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authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /boehm-gc/mark_rts.c
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Diffstat (limited to 'boehm-gc/mark_rts.c')
-rw-r--r--boehm-gc/mark_rts.c658
1 files changed, 658 insertions, 0 deletions
diff --git a/boehm-gc/mark_rts.c b/boehm-gc/mark_rts.c
new file mode 100644
index 000000000..94eb0ddb3
--- /dev/null
+++ b/boehm-gc/mark_rts.c
@@ -0,0 +1,658 @@
+/*
+ * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
+ * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+# include <stdio.h>
+# include "private/gc_priv.h"
+
+/* Data structure for list of root sets. */
+/* We keep a hash table, so that we can filter out duplicate additions. */
+/* Under Win32, we need to do a better job of filtering overlaps, so */
+/* we resort to sequential search, and pay the price. */
+/* This is really declared in gc_priv.h:
+struct roots {
+ ptr_t r_start;
+ ptr_t r_end;
+ # if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
+ struct roots * r_next;
+ # endif
+ GC_bool r_tmp;
+ -- Delete before registering new dynamic libraries
+};
+
+struct roots GC_static_roots[MAX_ROOT_SETS];
+*/
+
+int GC_no_dls = 0; /* Register dynamic library data segments. */
+
+static int n_root_sets = 0;
+
+ /* GC_static_roots[0..n_root_sets) contains the valid root sets. */
+
+# if !defined(NO_DEBUGGING)
+/* For debugging: */
+void GC_print_static_roots()
+{
+ register int i;
+ size_t total = 0;
+
+ for (i = 0; i < n_root_sets; i++) {
+ GC_printf2("From 0x%lx to 0x%lx ",
+ (unsigned long) GC_static_roots[i].r_start,
+ (unsigned long) GC_static_roots[i].r_end);
+ if (GC_static_roots[i].r_tmp) {
+ GC_printf0(" (temporary)\n");
+ } else {
+ GC_printf0("\n");
+ }
+ total += GC_static_roots[i].r_end - GC_static_roots[i].r_start;
+ }
+ GC_printf1("Total size: %ld\n", (unsigned long) total);
+ if (GC_root_size != total) {
+ GC_printf1("GC_root_size incorrect: %ld!!\n",
+ (unsigned long) GC_root_size);
+ }
+}
+# endif /* NO_DEBUGGING */
+
+/* Primarily for debugging support: */
+/* Is the address p in one of the registered static */
+/* root sections? */
+GC_bool GC_is_static_root(p)
+ptr_t p;
+{
+ static int last_root_set = MAX_ROOT_SETS;
+ register int i;
+
+
+ if (last_root_set < n_root_sets
+ && p >= GC_static_roots[last_root_set].r_start
+ && p < GC_static_roots[last_root_set].r_end) return(TRUE);
+ for (i = 0; i < n_root_sets; i++) {
+ if (p >= GC_static_roots[i].r_start
+ && p < GC_static_roots[i].r_end) {
+ last_root_set = i;
+ return(TRUE);
+ }
+ }
+ return(FALSE);
+}
+
+#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
+/*
+# define LOG_RT_SIZE 6
+# define RT_SIZE (1 << LOG_RT_SIZE) -- Power of 2, may be != MAX_ROOT_SETS
+
+ struct roots * GC_root_index[RT_SIZE];
+ -- Hash table header. Used only to check whether a range is
+ -- already present.
+ -- really defined in gc_priv.h
+*/
+
+static int rt_hash(addr)
+char * addr;
+{
+ word result = (word) addr;
+# if CPP_WORDSZ > 8*LOG_RT_SIZE
+ result ^= result >> 8*LOG_RT_SIZE;
+# endif
+# if CPP_WORDSZ > 4*LOG_RT_SIZE
+ result ^= result >> 4*LOG_RT_SIZE;
+# endif
+ result ^= result >> 2*LOG_RT_SIZE;
+ result ^= result >> LOG_RT_SIZE;
+ result &= (RT_SIZE-1);
+ return(result);
+}
+
+/* Is a range starting at b already in the table? If so return a */
+/* pointer to it, else NIL. */
+struct roots * GC_roots_present(b)
+char *b;
+{
+ register int h = rt_hash(b);
+ register struct roots *p = GC_root_index[h];
+
+ while (p != 0) {
+ if (p -> r_start == (ptr_t)b) return(p);
+ p = p -> r_next;
+ }
+ return(FALSE);
+}
+
+/* Add the given root structure to the index. */
+static void add_roots_to_index(p)
+struct roots *p;
+{
+ register int h = rt_hash(p -> r_start);
+
+ p -> r_next = GC_root_index[h];
+ GC_root_index[h] = p;
+}
+
+# else /* MSWIN32 || MSWINCE || CYGWIN32 */
+
+# define add_roots_to_index(p)
+
+# endif
+
+
+
+
+word GC_root_size = 0;
+
+void GC_add_roots(b, e)
+char * b; char * e;
+{
+ DCL_LOCK_STATE;
+
+ DISABLE_SIGNALS();
+ LOCK();
+ GC_add_roots_inner(b, e, FALSE);
+ UNLOCK();
+ ENABLE_SIGNALS();
+}
+
+
+/* Add [b,e) to the root set. Adding the same interval a second time */
+/* is a moderately fast noop, and hence benign. We do not handle */
+/* different but overlapping intervals efficiently. (We do handle */
+/* them correctly.) */
+/* Tmp specifies that the interval may be deleted before */
+/* reregistering dynamic libraries. */
+void GC_add_roots_inner(b, e, tmp)
+char * b; char * e;
+GC_bool tmp;
+{
+ struct roots * old;
+
+# if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
+ /* Spend the time to ensure that there are no overlapping */
+ /* or adjacent intervals. */
+ /* This could be done faster with e.g. a */
+ /* balanced tree. But the execution time here is */
+ /* virtually guaranteed to be dominated by the time it */
+ /* takes to scan the roots. */
+ {
+ register int i;
+
+ for (i = 0; i < n_root_sets; i++) {
+ old = GC_static_roots + i;
+ if ((ptr_t)b <= old -> r_end && (ptr_t)e >= old -> r_start) {
+ if ((ptr_t)b < old -> r_start) {
+ old -> r_start = (ptr_t)b;
+ GC_root_size += (old -> r_start - (ptr_t)b);
+ }
+ if ((ptr_t)e > old -> r_end) {
+ old -> r_end = (ptr_t)e;
+ GC_root_size += ((ptr_t)e - old -> r_end);
+ }
+ old -> r_tmp &= tmp;
+ break;
+ }
+ }
+ if (i < n_root_sets) {
+ /* merge other overlapping intervals */
+ struct roots *other;
+
+ for (i++; i < n_root_sets; i++) {
+ other = GC_static_roots + i;
+ b = (char *)(other -> r_start);
+ e = (char *)(other -> r_end);
+ if ((ptr_t)b <= old -> r_end && (ptr_t)e >= old -> r_start) {
+ if ((ptr_t)b < old -> r_start) {
+ old -> r_start = (ptr_t)b;
+ GC_root_size += (old -> r_start - (ptr_t)b);
+ }
+ if ((ptr_t)e > old -> r_end) {
+ old -> r_end = (ptr_t)e;
+ GC_root_size += ((ptr_t)e - old -> r_end);
+ }
+ old -> r_tmp &= other -> r_tmp;
+ /* Delete this entry. */
+ GC_root_size -= (other -> r_end - other -> r_start);
+ other -> r_start = GC_static_roots[n_root_sets-1].r_start;
+ other -> r_end = GC_static_roots[n_root_sets-1].r_end;
+ n_root_sets--;
+ }
+ }
+ return;
+ }
+ }
+# else
+ old = GC_roots_present(b);
+ if (old != 0) {
+ if ((ptr_t)e <= old -> r_end) /* already there */ return;
+ /* else extend */
+ GC_root_size += (ptr_t)e - old -> r_end;
+ old -> r_end = (ptr_t)e;
+ return;
+ }
+# endif
+ if (n_root_sets == MAX_ROOT_SETS) {
+ ABORT("Too many root sets\n");
+ }
+ GC_static_roots[n_root_sets].r_start = (ptr_t)b;
+ GC_static_roots[n_root_sets].r_end = (ptr_t)e;
+ GC_static_roots[n_root_sets].r_tmp = tmp;
+# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
+ GC_static_roots[n_root_sets].r_next = 0;
+# endif
+ add_roots_to_index(GC_static_roots + n_root_sets);
+ GC_root_size += (ptr_t)e - (ptr_t)b;
+ n_root_sets++;
+}
+
+static GC_bool roots_were_cleared = FALSE;
+
+void GC_clear_roots GC_PROTO((void))
+{
+ DCL_LOCK_STATE;
+
+ DISABLE_SIGNALS();
+ LOCK();
+ roots_were_cleared = TRUE;
+ n_root_sets = 0;
+ GC_root_size = 0;
+# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
+ {
+ register int i;
+
+ for (i = 0; i < RT_SIZE; i++) GC_root_index[i] = 0;
+ }
+# endif
+ UNLOCK();
+ ENABLE_SIGNALS();
+}
+
+/* Internal use only; lock held. */
+static void GC_remove_root_at_pos(i)
+int i;
+{
+ GC_root_size -= (GC_static_roots[i].r_end - GC_static_roots[i].r_start);
+ GC_static_roots[i].r_start = GC_static_roots[n_root_sets-1].r_start;
+ GC_static_roots[i].r_end = GC_static_roots[n_root_sets-1].r_end;
+ GC_static_roots[i].r_tmp = GC_static_roots[n_root_sets-1].r_tmp;
+ n_root_sets--;
+}
+
+#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
+static void GC_rebuild_root_index()
+{
+ register int i;
+
+ for (i = 0; i < RT_SIZE; i++) GC_root_index[i] = 0;
+ for (i = 0; i < n_root_sets; i++)
+ add_roots_to_index(GC_static_roots + i);
+}
+#endif
+
+/* Internal use only; lock held. */
+void GC_remove_tmp_roots()
+{
+ register int i;
+
+ for (i = 0; i < n_root_sets; ) {
+ if (GC_static_roots[i].r_tmp) {
+ GC_remove_root_at_pos(i);
+ } else {
+ i++;
+ }
+ }
+ #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
+ GC_rebuild_root_index();
+ #endif
+}
+
+#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
+void GC_remove_roots(b, e)
+char * b; char * e;
+{
+ DCL_LOCK_STATE;
+
+ DISABLE_SIGNALS();
+ LOCK();
+ GC_remove_roots_inner(b, e);
+ UNLOCK();
+ ENABLE_SIGNALS();
+}
+
+/* Should only be called when the lock is held */
+void GC_remove_roots_inner(b,e)
+char * b; char * e;
+{
+ int i;
+ for (i = 0; i < n_root_sets; ) {
+ if (GC_static_roots[i].r_start >= (ptr_t)b && GC_static_roots[i].r_end <= (ptr_t)e) {
+ GC_remove_root_at_pos(i);
+ } else {
+ i++;
+ }
+ }
+ GC_rebuild_root_index();
+}
+#endif /* !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32) */
+
+#if defined(MSWIN32) || defined(_WIN32_WCE_EMULATION) || defined(CYGWIN32)
+/* Workaround for the OS mapping and unmapping behind our back: */
+/* Is the address p in one of the temporary static root sections? */
+GC_bool GC_is_tmp_root(p)
+ptr_t p;
+{
+ static int last_root_set = MAX_ROOT_SETS;
+ register int i;
+
+ if (last_root_set < n_root_sets
+ && p >= GC_static_roots[last_root_set].r_start
+ && p < GC_static_roots[last_root_set].r_end)
+ return GC_static_roots[last_root_set].r_tmp;
+ for (i = 0; i < n_root_sets; i++) {
+ if (p >= GC_static_roots[i].r_start
+ && p < GC_static_roots[i].r_end) {
+ last_root_set = i;
+ return GC_static_roots[i].r_tmp;
+ }
+ }
+ return(FALSE);
+}
+#endif /* MSWIN32 || _WIN32_WCE_EMULATION || defined(CYGWIN32) */
+
+ptr_t GC_approx_sp()
+{
+ VOLATILE word dummy;
+
+ dummy = 42; /* Force stack to grow if necessary. Otherwise the */
+ /* later accesses might cause the kernel to think we're */
+ /* doing something wrong. */
+# ifdef _MSC_VER
+# pragma warning(disable:4172)
+# endif
+#ifdef __GNUC__
+ /* Eliminate a warning from GCC about taking the address of a
+ local variable. */
+ return __builtin_frame_address (0);
+#else
+ return ((ptr_t)(&dummy));
+#endif /* __GNUC__ */
+# ifdef _MSC_VER
+# pragma warning(default:4172)
+# endif
+}
+
+/*
+ * Data structure for excluded static roots.
+ * Real declaration is in gc_priv.h.
+
+struct exclusion {
+ ptr_t e_start;
+ ptr_t e_end;
+};
+
+struct exclusion GC_excl_table[MAX_EXCLUSIONS];
+ -- Array of exclusions, ascending
+ -- address order.
+*/
+
+size_t GC_excl_table_entries = 0; /* Number of entries in use. */
+
+/* Return the first exclusion range that includes an address >= start_addr */
+/* Assumes the exclusion table contains at least one entry (namely the */
+/* GC data structures). */
+struct exclusion * GC_next_exclusion(start_addr)
+ptr_t start_addr;
+{
+ size_t low = 0;
+ size_t high = GC_excl_table_entries - 1;
+ size_t mid;
+
+ while (high > low) {
+ mid = (low + high) >> 1;
+ /* low <= mid < high */
+ if ((word) GC_excl_table[mid].e_end <= (word) start_addr) {
+ low = mid + 1;
+ } else {
+ high = mid;
+ }
+ }
+ if ((word) GC_excl_table[low].e_end <= (word) start_addr) return 0;
+ return GC_excl_table + low;
+}
+
+void GC_exclude_static_roots(start, finish)
+GC_PTR start;
+GC_PTR finish;
+{
+ struct exclusion * next;
+ size_t next_index, i;
+
+ if (0 == GC_excl_table_entries) {
+ next = 0;
+ } else {
+ next = GC_next_exclusion(start);
+ }
+ if (0 != next) {
+ if ((word)(next -> e_start) < (word) finish) {
+ /* incomplete error check. */
+ ABORT("exclusion ranges overlap");
+ }
+ if ((word)(next -> e_start) == (word) finish) {
+ /* extend old range backwards */
+ next -> e_start = (ptr_t)start;
+ return;
+ }
+ next_index = next - GC_excl_table;
+ for (i = GC_excl_table_entries; i > next_index; --i) {
+ GC_excl_table[i] = GC_excl_table[i-1];
+ }
+ } else {
+ next_index = GC_excl_table_entries;
+ }
+ if (GC_excl_table_entries == MAX_EXCLUSIONS) ABORT("Too many exclusions");
+ GC_excl_table[next_index].e_start = (ptr_t)start;
+ GC_excl_table[next_index].e_end = (ptr_t)finish;
+ ++GC_excl_table_entries;
+}
+
+/* Invoke push_conditional on ranges that are not excluded. */
+void GC_push_conditional_with_exclusions(bottom, top, all)
+ptr_t bottom;
+ptr_t top;
+int all;
+{
+ struct exclusion * next;
+ ptr_t excl_start;
+
+ while (bottom < top) {
+ next = GC_next_exclusion(bottom);
+ if (0 == next || (excl_start = next -> e_start) >= top) {
+ GC_push_conditional(bottom, top, all);
+ return;
+ }
+ if (excl_start > bottom) GC_push_conditional(bottom, excl_start, all);
+ bottom = next -> e_end;
+ }
+}
+
+/*
+ * In the absence of threads, push the stack contents.
+ * In the presence of threads, push enough of the current stack
+ * to ensure that callee-save registers saved in collector frames have been
+ * seen.
+ */
+void GC_push_current_stack(cold_gc_frame)
+ptr_t cold_gc_frame;
+{
+# if defined(THREADS)
+ if (0 == cold_gc_frame) return;
+# ifdef STACK_GROWS_DOWN
+ GC_push_all_eager(GC_approx_sp(), cold_gc_frame);
+ /* For IA64, the register stack backing store is handled */
+ /* in the thread-specific code. */
+# else
+ GC_push_all_eager( cold_gc_frame, GC_approx_sp() );
+# endif
+# else
+# ifdef STACK_GROWS_DOWN
+ GC_push_all_stack_partially_eager( GC_approx_sp(), GC_stackbottom,
+ cold_gc_frame );
+# ifdef IA64
+ /* We also need to push the register stack backing store. */
+ /* This should really be done in the same way as the */
+ /* regular stack. For now we fudge it a bit. */
+ /* Note that the backing store grows up, so we can't use */
+ /* GC_push_all_stack_partially_eager. */
+ {
+ extern word GC_save_regs_ret_val;
+ /* Previously set to backing store pointer. */
+ ptr_t bsp = (ptr_t) GC_save_regs_ret_val;
+ ptr_t cold_gc_bs_pointer;
+ if (GC_all_interior_pointers) {
+ cold_gc_bs_pointer = bsp - 2048;
+ if (cold_gc_bs_pointer < BACKING_STORE_BASE) {
+ cold_gc_bs_pointer = BACKING_STORE_BASE;
+ } else {
+ GC_push_all_stack(BACKING_STORE_BASE, cold_gc_bs_pointer);
+ }
+ } else {
+ cold_gc_bs_pointer = BACKING_STORE_BASE;
+ }
+ GC_push_all_eager(cold_gc_bs_pointer, bsp);
+ /* All values should be sufficiently aligned that we */
+ /* dont have to worry about the boundary. */
+ }
+# endif
+# else
+ GC_push_all_stack_partially_eager( GC_stackbottom, GC_approx_sp(),
+ cold_gc_frame );
+# endif
+# endif /* !THREADS */
+}
+
+/*
+ * Push GC internal roots. Only called if there is some reason to believe
+ * these would not otherwise get registered.
+ */
+void GC_push_gc_structures GC_PROTO((void))
+{
+ GC_push_finalizer_structures();
+ GC_push_stubborn_structures();
+# if defined(THREADS)
+ GC_push_thread_structures();
+# endif
+}
+
+#ifdef THREAD_LOCAL_ALLOC
+ void GC_mark_thread_local_free_lists();
+#endif
+
+void GC_cond_register_dynamic_libraries()
+{
+# if (defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(MSWINCE) \
+ || defined(CYGWIN32) || defined(PCR)) && !defined(SRC_M3)
+ GC_remove_tmp_roots();
+ if (!GC_no_dls) GC_register_dynamic_libraries();
+# else
+ GC_no_dls = TRUE;
+# endif
+}
+
+/*
+ * Call the mark routines (GC_tl_push for a single pointer, GC_push_conditional
+ * on groups of pointers) on every top level accessible pointer.
+ * If all is FALSE, arrange to push only possibly altered values.
+ * Cold_gc_frame is an address inside a GC frame that
+ * remains valid until all marking is complete.
+ * A zero value indicates that it's OK to miss some
+ * register values.
+ */
+void GC_push_roots(all, cold_gc_frame)
+GC_bool all;
+ptr_t cold_gc_frame;
+{
+ int i;
+ int kind;
+
+ /*
+ * Next push static data. This must happen early on, since it's
+ * not robust against mark stack overflow.
+ */
+ /* Reregister dynamic libraries, in case one got added. */
+ /* There is some argument for doing this as late as possible, */
+ /* especially on win32, where it can change asynchronously. */
+ /* In those cases, we do it here. But on other platforms, it's */
+ /* not safe with the world stopped, so we do it earlier. */
+# if !defined(REGISTER_LIBRARIES_EARLY)
+ GC_cond_register_dynamic_libraries();
+# endif
+
+ /* Mark everything in static data areas */
+ for (i = 0; i < n_root_sets; i++) {
+ GC_push_conditional_with_exclusions(
+ GC_static_roots[i].r_start,
+ GC_static_roots[i].r_end, all);
+ }
+
+ /* Mark all free list header blocks, if those were allocated from */
+ /* the garbage collected heap. This makes sure they don't */
+ /* disappear if we are not marking from static data. It also */
+ /* saves us the trouble of scanning them, and possibly that of */
+ /* marking the freelists. */
+ for (kind = 0; kind < GC_n_kinds; kind++) {
+ GC_PTR base = GC_base(GC_obj_kinds[kind].ok_freelist);
+ if (0 != base) {
+ GC_set_mark_bit(base);
+ }
+ }
+
+ /* Mark from GC internal roots if those might otherwise have */
+ /* been excluded. */
+ if (GC_no_dls || roots_were_cleared) {
+ GC_push_gc_structures();
+ }
+
+ /* Mark thread local free lists, even if their mark */
+ /* descriptor excludes the link field. */
+ /* If the world is not stopped, this is unsafe. It is */
+ /* also unnecessary, since we will do this again with the */
+ /* world stopped. */
+# ifdef THREAD_LOCAL_ALLOC
+ if (GC_world_stopped) GC_mark_thread_local_free_lists();
+# endif
+
+ /*
+ * Now traverse stacks, and mark from register contents.
+ * These must be done last, since they can legitimately overflow
+ * the mark stack.
+ */
+# ifdef USE_GENERIC_PUSH_REGS
+ GC_generic_push_regs(cold_gc_frame);
+ /* Also pushes stack, so that we catch callee-save registers */
+ /* saved inside the GC_push_regs frame. */
+# else
+ /*
+ * push registers - i.e., call GC_push_one(r) for each
+ * register contents r.
+ */
+ GC_push_regs(); /* usually defined in machine_dep.c */
+ GC_push_current_stack(cold_gc_frame);
+ /* In the threads case, this only pushes collector frames. */
+ /* In the case of linux threads on IA64, the hot section of */
+ /* the main stack is marked here, but the register stack */
+ /* backing store is handled in the threads-specific code. */
+# endif
+ if (GC_push_other_roots != 0) (*GC_push_other_roots)();
+ /* In the threads case, this also pushes thread stacks. */
+ /* Note that without interior pointer recognition lots */
+ /* of stuff may have been pushed already, and this */
+ /* should be careful about mark stack overflows. */
+}
+