1 files changed, 160 insertions, 0 deletions
diff --git a/src/lib/eo/eo_add_fallback.c b/src/lib/eo/eo_add_fallback.c
new file mode 100644
index 0000000000..2adc39acff
--- /dev/null
+++ b/src/lib/eo/eo_add_fallback.c
@@ -0,0 +1,160 @@
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#if defined HAVE_DLADDR && ! defined _WIN32
+# include <dlfcn.h>
+#endif
+
+#include <Eina.h>
+
+#include "eo_ptr_indirection.h"
+#include "eo_private.h"
+
+#include "eo_add_fallback.h"
+
+// 1024 entries == 16k or 32k (32 or 64bit) for eo call stack. that's 1023
+// imbricated/recursive calls it can handle before barfing. i'd say that's ok
+#define EO_CALL_STACK_DEPTH_MIN 1024
+
+#define EO_CALL_STACK_SIZE (EO_CALL_STACK_DEPTH_MIN * sizeof(Eo_Stack_Frame))
+
+static Eina_TLS _eo_call_stack_key = 0;
+
+#define MEM_PAGE_SIZE 4096
+
+static void *
+_eo_call_stack_mem_alloc(size_t size)
+{
+#ifdef HAVE_MMAP
+   // allocate eo call stack via mmped anon segment if on linux - more
+   // secure and safe. also gives page aligned memory allowing madvise
+   void *ptr;
+   size_t newsize;
+   newsize = MEM_PAGE_SIZE * ((size + MEM_PAGE_SIZE - 1) /
+                              MEM_PAGE_SIZE);
+   ptr = mmap(NULL, newsize, PROT_READ | PROT_WRITE,
+              MAP_PRIVATE | MAP_ANON, -1, 0);
+   if (ptr == MAP_FAILED)
+     {
+        ERR("eo call stack mmap failed.");
+        return NULL;
+     }
+   return ptr;
+#else
+   //in regular cases just use malloc
+   return calloc(1, size);
+#endif
+}
+
+static void
+_eo_call_stack_mem_free(void *ptr, size_t size)
+{
+#ifdef HAVE_MMAP
+   munmap(ptr, size);
+#else
+   (void) size;
+   free(ptr);
+#endif
+}
+
+static Eo_Call_Stack *
+_eo_call_stack_create()
+{
+   Eo_Call_Stack *stack;
+
+   stack = calloc(1, sizeof(Eo_Call_Stack));
+   if (!stack)
+     return NULL;
+
+   stack->frames = _eo_call_stack_mem_alloc(EO_CALL_STACK_SIZE);
+   if (!stack->frames)
+     {
+        free(stack);
+        return NULL;
+     }
+
+   // first frame is never used
+   stack->frame_ptr = stack->frames;
+
+   return stack;
+}
+
+static void
+_eo_call_stack_free(void *ptr)
+{
+   Eo_Call_Stack *stack = (Eo_Call_Stack *) ptr;
+
+   if (!stack) return;
+
+   if (stack->frames)
+     _eo_call_stack_mem_free(stack->frames, EO_CALL_STACK_SIZE);
+
+   free(stack);
+}
+
+static Eo_Call_Stack *main_loop_stack = NULL;
+
+#define _EO_CALL_STACK_GET() ((EINA_LIKELY(eina_main_loop_is())) ? main_loop_stack : _eo_call_stack_get_thread())
+
+static inline Eo_Call_Stack *
+_eo_call_stack_get_thread(void)
+{
+   Eo_Call_Stack *stack = eina_tls_get(_eo_call_stack_key);
+
+   if (stack) return stack;
+
+   stack = _eo_call_stack_create();
+   eina_tls_set(_eo_call_stack_key, stack);
+
+   return stack;
+}
+
+Eo_Call_Stack *
+_eo_add_fallback_stack_get(void)
+{
+   return _EO_CALL_STACK_GET();
+}
+
+EAPI Eo *
+_eo_self_get(void)
+{
+   return _EO_CALL_STACK_GET()->frame_ptr->obj;
+}
+
+Eina_Bool
+_eo_add_fallback_init(void)
+{
+   if (_eo_call_stack_key != 0)
+     WRN("_eo_call_stack_key already set, this should not happen.");
+   else
+     {
+        if (!eina_tls_cb_new(&_eo_call_stack_key, _eo_call_stack_free))
+          {
+             EINA_LOG_ERR("Could not create TLS key for call stack.");
+             return EINA_FALSE;
+
+          }
+     }
+
+   main_loop_stack = _eo_call_stack_create();
+   if (!main_loop_stack)
+     {
+        EINA_LOG_ERR("Could not alloc eo call stack.");
+        return EINA_FALSE;
+     }
+
+   return EINA_TRUE;
+}
+
+Eina_Bool
+_eo_add_fallback_shutdown(void)
+{
+   if (_eo_call_stack_key != 0)
+     {
+        eina_tls_free(_eo_call_stack_key);
+        _eo_call_stack_key = 0;
+     }
+
+   return EINA_TRUE;
+}