[project @ 2002-11-21 09:36:48 by simonpj]

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

diff --git a/ghc/rts/MBlock.c b/ghc/rts/MBlock.c
index 2f083b3..57d113a 100644 (file)
--- a/ghc/rts/MBlock.c
+++ b/ghc/rts/MBlock.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: MBlock.c,v 1.35 2002/11/05 09:26:04 simonmar Exp $
+ * $Id: MBlock.c,v 1.38 2002/11/07 14:42:25 simonmar Exp $
  *
  * (c) The GHC Team 1998-1999
  *
@@ -120,8 +120,8 @@ my_mmap (void *addr, int size)
     if(!addr || err)   // try to allocate anywhere
        err = vm_allocate(mach_task_self(),(vm_address_t*) &ret, size, TRUE);
        
-    if(err)
-       ret = (void*) -1;
+    if(err) // don't know what the error codes mean exactly
+       barf("memory allocation failed (requested %d bytes)", size);
     else
        vm_protect(mach_task_self(),ret,size,FALSE,VM_PROT_READ|VM_PROT_WRITE);
 #else
@@ -129,8 +129,16 @@ my_mmap (void *addr, int size)
               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.
@@ -145,9 +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;
@@ -159,6 +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;
@@ -181,19 +189,11 @@ getMBlocks(nat n)
       ret = gen_map_mblocks(size);
   } else {
       ret = my_mmap(next_request, size);
-  
-      if (ret == (void *)-1) {
-         if (errno == ENOMEM) {
-             barf("out of memory (requested %d bytes)", n * MBLOCK_SIZE);
-         } else {
-             barf("getMBlock: mmap failed");
-         }
-      }
 
       if (((W_)ret & MBLOCK_MASK) != 0) {
          // misaligned block!
 #ifdef DEBUG
-         belch("getMBlock: misaligned block %p returned when allocating %d megablock(s) at %p", ret, n, next_request);
+         belch("warning: getMBlock: misaligned block %p returned when allocating %d megablock(s) at %p", ret, n, next_request);
 #endif
          
          // unmap this block...
@@ -206,6 +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));