clayborg created this revision.
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clayborg requested review of this revision.
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Herald added a subscriber: lldb-commits.
...and doesn't play with the async mode when doing normal launch/attach.
We discovered that when using "launchCommands" or "attachCommands" that there
was an issue where these commands were not being run synchronously. There were
further problems in this case where we would get thread events for the process
that was just launched or attached before the IDE was ready, which is after
"configurationDone" was sent to lldb-vscode.
This fix introduces the ability to wait for the process to stop after
"launchCommands" or "attachCommands" are run to ensure that we have a stopped
process point that is ready for the debug session to proceed. We spin up the
thread that listens for process events before we start the launch or attach,
but we don't want stop events being delivered through the DAP protocol until
the "configurationDone" packet is received. We now always ignore the stop event
with a stop ID of 1, which is the first stop. All normal launch and attach
scenarios use the synchronous mode, and "launchCommands and "attachCommands"
run an array of LLDB commands in async mode.
This should make our launch with "launchCommands" and attach with
"attachCommands" avoid a race condition when the process is being launched or
attached.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D120755
Files:
lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py
lldb/tools/lldb-vscode/VSCode.cpp
lldb/tools/lldb-vscode/VSCode.h
lldb/tools/lldb-vscode/lldb-vscode.cpp
lldb/tools/lldb-vscode/package.json
Index: lldb/tools/lldb-vscode/package.json
===================================================================
--- lldb/tools/lldb-vscode/package.json
+++ lldb/tools/lldb-vscode/package.json
@@ -215,7 +215,7 @@
},
"launchCommands": {
"type": "array",
- "description": "Custom commands that are executed instead of launching a process. A target will be created with the launch arguments prior to executing these commands. The commands may optionally create a new target and must perform a launch. A valid process must exist after these commands complete or the \"launch\" will fail.",
+ "description": "Custom commands that are executed instead of launching a process. A target will be created with the launch arguments prior to executing these commands. The commands may optionally create a new target and must perform a launch. A valid process must exist after these commands complete or the \"launch\" will fail. Launch the process with \"process launch -s\" to make the process to at the entry point since lldb-vscode will auto resume if necessary.",
"default": []
},
"stopCommands": {
@@ -232,6 +232,10 @@
"type": "boolean",
"description": "Launch the program inside an integrated terminal in the IDE. Useful for debugging interactive command line programs",
"default": false
+ },
+ "timeout": {
+ "type": "string",
+ "description": "The time in seconds to wait for a program to stop at entry point when launching with \"launchCommands\". Defaults to 30 seconds."
}
}
},
@@ -307,6 +311,10 @@
"coreFile": {
"type": "string",
"description": "Path to the core file to debug."
+ },
+ "timeout": {
+ "type": "string",
+ "description": "The time in seconds to wait for a program to stop when attaching using \"attachCommands\". Defaults to 30 seconds."
}
}
}
Index: lldb/tools/lldb-vscode/lldb-vscode.cpp
===================================================================
--- lldb/tools/lldb-vscode/lldb-vscode.cpp
+++ lldb/tools/lldb-vscode/lldb-vscode.cpp
@@ -449,10 +449,19 @@
case lldb::eStateSuspended:
break;
case lldb::eStateStopped:
- // Only report a stopped event if the process was not restarted.
- if (!lldb::SBProcess::GetRestartedFromEvent(event)) {
- SendStdOutStdErr(process);
- SendThreadStoppedEvent();
+ // We launch and attach in synchronous mode then the first stop
+ // event will not be delivered. If we use "launchCommands" during a
+ // launch or "attachCommands" during an attach we might get the
+ // first process stop event which we do not want to send an event
+ // for. The first stop event is always sent in
+ // request_configuarationDone() where it will manually deliver the
+ // event by calling the SendThreadStoppedEvent().
+ if (process.GetStopID() > 1) {
+ // Only report a stopped event if the process was not restarted.
+ if (!lldb::SBProcess::GetRestartedFromEvent(event)) {
+ SendStdOutStdErr(process);
+ SendThreadStoppedEvent();
+ }
}
break;
case lldb::eStateRunning:
@@ -600,6 +609,7 @@
g_vsc.terminate_commands = GetStrings(arguments, "terminateCommands");
auto attachCommands = GetStrings(arguments, "attachCommands");
llvm::StringRef core_file = GetString(arguments, "coreFile");
+ const uint64_t timeout_seconds = GetUnsigned(arguments, "timeout", 30);
g_vsc.stop_at_entry =
core_file.empty() ? GetBoolean(arguments, "stopOnEntry", false) : true;
std::vector<std::string> postRunCommands =
@@ -657,6 +667,10 @@
// The custom commands might have created a new target so we should use the
// selected target after these commands are run.
g_vsc.target = g_vsc.debugger.GetSelectedTarget();
+
+ // Make sure the process is attached and stopped before proceeding as the
+ // the launch commands are not run using the synchronous mode.
+ error = g_vsc.WaitForProcessToStop(timeout_seconds);
}
if (error.Success() && core_file.empty()) {
@@ -1652,6 +1666,7 @@
GetStrings(arguments, "postRunCommands");
g_vsc.stop_at_entry = GetBoolean(arguments, "stopOnEntry", false);
const llvm::StringRef debuggerRoot = GetString(arguments, "debuggerRoot");
+ const uint64_t timeout_seconds = GetUnsigned(arguments, "timeout", 30);
// This is a hack for loading DWARF in .o files on Mac where the .o files
// in the debug map of the main executable have relative paths which require
@@ -1726,6 +1741,10 @@
// The custom commands might have created a new target so we should use the
// selected target after these commands are run.
g_vsc.target = g_vsc.debugger.GetSelectedTarget();
+ // Make sure the process is launched and stopped at the entry point before
+ // proceeding as the the launch commands are not run using the synchronous
+ // mode.
+ error = g_vsc.WaitForProcessToStop(timeout_seconds);
}
if (error.Fail()) {
Index: lldb/tools/lldb-vscode/VSCode.h
===================================================================
--- lldb/tools/lldb-vscode/VSCode.h
+++ lldb/tools/lldb-vscode/VSCode.h
@@ -243,6 +243,19 @@
/// Debuggee will continue from stopped state.
void WillContinue() { variables.Clear(); }
+ /// Poll the process to wait for it to reach the eStateStopped state.
+ ///
+ /// We need to ensure the process is stopped and ready to resume before we
+ /// continue with the launch or attach. This is needed since we no longer play
+ /// with the synchronous mode in the debugger for launching (with or without
+ /// "launchCommands") or attaching (with or without "attachCommands").
+ ///
+ /// \param[in] seconds
+ /// The number of seconds to poll the process to wait until it is stopped.
+ ///
+ /// \return Error if waiting for the process fails, no error if succeeds.
+ lldb::SBError WaitForProcessToStop(uint32_t seconds);
+
private:
// Send the JSON in "json_str" to the "out" stream. Correctly send the
// "Content-Length:" field followed by the length, followed by the raw
Index: lldb/tools/lldb-vscode/VSCode.cpp
===================================================================
--- lldb/tools/lldb-vscode/VSCode.cpp
+++ lldb/tools/lldb-vscode/VSCode.cpp
@@ -528,6 +528,58 @@
request_handlers[request] = callback;
}
+lldb::SBError VSCode::WaitForProcessToStop(uint32_t seconds) {
+ // Wait for the process hit a stopped state. When running a launch (with or
+ // without "launchCommands") or attach (with or without)= "attachCommands"),
+ // the calls might take some time to stop at the entry point since the command
+ // is asynchronous. So we need to sync up with the process and make sure it is
+ // stopped before we proceed to do anything else as we will soon be asked to
+ // set breakpoints and other things that require the process to be stopped.
+ // We must use polling because attach doesn't send a process state change
+ // event for the first stop, while launching does. Since both "attachCommands"
+ // and "launchCommands" could end up using any combination of LLDB commands,
+ // we must ensure we can also catch when the process stops, so we must poll
+ // the process to make sure we handle all cases.
+
+ lldb::SBError error;
+ lldb::SBProcess process = target.GetProcess();
+ if (!process.IsValid()) {
+ error.SetErrorString("invalid process");
+ return error;
+ }
+ auto timeout_time =
+ std::chrono::high_resolution_clock::now() + std::chrono::seconds(seconds);
+ while (std::chrono::high_resolution_clock::now() < timeout_time) {
+ const auto state = process.GetState();
+ switch (state) {
+ case lldb::eStateAttaching:
+ case lldb::eStateConnected:
+ case lldb::eStateInvalid:
+ case lldb::eStateLaunching:
+ case lldb::eStateRunning:
+ case lldb::eStateStepping:
+ case lldb::eStateSuspended:
+ break;
+ case lldb::eStateDetached:
+ error.SetErrorString("process detached during launch or attach");
+ return error;
+ case lldb::eStateExited:
+ error.SetErrorString("process exited during launch or attach");
+ return error;
+ case lldb::eStateUnloaded:
+ error.SetErrorString("process unloaded during launch or attach");
+ return error;
+ case lldb::eStateCrashed:
+ case lldb::eStateStopped:
+ return lldb::SBError(); // Success!
+ }
+ std::this_thread::sleep_for(std::chrono::microseconds(250));
+ }
+ error.SetErrorStringWithFormat("process failed to stop within %u seconds",
+ seconds);
+ return error;
+}
+
void Variables::Clear() {
locals.Clear();
globals.Clear();
Index: lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py
===================================================================
--- lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py
+++ lldb/test/API/tools/lldb-vscode/launch/TestVSCode_launch.py
@@ -374,7 +374,7 @@
@skipIfRemote
def test_extra_launch_commands(self):
'''
- Tests the "luanchCommands" with extra launching settings
+ Tests the "launchCommands" with extra launching settings
'''
self.build_and_create_debug_adaptor()
program = self.getBuildArtifact("a.out")
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