allocate shared JIT code on pages shared by places

src/racket/include/mzwin.def

@@ -185,6 +185,7 @@ EXPORTS
  scheme_eval_compiled_sized_string_with_magic
  scheme_detach_multple_array
  scheme_malloc_code
+ scheme_malloc_permanent_code
  scheme_free_code
  scheme_malloc_gcable_code
  scheme_malloc_eternal

src/racket/include/mzwin3m.def

@@ -194,6 +194,7 @@ EXPORTS
  GC_malloc_atomic_allow_interior
  GC_malloc_tagged_allow_interior
  scheme_malloc_code
+ scheme_malloc_permanent_code
  scheme_free_code
  scheme_malloc_gcable_code
  scheme_malloc_eternal

src/racket/include/racket.exp

@@ -197,6 +197,7 @@ GC_malloc_atomic
 GC_malloc_stubborn
 GC_malloc_uncollectable
 scheme_malloc_code
+scheme_malloc_permanent_code
 scheme_free_code
 scheme_malloc_gcable_code
 scheme_malloc_eternal

src/racket/include/racket3m.exp

@@ -202,6 +202,7 @@ GC_malloc_allow_interior
 GC_malloc_atomic_allow_interior
 GC_malloc_tagged_allow_interior
 scheme_malloc_code
+scheme_malloc_permanent_code
 scheme_free_code
 scheme_malloc_gcable_code
 scheme_malloc_eternal

src/racket/src/jitstate.c

@@ -136,7 +136,7 @@ void *scheme_generate_one(mz_jit_state *old_jitter,
 	buffer = scheme_malloc_gcable_code(size);
 #endif
       } else {
-        buffer = scheme_malloc_code(size);
+        buffer = scheme_malloc_permanent_code(size);
       }
       RECORD_CODE_SIZE(size);
     } else if (old_jitter) {

src/racket/src/salloc.c

@@ -839,6 +839,12 @@ struct free_list_entry {
 THREAD_LOCAL_DECL(static struct free_list_entry *free_list;)
 THREAD_LOCAL_DECL(static int free_list_bucket_count;)
 
+#ifdef MZ_USE_PLACES
+static mzrt_mutex *permanent_code_mutex = NULL; 
+static void *permanent_code_page = NULL;
+static intptr_t available_code_page_amount = 0;
+#endif
+
 static intptr_t get_page_size()
 {
 # ifdef PAGESIZE
@@ -1095,6 +1101,47 @@ void *scheme_malloc_code(intptr_t size)
 #endif
 }
 
+void *scheme_malloc_permanent_code(intptr_t size)
+/* allocate code that will never be freed and that can be used
+   in multiple places */
+{
+#if defined(MZ_USE_PLACES) && (defined(MZ_JIT_USE_MPROTECT) || defined(MZ_JIT_USE_WINDOWS_VIRTUAL_ALLOC))
+  void *p;
+  intptr_t page_size;
+
+  if (!permanent_code_mutex) {
+    /* This function will be called at least once before any other place
+       is created, so it's ok to create the mutex here. */
+    mzrt_mutex_create(&permanent_code_mutex);
+  }
+
+  /* 16-byte alignment: */
+  if (size & 0xF) size += 16 - (size & 0xF);
+
+  mzrt_mutex_lock(permanent_code_mutex);
+  
+  if (available_code_page_amount < size) {
+    page_size = get_page_size();
+    page_size *= 4;
+    while (page_size < size) page_size *= 2;
+
+    permanent_code_page = malloc_page(page_size);
+
+    available_code_page_amount = page_size;
+  }
+   
+  p = permanent_code_page;
+  permanent_code_page = ((char *)permanent_code_page) + size;
+  available_code_page_amount -= size;
+  
+  mzrt_mutex_unlock(permanent_code_mutex);
+
+  return p;
+#else
+  return scheme_malloc_code(size);
+#endif
+}
+
 void scheme_free_code(void *p)
 {
 #if defined(MZ_JIT_USE_MPROTECT) || defined(MZ_JIT_USE_WINDOWS_VIRTUAL_ALLOC)

src/racket/src/schemef.h

@@ -399,6 +399,7 @@ MZ_EXTERN void *GC_malloc_uncollectable(size_t size_in_bytes);
 #endif
 
 MZ_EXTERN void *scheme_malloc_code(intptr_t size);
+MZ_EXTERN void *scheme_malloc_permanent_code(intptr_t size);
 MZ_EXTERN void scheme_free_code(void *p);
 #ifndef MZ_PRECISE_GC
 MZ_EXTERN void *scheme_malloc_gcable_code(intptr_t size);

src/racket/src/schemex.h

@@ -308,6 +308,7 @@ void *(*GC_malloc_uncollectable)(size_t size_in_bytes);
 # endif
 #endif
 void *(*scheme_malloc_code)(intptr_t size);
+void *(*scheme_malloc_permanent_code)(intptr_t size);
 void (*scheme_free_code)(void *p);
 #ifndef MZ_PRECISE_GC
 void *(*scheme_malloc_gcable_code)(intptr_t size);

src/racket/src/schemex.inc

@@ -219,6 +219,7 @@
 # endif
 #endif
   scheme_extension_table->scheme_malloc_code = scheme_malloc_code;
+  scheme_extension_table->scheme_malloc_permanent_code = scheme_malloc_permanent_code;
   scheme_extension_table->scheme_free_code = scheme_free_code;
 #ifndef MZ_PRECISE_GC
   scheme_extension_table->scheme_malloc_gcable_code = scheme_malloc_gcable_code;

src/racket/src/schemexm.h

@@ -219,6 +219,7 @@
 # endif
 #endif
 #define scheme_malloc_code (scheme_extension_table->scheme_malloc_code)
+#define scheme_malloc_permanent_code (scheme_extension_table->scheme_malloc_permanent_code)
 #define scheme_free_code (scheme_extension_table->scheme_free_code)
 #ifndef MZ_PRECISE_GC
 #define scheme_malloc_gcable_code (scheme_extension_table->scheme_malloc_gcable_code)