i#6745: Fix timestamp gap in -trace_after_instrs

Fixes a timestamp gap between the first and second timestamps in the trace caused when -trace_after_instrs is used. Fixes: #6745
DynamoRIO · Mar 29, 2024 · 14e306a · 14e306a
1 parent e698fa3
commit 14e306a
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Showing 2 changed files with 4 additions and 3 deletions.
diff --git a/clients/drcachesim/tracer/instr_counter.cpp b/clients/drcachesim/tracer/instr_counter.cpp
@@ -129,9 +129,10 @@ hit_instr_count_threshold(app_pc next_pc)
         return;
     }
     if (op_trace_after_instrs.get_value() > 0 &&
-        !reached_trace_after_instrs.load(std::memory_order_acquire))
+        !reached_trace_after_instrs.load(std::memory_order_acquire)) {
         NOTIFY(0, "Hit delay threshold: enabling tracing.\n");
-    else {
+        retrace_start_timestamp.store(instru_t::get_timestamp());
+    } else {
         NOTIFY(0, "Hit retrace threshold: enabling tracing for window #%zd.\n",
                tracing_window.load(std::memory_order_acquire));
         retrace_start_timestamp.store(instru_t::get_timestamp());

diff --git a/clients/drcachesim/tracer/output.cpp b/clients/drcachesim/tracer/output.cpp
@@ -1059,7 +1059,7 @@ process_and_output_buffer(void *drcontext, bool skip_size_cap)
         instru->clamp_unit_header_timestamp(data->buf_base + stamp_offs, min_timestamp);
     }
 
-    if (has_tracing_windows()) {
+    if (has_tracing_windows() || op_trace_after_instrs.get_value() > 0) {
         min_timestamp = retrace_start_timestamp.load(std::memory_order_acquire);
         instru->clamp_unit_header_timestamp(data->buf_base + stamp_offs, min_timestamp);
     }