X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fgencgc.c;h=a67748aba81d777df13b3bee71bdf6006adf6ffa;hb=df679ed627975948b1cee190f4d79c397588c43e;hp=af6b4ae08a1e9ee43aa34e67950eeef6a9c29277;hpb=040e4e707e4f7bc9bda2ab78774fd9205c44ee1f;p=sbcl.git diff --git a/src/runtime/gencgc.c b/src/runtime/gencgc.c index af6b4ae..a67748a 100644 --- a/src/runtime/gencgc.c +++ b/src/runtime/gencgc.c @@ -129,7 +129,8 @@ boolean gencgc_zero_check_during_free_heap = 0; /* 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. */ @@ -254,8 +255,11 @@ static int last_free_page; /* 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; @@ -706,8 +710,9 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region) 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)); @@ -809,7 +814,8 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region) 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); } @@ -2141,7 +2147,8 @@ search_dynamic_space(lispobj *pointer) /* 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) { @@ -2168,23 +2175,6 @@ 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: @@ -2582,7 +2572,7 @@ preserve_pointer(void *addr) * (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; @@ -3979,7 +3969,10 @@ collect_garbage(unsigned last_gen) 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"); } @@ -4189,8 +4182,20 @@ alloc(int nbytes) /* 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) { @@ -4203,7 +4208,6 @@ alloc(int nbytes) * 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; @@ -4214,22 +4218,6 @@ alloc(int nbytes) } -/* - * 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; -} - /* Find the code object for the given pc, or return NULL on failure. * * FIXME: PC shouldn't be lispobj*, should it? Maybe void*? */ @@ -4290,23 +4278,26 @@ gencgc_handle_wp_violation(void* fault_addr) 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