/* the total bytes allocated. These are seen by Lisp DYNAMIC-USAGE. */
unsigned long bytes_allocated = 0;
-static unsigned long auto_gc_trigger = 0;
+extern unsigned long bytes_consed_between_gcs; /* gc-common.c */
+unsigned long auto_gc_trigger = 0;
/* the source and destination generations. These are set before a GC starts
* scavenging. */
\f
/* This lock is to prevent multiple threads from simultaneously
* allocating new regions which overlap each other. Note that the
- * majority of GC is single-threaded, but alloc() may be called
- * from >1 thread at a time and must be thread-safe */
+ * majority of GC is single-threaded, but alloc() may be called from
+ * >1 thread at a time and must be thread-safe. This lock must be
+ * seized before all accesses to generations[] or to parts of
+ * page_table[] that other threads may want to see */
+
static lispobj free_pages_lock=0;
\f
next_page = first_page+1;
- /* Skip if no bytes were allocated. */
+ get_spinlock(&free_pages_lock,alloc_region);
if (alloc_region->free_pointer != alloc_region->start_addr) {
+ /* some bytes were allocated in the region */
orig_first_page_bytes_used = page_table[first_page].bytes_used;
gc_assert(alloc_region->start_addr == (page_address(first_page) + page_table[first_page].bytes_used));
page_table[next_page].allocated = FREE_PAGE;
next_page++;
}
-
+ free_pages_lock=0;
+ /* alloc_region is per-thread, we're ok to do this unlocked */
gc_set_region_empty(alloc_region);
}
/* Is there any possibility that pointer is a valid Lisp object
* reference, and/or something else (e.g. subroutine call return
- * address) which should prevent us from moving the referred-to thing? */
+ * address) which should prevent us from moving the referred-to thing?
+ * This is called from preserve_pointers() */
static int
possibly_valid_dynamic_space_pointer(lispobj *pointer)
{
/* Check that the object pointed to is consistent with the pointer
* low tag.
- *
- * FIXME: It's not safe to rely on the result from this check
- * before an object is initialized. Thus, if we were interrupted
- * just as an object had been allocated but not initialized, the
- * GC relying on this result could bogusly reclaim the memory.
- * However, we can't really afford to do without this check. So
- * we should make it safe somehow.
- * (1) Perhaps just review the code to make sure
- * that WITHOUT-GCING or WITHOUT-INTERRUPTS or some such
- * thing is wrapped around critical sections where allocated
- * memory type bits haven't been set.
- * (2) Perhaps find some other hack to protect against this, e.g.
- * recording the result of the last call to allocate-lisp-memory,
- * and returning true from this function when *pointer is
- * a reference to that result.
- *
- * (surely pseudo-atomic is supposed to be used for exactly this?)
*/
switch (lowtag_of((lispobj)pointer)) {
case FUN_POINTER_LOWTAG:
* (or, as a special case which also requires dont_move, a return
* address referring to something in a CodeObject). This is
* expensive but important, since it vastly reduces the
- * probability that random garbage will be bogusly interpreter as
+ * probability that random garbage will be bogusly interpreted as
* a pointer which prevents a page from moving. */
if (!(possibly_valid_dynamic_space_pointer(addr)))
return;
gc_alloc_generation = 0;
update_x86_dynamic_space_free_pointer();
-
+ auto_gc_trigger = bytes_allocated + bytes_consed_between_gcs;
+ if(gencgc_verbose)
+ fprintf(stderr,"Next gc when %d bytes have been consed\n",
+ auto_gc_trigger);
SHOW("returning from collect_garbage");
}
/* there are a few places in the C code that allocate data in the
* heap before Lisp starts. This is before interrupts are enabled,
* so we don't need to check for pseudo-atomic */
- gc_assert(SymbolValue(PSEUDO_ATOMIC_ATOMIC,th));
-
+#ifdef LISP_FEATURE_SB_THREAD
+ if(!SymbolValue(PSEUDO_ATOMIC_ATOMIC,th)) {
+ register u32 fs;
+ fprintf(stderr, "fatal error in thread 0x%x, pid=%d\n",
+ th,getpid());
+ __asm__("movl %fs,%0" : "=r" (fs) : );
+ fprintf(stderr, "fs is %x, th->tls_cookie=%x (should be identical)\n",
+ debug_get_fs(),th->tls_cookie);
+ lose("If you see this message before 2003.05.01, mail details to sbcl-devel\n");
+ }
+#else
+ gc_assert(SymbolValue(PSEUDO_ATOMIC_ATOMIC,th));
+#endif
+
/* maybe we can do this quickly ... */
new_free_pointer = region->free_pointer + nbytes;
if (new_free_pointer <= region->end_addr) {
* we should GC in the near future
*/
if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
- auto_gc_trigger *= 2;
/* set things up so that GC happens when we finish the PA
* section. */
maybe_gc_pending=1;
}
\f
-/*
- * noise to manipulate the gc trigger stuff
- */
-
-void
-set_auto_gc_trigger(os_vm_size_t dynamic_usage)
-{
- auto_gc_trigger += dynamic_usage;
-}
-
-void
-clear_auto_gc_trigger(void)
-{
- auto_gc_trigger = 0;
-}
-\f
/* Find the code object for the given pc, or return NULL on failure.
*
* FIXME: PC shouldn't be lispobj*, should it? Maybe void*? */
return 0;
} else {
-
- /* The only acceptable reason for an signal like this from the
- * heap is that the generational GC write-protected the page. */
- if (page_table[page_index].write_protected != 1) {
- lose("access failure in heap page not marked as write-protected");
+ if (page_table[page_index].write_protected) {
+ /* Unprotect the page. */
+ os_protect(page_address(page_index), PAGE_BYTES, OS_VM_PROT_ALL);
+ page_table[page_index].write_protected_cleared = 1;
+ page_table[page_index].write_protected = 0;
+ } else {
+ /* The only acceptable reason for this signal on a heap
+ * access is that GENCGC write-protected the page.
+ * However, if two CPUs hit a wp page near-simultaneously,
+ * we had better not have the second one lose here if it
+ * does this test after the first one has already set wp=0
+ */
+ if(page_table[page_index].write_protected_cleared != 1)
+ lose("fault in heap page not marked as write-protected");
+
+ /* Don't worry, we can handle it. */
+ return 1;
}
-
- /* Unprotect the page. */
- os_protect(page_address(page_index), 4096, OS_VM_PROT_ALL);
- page_table[page_index].write_protected = 0;
- page_table[page_index].write_protected_cleared = 1;
-
- /* Don't worry, we can handle it. */
- return 1;
}
}
-
/* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
* it's not just a case of the program hitting the write barrier, and
* are about to let Lisp deal with it. It's basically just a