From 6d0446e3386b7b9f704142e90a247e18cd419535 Mon Sep 17 00:00:00 2001
From: Daniel Trugman <dtrugman@gmail.com>
Date: Sun, 19 May 2024 09:23:38 +0100
Subject: [PATCH] Sample handles task enum exceptions better

---
 sample/enum_task.cpp | 79 +++++++++++++++++++++++++++++++++-----------
 sample/format.hpp    |  3 +-
 2 files changed, 62 insertions(+), 20 deletions(-)

diff --git a/sample/enum_task.cpp b/sample/enum_task.cpp
index edd03c9..35a19ff 100644
--- a/sample/enum_task.cpp
+++ b/sample/enum_task.cpp
@@ -20,74 +20,115 @@
 
 #include "pfs/procfs.hpp"
 
-static void enum_task(const pfs::task& task)
+static void safe(const std::string& what, const std::function<void(void)>& func)
 {
     try
     {
-        LOG("=========================================================");
-        LOG("Task ID[" << task.id() << "]");
-        LOG("=========================================================");
+        func();
+    }
+    catch (const std::runtime_error& ex)
+    {
+        LOG("Error getting [" << what << "]:");
+        LOG(TAB << ex.what());
+    }
+}
 
+static void enum_task(const pfs::task& task)
+{
+    LOG("=========================================================");
+    LOG("Task ID[" << task.id() << "]");
+    LOG("=========================================================");
+
+    safe("status", [&]{
         auto status = task.get_status();
         print(status);
+    });
 
+    bool is_kernel_thread = false;
+
+    safe("stat", [&]{
         auto stat = task.get_stat();
         print(stat);
 
+        is_kernel_thread = task.is_kernel_thread(stat);
+    });
+
+    safe("statm", [&]{
         auto mem_stat = task.get_statm();
         print(mem_stat);
+    });
 
+    safe("io", [&]{
         auto io_stat = task.get_io();
         print(io_stat);
+    });
 
+    safe("comm", [&]{
         auto comm = task.get_comm();
         print(comm);
+    });
 
-        if (!task.is_kernel_thread(stat))
-        {
+    if (!is_kernel_thread)
+    {
+        safe("exe", [&]{
             auto exe = task.get_exe();
             print(exe);
-        }
+        });
+    }
 
+    safe("cmdline", [&]{
         auto cmdline = task.get_cmdline();
         print(cmdline);
+    });
 
+    safe("cwd", [&]{
         auto cwd = task.get_cwd();
         print(cwd);
+    });
 
+    safe("environ", [&]{
         auto environ = task.get_environ();
         print(environ);
+    });
+
+    std::vector<pfs::mem_region> maps;
 
-        auto maps = task.get_maps();
+    safe("maps", [&]{
+        maps = task.get_maps();
         print(maps);
+    });
 
-        if (!maps.empty())
-        {
+    if (!maps.empty())
+    {
+        safe("mem", [&]{
             static const size_t BYTES = 8;
-            auto mem                  = task.get_mem();
-            auto first_map            = *maps.begin();
+            auto mem          = task.get_mem();
+            auto first_map    = *maps.begin();
             auto header_bytes = mem.read(first_map.start_address, BYTES);
             auto header       = hexlify(header_bytes);
             print(header);
-        }
+        });
+    }
 
+    safe("mountinfo", [&]{
         auto mountinfo = task.get_mountinfo();
         print(mountinfo);
+    });
 
+    safe("cgroups", [&]{
         auto cgroups = task.get_cgroups();
         print(cgroups);
+    });
 
+    safe("ns", [&]{
         auto ns = task.get_ns();
         print(ns);
+    });
 
+    safe("fds", [&]{
         auto fds = task.get_fds();
         print(fds);
-    }
-    catch (const std::runtime_error& ex)
-    {
-        LOG("Error when printing task[" << task.id() << "]:");
-        LOG(TAB << ex.what());
-    }
+    });
 }
 
 int enum_tasks(std::vector<std::string>&& args)
diff --git a/sample/format.hpp b/sample/format.hpp
index e7ed06d..842b07e 100644
--- a/sample/format.hpp
+++ b/sample/format.hpp
@@ -688,7 +688,8 @@ inline std::ostream& operator<<(std::ostream& out, const pfs::zone& zone)
 
 inline std::ostream& operator<<(std::ostream& out, const pfs::fd& fd)
 {
-    out << "target[" << fd.get_target() << "] ";
+    std::string target = fd.get_target();
+    out << "target[" << target << "] ";
     return out;
 }