From b0c779458221147ea55b1e60d5f06e593fb0931b Mon Sep 17 00:00:00 2001
From: Tim Haines <thaines.astro@gmail.com>
Date: Thu, 25 Jan 2024 00:02:41 -0600
Subject: [PATCH] Add stackwalker snippets from docs

---
 stackwalker/CMakeLists.txt           | 12 ++++++++
 stackwalker/complex3rdPartyWalk.cpp  | 43 ++++++++++++++++++++++++++++
 stackwalker/determineWalkerParty.cpp | 17 +++++++++++
 stackwalker/simple3rdPartyWalk.cpp   | 20 +++++++++++++
 4 files changed, 92 insertions(+)
 create mode 100644 stackwalker/complex3rdPartyWalk.cpp
 create mode 100644 stackwalker/determineWalkerParty.cpp
 create mode 100644 stackwalker/simple3rdPartyWalk.cpp

diff --git a/stackwalker/CMakeLists.txt b/stackwalker/CMakeLists.txt
index 253e1c5..b515cb7 100644
--- a/stackwalker/CMakeLists.txt
+++ b/stackwalker/CMakeLists.txt
@@ -3,3 +3,15 @@ project(stackwalker LANGUAGES CXX)
 add_executable(this_thread this_thread.cpp)
 target_compile_options(this_thread PRIVATE ${EXAMPLES_WARNING_FLAGS})
 target_link_libraries(this_thread Dyninst::stackwalk)
+
+add_executable(determineWalkerParty determineWalkerParty.cpp)
+target_compile_options(determineWalkerParty PRIVATE ${EXAMPLES_WARNING_FLAGS})
+target_link_libraries(determineWalkerParty Dyninst::stackwalk)
+
+add_library(simple3rdPartyWalk SHARED simple3rdPartyWalk.cpp)
+target_compile_options(simple3rdPartyWalk PRIVATE ${EXAMPLES_WARNING_FLAGS})
+target_link_libraries(simple3rdPartyWalk Dyninst::stackwalk)
+
+add_library(complex3rdPartyWalk SHARED complex3rdPartyWalk.cpp)
+target_compile_options(complex3rdPartyWalk PRIVATE ${EXAMPLES_WARNING_FLAGS})
+target_link_libraries(complex3rdPartyWalk Dyninst::stackwalk)
diff --git a/stackwalker/complex3rdPartyWalk.cpp b/stackwalker/complex3rdPartyWalk.cpp
new file mode 100644
index 0000000..ca04fa9
--- /dev/null
+++ b/stackwalker/complex3rdPartyWalk.cpp
@@ -0,0 +1,43 @@
+#include "frame.h"
+#include "procstate.h"
+#include "walker.h"
+
+#include <thread>
+#include <vector>
+
+#include <sys/select.h>
+
+// Collect a stack walk every five seconds.
+
+namespace sw = Dyninst::Stackwalker;
+
+void walk(Dyninst::PID pid) {
+  auto* walker = sw::Walker::newWalker(pid);
+  std::vector<sw::Frame> swalk;
+
+  struct timeval timeout;
+  timeout.tv_sec = 5;
+  timeout.tv_usec = 0;
+
+  for(;;) {
+    walker->walkStack(swalk);
+    int max = 1;
+    fd_set readfds, writefds, exceptfds;
+    FD_ZERO(&readfds);
+    FD_ZERO(&writefds);
+    FD_ZERO(&exceptfds);
+    FD_SET(sw::ProcDebug::getNotificationFD(), &readfds);
+
+    for(;;) {
+      int result = select(max, &readfds, &writefds, &exceptfds, &timeout);
+      if(FD_ISSET(sw::ProcDebug::getNotificationFD(), &readfds)) {
+        // Debug event
+        sw::ProcDebug::handleDebugEvent();
+      }
+      if(result == 0) {
+        // Timeout
+        break;
+      }
+    }
+  }
+}
diff --git a/stackwalker/determineWalkerParty.cpp b/stackwalker/determineWalkerParty.cpp
new file mode 100644
index 0000000..b7a9d3f
--- /dev/null
+++ b/stackwalker/determineWalkerParty.cpp
@@ -0,0 +1,17 @@
+#include "walker.h"
+#include "procstate.h"
+
+// How to determine if first-party or third-party walker
+
+namespace sw = Dyninst::Stackwalker;
+
+int main() {
+  auto* walker = sw::Walker::newWalker();
+  auto* debugger = dynamic_cast<sw::ProcDebug*>(walker->getProcessState());
+
+  if(debugger) {
+   //3rd party walker
+  } else {
+   //1st party walker
+  }
+}
diff --git a/stackwalker/simple3rdPartyWalk.cpp b/stackwalker/simple3rdPartyWalk.cpp
new file mode 100644
index 0000000..f6a4e1f
--- /dev/null
+++ b/stackwalker/simple3rdPartyWalk.cpp
@@ -0,0 +1,20 @@
+#include "frame.h"
+#include "walker.h"
+
+#include <vector>
+#include <thread>
+
+// Collect a stack walk every five seconds.
+
+namespace sw = Dyninst::Stackwalker;
+
+void walk(Dyninst::PID pid) {
+  auto* walker = sw::Walker::newWalker(pid);
+  std::vector<sw::Frame> swalk;
+  for(;;) {
+    walker->walkStack(swalk);
+
+    using namespace std::chrono_literals;
+    std::this_thread::sleep_for(5s);
+  }
+}