From 2dfb5da16b97a6c12e01977af5b5188522178a4e Mon Sep 17 00:00:00 2001 From: Stefan Boberg Date: Mon, 20 Apr 2026 21:50:41 +0200 Subject: zen trace analysis support (#945) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Integrates the **tourist** trace analysis library and builds a full `zen trace` command suite for working with Unreal Engine `.utrace` files. ### Trace analysis library (`thirdparty/tourist/`) - Adds the tourist library as a third-party dependency with three modules: **foundation** (platform primitives, memory, scheduling), **trace** (UE Trace protocol decoding), and **analysis** (event dispatching and analyzer framework). - Cross-platform support for Windows, Linux, and macOS. ### `zen trace` CLI commands (`src/zen/cmds/`, `src/zen/trace/`) - **`zen trace analyze`** — Summarize a `.utrace` file: session metadata, thread inventory, command line + build configuration, CPU profiling scopes, timing, event rates, log messages, and (with symbols) memory allocation metrics including live-allocs dumps, callstack-keyed aggregation, and allocation churn. Optional HTML output for memory reports. - **`zen trace inspect`** — Dump the event schema (declared types, fields, sizes) from a trace file. - **`zen trace trim`** — Extract a time-window from a trace into a new `.utrace` file. - **`zen trace serve`** — Launch a local HTTP server hosting an interactive trace viewer; opens in the default browser. ### Symbolication (`src/zen/trace/symbol_resolver.*`, `thirdparty/raw_pdb/`) - Pluggable resolver with multiple backends: `pdb` (in-tree raw_pdb), `dbghelp` (Windows), `llvm-symbolizer` (all platforms), `atos` (macOS). An `auto` backend picks the best available tool per platform. - Microsoft Symbol Server support: downloads PDBs on demand using a redirect-aware HTTP client. - Local PDB cache keyed by image GUID preserves symbols across binary recompilation. - Callstack trimming heuristic strips UE internal noise from reports. - Binary analysis cache (`.ucache_z`) avoids re-resolving the same trace. ### Interactive trace viewer (`src/zen/frontend/html/`, `src/zen/trace/trace_viewer_service.*`) - Timeline: scope-level detail, horizontal zoom/pan, vertical scrolling, viewport-driven loading with pre-computed LOD for responsive navigation of large traces. - Thread grouping (collapsible sidebar sections) synthesized from name suffixes, natural sort order, visual distinction between lane threads and OS threads. - Bookmark and region annotations; region categories with per-category toggles; bookmark marker toggle in the toolbar. - Filterable Logs tab showing captured `UE_LOG` output. - Stats tab with per-scope aggregate statistics. - Memory tab with interactive allocation analysis and an allocation size histogram. - CsvProfiler event parsing and chart UI. ### Other in-branch supporting changes - **Cross-platform browser launcher** (`browser_launcher.{h,cpp}`) used by `trace serve`. - **`ReciprocalU64`** fast 64-bit integer division (zencore/intmath) for trace analyzers. - **`parallelsort`** cross-platform parallel sort helper (zenutil). - Frontend zip build rule so the viewer's HTML assets are bundled into `zen.exe`. - `/Zo` flag for better optimized debug info on Windows release builds. - `trace-tests.cpp` in the `zen-test` harness (harness itself landed on main via #985). --- src/zencore/intmath.cpp | 94 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) (limited to 'src/zencore/intmath.cpp') diff --git a/src/zencore/intmath.cpp b/src/zencore/intmath.cpp index fedf76edc..b460b5b78 100644 --- a/src/zencore/intmath.cpp +++ b/src/zencore/intmath.cpp @@ -7,6 +7,43 @@ namespace zen { +ReciprocalU64::ReciprocalU64(uint64_t Divisor) +{ + if (Divisor <= 1) + { + Mul = 0; // Sentinel — Divide() returns Value directly. + Shift = 0; + return; + } + + // m = ceil(2^(64+s) / d). Start with s = 0; bump s only if + // the quotient doesn't fit in 64 bits (happens when d is a + // power of two, since 2^64 / 2^k = 2^(64-k) exactly and the + // +1 for ceil can overflow to zero). + for (uint32_t S = 0; S < 64; ++S) + { +#if ZEN_PLATFORM_WINDOWS + uint64_t Remainder = 0; + uint64_t Quotient = _udiv128(uint64_t(1) << S, 0, Divisor, &Remainder); + uint64_t M = Quotient + (Remainder ? 1 : 0); // ceil +#else + unsigned __int128 Num = (unsigned __int128)(uint64_t(1) << S) << 64; + uint64_t Quotient = uint64_t(Num / Divisor); + uint64_t Remainder = uint64_t(Num % Divisor); + uint64_t M = Quotient + (Remainder ? 1 : 0); +#endif + if (M != 0) + { + Mul = M; + Shift = S; + return; + } + } + // Unreachable for any Divisor > 1. + Mul = 0; + Shift = 0; +} + ////////////////////////////////////////////////////////////////////////// // // Testing related code follows... @@ -68,6 +105,63 @@ TEST_CASE("intmath") CHECK(ByteSwap(uint64_t(0x214d'6172'7469'6e21ull)) == 0x216e'6974'7261'4d21ull); } +TEST_CASE("ReciprocalU64 matches integer division") +{ + uint64_t Divisors[] = {1, 2, 3, 4, 5, 7, 10, 100, 1000, 3000, 3579}; + + for (uint64_t D : Divisors) + { + ReciprocalU64 R(D); + + uint64_t TestValues[] = { + 0, + 1, + D - 1, + D, + D + 1, + D * 2, + D * 2 + 1, + 1'000'000, + 10'000'000, + 100'000'000, + 1'000'000'000ULL, + 10'000'000'000ULL, + 100'000'000'000ULL, + 1'000'000'000'000ULL, + uint64_t(~0u), + }; + + for (uint64_t V : TestValues) + { + uint32_t Expected = uint32_t(V / D); + uint32_t Got = R.Divide(V); + CHECK_MESSAGE(Got == Expected, "V=", V, " D=", D, " expected=", Expected, " got=", Got); + } + } +} + +TEST_CASE("ReciprocalU64 rounding division") +{ + // Verify the rounding pattern used in AbsorbBatch: (Cycle + half) / d + uint64_t Divisors[] = {3, 4, 5, 10, 3579}; + + for (uint64_t D : Divisors) + { + ReciprocalU64 R(D); + uint64_t Half = D >> 1; + + uint64_t TestCycles[] = {0, 1, 100, 999'999, 1'000'000, 99'999'999, 1'000'000'000ULL, 50'000'000'000ULL}; + + for (uint64_t Cycle : TestCycles) + { + uint64_t Rounded = Cycle + Half; + uint32_t Expected = uint32_t(Rounded / D); + uint32_t Got = R.Divide(Rounded); + CHECK_MESSAGE(Got == Expected, "Cycle=", Cycle, " D=", D, " expected=", Expected, " got=", Got); + } + } +} + TEST_SUITE_END(); #endif -- cgit v1.2.3