From afe817741cc8e509c9c3b2fdfca7c2b7ac4c994a Mon Sep 17 00:00:00 2001
From: Corinna Vinschen <corinna@vinschen.de>
Date: Tue, 9 Aug 2011 12:00:27 +0000
Subject: [PATCH] 	* heap.cc (eval_initial_heap_size): New function
 fetching the heap 	size from the LoaderFlags field in the PE/COFF header.
 	(heap_init): Call eval_initial_heap_size rather than 
 cygwin_shared->heap_chunk_size to fetch the initial heap size. 	*
 shared.cc (shared_info::heap_chunk_size): Remove. 	* shared_info.h (class
 shared_info): Drop heap_chunk member. 	(CURR_SHARED_MAGIC): Update.

---
 winsup/cygwin/ChangeLog     | 10 ++++++++++
 winsup/cygwin/heap.cc       | 26 +++++++++++++++++++++++++-
 winsup/cygwin/shared.cc     | 31 -------------------------------
 winsup/cygwin/shared_info.h |  3 +--
 4 files changed, 36 insertions(+), 34 deletions(-)

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 8aad3c0ab..cdb1560ff 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,13 @@
+2011-08-09  Corinna Vinschen  <corinna@vinschen.de>
+
+	* heap.cc (eval_initial_heap_size): New function fetching the heap
+	size from the LoaderFlags field in the PE/COFF header.
+	(heap_init): Call eval_initial_heap_size rather than
+	cygwin_shared->heap_chunk_size to fetch the initial heap size.
+	* shared.cc (shared_info::heap_chunk_size): Remove.
+	* shared_info.h (class shared_info): Drop heap_chunk member.
+	(CURR_SHARED_MAGIC): Update.
+
 2011-08-09  Corinna Vinschen  <corinna@vinschen.de>
 
 	* ntdll.h (STATUS_NOT_FOUND): Define.
diff --git a/winsup/cygwin/heap.cc b/winsup/cygwin/heap.cc
index 977b93b4d..d58a4cfcc 100644
--- a/winsup/cygwin/heap.cc
+++ b/winsup/cygwin/heap.cc
@@ -56,6 +56,30 @@ eval_start_address ()
   return start_address;
 }
 
+static unsigned
+eval_initial_heap_size ()
+{
+  PIMAGE_DOS_HEADER dosheader;
+  PIMAGE_NT_HEADERS32 ntheader;
+  unsigned size;
+
+  dosheader = (PIMAGE_DOS_HEADER) GetModuleHandle (NULL);
+  ntheader = (PIMAGE_NT_HEADERS32) ((PBYTE) dosheader + dosheader->e_lfanew);
+  /* LoaderFlags is an obsolete DWORD member of the PE/COFF file header.
+     It's value is ignored by the loader, so we're free to use it for
+     Cygwin.  If it's 0, we default to the usual 384 Megs.  Otherwise,
+     we use it as the default initial heap size in megabyte.  Valid values
+     are between 4 and 2048 Megs. */
+  size = ntheader->OptionalHeader.LoaderFlags;
+  if (size == 0)
+    size = 384;
+  else if (size < 4)
+    size = 4;
+  else if (size > 2048)
+    size = 2048;
+  return size << 20;
+}
+
 /* Initialize the heap at process start up.  */
 void
 heap_init ()
@@ -73,7 +97,7 @@ heap_init ()
       SIZE_T ret;
       MEMORY_BASIC_INFORMATION mbi;
 
-      cygheap->user_heap.chunk = cygwin_shared->heap_chunk_size ();
+      cygheap->user_heap.chunk = eval_initial_heap_size ();
       do
 	{
 	  cygheap->user_heap.base = VirtualAlloc ((LPVOID) start_address,
diff --git a/winsup/cygwin/shared.cc b/winsup/cygwin/shared.cc
index b538af56f..b38beb971 100644
--- a/winsup/cygwin/shared.cc
+++ b/winsup/cygwin/shared.cc
@@ -444,34 +444,3 @@ memory_init (bool init_cygheap)
   shared_info::create ();	/* Initialize global shared memory */
   user_info::create (false);	/* Initialize per-user shared memory */
 }
-
-unsigned
-shared_info::heap_chunk_size ()
-{
-  if (!heap_chunk)
-    {
-      /* Fetch from registry, first user then local machine.  */
-      for (int i = 0; i < 2; i++)
-	{
-	  reg_key reg (i, KEY_READ, NULL);
-
-	  /* Note that reserving a huge amount of heap space does not result in
-	     the use of swap since we are not committing it. */
-	  /* FIXME: We should not be restricted to a fixed size heap no matter
-	     what the fixed size is. */
-
-	  if ((heap_chunk = reg.get_dword (L"heap_chunk_in_mb", 0)))
-	    break;
-	  heap_chunk = 384; /* Default */
-	}
-
-      if (heap_chunk < 4)
-	heap_chunk = 4 * 1024 * 1024;
-      else
-	heap_chunk <<= 20;
-      if (!heap_chunk)
-	heap_chunk = 384 * 1024 * 1024;
-    }
-
-  return heap_chunk;
-}
diff --git a/winsup/cygwin/shared_info.h b/winsup/cygwin/shared_info.h
index be1ebca51..e6f9c832e 100644
--- a/winsup/cygwin/shared_info.h
+++ b/winsup/cygwin/shared_info.h
@@ -34,7 +34,7 @@ public:
 /* Data accessible to all tasks */
 
 
-#define CURR_SHARED_MAGIC 0x34e5bfa7U
+#define CURR_SHARED_MAGIC 0x8fe4d9eeU
 
 #define USER_VERSION   1
 
@@ -46,7 +46,6 @@ class shared_info
   LONG version;
   DWORD cb;
  public:
-  DWORD heap_chunk;
   tty_list tty;
   LONG last_used_bindresvport;
   DWORD obcaseinsensitive;