solvespace · whitequark · May 22, 2020 · May 22, 2020
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -26,14 +26,6 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/config.h.in
 
 # platform utilities
 
-if(WIN32)
-    set(util_SOURCES
-        platform/utilwin.cpp)
-else()
-    set(util_SOURCES
-        platform/utilunix.cpp)
-endif()
-
 if(APPLE)
     set(util_LIBRARIES
         ${APPKIT_LIBRARY})

diff --git a/src/lib.cpp b/src/lib.cpp
@@ -67,9 +67,6 @@ void Slvs_MakeQuaternion(double ux, double uy, double uz,
 
 void Slvs_Solve(Slvs_System *ssys, Slvs_hGroup shg)
 {
-    // Create the temporary heap, if this is the first time we're solving.
-    FreeAllTemporary();
-
     int i;
     for(i = 0; i < ssys->params; i++) {
         Slvs_Param *sp = &(ssys->param[i]);

diff --git a/src/platform/platform.cpp b/src/platform/platform.cpp
@@ -18,6 +18,7 @@
 #else
 #   include <unistd.h>
 #   include <sys/stat.h>
+#   include <mutex>
 #endif
 
 namespace SolveSpace {
@@ -605,9 +606,6 @@ std::vector<std::string> InitCli(int argc, char **argv) {
     }
 #endif
 
-    // Create the heap that we use to store Exprs and other temp stuff.
-    FreeAllTemporary();
-
     // Extract the command-line arguments; the ones from main() are ignored,
     // since they are in the OEM encoding.
     int argcW;
@@ -681,5 +679,65 @@ void DebugPrint(const char *fmt, ...) {
 
 #endif
 
+//-----------------------------------------------------------------------------
+// Temporary arena, on Windows.
+//-----------------------------------------------------------------------------
+
+#if defined(WIN32)
+
+static HANDLE TempArena = NULL;
+
+void *AllocTemporary(size_t size)
+{
+    if(!TempArena)
+        TempArena = HeapCreate(0, 0, 0);
+    void *ptr = HeapAlloc(TempArena, HEAP_ZERO_MEMORY, size);
+    ssassert(ptr != NULL, "out of memory");
+    return ptr;
+}
+
+void FreeAllTemporary()
+{
+    HeapDestroy(TempArena);
+    TempArena = NULL;
+}
+
+#endif
+
+//-----------------------------------------------------------------------------
+// Temporary arena, on Linux.
+//-----------------------------------------------------------------------------
+
+#if !defined(WIN32)
+
+struct ArenaChunk {
+    ArenaChunk *next;
+};
+
+static std::mutex TempArenaMutex;
+static ArenaChunk *TempArena = NULL;
+
+void *AllocTemporary(size_t size)
+{
+    ArenaChunk *chunk = (ArenaChunk *)calloc(1, sizeof(ArenaChunk) + size);
+    ssassert(chunk != NULL, "out of memory");
+    std::lock_guard<std::mutex> guard(TempArenaMutex);
+    chunk->next = TempArena;
+    TempArena = chunk;
+    return (void *)(chunk + 1);
+}
+
+void FreeAllTemporary()
+{
+    std::lock_guard<std::mutex> guard(TempArenaMutex);
+    while(TempArena) {
+        ArenaChunk *chunk = TempArena;
+        TempArena = TempArena->next;
+        free(chunk);
+    }
+}
+
+#endif
+
 }
 }
diff --git a/src/platform/platform.h b/src/platform/platform.h
@@ -70,6 +70,10 @@ std::vector<std::string> InitCli(int argc, char **argv);
 // Debug print function.
 void DebugPrint(const char *fmt, ...);
 
+// Temporary arena functions.
+void *AllocTemporary(size_t size);
+void FreeAllTemporary();
+
 }
 
 #endif
diff --git a/src/platform/utilunix.cpp b/src/platform/utilunix.cpp
diff --git a/src/platform/utilwin.cpp b/src/platform/utilwin.cpp
diff --git a/src/solvespace.h b/src/solvespace.h
@@ -132,16 +132,15 @@ inline double Random(double vmax) {
 #include "platform/gui.h"
 #include "resource.h"
 
+using Platform::AllocTemporary;
+using Platform::FreeAllTemporary;
+
 class Expr;
 class ExprVector;
 class ExprQuaternion;
 class RgbaColor;
 enum class Command : uint32_t;
 
-// Temporary heap, defined in the platform-specific code.
-void *AllocTemporary(size_t n);
-void FreeAllTemporary();
-
 enum class Unit : uint32_t {
     MM = 0,
     INCHES,