erl_db_util.c

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/* ``The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved via the world wide web at http://www.erlang.org/.
 * 
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 * 
 * The Initial Developer of the Original Code is Ericsson Utvecklings AB.
 * Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
 * AB. All Rights Reserved.''
 * 
 *     $Id$
 */
/*
 * Common utilities for the different types of db tables.
 * Mostly matching etc.
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include "sys.h"
#include "erl_vm.h"
#include "global.h"
#include "erl_process.h"
#include "error.h"
#define ERTS_WANT_DB_INTERNAL__
#include "erl_db.h"
#include "bif.h"
#include "big.h"
#include "erl_binary.h"

#include "erl_db_util.h"


/*
** Flags for the guard bif's
*/

/* These are offsets from the DCOMP_* value */
#define DBIF_GUARD 1
#define DBIF_BODY  0

/* These are the DBIF flag bits corresponding to the DCOMP_* value.
 * If a bit is set, the BIF is allowed in that context. */
#define DBIF_TABLE_GUARD (1 << (DCOMP_TABLE + DBIF_GUARD))
#define DBIF_TABLE_BODY  (1 << (DCOMP_TABLE + DBIF_BODY))
#define DBIF_TRACE_GUARD (1 << (DCOMP_TRACE + DBIF_GUARD))
#define DBIF_TRACE_BODY  (1 << (DCOMP_TRACE + DBIF_BODY))
#define DBIF_ALL \
DBIF_TABLE_GUARD | DBIF_TABLE_BODY | DBIF_TRACE_GUARD | DBIF_TRACE_BODY



/*
** Some convenience macros for stacks (DMC == db_match_compile)
*/

#define DMC_DEFAULT_SIZE 25

#define DMC_STACK_TYPE(Type) DMC_##Type##_stack

#define DMC_DECLARE_STACK_TYPE(Type)            \
typedef struct DMC_STACK_TYPE(Type) {		\
    int pos;					\
    int siz;					\
    Type def[DMC_DEFAULT_SIZE];		        \
    Type *data;					\
} DMC_STACK_TYPE(Type)
    
#define DMC_INIT_STACK(Name) \
     (Name).pos = 0; (Name).siz = DMC_DEFAULT_SIZE; (Name).data = (Name).def

#define DMC_STACK_DATA(Name) (Name).data

#define DMC_STACK_NUM(Name) (Name).pos

#define DMC_PUSH(On, What)						\
do {									\
    if ((On).pos >= (On).siz) {						\
	(On).siz *= 2;							\
	(On).data							\
	    = (((On).def == (On).data)					\
	       ? memcpy(erts_alloc(ERTS_ALC_T_DB_MC_STK,		\
				   (On).siz*sizeof(*((On).data))),	\
			(On).def,					\
			DMC_DEFAULT_SIZE*sizeof(*((On).data)))		\
	       : erts_realloc(ERTS_ALC_T_DB_MC_STK,			\
			      (void *) (On).data,			\
			      (On).siz*sizeof(*((On).data))));		\
    }									\
    (On).data[(On).pos++] = What;					\
} while (0)

#define DMC_POP(From) (From).data[--(From).pos]

#define DMC_TOP(From) (From).data[(From).pos - 1]

#define DMC_EMPTY(Name) ((Name).pos == 0)

#define DMC_PEEK(On, At) (On).data[At]     

#define DMC_POKE(On, At, Value) ((On).data[At] = (Value))

#define DMC_CLEAR(Name) (Name).pos = 0

#define DMC_FREE(Name)							\
do {									\
    if ((Name).def != (Name).data)					\
	erts_free(ERTS_ALC_T_DB_MC_STK, (Name).data);			\
} while (0)

static ERTS_INLINE Process *
get_proc(Process *cp, Uint32 cp_locks, Eterm id, Uint32 id_locks)
{
    Process *proc = erts_pid2proc(cp, cp_locks, id, id_locks);
    if (!proc && is_atom(id))
	proc = erts_whereis_process(cp, cp_locks, id, id_locks, 0);
    return proc;
}


static Eterm
set_tracee_flags(Process *tracee_p, Eterm tracer, Uint d_flags, Uint e_flags) {
    Eterm ret;
    Uint flags;

    if (tracer == NIL) {
	flags = tracee_p->trace_flags & ~TRACEE_FLAGS;
    }  else {
	flags = ((tracee_p->trace_flags & ~d_flags) | e_flags);
	if (! flags) tracer = NIL;
    }
    ret = tracee_p->tracer_proc != tracer || tracee_p->trace_flags != flags
	? am_true : am_false;
    tracee_p->tracer_proc = tracer;
    tracee_p->trace_flags = flags;
    return ret;
}
/*
** Assuming all locks on tracee_p on entry
**
** Changes tracee_p->trace_flags and tracee_p->tracer_proc
** according to input disable/enable flags and tracer.
**
** Returns am_true|am_false on success, am_true if value changed,
** returns fail_term on failure. Fails if tracer pid or port is invalid.
*/
static Eterm 
set_match_trace(Process *tracee_p, Eterm fail_term, Eterm tracer,
		Uint d_flags, Uint e_flags) {
    Eterm ret = fail_term;
    Process *tracer_p;
    
    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCKS_ALL == 
		       erts_proc_lc_my_proc_locks(tracee_p));

    if (is_internal_pid(tracer)
	&& (tracer_p = 
	    erts_pid2proc(tracee_p, ERTS_PROC_LOCKS_ALL,
			  tracer, ERTS_PROC_LOCKS_ALL))) {
	if (tracee_p != tracer_p) {
	    ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
	    tracer_p->trace_flags |= tracee_p->trace_flags ? F_TRACER : 0;
	    erts_smp_proc_unlock(tracer_p, ERTS_PROC_LOCKS_ALL);
	}
    } else if (is_internal_port(tracer)) {
	Port *tracer_port = 
	    erts_id2port(tracer, tracee_p, ERTS_PROC_LOCKS_ALL);
	if (tracer_port) {
	    if (! INVALID_TRACER_PORT(tracer_port, tracer)) {
		ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
	    }
	    erts_smp_port_unlock(tracer_port);
	}
    } else {
	ASSERT(is_nil(tracer));
	ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
    }
    return ret;
}


/* Type checking... */

#define BOXED_IS_TUPLE(Boxed) is_arity_value(*boxed_val((Boxed)))

/*
**
** Types and enum's (compiled matches)
**
*/

/*
** match VM instructions
*/
typedef enum {
    matchArray, /* Only when parameter is an array (DCOMP_TRACE) */
    matchArrayBind, /* ------------- " ------------ */
    matchTuple,
    matchPushT,
    matchPushL,
    matchPop,
    matchBind,
    matchCmp,
    matchEqBin,
    matchEqFloat,
    matchEqBig,
    matchEqRef,
    matchEq,
    matchList,
    matchSkip,
    matchPushC,
    matchConsA, /* Car is below Cdr */
    matchConsB, /* Cdr is below Car (unusual) */
    matchMkTuple,
    matchCall0,
    matchCall1,
    matchCall2,
    matchCall3,
    matchPushV,
    matchPushExpr, /* Push the whole expression we're matching ('$_') */
    matchPushArrayAsList, /* Only when parameter is an Array and 
			     not an erlang term  (DCOMP_TRACE) */
    matchPushArrayAsListU, /* As above but unknown size */
    matchTrue,
    matchOr,
    matchAnd,
    matchOrElse,
    matchAndThen,
    matchSelf,
    matchWaste,
    matchReturn,
    matchProcessDump,
    matchDisplay,
    matchIsSeqTrace,
    matchSetSeqToken,
    matchGetSeqToken,
    matchSetReturnTrace,
    matchSetExceptionTrace,
    matchCatch,
    matchEnableTrace,
    matchDisableTrace,
    matchEnableTrace2,
    matchDisableTrace2,
    matchTryMeElse,
    matchCaller,
    matchHalt,
    matchSilent,
    matchSetSeqTokenFake,
    matchTrace2,
    matchTrace3
} MatchOps;

/*
** Guard bif's
*/

typedef struct dmc_guard_bif {
    Eterm name; /* atom */
    void *biff;
    /*    BIF_RETTYPE (*biff)(); */
    int arity;
    Uint32 flags;
} DMCGuardBif; 

/*
** Error information (for lint)
*/

/*
** Type declarations for stacks
*/
DMC_DECLARE_STACK_TYPE(Eterm);

DMC_DECLARE_STACK_TYPE(Uint);

DMC_DECLARE_STACK_TYPE(unsigned);

/*
** Data about the heap during compilation
*/

typedef struct DMCHeap {
    int size;
    unsigned def[DMC_DEFAULT_SIZE];
    unsigned *data;
    int used;
} DMCHeap;

/*
** Return values from sub compilation steps (guard compilation)
*/

typedef enum dmc_ret { 
    retOk, 
    retFail, 
    retRestart 
} DMCRet; 

/*
** Diverse context information
*/

typedef struct dmc_context {
    int stack_need;
    int stack_used;
    ErlHeapFragment *save;
    ErlHeapFragment *copy;
    Eterm *matchexpr;
    Eterm *guardexpr;
    Eterm *bodyexpr;
    int num_match;
    int current_match;
    int eheap_need;
    Uint cflags;
    DMC_STACK_TYPE(Uint) *labels;
    int is_guard; /* 1 if in guard, 0 if in body */
    int special; /* 1 if the head in the match was a single expression */ 
    DMCErrInfo *err_info;
} DMCContext;

/*
**
** Global variables 
**
*/

/*
** Internal
*/

/* 
** The pseudo process used by the VM (pam).
*/

#define ERTS_DEFAULT_MS_HEAP_SIZE 128

typedef struct {
    Process process;
    Eterm *heap;
    Eterm default_heap[ERTS_DEFAULT_MS_HEAP_SIZE];
} ErtsMatchPseudoProcess;


#ifdef ERTS_SMP
static erts_smp_tsd_key_t match_pseudo_process_key;
#else
static ErtsMatchPseudoProcess *match_pseudo_process;
#endif

static ERTS_INLINE void
cleanup_match_pseudo_process(ErtsMatchPseudoProcess *mpsp, int keep_heap)
{
    if (mpsp->process.mbuf
	|| mpsp->process.off_heap.mso
#ifndef HYBRID /* FIND ME! */
	|| mpsp->process.off_heap.funs
#endif
	|| mpsp->process.off_heap.externals) {
	erts_cleanup_empty_process(&mpsp->process);
    }
#ifdef DEBUG
    else {
	erts_debug_verify_clean_empty_process(&mpsp->process);
    }
#endif
    if (!keep_heap) {
	if (mpsp->heap != &mpsp->default_heap[0]) {
	    /* Have to be done *after* call to erts_cleanup_empty_process() */
	    erts_free(ERTS_ALC_T_DB_MS_RUN_HEAP, (void *) mpsp->heap);
	    mpsp->heap = &mpsp->default_heap[0];
	}
#ifdef DEBUG
	else {
	    int i;
	    for (i = 0; i < ERTS_DEFAULT_MS_HEAP_SIZE; i++) {
#ifdef ARCH_64
		mpsp->default_heap[i] = (Eterm) 0xdeadbeefdeadbeef;
#else
		mpsp->default_heap[i] = (Eterm) 0xdeadbeef;
#endif
	    }
	}
#endif
    }
}

static ErtsMatchPseudoProcess *
create_match_pseudo_process(void)
{
    ErtsMatchPseudoProcess *mpsp;
    mpsp = (ErtsMatchPseudoProcess *)erts_alloc(ERTS_ALC_T_DB_MS_PSDO_PROC,
						sizeof(ErtsMatchPseudoProcess));
    erts_init_empty_process(&mpsp->process);
    mpsp->heap = &mpsp->default_heap[0];
    return mpsp;
}

static ERTS_INLINE ErtsMatchPseudoProcess *
get_match_pseudo_process(Process *c_p, Uint heap_size)
{
    ErtsMatchPseudoProcess *mpsp;
#ifdef ERTS_SMP
    mpsp = (ErtsMatchPseudoProcess *) c_p->scheduler_data->match_pseudo_process;
    if (mpsp)
	cleanup_match_pseudo_process(mpsp, 0);
    else {
	ASSERT(erts_smp_tsd_get(match_pseudo_process_key) == NULL);
	mpsp = create_match_pseudo_process();
	c_p->scheduler_data->match_pseudo_process = (void *) mpsp;
	erts_smp_tsd_set(match_pseudo_process_key, (void *) mpsp);
    }
    ASSERT(mpsp == erts_smp_tsd_get(match_pseudo_process_key));
    mpsp->process.scheduler_data = c_p->scheduler_data;
#else
    mpsp = match_pseudo_process;
    cleanup_match_pseudo_process(mpsp, 0);
#endif
    if (heap_size > ERTS_DEFAULT_MS_HEAP_SIZE)
	mpsp->heap = (Eterm *) erts_alloc(ERTS_ALC_T_DB_MS_RUN_HEAP,
					  heap_size*sizeof(Uint));
    else {
	ASSERT(mpsp->heap == &mpsp->default_heap[0]);
    }
    return mpsp;
}

#ifdef ERTS_SMP
static void
destroy_match_pseudo_process(void)
{
    ErtsMatchPseudoProcess *mpsp;
    mpsp = (ErtsMatchPseudoProcess *)erts_smp_tsd_get(match_pseudo_process_key);
    if (mpsp) {
	cleanup_match_pseudo_process(mpsp, 0);
	erts_free(ERTS_ALC_T_DB_MS_PSDO_PROC, (void *) mpsp);
	erts_smp_tsd_set(match_pseudo_process_key, (void *) NULL);
    }
}
#endif

static
void
match_pseudo_process_init(void)
{
#ifdef ERTS_SMP
    erts_smp_tsd_key_create(&match_pseudo_process_key);
    erts_smp_install_exit_handler(destroy_match_pseudo_process);
#else
    match_pseudo_process = create_match_pseudo_process();
#endif
}

void
erts_match_set_release_result(Process* c_p)
{
    (void) get_match_pseudo_process(c_p, 0); /* Clean it up */
}

/* The trace control word. */

static erts_smp_atomic_t trace_control_word;


Eterm
erts_ets_copy_object(Eterm obj, Process* to)
{
    Uint size = size_object(obj);
    Eterm* hp = HAlloc(to, size);
    Eterm res;

    res = copy_struct(obj, size, &hp, &MSO(to));
#ifdef DEBUG
    if (eq(obj, res) == 0) {
	erl_exit(1, "copy not equal to source\n");
    }
#endif
    return res;
}

/* This needs to be here, before the bif table... */

static Eterm db_set_trace_control_word_fake_1(Process *p, Eterm val);

/*
** The table of callable bif's, i e guard bif's and 
** some special animals that can provide us with trace
** information. This array is sorted on init.
*/
static DMCGuardBif guard_tab[] =
{
    {
	am_is_atom,
	&is_atom_1,
	1,
	DBIF_ALL
    },
    {
	am_is_constant,
	&is_constant_1,
	1,
	DBIF_ALL
    },    
    {
	am_is_float,
	&is_float_1,
	1,
	DBIF_ALL
    },
    {
	am_is_integer,
	&is_integer_1,
	1,
	DBIF_ALL
    },
    {
	am_is_list,
	&is_list_1,
	1,
	DBIF_ALL
    },
    {
	am_is_number,
	&is_number_1,
	1,
	DBIF_ALL
    },
    {
	am_is_pid,
	&is_pid_1,
	1,
	DBIF_ALL
    },
    {
	am_is_port,
	&is_port_1,
	1,
	DBIF_ALL
    },
    {
	am_is_reference,
	&is_reference_1,
	1,
	DBIF_ALL
    },
    {
	am_is_tuple,
	&is_tuple_1,
	1,
	DBIF_ALL
    },
    {
	am_is_binary,
	&is_binary_1,
	1,
	DBIF_ALL