response packet of "$#00" would get stripped and the WaitForResponse* packets would return 0.
These new error codes give us flexibility to to more intelligent things in response to what is returned.
llvm-svn: 196610
Improved the detection of a valid GDB server where we actually can connect to a socket, but then it doesn't read or write anything (which happens with some USB mux software).
Host::MakeDirectory() now can make as many intermediate directories as needed.
The testsuite now has very initial support for remote test suite running. When running on a remote platform, the setUp function for the test will make a new directory and select it as the working directory on the remote host.
Added a common function that can be used to create the short option string for getopt_long calls.
llvm-svn: 195541
Example code:
remote_platform = lldb.SBPlatform("remote-macosx");
remote_platform.SetWorkingDirectory("/private/tmp")
debugger.SetSelectedPlatform(remote_platform)
connect_options = lldb.SBPlatformConnectOptions("connect://localhost:1111");
err = remote_platform.ConnectRemote(connect_options)
if err.Success():
print >> result, 'Connected to remote platform:'
print >> result, 'hostname: %s' % (remote_platform.GetHostname())
src = lldb.SBFileSpec("/Applications/Xcode.app/Contents/SharedFrameworks/LLDB.framework", False)
dst = lldb.SBFileSpec()
# copy src to platform working directory since "dst" is empty
err = remote_platform.Install(src, dst);
if err.Success():
print >> result, '%s installed successfully' % (src)
else:
print >> result, 'error: failed to install "%s": %s' % (src, err)
Implemented many calls needed in lldb-platform to be able to install a directory that contains symlinks, file and directories.
The remote lldb-platform can now launch GDB servers on the remote system so that remote debugging can be spawned through the remote platform when connected to a remote platform.
The API in SBPlatform is subject to change and will be getting many new functions.
llvm-svn: 195273
Added two new GDB server packets to debugserver: "QSaveRegisterState" and "QRestoreRegiterState".
"QSaveRegisterState" makes the remote GDB server save all register values and it returns a save identifier as an unsigned integer. This packet can be used prior to running expressions to save all registers.
All registers can them we later restored with "QRestoreRegiterState:SAVEID" what SAVEID is the integer identifier that was returned from the call to QSaveRegisterState.
Cleaned up redundant code in lldb_private::Thread, lldb_private::ThreadPlanCallFunction.
Moved the lldb_private::Thread::RegisterCheckpoint into its own header file and it is now in the lldb_private namespace. Trimmed down the RegisterCheckpoint class to omit stuff that wasn't used (the stack ID).
Added a few new virtual methods to lldb_private::RegisterContext that allow subclasses to efficiently save/restore register states and changed the RegisterContextGDBRemote to take advantage of these new calls.
llvm-svn: 194621
Added a new key that we understand for the "qHostInfo" packet: "default_packet_timeout:T;" where T is a default packet timeout in seconds.
This allows GDB servers with known slow packet response times to increase the default timeout to a value that makes sense for the connection.
llvm-svn: 193425
Fixed an issue where environment variables that contained special characters '$' and '#' would hose up the GDB server packet. We now use the QEnvironmentHexEncoded packet that has existed for a long time when we need to. Also added code that will stop sending the QEnvironmentHexEncoded and QEnvironment packets if they aren't supported.
llvm-svn: 192373
