Use a thread-safe temporary arena on every platform.

This commit continues the work started in commits 521473e and e84fd46 that parallelizes certain geometric operations. This commit cleans up the temporary arena implementations and makes them thread-safe. Also, in commit 521473e, a call to FreeAllTemporary() was added during initialization to create the heap on Windows. This is now not necessary as the heap is created transparently on the first call to AllocTemporary().
solvespace · May 22, 2020 · 7f1f9bb · 7f1f9bb
1 parent 060a328
commit 7f1f9bb
Show file tree

Hide file tree

Showing 7 changed files with 68 additions and 100 deletions.
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,