[project @ 2003-01-27 23:23:30 by wolfgang]

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

diff --git a/ghc/rts/MBlock.c b/ghc/rts/MBlock.c
index eb1c06d..93478a2 100644 (file)
--- a/ghc/rts/MBlock.c
+++ b/ghc/rts/MBlock.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: MBlock.c,v 1.32 2002/10/23 12:26:11 mthomas Exp $
+ * $Id: MBlock.c,v 1.42 2002/12/11 15:36:42 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>
 
@@ -47,13 +50,9 @@ lnat mblocks_allocated = 0;
    The MBlock Map: provides our implementation of HEAP_ALLOCED()
    -------------------------------------------------------------------------- */
 
-StgWord8 mblock_map[4096]; // initially all zeros
-
-static void
-mblockIsHeap (void *p)
-{
-    mblock_map[((StgWord)p & ~MBLOCK_MASK) >> MBLOCK_SHIFT] = 1;
-}
+#ifdef MBLOCK_MAP_SIZE
+StgWord8 mblock_map[MBLOCK_MAP_SIZE]; // initially all zeros
+#endif
 
 /* -----------------------------------------------------------------------------
    Allocate new mblock(s)
@@ -95,23 +94,47 @@ 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) // 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
-    ret = mmap(addr, size, PROT_READ | PROT_WRITE, 
+    ret = mmap(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC, 
               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 +149,6 @@ 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 +160,9 @@ 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;
@@ -162,22 +185,13 @@ 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!
-#ifdef DEBUG
-         belch("getMBlock: misaligned block %p returned when allocating %d megablock(s) at %p", ret, n, next_request);
+#if 0 // defined(DEBUG)
+         belch("warning: getMBlock: misaligned block %p returned when allocating %d megablock(s) at %p", ret, n, next_request);
 #endif
-         
+
          // unmap this block...
          if (munmap(ret, size) == -1) {
              barf("getMBlock: munmap failed");
@@ -188,13 +202,14 @@ 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));
 
   // fill in the table
   for (i = 0; i < n; i++) {
-      mblockIsHeap( ret + i * MBLOCK_SIZE );
+      MARK_HEAP_ALLOCED( ret + i * MBLOCK_SIZE );
   }
 
   mblocks_allocated += n;
@@ -297,7 +312,7 @@ getMBlocks(nat n)
   
   // fill in the table
   for (i = 0; i < n; i++) {
-      mblockIsHeap( ret + i * MBLOCK_SIZE );
+      MARK_HEAP_ALLOCED ( ret + i * MBLOCK_SIZE );
   }
 
   return ret;