/*--------------------------------------------------------------------*/
/*--- Callgrind ---*/
/*--- ct_context.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Callgrind, a Valgrind tool for call tracing.
Copyright (C) 2002-2013, Josef Weidendorfer (Josef.Weidendorfer@gmx.de)
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "global.h"
/*------------------------------------------------------------*/
/*--- Context operations ---*/
/*------------------------------------------------------------*/
#define N_FNSTACK_INITIAL_ENTRIES 500
#define N_CXT_INITIAL_ENTRIES 2537
fn_stack CLG_(current_fn_stack);
void CLG_(init_fn_stack)(fn_stack* s)
{
CLG_ASSERT(s != 0);
s->size = N_FNSTACK_INITIAL_ENTRIES;
s->bottom = (fn_node**) CLG_MALLOC("cl.context.ifs.1",
s->size * sizeof(fn_node*));
s->top = s->bottom;
s->bottom[0] = 0;
}
void CLG_(copy_current_fn_stack)(fn_stack* dst)
{
CLG_ASSERT(dst != 0);
dst->size = CLG_(current_fn_stack).size;
dst->bottom = CLG_(current_fn_stack).bottom;
dst->top = CLG_(current_fn_stack).top;
}
void CLG_(set_current_fn_stack)(fn_stack* s)
{
CLG_ASSERT(s != 0);
CLG_(current_fn_stack).size = s->size;
CLG_(current_fn_stack).bottom = s->bottom;
CLG_(current_fn_stack).top = s->top;
}
static cxt_hash cxts;
void CLG_(init_cxt_table)()
{
Int i;
cxts.size = N_CXT_INITIAL_ENTRIES;
cxts.entries = 0;
cxts.table = (Context**) CLG_MALLOC("cl.context.ict.1",
cxts.size * sizeof(Context*));
for (i = 0; i < cxts.size; i++)
cxts.table[i] = 0;
}
/* double size of cxt table */
static void resize_cxt_table(void)
{
UInt i, new_size, conflicts1 = 0, conflicts2 = 0;
Context **new_table, *curr, *next;
UInt new_idx;
new_size = 2* cxts.size +3;
new_table = (Context**) CLG_MALLOC("cl.context.rct.1",
new_size * sizeof(Context*));
for (i = 0; i < new_size; i++)
new_table[i] = NULL;
for (i = 0; i < cxts.size; i++) {
if (cxts.table[i] == NULL) continue;
curr = cxts.table[i];
while (NULL != curr) {
next = curr->next;
new_idx = (UInt) (curr->hash % new_size);
curr->next = new_table[new_idx];
new_table[new_idx] = curr;
if (curr->next) {
conflicts1++;
if (curr->next->next)
conflicts2++;
}
curr = next;
}
}
VG_(free)(cxts.table);
CLG_DEBUG(0, "Resize Context Hash: %d => %d (entries %d, conflicts %d/%d)\n",
cxts.size, new_size,
cxts.entries, conflicts1, conflicts2);
cxts.size = new_size;
cxts.table = new_table;
CLG_(stat).cxt_hash_resizes++;
}
__inline__
static UWord cxt_hash_val(fn_node** fn, UInt size)
{
UWord hash = 0;
UInt count = size;
while(*fn != 0) {
hash = (hash<<7) + (hash>>25) + (UWord)(*fn);
fn--;
count--;
if (count==0) break;
}
return hash;
}
__inline__
static Bool is_cxt(UWord hash, fn_node** fn, Context* cxt)
{
int count;
fn_node** cxt_fn;
if (hash != cxt->hash) return False;
count = cxt->size;
cxt_fn = &(cxt->fn[0]);
while((*fn != 0) && (count>0)) {
if (*cxt_fn != *fn) return False;
fn--;
cxt_fn++;
count--;
}
return True;
}
/**
* Allocate new Context structure
*/
static Context* new_cxt(fn_node** fn)
{
Context* cxt;
UInt idx, offset;
UWord hash;
int size, recs;
fn_node* top_fn;
CLG_ASSERT(fn);
top_fn = *fn;
if (top_fn == 0) return 0;
size = top_fn->separate_callers +1;
recs = top_fn->separate_recursions;
if (recs<1) recs=1;
/* check fill degree of context hash table and resize if needed (>80%) */
cxts.entries++;
if (10 * cxts.entries / cxts.size > 8)
resize_cxt_table();
cxt = (Context*) CLG_MALLOC("cl.context.nc.1",
sizeof(Context)+sizeof(fn_node*)*size);
// hash value calculation similar to cxt_hash_val(), but additionally
// copying function pointers in one run
hash = 0;
offset = 0;
while(*fn != 0) {
hash = (hash<<7) + (hash>>25) + (UWord)(*fn);
cxt->fn[offset] = *fn;
offset++;
fn--;
if (offset >= size) break;
}
if (offset < size) size = offset;
cxt->size = size;
cxt->base_number = CLG_(stat).context_counter;
cxt->hash = hash;
CLG_(stat).context_counter += recs;
CLG_(stat).distinct_contexts++;
/* insert into Context hash table */
idx = (UInt) (hash % cxts.size);
cxt->next = cxts.table[idx];
cxts.table[idx] = cxt;
#if CLG_ENABLE_DEBUG
CLG_DEBUGIF(3) {
VG_(printf)(" new_cxt ox%p: ", cxt);
CLG_(print_cxt)(12, cxt, 0);
}
#endif
return cxt;
}
/* get the Context structure for current context */
Context* CLG_(get_cxt)(fn_node** fn)
{
Context* cxt;
UInt size, idx;
UWord hash;
CLG_ASSERT(fn != 0);
if (*fn == 0) return 0;
size = (*fn)->separate_callers+1;
if (size<=0) { size = -size+1; }
CLG_DEBUG(5, "+ get_cxt(fn '%s'): size %d\n",
(*fn)->name, size);
hash = cxt_hash_val(fn, size);
if ( ((cxt = (*fn)->last_cxt) != 0) && is_cxt(hash, fn, cxt)) {
CLG_DEBUG(5, "- get_cxt: %p\n", cxt);
return cxt;
}
CLG_(stat).cxt_lru_misses++;
idx = (UInt) (hash % cxts.size);
cxt = cxts.table[idx];
while(cxt) {
if (is_cxt(hash,fn,cxt)) break;
cxt = cxt->next;
}
if (!cxt)
cxt = new_cxt(fn);
(*fn)->last_cxt = cxt;
CLG_DEBUG(5, "- get_cxt: %p\n", cxt);
return cxt;
}
/**
* Change execution context by calling a new function from current context
* Pushing 0x0 specifies a marker for a signal handler entry
*/
void CLG_(push_cxt)(fn_node* fn)
{
call_stack* cs = &CLG_(current_call_stack);
Int fn_entries;
CLG_DEBUG(5, "+ push_cxt(fn '%s'): old ctx %d\n",
fn ? fn->name : "0x0",
CLG_(current_state).cxt ?
CLG_(current_state).cxt->base_number : -1);
/* save old context on stack (even if not changed at all!) */
CLG_ASSERT(cs->sp < cs->size);
CLG_ASSERT(cs->entry[cs->sp].cxt == 0);
cs->entry[cs->sp].cxt = CLG_(current_state).cxt;
cs->entry[cs->sp].fn_sp = CLG_(current_fn_stack).top - CLG_(current_fn_stack).bottom;
if (fn && (*(CLG_(current_fn_stack).top) == fn)) return;
if (fn && (fn->group>0) &&
((*(CLG_(current_fn_stack).top))->group == fn->group)) return;
/* resizing needed ? */
fn_entries = CLG_(current_fn_stack).top - CLG_(current_fn_stack).bottom;
if (fn_entries == CLG_(current_fn_stack).size-1) {
int new_size = CLG_(current_fn_stack).size *2;
fn_node** new_array = (fn_node**) CLG_MALLOC("cl.context.pc.1",
new_size * sizeof(fn_node*));
int i;
for(i=0;i<CLG_(current_fn_stack).size;i++)
new_array[i] = CLG_(current_fn_stack).bottom[i];
VG_(free)(CLG_(current_fn_stack).bottom);
CLG_(current_fn_stack).top = new_array + fn_entries;
CLG_(current_fn_stack).bottom = new_array;
CLG_DEBUG(0, "Resize Context Stack: %d => %d (pushing '%s')\n",
CLG_(current_fn_stack).size, new_size,
fn ? fn->name : "0x0");
CLG_(current_fn_stack).size = new_size;
}
if (fn && (*(CLG_(current_fn_stack).top) == 0)) {
UInt *pactive;
/* this is first function: increment its active count */
pactive = CLG_(get_fn_entry)(fn->number);
(*pactive)++;
}
CLG_(current_fn_stack).top++;
*(CLG_(current_fn_stack).top) = fn;
CLG_(current_state).cxt = CLG_(get_cxt)(CLG_(current_fn_stack).top);
CLG_DEBUG(5, "- push_cxt(fn '%s'): new cxt %d, fn_sp %ld\n",
fn ? fn->name : "0x0",
CLG_(current_state).cxt ?
CLG_(current_state).cxt->base_number : -1,
CLG_(current_fn_stack).top - CLG_(current_fn_stack).bottom + 0L);
}