422 lines
12 KiB
C
422 lines
12 KiB
C
/*-
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* Copyright (c) 1983, 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/* This file implements a subset of the profiling support functions.
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It has been copied and adapted from mcount.c, gmon.c and gmon.h in
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the glibc sources.
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Since we do not have access to a timer interrupt in the simulator
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the histogram and basic block information is not generated. */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <fcntl.h>
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/* Fraction of text space to allocate for histogram counters here, 1/2. */
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#define HISTFRACTION 2
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/* Fraction of text space to allocate for from hash buckets.
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The value of HASHFRACTION is based on the minimum number of bytes
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of separation between two subroutine call points in the object code.
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Given MIN_SUBR_SEPARATION bytes of separation the value of
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HASHFRACTION is calculated as:
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HASHFRACTION = MIN_SUBR_SEPARATION / (2 * sizeof (short) - 1);
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For example, on the VAX, the shortest two call sequence is:
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calls $0,(r0)
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calls $0,(r0)
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which is separated by only three bytes, thus HASHFRACTION is
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calculated as:
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HASHFRACTION = 3 / (2 * 2 - 1) = 1
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Note that the division above rounds down, thus if MIN_SUBR_FRACTION
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is less than three, this algorithm will not work!
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In practice, however, call instructions are rarely at a minimal
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distance. Hence, we will define HASHFRACTION to be 2 across all
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architectures. This saves a reasonable amount of space for
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profiling data structures without (in practice) sacrificing
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any granularity. */
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#define HASHFRACTION 2
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/* Percent of text space to allocate for tostructs.
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This is a heuristic; we will fail with a warning when profiling
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programs with a very large number of very small functions, but
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that's normally OK.
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2 is probably still a good value for normal programs.
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Profiling a test case with 64000 small functions will work if
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you raise this value to 3 and link statically (which bloats the
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text size, thus raising the number of arcs expected by the heuristic). */
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#define ARCDENSITY 3
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/* Always allocate at least this many tostructs. This hides the
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inadequacy of the ARCDENSITY heuristic, at least for small programs. */
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#define MINARCS 50
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/* Maximum number of arcs we want to allow.
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Used to be max representable value of ARCINDEX minus 2, but now
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that ARCINDEX is a long, that's too large; we don't really want
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to allow a 48 gigabyte table.
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The old value of 1<<16 wasn't high enough in practice for large C++
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programs; will 1<<20 be adequate for long? FIXME */
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#define MAXARCS (1L << 20)
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#define SCALE_1_TO_1 0x10000L
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#define GMON_MAGIC "gmon" /* Magic cookie. */
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#define GMON_VERSION 1 /* Version number. */
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/* General rounding functions. */
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#define ROUNDDOWN(x ,y) (((x) / (y)) * (y))
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#define ROUNDUP(x, y) ((((x) + (y) - 1) / (y)) * (y))
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struct tostruct
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{
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unsigned long selfpc;
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unsigned long count;
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unsigned long link;
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};
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/* Possible states of profiling. */
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enum profiling_state
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{
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GMON_PROF_OFF,
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GMON_PROF_ON,
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GMON_PROF_BUSY,
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GMON_PROF_ERROR
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};
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/* The profiling data structures are housed in this structure. */
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struct gmonparam
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{
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enum profiling_state state;
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unsigned short * kcount;
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unsigned long kcountsize;
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unsigned long * froms;
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unsigned long fromssize;
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struct tostruct * tos;
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unsigned long tossize;
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long tolimit;
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unsigned long lowpc;
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unsigned long highpc;
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unsigned long textsize;
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unsigned long hashfraction;
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long log_hashfraction;
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};
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/* Raw header as it appears in the gmon.out file (without padding).
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This header always comes first and is then followed by a series
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records defined below. */
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struct gmon_hdr
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{
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char cookie[4];
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char version[4];
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char spare[3 * 4];
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};
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/* Types of records in this file. */
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typedef enum
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{
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GMON_TAG_TIME_HIST = 0,
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GMON_TAG_CG_ARC = 1,
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} GMON_Record_Tag;
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struct gmon_cg_arc_record
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{
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char tag; /* Set to GMON_TAG_CG_ARC. */
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char from_pc[sizeof (char *)]; /* Address within caller's body. */
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char self_pc[sizeof (char *)]; /* Address within callee's body. */
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char count[4]; /* Number of arc traversals. */
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};
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/* Forward declarations. */
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void _mcount_internal (unsigned long);
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void _monstartup (unsigned long, unsigned long);
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void _mcleanup (void);
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static struct gmonparam _gmonparam;
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void
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_mcount_internal (unsigned long frompc)
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{
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unsigned long selfpc = frompc;
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unsigned long * frompcindex;
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struct tostruct * top;
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struct tostruct * prevtop;
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struct gmonparam * p;
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unsigned long toindex;
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int i;
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p = & _gmonparam;
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/* Check that we are profiling and that we aren't recursively invoked.
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NB/ This version is not thread-safe. */
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if (p->state != GMON_PROF_ON)
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return;
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p->state = GMON_PROF_BUSY;
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/* Check that frompcindex is a reasonable pc value.
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For example: signal catchers get called from the stack,
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not from text space. Too bad. */
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frompc -= p->lowpc;
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if (frompc > p->textsize)
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goto done;
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i = frompc >> p->log_hashfraction;
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frompcindex = p->froms + i;
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toindex = * frompcindex;
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if (toindex == 0)
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{
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/* First time traversing this arc. */
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toindex = ++ p->tos[0].link;
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if (toindex >= p->tolimit)
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/* Halt further profiling. */
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goto overflow;
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* frompcindex = toindex;
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top = p->tos + toindex;
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top->selfpc = selfpc;
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top->count = 1;
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top->link = 0;
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goto done;
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}
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top = p->tos + toindex;
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if (top->selfpc == selfpc)
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{
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/* Arc at front of chain: usual case. */
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top->count ++;
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goto done;
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}
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/* Have to go looking down chain for it.
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Top points to what we are looking at,
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prevtop points to previous top.
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We know it is not at the head of the chain. */
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for (;;)
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{
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if (top->link == 0)
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{
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/* Top is end of the chain and none of the chain
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had top->selfpc == selfpc. So we allocate a
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new tostruct and link it to the head of the
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chain. */
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toindex = ++ p->tos[0].link;
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if (toindex >= p->tolimit)
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goto overflow;
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top = p->tos + toindex;
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top->selfpc = selfpc;
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top->count = 1;
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top->link = * frompcindex;
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* frompcindex = toindex;
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goto done;
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}
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/* Otherwise, check the next arc on the chain. */
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prevtop = top;
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top = p->tos + top->link;
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if (top->selfpc == selfpc)
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{
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/* There it is. Increment its count
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move it to the head of the chain. */
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top->count ++;
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toindex = prevtop->link;
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prevtop->link = top->link;
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top->link = * frompcindex;
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* frompcindex = toindex;
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goto done;
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}
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}
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done:
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p->state = GMON_PROF_ON;
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return;
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overflow:
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p->state = GMON_PROF_ERROR;
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return;
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}
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void
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_monstartup (unsigned long lowpc, unsigned long highpc)
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{
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char * cp;
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struct gmonparam * p = & _gmonparam;
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/* If the calloc() function has been instrumented we must make sure
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that it is not profiled until we are ready. */
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p->state = GMON_PROF_BUSY;
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/* Round lowpc and highpc to multiples of the density we're using
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so the rest of the scaling (here and in gprof) stays in ints. */
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p->lowpc = ROUNDDOWN (lowpc, HISTFRACTION * sizeof (* p->kcount));
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p->highpc = ROUNDUP (highpc, HISTFRACTION * sizeof (* p->kcount));
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p->textsize = p->highpc - p->lowpc;
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p->kcountsize = ROUNDUP (p->textsize / HISTFRACTION, sizeof (*p->froms));
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p->hashfraction = HASHFRACTION;
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p->log_hashfraction = -1;
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p->log_hashfraction = ffs (p->hashfraction * sizeof (*p->froms)) - 1;
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p->fromssize = p->textsize / HASHFRACTION;
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p->tolimit = p->textsize * ARCDENSITY / 100;
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if (p->tolimit < MINARCS)
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p->tolimit = MINARCS;
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else if (p->tolimit > MAXARCS)
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p->tolimit = MAXARCS;
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p->tossize = p->tolimit * sizeof (struct tostruct);
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cp = calloc (p->kcountsize + p->fromssize + p->tossize, 1);
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if (cp == NULL)
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{
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write (2, "monstartup: out of memory\n", 26);
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p->tos = NULL;
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p->state = GMON_PROF_ERROR;
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return;
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}
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p->tos = (struct tostruct *) cp;
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cp += p->tossize;
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p->kcount = (unsigned short *) cp;
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cp += p->kcountsize;
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p->froms = (unsigned long *) cp;
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p->tos[0].link = 0;
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p->state = GMON_PROF_ON;
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}
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static void
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write_call_graph (int fd)
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{
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#define NARCS_PER_WRITE 32
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struct gmon_cg_arc_record raw_arc[NARCS_PER_WRITE]
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__attribute__ ((aligned (__alignof__ (char *))));
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unsigned long from_index;
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unsigned long to_index;
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unsigned long from_len;
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unsigned long frompc;
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int nfilled;
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for (nfilled = 0; nfilled < NARCS_PER_WRITE; ++ nfilled)
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raw_arc[nfilled].tag = GMON_TAG_CG_ARC;
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nfilled = 0;
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from_len = _gmonparam.fromssize / sizeof (*_gmonparam.froms);
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for (from_index = 0; from_index < from_len; ++from_index)
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{
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if (_gmonparam.froms[from_index] == 0)
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continue;
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frompc = _gmonparam.lowpc;
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frompc += (from_index * _gmonparam.hashfraction
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* sizeof (*_gmonparam.froms));
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for (to_index = _gmonparam.froms[from_index];
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to_index != 0;
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to_index = _gmonparam.tos[to_index].link)
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{
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struct gmon_cg_arc_record * arc = raw_arc + nfilled;
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memcpy (arc->from_pc, & frompc, sizeof (arc->from_pc));
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memcpy (arc->self_pc, & _gmonparam.tos[to_index].selfpc, sizeof (arc->self_pc));
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memcpy (arc->count, & _gmonparam.tos[to_index].count, sizeof (arc->count));
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if (++ nfilled == NARCS_PER_WRITE)
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{
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write (fd, raw_arc, sizeof raw_arc);
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nfilled = 0;
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}
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}
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}
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if (nfilled > 0)
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write (fd, raw_arc, nfilled * sizeof (raw_arc[0]));
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}
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#include <errno.h>
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static void
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write_gmon (void)
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{
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struct gmon_hdr ghdr __attribute__ ((aligned (__alignof__ (int))));
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int fd;
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fd = open ("gmon.out", O_CREAT|O_TRUNC|O_WRONLY, 0666);
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if (fd < 0)
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{
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write (2, "_mcleanup: could not create gmon.out\n", 37);
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return;
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}
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/* Write gmon.out header: */
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memset (& ghdr, '\0', sizeof (ghdr));
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memcpy (ghdr.cookie, GMON_MAGIC, sizeof (ghdr.cookie));
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* (unsigned long *) ghdr.version = GMON_VERSION;
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write (fd, & ghdr, sizeof (ghdr));
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/* We do not have histogram or basic block information,
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so we do not generate these parts of the gmon.out file. */
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/* Write call-graph. */
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write_call_graph (fd);
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close (fd);
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}
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void
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_mcleanup (void)
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{
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if (_gmonparam.state != GMON_PROF_ERROR)
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{
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_gmonparam.state = GMON_PROF_OFF;
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write_gmon ();
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}
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/* Free the memory. */
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if (_gmonparam.tos != NULL)
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{
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free (_gmonparam.tos);
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_gmonparam.tos = NULL;
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}
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}
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