Refactor interface between backend and frontend (#530)

* Rename to use Config, rather than StateHandle/Globals/Backend
* Make Backend a type on Config that contains the address space management implementation
* Make Ranges part of the Backend configuration, so we can reuse code for different ways of managing memory
* Pull the common chains of range definitions into separate files for reuse.
* Move PagemapEntry to CommonConfig
* Expose Pagemap through backend, so frontend doesn't see Pagemap directly
* Remove global Pal and use DefaultPal, where one is not pass explicitly.

Co-authored-by: David Chisnall <davidchisnall@users.noreply.github.com>
Co-authored-by: Nathaniel Filardo <105816689+nwf-msr@users.noreply.github.com>

src/test/func/domestication/domestication.cc

@@ -11,20 +11,38 @@ int main()
 // #  define SNMALLOC_TRACING
 
 #  include <snmalloc/backend/backend.h>
+#  include <snmalloc/backend/standard_range.h>
+#  include <snmalloc/backend_helpers/backend_helpers.h>
 #  include <snmalloc/snmalloc_core.h>
 
 // Specify type of allocator
 #  define SNMALLOC_PROVIDE_OWN_CONFIG
 namespace snmalloc
 {
-  class CustomGlobals : public BackendAllocator<Pal, false>
+  class CustomConfig : public CommonConfig
   {
   public:
-    using GlobalPoolState = PoolState<CoreAllocator<CustomGlobals>>;
+    using Pal = DefaultPal;
+    using PagemapEntry = DefaultPagemapEntry;
 
   private:
-    using Backend = BackendAllocator<Pal, false>;
+    using ConcretePagemap =
+      FlatPagemap<MIN_CHUNK_BITS, PagemapEntry, Pal, false>;
 
+  public:
+    using Pagemap = BasicPagemap<Pal, ConcretePagemap, PagemapEntry, false>;
+
+  public:
+    using LocalState = StandardLocalState<
+      Pal,
+      Pagemap,
+      Pipe<PalRange<Pal>, PagemapRegisterRange<Pagemap, false>>>;
+
+    using GlobalPoolState = PoolState<CoreAllocator<CustomConfig>>;
+
+    using Backend = BackendAllocator<Pal, PagemapEntry, Pagemap, LocalState>;
+
+  private:
     SNMALLOC_REQUIRE_CONSTINIT
     inline static GlobalPoolState alloc_pool;
 
@@ -65,7 +83,7 @@ namespace snmalloc
     static CapPtr<
       T,
       typename B::template with_wildness<capptr::dimension::Wildness::Tame>>
-    capptr_domesticate(typename Backend::LocalState*, CapPtr<T, B> p)
+    capptr_domesticate(LocalState*, CapPtr<T, B> p)
     {
       domesticate_count++;
 
@@ -85,7 +103,7 @@ namespace snmalloc
       {
         std::cout << "Patching over corruption" << std::endl;
         *domesticate_patch_location = domesticate_patch_value;
-        snmalloc::CustomGlobals::domesticate_patch_location = nullptr;
+        snmalloc::CustomConfig::domesticate_patch_location = nullptr;
       }
 
       return CapPtr<
@@ -95,7 +113,7 @@ namespace snmalloc
     }
   };
 
-  using Alloc = LocalAllocator<CustomGlobals>;
+  using Alloc = LocalAllocator<CustomConfig>;
 }
 
 #  define SNMALLOC_NAME_MANGLE(a) test_##a
@@ -103,11 +121,11 @@ namespace snmalloc
 
 int main()
 {
-  snmalloc::CustomGlobals::init(); // init pagemap
-  snmalloc::CustomGlobals::domesticate_count = 0;
+  snmalloc::CustomConfig::Pagemap::concretePagemap.init(); // init pagemap
+  snmalloc::CustomConfig::domesticate_count = 0;
 
   LocalEntropy entropy;
-  entropy.init<Pal>();
+  entropy.init<DefaultPal>();
   key_global = FreeListKey(entropy.get_free_list_key());
 
   auto alloc1 = new Alloc();
@@ -123,21 +141,20 @@ int main()
   alloc2->flush();
 
   // Clobber the linkage but not the back pointer
-  snmalloc::CustomGlobals::domesticate_patch_location =
+  snmalloc::CustomConfig::domesticate_patch_location =
     static_cast<uintptr_t*>(p);
-  snmalloc::CustomGlobals::domesticate_patch_value =
-    *static_cast<uintptr_t*>(p);
+  snmalloc::CustomConfig::domesticate_patch_value = *static_cast<uintptr_t*>(p);
   memset(p, 0xA5, sizeof(void*));
 
-  snmalloc::CustomGlobals::domesticate_trace = true;
-  snmalloc::CustomGlobals::domesticate_count = 0;
+  snmalloc::CustomConfig::domesticate_trace = true;
+  snmalloc::CustomConfig::domesticate_count = 0;
 
   // Open a new slab, so that slow path will pick up the message queue.  That
   // means this should be a sizeclass we've not used before, even internally.
   auto q = alloc1->alloc(512);
   std::cout << "Allocated q " << q << std::endl;
 
-  snmalloc::CustomGlobals::domesticate_trace = false;
+  snmalloc::CustomConfig::domesticate_trace = false;
 
   /*
    * Expected domestication calls in the above message passing:
@@ -152,8 +169,8 @@ int main()
    *     after q).
    */
   static constexpr size_t expected_count =
-    snmalloc::CustomGlobals::Options.QueueHeadsAreTame ? 2 : 3;
-  SNMALLOC_CHECK(snmalloc::CustomGlobals::domesticate_count == expected_count);
+    snmalloc::CustomConfig::Options.QueueHeadsAreTame ? 2 : 3;
+  SNMALLOC_CHECK(snmalloc::CustomConfig::domesticate_count == expected_count);
 
   // Prevent the allocators from going out of scope during the above test
   alloc1->flush();

src/test/func/fixed_region/fixed_region.cc

@@ -11,7 +11,7 @@
 
 using namespace snmalloc;
 
-using CustomGlobals = FixedGlobals<PALNoAlloc<DefaultPal>>;
+using CustomGlobals = FixedRangeConfig<PALNoAlloc<DefaultPal>>;
 using FixedAlloc = LocalAllocator<CustomGlobals>;
 
 int main()
@@ -23,8 +23,8 @@ int main()
   // It is also large enough for the example to run in.
   // For 1MiB superslabs, SUPERSLAB_BITS + 4 is not big enough for the example.
   auto size = bits::one_at_bit(28);
-  auto oe_base = Pal::reserve(size);
-  Pal::notify_using<NoZero>(oe_base, size);
+  auto oe_base = DefaultPal::reserve(size);
+  DefaultPal::notify_using<NoZero>(oe_base, size);
   auto oe_end = pointer_offset(oe_base, size);
   std::cout << "Allocated region " << oe_base << " - "
             << pointer_offset(oe_base, size) << std::endl;

src/test/func/malloc/malloc.cc

@@ -367,6 +367,6 @@ int main(int argc, char** argv)
     our_malloc_usable_size(nullptr) == 0,
     "malloc_usable_size(nullptr) should be zero");
 
-  snmalloc::debug_check_empty<snmalloc::Globals>();
+  snmalloc::debug_check_empty<snmalloc::StandardConfig>();
   return 0;
 }

src/test/func/memory/memory.cc

@@ -184,7 +184,7 @@ void test_calloc()
     alloc.dealloc(p, size);
   }
 
-  snmalloc::debug_check_empty<Globals>();
+  snmalloc::debug_check_empty<StandardConfig>();
 }
 
 void test_double_alloc()
@@ -229,7 +229,7 @@ void test_double_alloc()
       }
     }
   }
-  snmalloc::debug_check_empty<Globals>();
+  snmalloc::debug_check_empty<StandardConfig>();
 }
 
 void test_external_pointer()
@@ -273,7 +273,7 @@ void test_external_pointer()
     alloc.dealloc(p1, size);
   }
 
-  snmalloc::debug_check_empty<Globals>();
+  snmalloc::debug_check_empty<StandardConfig>();
 };
 
 void check_offset(void* base, void* interior)
@@ -305,7 +305,7 @@ void test_external_pointer_large()
 
   auto& alloc = ThreadAlloc::get();
 
-  constexpr size_t count_log = Pal::address_bits > 32 ? 5 : 3;
+  constexpr size_t count_log = DefaultPal::address_bits > 32 ? 5 : 3;
   constexpr size_t count = 1 << count_log;
   // Pre allocate all the objects
   size_t* objects[count];

src/test/func/pagemap/pagemap.cc

@@ -65,8 +65,8 @@ void test_pagemap(bool bounded)
   if (bounded)
   {
     auto size = bits::one_at_bit(30);
-    auto base = Pal::reserve(size);
-    Pal::notify_using<NoZero>(base, size);
+    auto base = DefaultPal::reserve(size);
+    DefaultPal::notify_using<NoZero>(base, size);
     std::cout << "Fixed base: " << base << " (" << size << ") "
               << " end: " << pointer_offset(base, size) << std::endl;
     auto [heap_base, heap_size] = pagemap_test_bound.init(base, size);

src/test/func/pool/pool.cc

@@ -12,7 +12,7 @@ struct PoolAEntry : Pooled<PoolAEntry>
   PoolAEntry() : field(1){};
 };
 
-using PoolA = Pool<PoolAEntry, Alloc::StateHandle>;
+using PoolA = Pool<PoolAEntry, Alloc::Config>;
 
 struct PoolBEntry : Pooled<PoolBEntry>
 {
@@ -22,14 +22,14 @@ struct PoolBEntry : Pooled<PoolBEntry>
   PoolBEntry(int f) : field(f){};
 };
 
-using PoolB = Pool<PoolBEntry, Alloc::StateHandle>;
+using PoolB = Pool<PoolBEntry, Alloc::Config>;
 
 void test_alloc()
 {
   auto ptr = PoolA::acquire();
   SNMALLOC_CHECK(ptr != nullptr);
   // Pool allocations should not be visible to debug_check_empty.
-  snmalloc::debug_check_empty<Alloc::StateHandle>();
+  snmalloc::debug_check_empty<Alloc::Config>();
   PoolA::release(ptr);
 }
 

src/test/func/statistics/stats.cc

@@ -8,7 +8,7 @@ int main()
 
   auto r = a.alloc(16);
 
-  snmalloc::debug_check_empty<snmalloc::Globals>(&result);
+  snmalloc::debug_check_empty<snmalloc::StandardConfig>(&result);
   if (result != false)
   {
     abort();
@@ -16,7 +16,7 @@ int main()
 
   a.dealloc(r);
 
-  snmalloc::debug_check_empty<snmalloc::Globals>(&result);
+  snmalloc::debug_check_empty<snmalloc::StandardConfig>(&result);
   if (result != true)
   {
     abort();
@@ -24,7 +24,7 @@ int main()
 
   r = a.alloc(16);
 
-  snmalloc::debug_check_empty<snmalloc::Globals>(&result);
+  snmalloc::debug_check_empty<snmalloc::StandardConfig>(&result);
   if (result != false)
   {
     abort();
@@ -32,7 +32,7 @@ int main()
 
   a.dealloc(r);
 
-  snmalloc::debug_check_empty<snmalloc::Globals>(&result);
+  snmalloc::debug_check_empty<snmalloc::StandardConfig>(&result);
   if (result != true)
   {
     abort();

src/test/func/thread_alloc_external/thread_alloc_external.cc

@@ -12,7 +12,7 @@
 
 namespace snmalloc
 {
-  using Alloc = snmalloc::LocalAllocator<snmalloc::Globals>;
+  using Alloc = snmalloc::LocalAllocator<snmalloc::StandardConfig>;
 }
 
 using namespace snmalloc;

src/test/func/two_alloc_types/alloc1.cc

@@ -12,7 +12,7 @@
 #define SNMALLOC_PROVIDE_OWN_CONFIG
 namespace snmalloc
 {
-  using CustomGlobals = FixedGlobals<PALNoAlloc<DefaultPal>>;
+  using CustomGlobals = FixedRangeConfig<PALNoAlloc<DefaultPal>>;
   using Alloc = LocalAllocator<CustomGlobals>;
 }
 

src/test/helpers.h

@@ -19,7 +19,7 @@ namespace snmalloc
   { \
     current_test = __PRETTY_FUNCTION__; \
     MessageBuilder<1024> mb{"Starting test: " msg "\n", ##__VA_ARGS__}; \
-    Pal::message(mb.get_message()); \
+    DefaultPal::message(mb.get_message()); \
   } while (0)
 
   /**
@@ -33,7 +33,7 @@ namespace snmalloc
   do \
   { \
     MessageBuilder<1024> mb{msg "\n", ##__VA_ARGS__}; \
-    Pal::message(mb.get_message()); \
+    DefaultPal::message(mb.get_message()); \
   } while (0)
 
 }

src/test/perf/contention/contention.cc

@@ -154,7 +154,7 @@ void test_tasks(size_t num_tasks, size_t count, size_t size)
   }
 
 #ifndef NDEBUG
-  snmalloc::debug_check_empty<Globals>();
+  snmalloc::debug_check_empty<StandardConfig>();
 #endif
 };
 

src/test/perf/external_pointer/externalpointer.cc

@@ -19,7 +19,7 @@ namespace test
     {
       size_t rand = (size_t)r.next();
       size_t offset = bits::clz(rand);
-      if constexpr (Pal::address_bits > 32)
+      if constexpr (DefaultPal::address_bits > 32)
       {
         if (offset > 30)
           offset = 30;
@@ -47,7 +47,7 @@ namespace test
       alloc.dealloc(objects[i]);
     }
 
-    snmalloc::debug_check_empty<Globals>();
+    snmalloc::debug_check_empty<StandardConfig>();
   }
 
   void test_external_pointer(xoroshiro::p128r64& r)

src/test/perf/singlethread/singlethread.cc

@@ -60,7 +60,7 @@ void test_alloc_dealloc(size_t count, size_t size, bool write)
     }
   }
 
-  snmalloc::debug_check_empty<Globals>();
+  snmalloc::debug_check_empty<StandardConfig>();
 }
 
 int main(int, char**)

src/test/setup.h

@@ -64,7 +64,7 @@ void print_stack_trace()
 void _cdecl error(int signal)
 {
   snmalloc::UNUSED(signal);
-  snmalloc::Pal::message("*****ABORT******");
+  snmalloc::DefaultPal::message("*****ABORT******");
 
   print_stack_trace();
 
@@ -75,7 +75,7 @@ LONG WINAPI VectoredHandler(struct _EXCEPTION_POINTERS* ExceptionInfo)
 {
   snmalloc::UNUSED(ExceptionInfo);
 
-  snmalloc::Pal::message("*****UNHANDLED EXCEPTION******");
+  snmalloc::DefaultPal::message("*****UNHANDLED EXCEPTION******");
 
   print_stack_trace();