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Commit a930d2c0 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

perf_counter tools: Add built-in pager support 



Add Git's pager.c (and sigchain) code. A command only
has to call setup_pager() to get paged interactive
output.

Non-interactive (redirected, command-piped, etc.) uses
are not affected.

Update perf-report to make use of this.

[ Impact: new feature ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 23ac9cbe

Documentation/perf_counter/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -297,11 +297,13 @@ LIB_H += util/util.h 
LIB_H += util/help.h

LIB_H += util/strbuf.h

LIB_H += util/run-command.h

LIB_H += util/sigchain.h



LIB_OBJS += util/abspath.o

LIB_OBJS += util/alias.o

LIB_OBJS += util/config.o

LIB_OBJS += util/ctype.o

LIB_OBJS += util/environment.o

LIB_OBJS += util/exec_cmd.o

LIB_OBJS += util/help.o

LIB_OBJS += util/levenshtein.o
@@ -314,6 +316,8 @@ LIB_OBJS += util/quote.o 
LIB_OBJS += util/strbuf.o

LIB_OBJS += util/usage.o

LIB_OBJS += util/wrapper.o

LIB_OBJS += util/sigchain.o

LIB_OBJS += util/pager.o



BUILTIN_OBJS += builtin-help.o

BUILTIN_OBJS += builtin-record.o

Documentation/perf_counter/builtin-report.c

+3 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <ctype.h>



#include "util/list.h"

#include "util/cache.h"

#include "util/rbtree.h"



#include "perf.h"
@@ -992,5 +993,7 @@ int cmd_report(int argc, const char **argv, const char *prefix) 


	parse_options(argc, argv, options, report_usage, 0);



	setup_pager();



	return __cmd_report();

}

Documentation/perf_counter/util/environment.c

0 → 100644
+8 −0
Original line number Diff line number Diff line 
/*

 * We put all the perf config variables in this same object

 * file, so that programs can link against the config parser

 * without having to link against all the rest of perf.

 */

#include "cache.h"



const char *pager_program;

Documentation/perf_counter/util/pager.c

0 → 100644
+99 −0
Original line number Diff line number Diff line 
#include "cache.h"

#include "run-command.h"

#include "sigchain.h"



/*

 * This is split up from the rest of git so that we can do

 * something different on Windows.

 */



static int spawned_pager;



#ifndef __MINGW32__

static void pager_preexec(void)

{

	/*

	 * Work around bug in "less" by not starting it until we

	 * have real input

	 */

	fd_set in;



	FD_ZERO(&in);

	FD_SET(0, &in);

	select(1, &in, NULL, &in, NULL);



	setenv("LESS", "FRSX", 0);

}

#endif



static const char *pager_argv[] = { "sh", "-c", NULL, NULL };

static struct child_process pager_process;



static void wait_for_pager(void)

{

	fflush(stdout);

	fflush(stderr);

	/* signal EOF to pager */

	close(1);

	close(2);

	finish_command(&pager_process);

}



static void wait_for_pager_signal(int signo)

{

	wait_for_pager();

	sigchain_pop(signo);

	raise(signo);

}



void setup_pager(void)

{

	const char *pager = getenv("PERF_PAGER");



	if (!isatty(1))

		return;

	if (!pager) {

		if (!pager_program)

			perf_config(perf_default_config, NULL);

		pager = pager_program;

	}

	if (!pager)

		pager = getenv("PAGER");

	if (!pager)

		pager = "less";

	else if (!*pager || !strcmp(pager, "cat"))

		return;



	spawned_pager = 1; /* means we are emitting to terminal */



	/* spawn the pager */

	pager_argv[2] = pager;

	pager_process.argv = pager_argv;

	pager_process.in = -1;

#ifndef __MINGW32__

	pager_process.preexec_cb = pager_preexec;

#endif

	if (start_command(&pager_process))

		return;



	/* original process continues, but writes to the pipe */

	dup2(pager_process.in, 1);

	if (isatty(2))

		dup2(pager_process.in, 2);

	close(pager_process.in);



	/* this makes sure that the parent terminates after the pager */

	sigchain_push_common(wait_for_pager_signal);

	atexit(wait_for_pager);

}



int pager_in_use(void)

{

	const char *env;



	if (spawned_pager)

		return 1;



	env = getenv("PERF_PAGER_IN_USE");

	return env ? perf_config_bool("PERF_PAGER_IN_USE", env) : 0;

}

Documentation/perf_counter/util/sigchain.c

0 → 100644
+52 −0
Original line number Diff line number Diff line 
#include "sigchain.h"

#include "cache.h"



#define SIGCHAIN_MAX_SIGNALS 32



struct sigchain_signal {

	sigchain_fun *old;

	int n;

	int alloc;

};

static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];



static void check_signum(int sig)

{

	if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS)

		die("BUG: signal out of range: %d", sig);

}



int sigchain_push(int sig, sigchain_fun f)

{

	struct sigchain_signal *s = signals + sig;

	check_signum(sig);



	ALLOC_GROW(s->old, s->n + 1, s->alloc);

	s->old[s->n] = signal(sig, f);

	if (s->old[s->n] == SIG_ERR)

		return -1;

	s->n++;

	return 0;

}



int sigchain_pop(int sig)

{

	struct sigchain_signal *s = signals + sig;

	check_signum(sig);

	if (s->n < 1)

		return 0;



	if (signal(sig, s->old[s->n - 1]) == SIG_ERR)

		return -1;

	s->n--;

	return 0;

}



void sigchain_push_common(sigchain_fun f)

{

	sigchain_push(SIGINT, f);

	sigchain_push(SIGHUP, f);

	sigchain_push(SIGTERM, f);

	sigchain_push(SIGQUIT, f);

	sigchain_push(SIGPIPE, f);

}