Build MobilityDuck without GSL (#520)

MEOS draws its random numbers from the pg_prng generators of PostgreSQL and calls no GSL function, and the MobilityDB commit the meos port builds finds no GSL package. MobilityDuck therefore neither installs nor links GSL: the manifest and the meos port name no gsl dependency, and CMakeLists.txt finds no GSL package and links no GSL target. The meos port's version is 18.

The comments state what MEOS is: it keeps the PROJ context and its two random number generators in thread-local storage and holds no GEOS or GSL context, its convex hull of a temporal circular buffer is its own, and the mutex around a MEOS-backed scalar function body keeps the MEOS calls of concurrent pipelines from overlapping. The vcpkg-built libraries the artifact must absorb are MEOS, PROJ, GDAL, json-c, h3 and libxml2, and the meos port leaves out the MEOS C test binaries because the extension links only the library.

Author: estebanzimanyi

.github/workflows/MainDistributionPipeline.yml

@@ -187,7 +187,7 @@ jobs:
           else
             readelf -d "$EXT" | sed -n 's/.*NEEDED.*\[\(.*\)\]/\1/p' > deps.txt
             # glibc's own set plus the C++ runtime. Anything vcpkg built (MEOS,
-            # PROJ, GDAL, GSL, json-c, h3, libxml2) must be absorbed into
+            # PROJ, GDAL, json-c, h3, libxml2) must be absorbed into
             # the binary, so none of them may appear here.
             ALLOW='^(libc\.so|libm\.so|libdl\.so|libpthread\.so|librt\.so|libresolv\.so|libstdc\+\+\.so|libgcc_s\.so|libz\.so|ld-linux)'
           fi

CMakeLists.txt

@@ -26,7 +26,6 @@ endif()
 # Dependencies (vcpkg)
 # -----------------------------
 find_package(PROJ CONFIG REQUIRED)
-find_package(GSL REQUIRED)
 find_package(OpenSSL REQUIRED)
 find_package(json-c CONFIG QUIET)
 if(NOT json-c_FOUND)
@@ -251,7 +250,7 @@ endforeach()
 # libmeos is a static archive (the meos port follows the triplet's static
 # linkage), so it carries only MEOS's objects: every library MEOS itself calls
 # into has to be resolved on this link line instead of inside a shared libmeos.
-# PROJ, GSL and json-c already appear in the link list below; these four
+# PROJ and json-c already appear in the link list below; these four
 # are the ones the list was missing, one per optional family the meos port
 # enables with -DALL=ON — H3 for th3index, GDAL for the raster operators, and
 # libxml2 plus zlib for the pgPointCloud core.
@@ -266,8 +265,6 @@ find_package(ZLIB REQUIRED)
 set(MOBILITYDUCK_LINK_LIBS
   MEOS::meos
   PROJ::proj
-  GSL::gsl
-  GSL::gslcblas
   ${JSONC_TGT}
   OpenSSL::SSL
   OpenSSL::Crypto

src/include/mobilityduck/meos_exec_serial.hpp

@@ -15,14 +15,9 @@
 namespace duckdb {
 
 /**
- * Mutex serialization for MobilityDuck scalar function bodies that ultimately call
- * MEOS / liblwgeom. MEOS uses GEOS's legacy global API (`initGEOS` / `finishGEOS`)
- * internally from worker threads; concurrent legacy GEOS init/teardown from DuckDB's
- * parallelism triggers intermittent GEOS errors and allocator corruption when spatial
- * and MobilityDuck coexist.
- *
- * Wrapping each MEOS-backed ScalarFunction execution prevents overlapping MEOS/GEOS
- * legacy pairs across concurrent pipelines while preserving parallelism elsewhere.
+ * Mutex serialization for MobilityDuck scalar function bodies that call MEOS:
+ * wrapping each MEOS-backed ScalarFunction execution keeps the MEOS calls of
+ * concurrent pipelines from overlapping while preserving parallelism elsewhere.
  */
 inline std::mutex &MeosSerializedExecMutex() {
 	static std::mutex mutex;

src/include/mobilityduck/meos_thread.hpp

@@ -24,8 +24,8 @@ inline std::string &MeosThreadTimezone() {
 	return zone;
 }
 
-// MEOS keeps the session timezone, the collation cache, errno, the PROJ and
-// GEOS contexts and the RNGs in thread-local storage, so a thread that calls
+// MEOS keeps the session timezone, the collation cache, errno, the PROJ
+// context and the RNGs in thread-local storage, so a thread that calls
 // MEOS initialises its own caches before its first call (see meos.h,
 // "Multithreading"). DuckDB runs scalar, cast and aggregate bodies on
 // TaskScheduler worker threads, so a one-shot init on the load thread leaves
@@ -38,9 +38,9 @@ inline std::string &MeosThreadTimezone() {
 // process-global error handler to the exit-on-error default, so an error
 // raised on any other thread during that window would print a bare message and
 // end the process rather than reach the handler that turns it into a DuckDB
-// exception. The PROJ, GEOS and GSL contexts are thread-local statics inside
-// MEOS that it creates lazily on first use, so a caller neither can nor needs
-// to initialise them.
+// exception. The PROJ context and the RNGs are thread-local statics inside MEOS
+// that it creates lazily on first use, so a caller neither can nor needs to
+// initialise them.
 inline void EnsureMeosThreadInitialized() {
 	static thread_local const bool meos_thread_ready = []() {
 		meos_initialize_timezone(MEOS_DEFAULT_TIMEZONE);

test/sql/tcbuffer.test

@@ -128,10 +128,10 @@ SELECT endValue(tcbuffer '{Cbuffer(Point(1 1),0.5)@2000-01-01, Cbuffer(Point(2 2
 ----
 Cbuffer(010100000000000000000000400000000000000040,1)
 
-# spatial accessor: convex hull of the swept region. convexHull is a linear (GEOS-polygonized)
-# hull of the traversed area, not a curved CURVEDPOLYGON (see the tcbuffer manual note); a
-# zero-radius input yields the point trajectory's stable, arc-free triangle. The geometry
-# marshals to the DuckDB GEOMETRY type.
+# spatial accessor: convex hull of the swept region. convexHull is computed on the exact
+# traversed area, arcs included, so a buffer of nonzero radius yields a CURVEPOLYGON (see the
+# tcbuffer manual note); a zero-radius input carries no arc and yields the point trajectory's
+# triangle. The geometry marshals to the DuckDB GEOMETRY type.
 query I
 SELECT ST_AsText(convexHull(tcbuffer '[Cbuffer(Point(0 0),0)@2000-01-01, Cbuffer(Point(3 0),0)@2000-01-02, Cbuffer(Point(3 4),0)@2000-01-03]'));
 ----

vcpkg.json

@@ -1,6 +1,5 @@
 {
         "dependencies": [
-          "gsl",
           { "name": "meos", "version>=": "0" },
 
           "vcpkg-cmake",

vcpkg_ports/meos/portfile.cmake

@@ -85,8 +85,8 @@ vcpkg_cmake_configure(
         # one .duckdb_extension file with nowhere to put a sidecar libmeos, so
         # forcing a shared build here produced a binary that referenced
         # @rpath/libmeos.dylib and failed to load anywhere but the CI runner.
-        # Build only the MEOS library, not the MEOS C test binaries: those link
-        # the GEOS C++ API, which the arm64-linux vcpkg triplet does not carry.
+        # Build only the MEOS library, the one artifact the extension links, not
+        # the MEOS C test binaries.
         -DBUILD_TESTING=OFF
         "-DCMAKE_PROJECT_INCLUDE=${CMAKE_CURRENT_LIST_DIR}/cmake-project-include.cmake"
 )

vcpkg_ports/meos/vcpkg.json

@@ -1,15 +1,14 @@
 {
     "name": "meos",
     "version-string": "git",
-    "port-version": 17,
+    "port-version": 18,
     "description": "MEOS - Mobility Engine Open Source C library (built from MobilityDB with -DMEOS=ON)",
     "homepage": "https://libmeos.org/",
     "dependencies": [
         "vcpkg-cmake",
         "vcpkg-cmake-config",
         "proj",
         "json-c",
-        "gsl",
         "h3",
         { "name": "gdal", "default-features": false },
         { "name": "libxml2", "features": [ "zlib" ], "default-features": false },