FM / dyninst

/usr/share/systemtap/runtime/dyninst

Name	Size	Mode	Actions
addr-map.c	565	0644	edit dl rm
alloc.c	1188	0644	edit dl rm
arith.c	2291	0644	edit dl rm
common_session_state.h	6921	0644	edit dl rm
copy.c	4095	0644	edit dl rm
debug.h	413	0644	edit dl rm
ilog2.h	2943	0644	edit dl rm
io.c	4541	0644	edit dl rm
linux_defs.h	5602	0644	edit dl rm
linux_hash.h	1877	0644	edit dl rm
linux_types.h	654	0644	edit dl rm
loc2c-runtime.h	2494	0644	edit dl rm
map_list.h	1059	0644	edit dl rm
map_runtime.h	5160	0644	edit dl rm
namespaces.h	0	0644	edit dl rm
offptr.h	4788	0644	edit dl rm
offset_list.h	4428	0644	edit dl rm
perf.c	0	0644	edit dl rm
print.c	2700	0644	edit dl rm
probe_lock.h	1849	0644	edit dl rm
regs.c	2557	0644	edit dl rm
runtime.h	10292	0644	edit dl rm
runtime_context.h	6556	0644	edit dl rm
runtime_defines.h	280	0644	edit dl rm
session_attributes.c	1717	0644	edit dl rm
session_attributes.h	772	0644	edit dl rm
shm.c	6171	0644	edit dl rm
stapdyn.h	4617	0644	edit dl rm
stat_runtime.h	1832	0644	edit dl rm
sym.c	1621	0644	edit dl rm
task_finder.c	0	0644	edit dl rm
timer.c	2770	0644	edit dl rm
transport.c	31128	0644	edit dl rm
transport.h	3968	0644	edit dl rm
unwind.c	0	0644	edit dl rm
uprobes-regs.c	3163	0644	edit dl rm
uprobes.c	1798	0644	edit dl rm
uprobes.h	953	0644	edit dl rm

Edit: /usr/share/systemtap/runtime/dyninst/probe_lock.h (1849B)

/* dyninst probe locking header file
 * Copyright (C) 2012, 2017 Red Hat Inc.
 *
 * This file is part of systemtap, and is free software.  You can
 * redistribute it and/or modify it under the terms of the GNU General
 * Public License (GPL); either version 2, or (at your option) any
 * later version.
 */

#ifndef _STAPDYN_PROBE_LOCK_H
#define _STAPDYN_PROBE_LOCK_H

#include <pthread.h>

struct stp_probe_lock {
	#ifdef STP_TIMING
	atomic_t *skipped;
	atomic_t *contention;
	#endif
	pthread_rwlock_t *lock;
	unsigned write_p;
};

static void
stp_unlock_probe(const struct stp_probe_lock *locks, unsigned num_locks)
{
	unsigned i;
	for (i = num_locks; i-- > 0;) {
		pthread_rwlock_unlock(locks[i].lock);
	}
}

static unsigned
stp_lock_probe(const struct stp_probe_lock *locks, unsigned num_locks)
{
#if 0 // XXX: should we bother with trylocks in pure userspace?
	unsigned i, retries = 0;
	for (i = 0; i < num_locks; ++i) {
		if (locks[i].write_p)
			while (!pthread_rwlock_trywrlock(locks[i].lock)) {
#if !define(STAP_SUPRESS_TIME_LIMITS_ENABLE)
				if (++retries > MAXTRYLOCK)
					goto skip;
#endif
				#ifdef STP_TIMING
					atomic_inc(locks[i].contention);
				#endif
				udelay (TRYLOCKDELAY);
			}
		else
			while (!pthread_rwlock_tryrdlock(locks[i].lock)) {
#if !define(STAP_SUPPRESS_TIME_LIMITS_ENABLE)
				if (++retries > MAXTRYLOCK)
					goto skip;
#endif
				#ifdef STP_TIMING
					atomic_inc(locks[i].contention);
				#endif
				udelay (TRYLOCKDELAY);
			}
	}
	return 1;

skip:
	atomic_inc(skipped_count());
#ifdef STP_TIMING
	atomic_inc(locks[i].skipped);
#endif
	stp_unlock_probe(locks, i);
	return 0;
#else
	unsigned i;
	for (i = 0; i < num_locks; ++i) {
		if (locks[i].write_p)
			pthread_rwlock_wrlock(locks[i].lock);
		else
			pthread_rwlock_rdlock(locks[i].lock);
	}
	return 1;
#endif
}

#endif /* _STAPDYN_PROBE_LOCK_H */

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