Stack traces for all task execution (#7718)

Author: eddyashton

src/enclave/enclave.h

@@ -32,6 +32,7 @@
 #include "node/rpc/user_frontend.h"
 #include "rpc_map.h"
 #include "rpc_sessions.h"
+#include "tasks/worker.h"
 
 #include <openssl/engine.h>
 
@@ -390,7 +391,7 @@ namespace ccf
           size_t tasks_done = 0;
           while (task != nullptr)
           {
-            task->do_task();
+            ccf::tasks::try_do_task(*task);
             ++tasks_done;
             if (tasks_done >= max_messages)
             {
@@ -427,7 +428,7 @@ namespace ccf
           auto task = job_board.wait_for_task(timeout);
           if (task != nullptr)
           {
-            task->do_task();
+            ccf::tasks::try_do_task(*task);
           }
         }
       }

src/tasks/worker.h

@@ -13,11 +13,43 @@
 
 namespace ccf::tasks
 {
-  // Logs the error message and prints a demangled stacktrace to stderr.
-  // Prefers the throw-point backtrace (captured via __cxa_throw interposition)
-  // when available, otherwise falls back to a catch-point backtrace.
+  // Logs the error message and a demangled throw-point stacktrace when
+  // available.
   void dump_stacktrace(const std::string& msg);
 
+  // Executes a task with exception handling. On any exception, logs a
+  // stacktrace and aborts (unless abort_on_throw is false).
+  inline void try_do_task(BaseTask& task, bool abort_on_throw = true)
+  {
+    if (task.is_cancelled())
+    {
+      return;
+    }
+
+    try
+    {
+      task.do_task();
+    }
+    catch (const std::exception& e)
+    {
+      dump_stacktrace(fmt::format(
+        "{} task failed with exception: {}", task.get_name(), e.what()));
+      if (abort_on_throw)
+      {
+        std::abort();
+      }
+    }
+    catch (...)
+    {
+      dump_stacktrace(
+        fmt::format("{} task failed with unknown exception", task.get_name()));
+      if (abort_on_throw)
+      {
+        std::abort();
+      }
+    }
+  }
+
   inline void task_worker_loop(
     JobBoard& job_board,
     std::atomic<bool>& stop_signal,
@@ -30,31 +62,7 @@ namespace ccf::tasks
       auto task = job_board.wait_for_task(wait_time);
       if (task != nullptr)
       {
-        if (!task->is_cancelled())
-        {
-          try
-          {
-            task->do_task();
-          }
-          catch (const std::exception& e)
-          {
-            dump_stacktrace(fmt::format(
-              "{} task failed with exception: {}", task->get_name(), e.what()));
-            if (abort_on_throw)
-            {
-              std::abort();
-            }
-          }
-          catch (...)
-          {
-            dump_stacktrace(fmt::format(
-              "{} task failed with unknown exception", task->get_name()));
-            if (abort_on_throw)
-            {
-              std::abort();
-            }
-          }
-        }
+        try_do_task(*task, abort_on_throw);
       }
     }
   }