[project @ 2002-11-05 09:31:37 by simonmar]

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

diff --git a/ghc/rts/MBlock.c b/ghc/rts/MBlock.c
index a59ba9d..6011709 100644 (file)
--- a/ghc/rts/MBlock.c
+++ b/ghc/rts/MBlock.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: MBlock.c,v 1.30 2002/10/21 11:38:53 simonmar Exp $
+ * $Id: MBlock.c,v 1.36 2002/11/05 09:31:37 simonmar 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>
 
@@ -95,23 +98,47 @@ 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);
 #endif
 
+    if (ret == (void *)-1) {
+       if (errno == ENOMEM) {
+           barf("out of memory (requested %d bytes)", size);
+       } else {
+           barf("getMBlock: mmap failed");
+       }
+    }
+
     return ret;
-}    
+}
 
 // Implements the general case: allocate a chunk of memory of 'size'
 // mblocks.
@@ -126,9 +153,6 @@ gen_map_mblocks (int size)
     // it (unmap the rest).
     size += MBLOCK_SIZE;
     ret = my_mmap(0, size);
-    if (ret == (void *)-1) {
-       barf("gen_map_mblocks: mmap failed");
-    }
     
     // unmap the slop bits around the chunk we allocated
     slop = (W_)ret & MBLOCK_MASK;
@@ -140,6 +164,9 @@ gen_map_mblocks (int size)
        barf("gen_map_mblocks: munmap failed");
     }
     
+    // ToDo: if we happened to get an aligned block, then don't
+    // unmap the excess, just use it.
+
     // next time, try after the block we just got.
     ret += MBLOCK_SIZE - slop;
     return ret;
@@ -162,15 +189,6 @@ getMBlocks(nat n)
       ret = gen_map_mblocks(size);
   } else {
       ret = my_mmap(next_request, size);
-  
-      if (ret == (void *)-1) {
-         if (errno == ENOMEM) {
-             belch("out of memory (requested %d bytes)", n * BLOCK_SIZE);
-             stg_exit(EXIT_FAILURE);
-         } else {
-             barf("getMBlock: mmap failed");
-         }
-      }
 
       if (((W_)ret & MBLOCK_MASK) != 0) {
          // misaligned block!
@@ -188,6 +206,7 @@ getMBlocks(nat n)
   }
 
   // Next time, we'll try to allocate right after the block we just got.
+  // ToDo: check that we haven't already grabbed the memory at next_request
   next_request = ret + size;
 
   IF_DEBUG(gc,fprintf(stderr,"Allocated %d megablock(s) at %p\n",n,ret));
@@ -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;
   
@@ -258,7 +278,7 @@ getMBlocks(nat n)
     } else {
       end_non_committed = (char*)base_non_committed + (unsigned long)size_reserved_pool;
       /* The returned pointer is not aligned on a mega-block boundary. Make it. */
-      base_mblocks = (char*)((unsigned long)base_non_committed & (unsigned long)0xfff00000) + MBLOCK_SIZE;
+      base_mblocks = (char*)((unsigned long)base_non_committed & (unsigned long)~MBLOCK_MASK) + MBLOCK_SIZE;
 #      if 0
        fprintf(stderr, "getMBlocks: Dropping %d bytes off of 256M chunk\n", 
                       (unsigned)base_mblocks - (unsigned)base_non_committed);