blob: dc5c9f5f812cb968d0181838ea86893d583e2597 [file] [log] [blame]
/*
This file is part of drd, a data race detector.
Copyright (C) 2006-2008 Bart Van Assche
bart.vanassche@gmail.com
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "drd_clientobj.h"
#include "drd_error.h"
#include "drd_semaphore.h"
#include "drd_suppression.h"
#include "priv_drd_clientreq.h"
#include "pub_tool_errormgr.h" // VG_(maybe_record_error)()
#include "pub_tool_libcassert.h" // tl_assert()
#include "pub_tool_libcprint.h" // VG_(printf)()
#include "pub_tool_machine.h" // VG_(get_IP)()
#include "pub_tool_threadstate.h" // VG_(get_running_tid)()
// Local functions.
static void semaphore_cleanup(struct semaphore_info* p);
// Local variables.
static Bool s_trace_semaphore;
// Function definitions.
void semaphore_set_trace(const Bool trace_semaphore)
{
s_trace_semaphore = trace_semaphore;
}
static
void semaphore_initialize(struct semaphore_info* const p,
const Addr semaphore, const UWord value)
{
tl_assert(semaphore != 0);
tl_assert(p->a1 == semaphore);
tl_assert(p->type == ClientSemaphore);
p->cleanup = (void(*)(DrdClientobj*))semaphore_cleanup;
p->value = value;
p->waiters = 0;
p->last_sem_post_tid = DRD_INVALID_THREADID;
p->last_sem_post_segment = 0;
}
/** Free the memory that was allocated by semaphore_initialize(). Called by
* clientobj_remove().
*/
static void semaphore_cleanup(struct semaphore_info* p)
{
if (p->waiters > 0)
{
SemaphoreErrInfo sei = { p->a1 };
VG_(maybe_record_error)(VG_(get_running_tid)(),
SemaphoreErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Destruction of semaphore that is being waited"
" upon",
&sei);
}
sg_put(p->last_sem_post_segment);
}
static
struct semaphore_info*
semaphore_get_or_allocate(const Addr semaphore)
{
struct semaphore_info *p;
tl_assert(offsetof(DrdClientobj, semaphore) == 0);
p = &clientobj_get(semaphore, ClientSemaphore)->semaphore;
if (p == 0)
{
tl_assert(offsetof(DrdClientobj, semaphore) == 0);
p = &clientobj_add(semaphore, ClientSemaphore)->semaphore;
semaphore_initialize(p, semaphore, 0);
}
return p;
}
static struct semaphore_info* semaphore_get(const Addr semaphore)
{
tl_assert(offsetof(DrdClientobj, semaphore) == 0);
return &clientobj_get(semaphore, ClientSemaphore)->semaphore;
}
/** Called before sem_init(). */
struct semaphore_info* semaphore_init(const Addr semaphore,
const Word pshared, const UWord value)
{
struct semaphore_info* p;
if (s_trace_semaphore)
{
VG_(message)(Vg_UserMsg,
"[%d/%d] semaphore_init 0x%lx",
VG_(get_running_tid)(),
thread_get_running_tid(),
semaphore);
}
if (semaphore_get(semaphore))
{
// To do: print an error message that a semaphore is being reinitialized.
}
p = semaphore_get_or_allocate(semaphore);
p->value = value;
return p;
}
/** Called after sem_destroy(). */
void semaphore_destroy(const Addr semaphore)
{
struct semaphore_info* p;
if (s_trace_semaphore)
{
VG_(message)(Vg_UserMsg,
"[%d/%d] semaphore_destroy 0x%lx",
VG_(get_running_tid)(),
thread_get_running_tid(),
semaphore);
}
p = semaphore_get(semaphore);
if (p == 0)
{
GenericErrInfo GEI;
VG_(maybe_record_error)(VG_(get_running_tid)(),
GenericErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Not a semaphore",
&GEI);
return;
}
clientobj_remove(semaphore, ClientSemaphore);
}
/** Called before sem_wait(). */
void semaphore_pre_wait(const Addr semaphore)
{
struct semaphore_info* p;
p = semaphore_get_or_allocate(semaphore);
if (s_trace_semaphore)
{
VG_(message)(Vg_UserMsg,
"[%d/%d] semaphore_pre_wait 0x%lx",
VG_(get_running_tid)(),
thread_get_running_tid(),
semaphore);
}
tl_assert(p);
tl_assert(p->waiters >= 0);
p->waiters++;
tl_assert(p->waiters > 0);
}
/** Called after sem_wait() finished.
* @note Do not rely on the value of 'waited' -- some glibc versions do
* not set it correctly.
*/
void semaphore_post_wait(const DrdThreadId tid, const Addr semaphore,
const Bool waited)
{
struct semaphore_info* p;
p = semaphore_get(semaphore);
if (s_trace_semaphore)
{
VG_(message)(Vg_UserMsg,
"[%d/%d] semaphore_post_wait 0x%lx",
VG_(get_running_tid)(),
thread_get_running_tid(),
semaphore);
}
tl_assert(p->waiters > 0);
p->waiters--;
tl_assert(p->waiters >= 0);
tl_assert(p->value >= 0);
if (p->value == 0)
{
SemaphoreErrInfo sei = { semaphore };
VG_(maybe_record_error)(VG_(get_running_tid)(),
SemaphoreErr,
VG_(get_IP)(VG_(get_running_tid)()),
"Invalid semaphore",
&sei);
return;
}
p->value--;
tl_assert(p->value >= 0);
if (p->last_sem_post_tid != tid
&& p->last_sem_post_tid != DRD_INVALID_THREADID)
{
tl_assert(p->last_sem_post_segment);
thread_combine_vc2(tid, &p->last_sem_post_segment->vc);
}
thread_new_segment(tid);
}
/** Called before sem_post(). */
void semaphore_pre_post(const DrdThreadId tid, const Addr semaphore)
{
struct semaphore_info* p;
if (s_trace_semaphore)
{
VG_(message)(Vg_UserMsg,
"[%d/%d] semaphore_post 0x%lx",
VG_(get_running_tid)(),
thread_get_running_tid(),
semaphore);
}
p = semaphore_get_or_allocate(semaphore);
p->value++;
if (p->value == 1)
{
p->last_sem_post_tid = tid;
thread_new_segment(tid);
thread_get_latest_segment(&p->last_sem_post_segment, tid);
}
}
/** Called after sem_post() finished successfully. */
void semaphore_post_post(const DrdThreadId tid, const Addr semaphore,
const Bool waited)
{
/* Note: it is hard to implement the sem_post() wrapper correctly in */
/* case sem_post() returns an error code. This is because handling this */
/* case correctly requires restoring the vector clock associated with */
/* the semaphore to its original value here. In order to do that without */
/* introducing a race condition, extra locking has to be added around */
/* each semaphore call. Such extra locking would have to be added in */
/* drd_intercepts.c. However, it is hard to implement synchronization */
/* in drd_intercepts.c in a portable way without calling already */
/* redirected functions. */
}
void semaphore_thread_delete(const DrdThreadId threadid)
{ }