Add a flag to enable rr's chaos mode. (#105)

Project.toml

@@ -1,7 +1,7 @@
 name = "BugReporting"
 uuid = "bcf9a6e7-4020-453c-b88e-690564246bb8"
 authors = ["Keno Fischer <[email protected]>", "Tim Besard <[email protected]>"]
-version = "0.3.0"
+version = "0.3.1"
 
 [deps]
 Downloads = "f43a241f-c20a-4ad4-852c-f6b1247861c6"

README.md

@@ -30,10 +30,15 @@ Run `julia` inside `rr record` but do not upload the recorded trace. Useful for
 Generate a bug report, but limit the execution time of the debugged process to `SECONDS` seconds.
 This is useful for generating reports for hangs.
 
+### `--bug-report=rr,chaos`
+
+Generate an rr trace, while enabling so-called chaos mode. This is useful for flushing
+out threading-related issues (refer to the rr documentation for more details).
+
 
 ## Using the traces for local debugging
 
 You can use this package also for debugging your own Julia code locally. Use `--bug-report=rr-local`
-to record a trace, and `replay(PATH)` to replay a trace.
+to record a trace, and `replay()` to replay the latest trace.
 
 For example, if you have a script in a project that you'd like to trace, run `julia --bug-report=rr -- --project=foo run.jl`.

src/BugReporting.jl

@@ -148,7 +148,7 @@ function compress_trace(trace_directory::String, output_file::String)
 end
 
 function rr_record(julia_cmd::Cmd, julia_args...; rr_flags=default_rr_record_flags,
-                   trace_dir=default_rr_trace_dir(), timeout=0, extras=false)
+                   trace_dir=default_rr_trace_dir(), timeout=0, chaos=false, extras=false)
     check_rr_available()
     check_perf_event_paranoid(; rr_flags=rr_flags)
 
@@ -159,6 +159,10 @@ function rr_record(julia_cmd::Cmd, julia_args...; rr_flags=default_rr_record_fla
     # and shouldn't leak into the record environment (where we may load another Python)
     delete!(new_env, "PYTHONHOME")
 
+    if chaos
+        rr_flags = `--chaos $rr_flags`
+    end
+
     proc = rr() do rr_path
         rr_cmd = `$(rr_path) record $rr_flags $julia_cmd $julia_args`
         cmd = ignorestatus(setenv(rr_cmd, new_env))
@@ -293,17 +297,16 @@ function get_sourcecode(commit)
     return dir
 end
 
-function replay(trace_url=default_rr_trace_dir(); gdb_commands=[], gdb_flags=``,
-                rr_replay_flags=``)
+function get_trace_dir(trace_url)
     # download remote traces
     if startswith(trace_url, "s3://")
         trace_url = string("https://s3.amazonaws.com/julialang-dumps/", trace_url[6:end])
     end
     if startswith(trace_url, "http://") || startswith(trace_url, "https://")
         trace_url = download_rr_trace(trace_url)
-        rr_replay_flags = `$rr_replay_flags --serve-files`
-        # for remote traces, we assume it originated on a different system, so we need to
-        # tell rr to serve files as it's unlikely they will be available locally.
+        remote = true
+    else
+        remote = false
     end
 
     # If it's a file, try to decompress it
@@ -315,7 +318,24 @@ function replay(trace_url=default_rr_trace_dir(); gdb_commands=[], gdb_flags=``,
     if !isdir(trace_url)
         error("Invalid trace location: $(trace_url)")
     end
-    trace_dir = find_latest_trace(trace_url)
+
+    (; dir=find_latest_trace(trace_url), remote=remote)
+end
+
+function read_trace_info(trace_url=default_rr_trace_dir();)
+    trace_dir, _ = get_trace_dir(trace_url)
+    json = read(`$(rr()) traceinfo $trace_dir`, String)
+    JSON.parse(json)
+end
+
+function replay(trace_url=default_rr_trace_dir(); gdb_commands=[], gdb_flags=``,
+                rr_replay_flags=``)
+    trace_dir, remote = get_trace_dir(trace_url)
+    if remote
+        rr_replay_flags = `$rr_replay_flags --serve-files`
+        # for remote traces, we assume it originated on a different system, so we need to
+        # tell rr to serve files as it's unlikely they will be available locally.
+    end
 
     # read Julia-specific metadata from the trace
     if ispath(joinpath(trace_dir, "julia_metadata.json"))
@@ -483,12 +503,17 @@ function make_interactive_report(report_arg, ARGS=[])
     # split the report specification into the type and any modifiers
     report_type, report_modifiers... = split(report_arg, ',')
     timeout = 0
+    chaos = false
     for report_modifier in report_modifiers
-        option, value = split(report_modifier, '=')
+        option, values... = split(report_modifier, '=')
         if option == "timeout"
-            timeout = parse_time(value)
+            length(values) == 1 || error("Invalid report option: $(report_modifier)")
+            timeout = parse_time(values[1])
+        elseif option == "chaos"
+            length(values) == 0 || error("Invalid report option: $(report_modifier)")
+            chaos = true
         else
-            error("Unknown report option: $(option)")
+            error("Unknown report option: $(report_modifier)")
         end
     end
 
@@ -508,11 +533,11 @@ function make_interactive_report(report_arg, ARGS=[])
     cmd = `$cmd --history-file=no`
 
     if report_type == "rr-local"
-        proc = rr_record(cmd, ARGS...; timeout=timeout, extras=true)
+        proc = rr_record(cmd, ARGS...; timeout=timeout, chaos=chaos, extras=true)
         handle_child_error(proc)
     elseif report_type == "rr"
         mktempdir() do trace_dir
-            proc = rr_record(cmd, ARGS...; trace_dir=trace_dir, timeout=timeout, extras=true)
+            proc = rr_record(cmd, ARGS...; trace_dir=trace_dir, timeout=timeout, chaos=chaos, extras=true)
             "Preparing trace for upload (if your trace is large this may take a few minutes)..."
             rr_pack(trace_dir)
             params = get_upload_params()

test/rr.jl

@@ -227,4 +227,19 @@ end
         @test success(proc)
         @test contains(output.stdout, "Starting sleep")
     end
+
+    # Test that we can enable chaos mode
+    mktempdir() do temp_trace_dir
+        proc, output = withenv("_RR_TRACE_DIR" => temp_trace_dir) do
+            cmd = ```$(Base.julia_cmd()) --project=$(dirname(@__DIR__))
+                                         --bug-report=rr-local,chaos
+                                         --eval "42"```
+            communicate(cmd)
+        end
+        success(proc) || println(output.stderr)
+        @test success(proc)
+
+        trace_info = BugReporting.read_trace_info(temp_trace_dir)
+        @test get(trace_info, "chaosMode", missing) == true
+    end
 end