[gdb/cli] Use captured per_command_time in worker threads

With test-case gdb.base/maint.exp, I ran into:
...
(gdb) file maint^M
Reading symbols from maint...^M
(gdb) mt set per-command on^M
(gdb) Time for "DWARF indexing worker": ...^M
Time for "DWARF indexing worker": ...^M
Time for "DWARF indexing worker": ...^M
Time for "DWARF indexing worker": ...^M
Time for "DWARF skeletonless type units": ...^M
Time for "DWARF add parent map": ...^M
Time for "DWARF finalize worker": ...^M
Time for "DWARF finalize worker": ...^M
Time for "DWARF finalize worker": ...^M
Time for "DWARF finalize worker": ...^M
Time for "DWARF finalize worker": ...^M
FAIL: $exp: warnings: per-command: mt set per-command on (timeout)
mt set per-command off^M
2025-05-31 09:33:44.711 - command started^M
(gdb) PASS: $exp: warnings: per-command: mt set per-command off
...

I didn't manage to reproduce this by rerunning the test-case, but it's fairly
easy to reproduce using a file with more debug info, for instance gdb:
...
$ gdb -q -batch -ex "file build/gdb/gdb" -ex "mt set per-command on"
...

Due to the default "mt dwarf synchronous" == off, the file command starts
building the cooked index in the background, and returns immediately without
waiting for the result.

The subsequent "mt set per-command on" implies "mt set per-command time on",
which switches on displaying of per-command execution time.

The "Time for" lines are the result of those two commands, but these lines
shouldn't be there because "mt per-command time" == off at the point of
issuing the file command.

Fix this by capturing the per_command_time variable, and using the captured
value instead.

Tested on x86_64-linux.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
PR cli/33039
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33039

diff --git a/gdb/dwarf2/cooked-index-worker.c b/gdb/dwarf2/cooked-index-worker.c
index 5d7fc462a05dd4df19244c9cd922f16d0c980ad9..09d80eff629c4d168e3108e5ee5d9bd082be6543 100644 (file)
--- a/gdb/dwarf2/cooked-index-worker.c
+++ b/gdb/dwarf2/cooked-index-worker.c
@@ -246,7 +246,7 @@ void
 cooked_index_worker::done_reading ()
 {
   {
-    scoped_time_it time_it ("DWARF add parent map");
+    scoped_time_it time_it ("DWARF add parent map", m_per_command_time);
 
     for (auto &one_result : m_results)
       m_all_parents_map.add_map (*one_result.get_parent_map ());

diff --git a/gdb/dwarf2/cooked-index-worker.h b/gdb/dwarf2/cooked-index-worker.h
index c68620578cc7b1fbfe6e665bf0666079093395b3..8b9766cddcbf1c58361d61ffebc9ca15de8deb84 100644 (file)
--- a/gdb/dwarf2/cooked-index-worker.h
+++ b/gdb/dwarf2/cooked-index-worker.h
@@ -25,6 +25,8 @@
 #include "dwarf2/cooked-index-shard.h"
 #include "dwarf2/types.h"
 #include "dwarf2/read.h"
+#include "maint.h"
+#include "run-on-main-thread.h"
 
 #if CXX_STD_THREAD
 #include <mutex>
@@ -216,8 +218,12 @@ public:
 
   explicit cooked_index_worker (dwarf2_per_objfile *per_objfile)
     : m_per_objfile (per_objfile),
-      m_cache_store (global_index_cache, per_objfile->per_bfd)
-  { }
+      m_cache_store (global_index_cache, per_objfile->per_bfd),
+      m_per_command_time (per_command_time)
+  {
+    /* Make sure we capture per_command_time from the main thread.  */
+    gdb_assert (is_main_thread ());
+  }
   virtual ~cooked_index_worker ()
   { }
   DISABLE_COPY_AND_ASSIGN (cooked_index_worker);
@@ -307,6 +313,9 @@ protected:
   std::optional<gdb_exception> m_failed;
   /* An object used to write to the index cache.  */
   index_cache_store_context m_cache_store;
+
+  /* Captured value of per_command_time.  */
+  bool m_per_command_time;
 };
 
 using cooked_index_worker_up = std::unique_ptr<cooked_index_worker>;

diff --git a/gdb/dwarf2/cooked-index.c b/gdb/dwarf2/cooked-index.c
index 2c7e31e5676cc6de7b50834e130a0b4ed42f2007..7232f286a40b7976a5b8795352ab0a7635b77ab5 100644 (file)
--- a/gdb/dwarf2/cooked-index.c
+++ b/gdb/dwarf2/cooked-index.c
@@ -104,7 +104,8 @@ cooked_index::set_contents ()
       const parent_map_map *parent_maps = m_state->get_parent_map_map ();
       finalizers.add_task ([=] ()
        {
-         scoped_time_it time_it ("DWARF finalize worker");
+         scoped_time_it time_it ("DWARF finalize worker",
+                                 m_state->m_per_command_time);
          this_shard->finalize (parent_maps);
        });
     }

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index b178dacbe3d18b28abca453edecf805ba0c22a71..d3d0d4c303e8f328d5ce2430c3ce5f495a2f467f 100644 (file)
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -3464,7 +3464,7 @@ void
 cooked_index_worker_debug_info::process_skeletonless_type_units
   (dwarf2_per_objfile *per_objfile, cooked_index_worker_result *storage)
 {
-  scoped_time_it time_it ("DWARF skeletonless type units");
+  scoped_time_it time_it ("DWARF skeletonless type units", m_per_command_time);
 
   /* Skeletonless TUs in DWP files without .gdb_index is not supported yet.  */
   if (per_objfile->per_bfd->dwp_file == nullptr)
@@ -3573,7 +3573,7 @@ cooked_index_worker_debug_info::do_reading ()
       gdb_assert (iter != last);
       workers.add_task ([this, task_count, iter, last] ()
        {
-         scoped_time_it time_it ("DWARF indexing worker");
+         scoped_time_it time_it ("DWARF indexing worker", m_per_command_time);
          process_units (task_count, iter, last);
        });
 

diff --git a/gdb/maint.c b/gdb/maint.c
index e017d05ef41bbdd9e9a466d5a726de733f8b76ee..49a308d36e25f5ee26f34cb68609789a19476824 100644 (file)
--- a/gdb/maint.c
+++ b/gdb/maint.c
@@ -920,9 +920,9 @@ maintenance_show_worker_threads (struct ui_file *file, int from_tty,
 }
 
 \f
-/* If true, display time usage both at startup and for each command.  */
+/* See maint.h.  */
 
-static bool per_command_time;
+bool per_command_time;
 
 /* If true, display space usage both at startup and for each command.  */
 
@@ -1175,8 +1175,8 @@ per-thread run time information not available on this platform"));
 
 /* See maint.h.  */
 
-scoped_time_it::scoped_time_it (const char *what)
-  : m_enabled (per_command_time),
+scoped_time_it::scoped_time_it (const char *what, bool enabled)
+  : m_enabled (enabled),
     m_what (what),
     m_start_wall (m_enabled
                  ? std::chrono::steady_clock::now ()

diff --git a/gdb/maint.h b/gdb/maint.h
index 28e6280a464c0c7f032684c3e5f88d574cafb8d0..cccb6f60354f2d13d4dd6cab562ec93ced933663 100644 (file)
--- a/gdb/maint.h
+++ b/gdb/maint.h
@@ -70,13 +70,17 @@ class scoped_command_stats
   int m_start_nr_blocks;
 };
 
+/* If true, display time usage both at startup and for each command.  */
+
+extern bool per_command_time;
+
 /* RAII structure used to measure the time spent by the current thread in a
    given scope.  */
 
 struct scoped_time_it
 {
   /* WHAT is the prefix to show when the summary line is printed.  */
-  scoped_time_it (const char *what);
+  scoped_time_it (const char *what, bool enabled = per_command_time);
 
   DISABLE_COPY_AND_ASSIGN (scoped_time_it);
   ~scoped_time_it ();