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authorEric Andersen <andersen@codepoet.org>2003-03-03 20:58:42 +0000
committerEric Andersen <andersen@codepoet.org>2003-03-03 20:58:42 +0000
commit67eff66438688fddebe41f77fd252a3b2b135271 (patch)
tree18dbee3e9afe50d27095140198e2aa34df1de061 /libc/sysdeps/linux/common/gmon.c
parent2229d0fa131387b9b8ad16ac88347350a080aeb5 (diff)
Initial effort at adding profiling support.
Diffstat (limited to 'libc/sysdeps/linux/common/gmon.c')
-rw-r--r--libc/sysdeps/linux/common/gmon.c641
1 files changed, 641 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/gmon.c b/libc/sysdeps/linux/common/gmon.c
new file mode 100644
index 000000000..b3fe788f7
--- /dev/null
+++ b/libc/sysdeps/linux/common/gmon.c
@@ -0,0 +1,641 @@
+/*-
+ * Copyright (c) 1983, 1992, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <features.h>
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/gmon.h>
+#include <sys/gmon_out.h>
+#include <sys/uio.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+#ifdef __UCLIBC_PROFILING__
+
+/* Head of basic-block list or NULL. */
+struct __bb *__bb_head;
+
+struct gmonparam _gmonparam = { GMON_PROF_OFF };
+
+/*
+ * See profil(2) where this is described:
+ */
+static int s_scale;
+#define SCALE_1_TO_1 0x10000L
+
+#define ERR(s) write (STDERR_FILENO, s, sizeof (s) - 1)
+
+void moncontrol __P ((int mode));
+static void write_hist __P ((int fd));
+static void write_call_graph __P ((int fd));
+static void write_bb_counts __P ((int fd));
+
+/*
+ * Control profiling
+ * profiling is what mcount checks to see if
+ * all the data structures are ready.
+ */
+void moncontrol (int mode)
+{
+ struct gmonparam *p = &_gmonparam;
+
+ /* Don't change the state if we ran into an error. */
+ if (p->state == GMON_PROF_ERROR)
+ return;
+
+ if (mode)
+ {
+ /* start */
+ profil((void *) p->kcount, p->kcountsize, p->lowpc, s_scale);
+ p->state = GMON_PROF_ON;
+ }
+ else
+ {
+ /* stop */
+ profil(NULL, 0, 0, 0);
+ p->state = GMON_PROF_OFF;
+ }
+}
+
+
+void monstartup (u_long lowpc, u_long highpc)
+{
+ register int o;
+ char *cp;
+ struct gmonparam *p = &_gmonparam;
+
+ /*
+ * round lowpc and highpc to multiples of the density we're using
+ * so the rest of the scaling (here and in gprof) stays in ints.
+ */
+ p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
+ p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
+ p->textsize = p->highpc - p->lowpc;
+ p->kcountsize = p->textsize / HISTFRACTION;
+ p->hashfraction = HASHFRACTION;
+ p->log_hashfraction = -1;
+ /* The following test must be kept in sync with the corresponding
+ test in mcount.c. */
+ if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) {
+ /* if HASHFRACTION is a power of two, mcount can use shifting
+ instead of integer division. Precompute shift amount. */
+ p->log_hashfraction = ffs(p->hashfraction * sizeof(*p->froms)) - 1;
+ }
+ p->fromssize = p->textsize / HASHFRACTION;
+ p->tolimit = p->textsize * ARCDENSITY / 100;
+ if (p->tolimit < MINARCS)
+ p->tolimit = MINARCS;
+ else if (p->tolimit > MAXARCS)
+ p->tolimit = MAXARCS;
+ p->tossize = p->tolimit * sizeof(struct tostruct);
+
+ cp = calloc (p->kcountsize + p->fromssize + p->tossize, 1);
+ if (! cp)
+ {
+ ERR("monstartup: out of memory\n");
+ p->tos = NULL;
+ p->state = GMON_PROF_ERROR;
+ return;
+ }
+ p->tos = (struct tostruct *)cp;
+ cp += p->tossize;
+ p->kcount = (HISTCOUNTER *)cp;
+ cp += p->kcountsize;
+ p->froms = (ARCINDEX *)cp;
+
+ p->tos[0].link = 0;
+
+ o = p->highpc - p->lowpc;
+ if (p->kcountsize < (u_long) o)
+ {
+#ifndef hp300
+ s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
+#else
+ /* avoid floating point operations */
+ int quot = o / p->kcountsize;
+
+ if (quot >= 0x10000)
+ s_scale = 1;
+ else if (quot >= 0x100)
+ s_scale = 0x10000 / quot;
+ else if (o >= 0x800000)
+ s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
+ else
+ s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
+#endif
+ } else
+ s_scale = SCALE_1_TO_1;
+
+ moncontrol(1);
+}
+
+
+/* Return frequency of ticks reported by profil. */
+static int profile_frequency (void)
+{
+ /*
+ * Discover the tick frequency of the machine if something goes wrong,
+ * we return 0, an impossible hertz.
+ */
+ struct itimerval tim;
+
+ tim.it_interval.tv_sec = 0;
+ tim.it_interval.tv_usec = 1;
+ tim.it_value.tv_sec = 0;
+ tim.it_value.tv_usec = 0;
+ setitimer(ITIMER_REAL, &tim, 0);
+ setitimer(ITIMER_REAL, 0, &tim);
+ if (tim.it_interval.tv_usec < 2)
+ return 0;
+ return (1000000 / tim.it_interval.tv_usec);
+}
+
+
+static void write_hist (int fd)
+{
+ u_char tag = GMON_TAG_TIME_HIST;
+ struct gmon_hist_hdr thdr __attribute__ ((aligned (__alignof__ (char *))));
+
+ if (_gmonparam.kcountsize > 0)
+ {
+ struct iovec iov[3] =
+ {
+ { &tag, sizeof (tag) },
+ { &thdr, sizeof (struct gmon_hist_hdr) },
+ { _gmonparam.kcount, _gmonparam.kcountsize }
+ };
+
+ *(char **) thdr.low_pc = (char *) _gmonparam.lowpc;
+ *(char **) thdr.high_pc = (char *) _gmonparam.highpc;
+ *(int32_t *) thdr.hist_size = (_gmonparam.kcountsize
+ / sizeof (HISTCOUNTER));
+ *(int32_t *) thdr.prof_rate = profile_frequency ();
+ strncpy (thdr.dimen, "seconds", sizeof (thdr.dimen));
+ thdr.dimen_abbrev = 's';
+
+ writev (fd, iov, 3);
+ }
+}
+
+
+static void write_call_graph (int fd)
+{
+#define NARCS_PER_WRITEV 32
+ u_char tag = GMON_TAG_CG_ARC;
+ struct gmon_cg_arc_record raw_arc[NARCS_PER_WRITEV]
+ __attribute__ ((aligned (__alignof__ (char*))));
+ ARCINDEX from_index, to_index;
+ int from_len;
+ u_long frompc;
+ struct iovec iov[2 * NARCS_PER_WRITEV];
+ int nfilled;
+
+ for (nfilled = 0; nfilled < NARCS_PER_WRITEV; ++nfilled)
+ {
+ iov[2 * nfilled].iov_base = &tag;
+ iov[2 * nfilled].iov_len = sizeof (tag);
+
+ iov[2 * nfilled + 1].iov_base = &raw_arc[nfilled];
+ iov[2 * nfilled + 1].iov_len = sizeof (struct gmon_cg_arc_record);
+ }
+
+ nfilled = 0;
+ from_len = _gmonparam.fromssize / sizeof (*_gmonparam.froms);
+ for (from_index = 0; from_index < from_len; ++from_index)
+ {
+ if (_gmonparam.froms[from_index] == 0)
+ continue;
+
+ frompc = _gmonparam.lowpc;
+ frompc += (from_index * _gmonparam.hashfraction
+ * sizeof (*_gmonparam.froms));
+ for (to_index = _gmonparam.froms[from_index];
+ to_index != 0;
+ to_index = _gmonparam.tos[to_index].link)
+ {
+ struct arc
+ {
+ char *frompc;
+ char *selfpc;
+ int32_t count;
+ }
+ arc;
+
+ arc.frompc = (char *) frompc;
+ arc.selfpc = (char *) _gmonparam.tos[to_index].selfpc;
+ arc.count = _gmonparam.tos[to_index].count;
+ memcpy (raw_arc + nfilled, &arc, sizeof (raw_arc [0]));
+
+ if (++nfilled == NARCS_PER_WRITEV)
+ {
+ writev (fd, iov, 2 * nfilled);
+ nfilled = 0;
+ }
+ }
+ }
+ if (nfilled > 0)
+ writev (fd, iov, 2 * nfilled);
+}
+
+
+static void write_bb_counts (int fd)
+{
+ struct __bb *grp;
+ u_char tag = GMON_TAG_BB_COUNT;
+ size_t ncounts;
+ size_t i;
+
+ struct iovec bbhead[2] =
+ {
+ { &tag, sizeof (tag) },
+ { &ncounts, sizeof (ncounts) }
+ };
+ struct iovec bbbody[8];
+ size_t nfilled;
+
+ for (i = 0; i < (sizeof (bbbody) / sizeof (bbbody[0])); i += 2)
+ {
+ bbbody[i].iov_len = sizeof (grp->addresses[0]);
+ bbbody[i + 1].iov_len = sizeof (grp->counts[0]);
+ }
+
+ /* Write each group of basic-block info (all basic-blocks in a
+ compilation unit form a single group). */
+
+ for (grp = __bb_head; grp; grp = grp->next)
+ {
+ ncounts = grp->ncounts;
+ writev (fd, bbhead, 2);
+ for (nfilled = i = 0; i < ncounts; ++i)
+ {
+ if (nfilled > (sizeof (bbbody) / sizeof (bbbody[0])) - 2)
+ {
+ writev (fd, bbbody, nfilled);
+ nfilled = 0;
+ }
+
+ bbbody[nfilled++].iov_base = (char *) &grp->addresses[i];
+ bbbody[nfilled++].iov_base = &grp->counts[i];
+ }
+ if (nfilled > 0)
+ writev (fd, bbbody, nfilled);
+ }
+}
+
+
+static void write_gmon (void)
+{
+ struct gmon_hdr ghdr __attribute__ ((aligned (__alignof__ (int))));
+ int fd = -1;
+ char *env;
+
+#ifndef O_NOFOLLOW
+# define O_NOFOLLOW 0
+#endif
+
+ env = getenv ("GMON_OUT_PREFIX");
+ if (env != NULL
+#if 0
+ && !__libc_enable_secure
+#endif
+ )
+ {
+ size_t len = strlen (env);
+ char buf[len + 20];
+ sprintf (buf, "%s.%u", env, getpid ());
+ fd = open (buf, O_CREAT|O_TRUNC|O_WRONLY|O_NOFOLLOW, 0666);
+ }
+
+ if (fd == -1)
+ {
+ fd = open ("gmon.out", O_CREAT|O_TRUNC|O_WRONLY|O_NOFOLLOW, 0666);
+ if (fd < 0)
+ {
+ char buf[300];
+ int errnum = errno;
+ fprintf (stderr, "_mcleanup: gmon.out: %s\n",
+ strerror_r (errnum, buf, sizeof buf));
+ return;
+ }
+ }
+
+ /* write gmon.out header: */
+ memset (&ghdr, '\0', sizeof (struct gmon_hdr));
+ memcpy (&ghdr.cookie[0], GMON_MAGIC, sizeof (ghdr.cookie));
+ *(int32_t *) ghdr.version = GMON_VERSION;
+ write (fd, &ghdr, sizeof (struct gmon_hdr));
+
+ /* write PC histogram: */
+ write_hist (fd);
+
+ /* write call-graph: */
+ write_call_graph (fd);
+
+ /* write basic-block execution counts: */
+ write_bb_counts (fd);
+
+ close (fd);
+}
+
+
+void write_profiling (void)
+{
+ int save = _gmonparam.state;
+ _gmonparam.state = GMON_PROF_OFF;
+ if (save == GMON_PROF_ON)
+ write_gmon ();
+ _gmonparam.state = save;
+}
+
+
+void _mcleanup (void)
+{
+ moncontrol (0);
+
+ if (_gmonparam.state != GMON_PROF_ERROR)
+ write_gmon ();
+
+ /* free the memory. */
+ if (_gmonparam.tos != NULL)
+ free (_gmonparam.tos);
+}
+
+#ifndef SIGPROF
+
+/* Enable statistical profiling, writing samples of the PC into at most
+ SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
+ is enabled, the system examines the user PC and increments
+ SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero,
+ disable profiling. Returns zero on success, -1 on error. */
+
+int profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale)
+{
+ if (scale == 0)
+ /* Disable profiling. */
+ return 0;
+
+ __set_errno (ENOSYS);
+ return -1;
+}
+
+#else
+
+static u_short *samples;
+static size_t nsamples;
+static size_t pc_offset;
+static u_int pc_scale;
+
+static inline void profil_count (void *pc)
+{
+ size_t i = (pc - pc_offset - (void *) 0) / 2;
+
+ if (sizeof (unsigned long long int) > sizeof (size_t))
+ i = (unsigned long long int) i * pc_scale / 65536;
+ else
+ i = i / 65536 * pc_scale + i % 65536 * pc_scale / 65536;
+
+ if (i < nsamples)
+ ++samples[i];
+}
+
+/* Get the machine-dependent definition of `profil_counter', the signal
+ handler for SIGPROF. It calls `profil_count' (above) with the PC of the
+ interrupted code. */
+#include <bits/profil-counter.h>
+
+/* Enable statistical profiling, writing samples of the PC into at most
+ SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
+ is enabled, the system examines the user PC and increments
+ SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero,
+ disable profiling. Returns zero on success, -1 on error. */
+
+int profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale)
+{
+ static struct sigaction oact;
+ static struct itimerval otimer;
+ struct sigaction act;
+ struct itimerval timer;
+
+ if (sample_buffer == NULL)
+ {
+ /* Disable profiling. */
+ if (samples == NULL)
+ /* Wasn't turned on. */
+ return 0;
+
+ if (setitimer (ITIMER_PROF, &otimer, NULL) < 0)
+ return -1;
+ samples = NULL;
+ return sigaction (SIGPROF, &oact, NULL);
+ }
+
+ if (samples)
+ {
+ /* Was already turned on. Restore old timer and signal handler
+ first. */
+ if (setitimer (ITIMER_PROF, &otimer, NULL) < 0
+ || sigaction (SIGPROF, &oact, NULL) < 0)
+ return -1;
+ }
+
+ samples = sample_buffer;
+ nsamples = size / sizeof *samples;
+ pc_offset = offset;
+ pc_scale = scale;
+
+ act.sa_handler = (__sighandler_t) &profil_counter;
+ act.sa_flags = SA_RESTART;
+ __sigfillset (&act.sa_mask);
+ if (sigaction (SIGPROF, &act, &oact) < 0)
+ return -1;
+
+ timer.it_value.tv_sec = 0;
+ timer.it_value.tv_usec = 1;
+ timer.it_interval = timer.it_value;
+ return setitimer (ITIMER_PROF, &timer, &otimer);
+}
+
+#endif
+
+
+/* This file provides the machine-dependent definitions of the _MCOUNT_DECL
+ and MCOUNT macros. */
+#include <bits/machine-gmon.h>
+#include <bits/atomicity.h>
+
+/*
+ * mcount is called on entry to each function compiled with the profiling
+ * switch set. _mcount(), which is declared in a machine-dependent way
+ * with _MCOUNT_DECL, does the actual work and is either inlined into a
+ * C routine or called by an assembly stub. In any case, this magic is
+ * taken care of by the MCOUNT definition in <machine/profile.h>.
+ *
+ * _mcount updates data structures that represent traversals of the
+ * program's call graph edges. frompc and selfpc are the return
+ * address and function address that represents the given call graph edge.
+ *
+ * Note: the original BSD code used the same variable (frompcindex) for
+ * both frompcindex and frompc. Any reasonable, modern compiler will
+ * perform this optimization.
+ */
+_MCOUNT_DECL(frompc, selfpc) /* _mcount; may be static, inline, etc */
+{
+ register ARCINDEX *frompcindex;
+ register struct tostruct *top, *prevtop;
+ register struct gmonparam *p;
+ register ARCINDEX toindex;
+ int i;
+
+ p = &_gmonparam;
+ /*
+ * check that we are profiling
+ * and that we aren't recursively invoked.
+ */
+ if (! compare_and_swap (&p->state, GMON_PROF_ON, GMON_PROF_BUSY))
+ return;
+
+ /*
+ * check that frompcindex is a reasonable pc value.
+ * for example: signal catchers get called from the stack,
+ * not from text space. too bad.
+ */
+ frompc -= p->lowpc;
+ if (frompc > p->textsize)
+ goto done;
+
+ /* The following test used to be
+ if (p->log_hashfraction >= 0)
+ But we can simplify this if we assume the profiling data
+ is always initialized by the functions in gmon.c. But
+ then it is possible to avoid a runtime check and use the
+ smae `if' as in gmon.c. So keep these tests in sync. */
+ if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) {
+ /* avoid integer divide if possible: */
+ i = frompc >> p->log_hashfraction;
+ } else {
+ i = frompc / (p->hashfraction * sizeof(*p->froms));
+ }
+ frompcindex = &p->froms[i];
+ toindex = *frompcindex;
+ if (toindex == 0) {
+ /*
+ * first time traversing this arc
+ */
+ toindex = ++p->tos[0].link;
+ if (toindex >= p->tolimit)
+ /* halt further profiling */
+ goto overflow;
+
+ *frompcindex = toindex;
+ top = &p->tos[toindex];
+ top->selfpc = selfpc;
+ top->count = 1;
+ top->link = 0;
+ goto done;
+ }
+ top = &p->tos[toindex];
+ if (top->selfpc == selfpc) {
+ /*
+ * arc at front of chain; usual case.
+ */
+ top->count++;
+ goto done;
+ }
+ /*
+ * have to go looking down chain for it.
+ * top points to what we are looking at,
+ * prevtop points to previous top.
+ * we know it is not at the head of the chain.
+ */
+ for (; /* goto done */; ) {
+ if (top->link == 0) {
+ /*
+ * top is end of the chain and none of the chain
+ * had top->selfpc == selfpc.
+ * so we allocate a new tostruct
+ * and link it to the head of the chain.
+ */
+ toindex = ++p->tos[0].link;
+ if (toindex >= p->tolimit)
+ goto overflow;
+
+ top = &p->tos[toindex];
+ top->selfpc = selfpc;
+ top->count = 1;
+ top->link = *frompcindex;
+ *frompcindex = toindex;
+ goto done;
+ }
+ /*
+ * otherwise, check the next arc on the chain.
+ */
+ prevtop = top;
+ top = &p->tos[top->link];
+ if (top->selfpc == selfpc) {
+ /*
+ * there it is.
+ * increment its count
+ * move it to the head of the chain.
+ */
+ top->count++;
+ toindex = prevtop->link;
+ prevtop->link = top->link;
+ top->link = *frompcindex;
+ *frompcindex = toindex;
+ goto done;
+ }
+
+ }
+done:
+ p->state = GMON_PROF_ON;
+ return;
+overflow:
+ p->state = GMON_PROF_ERROR;
+ return;
+}
+
+/*
+ * Actual definition of mcount function. Defined in <machine/profile.h>,
+ * which is included by <sys/gmon.h>.
+ */
+MCOUNT
+
+#endif
+