/*--------------------------------------------------------------------*/
/*--- Callgrind ---*/
/*--- ct_threads.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Callgrind, a Valgrind tool for call tracing.
Copyright (C) 2002-2012, 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"
#include "pub_tool_threadstate.h"
/* forward decls */
static exec_state* exec_state_save(void);
static exec_state* exec_state_restore(void);
static exec_state* push_exec_state(int);
static exec_state* top_exec_state(void);
static exec_stack current_states;
/*------------------------------------------------------------*/
/*--- Support for multi-threading ---*/
/*------------------------------------------------------------*/
/*
* For Valgrind, MT is cooperative (no preemting in our code),
* so we don't need locks...
*
* Per-thread data:
* - BBCCs
* - call stack
* - call hash
* - event counters: last, current
*
* Even when ignoring MT, we need this functions to set up some
* datastructures for the process (= Thread 1).
*/
/* current running thread */
ThreadId CLG_(current_tid);
static thread_info* thread[VG_N_THREADS];
thread_info** CLG_(get_threads)()
{
return thread;
}
thread_info* CLG_(get_current_thread)()
{
return thread[CLG_(current_tid)];
}
void CLG_(init_threads)()
{
Int i;
for(i=0;i<VG_N_THREADS;i++)
thread[i] = 0;
CLG_(current_tid) = VG_INVALID_THREADID;
}
/* switches through all threads and calls func */
void CLG_(forall_threads)(void (*func)(thread_info*))
{
Int t, orig_tid = CLG_(current_tid);
for(t=1;t<VG_N_THREADS;t++) {
if (!thread[t]) continue;
CLG_(switch_thread)(t);
(*func)(thread[t]);
}
CLG_(switch_thread)(orig_tid);
}
static
thread_info* new_thread(void)
{
thread_info* t;
t = (thread_info*) CLG_MALLOC("cl.threads.nt.1",
sizeof(thread_info));
/* init state */
CLG_(init_exec_stack)( &(t->states) );
CLG_(init_call_stack)( &(t->calls) );
CLG_(init_fn_stack) ( &(t->fns) );
/* t->states.entry[0]->cxt = CLG_(get_cxt)(t->fns.bottom); */
/* event counters */
t->lastdump_cost = CLG_(get_eventset_cost)( CLG_(sets).full );
t->sighandler_cost = CLG_(get_eventset_cost)( CLG_(sets).full );
CLG_(init_cost)( CLG_(sets).full, t->lastdump_cost );
CLG_(init_cost)( CLG_(sets).full, t->sighandler_cost );
/* init data containers */
CLG_(init_fn_array)( &(t->fn_active) );
CLG_(init_bbcc_hash)( &(t->bbccs) );
CLG_(init_jcc_hash)( &(t->jccs) );
return t;
}
void CLG_(switch_thread)(ThreadId tid)
{
if (tid == CLG_(current_tid)) return;
CLG_DEBUG(0, ">> thread %d (was %d)\n", tid, CLG_(current_tid));
if (CLG_(current_tid) != VG_INVALID_THREADID) {
/* save thread state */
thread_info* t = thread[CLG_(current_tid)];
CLG_ASSERT(t != 0);
/* current context (including signal handler contexts) */
exec_state_save();
CLG_(copy_current_exec_stack)( &(t->states) );
CLG_(copy_current_call_stack)( &(t->calls) );
CLG_(copy_current_fn_stack) ( &(t->fns) );
CLG_(copy_current_fn_array) ( &(t->fn_active) );
/* If we cumulate costs of threads, use TID 1 for all jccs/bccs */
if (!CLG_(clo).separate_threads) t = thread[1];
CLG_(copy_current_bbcc_hash)( &(t->bbccs) );
CLG_(copy_current_jcc_hash) ( &(t->jccs) );
}
CLG_(current_tid) = tid;
CLG_ASSERT(tid < VG_N_THREADS);
if (tid != VG_INVALID_THREADID) {
thread_info* t;
/* load thread state */
if (thread[tid] == 0) thread[tid] = new_thread();
t = thread[tid];
/* current context (including signal handler contexts) */
CLG_(set_current_exec_stack)( &(t->states) );
exec_state_restore();
CLG_(set_current_call_stack)( &(t->calls) );
CLG_(set_current_fn_stack) ( &(t->fns) );
CLG_(set_current_fn_array) ( &(t->fn_active) );
/* If we cumulate costs of threads, use TID 1 for all jccs/bccs */
if (!CLG_(clo).separate_threads) t = thread[1];
CLG_(set_current_bbcc_hash) ( &(t->bbccs) );
CLG_(set_current_jcc_hash) ( &(t->jccs) );
}
}
void CLG_(run_thread)(ThreadId tid)
{
/* check for dumps needed */
static ULong bbs_done = 0;
static Char buf[512];
if (CLG_(clo).dump_every_bb >0) {
if (CLG_(stat).bb_executions - bbs_done > CLG_(clo).dump_every_bb) {
VG_(sprintf)(buf, "--dump-every-bb=%llu", CLG_(clo).dump_every_bb);
CLG_(dump_profile)(buf, False);
bbs_done = CLG_(stat).bb_executions;
}
}
/* now check for thread switch */
CLG_(switch_thread)(tid);
}
void CLG_(pre_signal)(ThreadId tid, Int sigNum, Bool alt_stack)
{
exec_state *es;
CLG_DEBUG(0, ">> pre_signal(TID %d, sig %d, alt_st %s)\n",
tid, sigNum, alt_stack ? "yes":"no");
/* switch to the thread the handler runs in */
CLG_(switch_thread)(tid);
/* save current execution state */
exec_state_save();
/* setup new cxtinfo struct for this signal handler */
es = push_exec_state(sigNum);
CLG_(zero_cost)( CLG_(sets).full, es->cost );
CLG_(current_state).cost = es->cost;
es->call_stack_bottom = CLG_(current_call_stack).sp;
/* setup current state for a spontaneous call */
CLG_(init_exec_state)( &CLG_(current_state) );
CLG_(current_state).sig = sigNum;
CLG_(push_cxt)(0);
}
/* Run post-signal if the stackpointer for call stack is at
* the bottom in current exec state (e.g. a signal handler)
*
* Called from CLG_(pop_call_stack)
*/
void CLG_(run_post_signal_on_call_stack_bottom)()
{
exec_state* es = top_exec_state();
CLG_ASSERT(es != 0);
CLG_ASSERT(CLG_(current_state).sig >0);
if (CLG_(current_call_stack).sp == es->call_stack_bottom)
CLG_(post_signal)( CLG_(current_tid), CLG_(current_state).sig );
}
void CLG_(post_signal)(ThreadId tid, Int sigNum)
{
exec_state* es;
UInt fn_number, *pactive;
CLG_DEBUG(0, ">> post_signal(TID %d, sig %d)\n",
tid, sigNum);
/* thread switching potentially needed, eg. with instrumentation off */
CLG_(switch_thread)(tid);
CLG_ASSERT(sigNum == CLG_(current_state).sig);
/* Unwind call stack of this signal handler.
* This should only be needed at finalisation time
*/
es = top_exec_state();
CLG_ASSERT(es != 0);
while(CLG_(current_call_stack).sp > es->call_stack_bottom)
CLG_(pop_call_stack)();
if (CLG_(current_state).cxt) {
/* correct active counts */
fn_number = CLG_(current_state).cxt->fn[0]->number;
pactive = CLG_(get_fn_entry)(fn_number);
(*pactive)--;
CLG_DEBUG(0, " set active count of %s back to %d\n",
CLG_(current_state).cxt->fn[0]->name, *pactive);
}
if (CLG_(current_fn_stack).top > CLG_(current_fn_stack).bottom) {
/* set fn_stack_top back.
* top can point to 0 if nothing was executed in the signal handler;
* this is possible at end on unwinding handlers.
*/
if (*(CLG_(current_fn_stack).top) != 0) {
CLG_(current_fn_stack).top--;
CLG_ASSERT(*(CLG_(current_fn_stack).top) == 0);
}
if (CLG_(current_fn_stack).top > CLG_(current_fn_stack).bottom)
CLG_(current_fn_stack).top--;
}
/* sum up costs */
CLG_ASSERT(CLG_(current_state).cost == es->cost);
CLG_(add_and_zero_cost)( CLG_(sets).full,
thread[CLG_(current_tid)]->sighandler_cost,
CLG_(current_state).cost );
/* restore previous context */
es->sig = -1;
current_states.sp--;
es = top_exec_state();
CLG_(current_state).sig = es->sig;
exec_state_restore();
/* There is no way to reliable get the thread ID we are switching to
* after this handler returns. So we sync with actual TID at start of
* CLG_(setup_bb)(), which should be the next for callgrind.
*/
}
/*------------------------------------------------------------*/
/*--- Execution states in a thread & signal handlers ---*/
/*------------------------------------------------------------*/
/* Each thread can be interrupted by a signal handler, and they
* themselves again. But as there's no scheduling among handlers
* of the same thread, we don't need additional stacks.
* So storing execution contexts and
* adding separators in the callstack(needed to not intermix normal/handler
* functions in contexts) should be enough.
*/
/* not initialized: call_stack_bottom, sig */
void CLG_(init_exec_state)(exec_state* es)
{
es->collect = CLG_(clo).collect_atstart;
es->cxt = 0;
es->jmps_passed = 0;
es->bbcc = 0;
es->nonskipped = 0;
}
static exec_state* new_exec_state(Int sigNum)
{
exec_state* es;
es = (exec_state*) CLG_MALLOC("cl.threads.nes.1",
sizeof(exec_state));
/* allocate real cost space: needed as incremented by
* simulation functions */
es->cost = CLG_(get_eventset_cost)(CLG_(sets).full);
CLG_(zero_cost)( CLG_(sets).full, es->cost );
CLG_(init_exec_state)(es);
es->sig = sigNum;
es->call_stack_bottom = 0;
return es;
}
void CLG_(init_exec_stack)(exec_stack* es)
{
Int i;
/* The first element is for the main thread */
es->entry[0] = new_exec_state(0);
for(i=1;i<MAX_SIGHANDLERS;i++)
es->entry[i] = 0;
es->sp = 0;
}
void CLG_(copy_current_exec_stack)(exec_stack* dst)
{
Int i;
dst->sp = current_states.sp;
for(i=0;i<MAX_SIGHANDLERS;i++)
dst->entry[i] = current_states.entry[i];
}
void CLG_(set_current_exec_stack)(exec_stack* dst)
{
Int i;
current_states.sp = dst->sp;
for(i=0;i<MAX_SIGHANDLERS;i++)
current_states.entry[i] = dst->entry[i];
}
/* Get top context info struct of current thread */
static
exec_state* top_exec_state(void)
{
Int sp = current_states.sp;
exec_state* es;
CLG_ASSERT((sp >= 0) && (sp < MAX_SIGHANDLERS));
es = current_states.entry[sp];
CLG_ASSERT(es != 0);
return es;
}
/* Allocates a free context info structure for a new entered
* signal handler, putting it on the context stack.
* Returns a pointer to the structure.
*/
static exec_state* push_exec_state(int sigNum)
{
Int sp;
exec_state* es;
current_states.sp++;
sp = current_states.sp;
CLG_ASSERT((sigNum > 0) && (sigNum <= _VKI_NSIG));
CLG_ASSERT((sp > 0) && (sp < MAX_SIGHANDLERS));
es = current_states.entry[sp];
if (!es) {
es = new_exec_state(sigNum);
current_states.entry[sp] = es;
}
else
es->sig = sigNum;
return es;
}
/* Save current context to top cxtinfo struct */
static
exec_state* exec_state_save(void)
{
exec_state* es = top_exec_state();
es->cxt = CLG_(current_state).cxt;
es->collect = CLG_(current_state).collect;
es->jmps_passed = CLG_(current_state).jmps_passed;
es->bbcc = CLG_(current_state).bbcc;
es->nonskipped = CLG_(current_state).nonskipped;
CLG_ASSERT(es->cost == CLG_(current_state).cost);
CLG_DEBUGIF(1) {
CLG_DEBUG(1, " cxtinfo_save(sig %d): collect %s, jmps_passed %d\n",
es->sig, es->collect ? "Yes": "No", es->jmps_passed);
CLG_(print_bbcc)(-9, es->bbcc);
CLG_(print_cost)(-9, CLG_(sets).full, es->cost);
}
/* signal number does not need to be saved */
CLG_ASSERT(CLG_(current_state).sig == es->sig);
return es;
}
static
exec_state* exec_state_restore(void)
{
exec_state* es = top_exec_state();
CLG_(current_state).cxt = es->cxt;
CLG_(current_state).collect = es->collect;
CLG_(current_state).jmps_passed = es->jmps_passed;
CLG_(current_state).bbcc = es->bbcc;
CLG_(current_state).nonskipped = es->nonskipped;
CLG_(current_state).cost = es->cost;
CLG_(current_state).sig = es->sig;
CLG_DEBUGIF(1) {
CLG_DEBUG(1, " exec_state_restore(sig %d): collect %s, jmps_passed %d\n",
es->sig, es->collect ? "Yes": "No", es->jmps_passed);
CLG_(print_bbcc)(-9, es->bbcc);
CLG_(print_cxt)(-9, es->cxt, 0);
CLG_(print_cost)(-9, CLG_(sets).full, es->cost);
}
return es;
}