[project @ 2002-11-01 11:17:29 by simonmar]

[ghc-hetmet.git] / ghc / rts / MBlock.c

diff --git a/ghc/rts/MBlock.c b/ghc/rts/MBlock.c
index 9f0e89b..5f6cfb7 100644 (file)
--- a/ghc/rts/MBlock.c
+++ b/ghc/rts/MBlock.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: MBlock.c,v 1.31 2002/10/21 12:42:31 simonmar Exp $
+ * $Id: MBlock.c,v 1.34 2002/10/27 21:46:27 wolfgang Exp $
  *
  * (c) The GHC Team 1998-1999
  *
@@ -38,6 +38,9 @@
 #if HAVE_WINDOWS_H
 #include <windows.h>
 #endif
+#if darwin_TARGET_OS
+#include <mach/vm_map.h>
+#endif
 
 #include <errno.h>
 
@@ -95,16 +98,32 @@ my_mmap (void *addr, int size)
 #ifdef solaris2_TARGET_OS
     { 
        int fd = open("/dev/zero",O_RDONLY);
-       ret = mmap(addr, size, PROT_READ | PROT_WRITE, 
-                  MAP_FIXED | MAP_PRIVATE, fd, 0);
+       ret = mmap(addr, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
        close(fd);
     }
 #elif hpux_TARGET_OS
     ret = mmap(addr, size, PROT_READ | PROT_WRITE, 
               MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
 #elif darwin_TARGET_OS
-    ret = mmap(addr, size, PROT_READ | PROT_WRITE, 
-              MAP_FIXED | MAP_ANON | MAP_PRIVATE, -1, 0);
+    // Without MAP_FIXED, Apple's mmap ignores addr.
+    // With MAP_FIXED, it overwrites already mapped regions, whic
+    // mmap(0, ... MAP_FIXED ...) is worst of all: It unmaps the program text
+    // and replaces it with zeroes, causing instant death.
+    // This behaviour seems to be conformant with IEEE Std 1003.1-2001.
+    // Let's just use the underlying Mach Microkernel calls directly,
+    // they're much nicer.
+    
+    kern_return_t err;
+    ret = addr;
+    if(addr)   // try to allocate at adress
+       err = vm_allocate(mach_task_self(),(vm_address_t*) &ret, size, FALSE);
+    if(!addr || err)   // try to allocate anywhere
+       err = vm_allocate(mach_task_self(),(vm_address_t*) &ret, size, TRUE);
+       
+    if(err)
+       ret = (void*) -1;
+    else
+       vm_protect(mach_task_self(),ret,size,FALSE,VM_PROT_READ|VM_PROT_WRITE);
 #else
     ret = mmap(addr, size, PROT_READ | PROT_WRITE, 
               MAP_ANON | MAP_PRIVATE, -1, 0);
@@ -234,6 +253,7 @@ getMBlocks(nat n)
   static char* base_mblocks       = (char*)0;
   static char* next_request       = (char*)0;
   void* ret                       = (void*)0;
+  int i;
 
   lnat size = MBLOCK_SIZE * n;