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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-10-30 13:29:40 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-10-31 11:09:10 -0300
commit6b1472eb2ea16f99c4729f975ca25af980ce3894 (patch)
tree14cd1db1ac52188e91e81ab3ef3a93735d1683be /nptl
parentfbb4a3143724ef3f044a4f05351fe041300ee382 (diff)
downloadglibc-6b1472eb2ea16f99c4729f975ca25af980ce3894.tar.gz
Refactor PI mutexes internal definitions
This patch adds the generic futex_lock_pi and futex_unlock_pi to wrap around the syscall machinery required to issue the syscall calls. It simplifies a bit the futex code required to implement PI mutexes. No function changes, checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'nptl')
-rw-r--r--nptl/pthread_mutex_init.c13
-rw-r--r--nptl/pthread_mutex_lock.c24
-rw-r--r--nptl/pthread_mutex_timedlock.c60
-rw-r--r--nptl/pthread_mutex_trylock.c8
-rw-r--r--nptl/pthread_mutex_unlock.c6
5 files changed, 42 insertions, 69 deletions
diff --git a/nptl/pthread_mutex_init.c b/nptl/pthread_mutex_init.c
index fe4eeee37c..20800b80f5 100644
--- a/nptl/pthread_mutex_init.c
+++ b/nptl/pthread_mutex_init.c
@@ -24,6 +24,7 @@
#include "pthreadP.h"
#include <atomic.h>
#include <pthread-offsets.h>
+#include <futex-internal.h>
#include <stap-probe.h>
@@ -37,19 +38,13 @@ static const struct pthread_mutexattr default_mutexattr =
static bool
prio_inherit_missing (void)
{
-#ifdef __NR_futex
static int tpi_supported;
- if (__glibc_unlikely (tpi_supported == 0))
+ if (__glibc_unlikely (atomic_load_relaxed (&tpi_supported) == 0))
{
- int lock = 0;
- INTERNAL_SYSCALL_DECL (err);
- int ret = INTERNAL_SYSCALL (futex, err, 4, &lock, FUTEX_UNLOCK_PI, 0, 0);
- assert (INTERNAL_SYSCALL_ERROR_P (ret, err));
- tpi_supported = INTERNAL_SYSCALL_ERRNO (ret, err) == ENOSYS ? -1 : 1;
+ int e = futex_unlock_pi (&(unsigned int){0}, 0);
+ atomic_store_relaxed (&tpi_supported, e == ENOSYS ? -1 : 1);
}
return __glibc_unlikely (tpi_supported < 0);
-#endif
- return true;
}
int
diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
index ace436d5a6..05bba50666 100644
--- a/nptl/pthread_mutex_lock.c
+++ b/nptl/pthread_mutex_lock.c
@@ -24,7 +24,7 @@
#include <not-cancel.h>
#include "pthreadP.h"
#include <atomic.h>
-#include <lowlevellock.h>
+#include <futex-internal.h>
#include <stap-probe.h>
#ifndef lll_lock_elision
@@ -416,21 +416,16 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
int private = (robust
? PTHREAD_ROBUST_MUTEX_PSHARED (mutex)
: PTHREAD_MUTEX_PSHARED (mutex));
- INTERNAL_SYSCALL_DECL (__err);
- int e = INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
- __lll_private_flag (FUTEX_LOCK_PI,
- private), 1, 0);
-
- if (INTERNAL_SYSCALL_ERROR_P (e, __err)
- && (INTERNAL_SYSCALL_ERRNO (e, __err) == ESRCH
- || INTERNAL_SYSCALL_ERRNO (e, __err) == EDEADLK))
+ int e = futex_lock_pi ((unsigned int *) &mutex->__data.__lock,
+ NULL, private);
+ if (e == ESRCH || e == EDEADLK)
{
- assert (INTERNAL_SYSCALL_ERRNO (e, __err) != EDEADLK
+ assert (e != EDEADLK
|| (kind != PTHREAD_MUTEX_ERRORCHECK_NP
&& kind != PTHREAD_MUTEX_RECURSIVE_NP));
/* ESRCH can happen only for non-robust PI mutexes where
the owner of the lock died. */
- assert (INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH || !robust);
+ assert (e != ESRCH || !robust);
/* Delay the thread indefinitely. */
while (1)
@@ -479,11 +474,8 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
/* This mutex is now not recoverable. */
mutex->__data.__count = 0;
- INTERNAL_SYSCALL_DECL (__err);
- INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
- __lll_private_flag (FUTEX_UNLOCK_PI,
- PTHREAD_ROBUST_MUTEX_PSHARED (mutex)),
- 0, 0);
+ futex_unlock_pi ((unsigned int *) &mutex->__data.__lock,
+ PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
/* To the kernel, this will be visible after the kernel has
acquired the mutex in the syscall. */
diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c
index 76b93bddc6..eb4baae93b 100644
--- a/nptl/pthread_mutex_timedlock.c
+++ b/nptl/pthread_mutex_timedlock.c
@@ -25,6 +25,7 @@
#include <atomic.h>
#include <lowlevellock.h>
#include <not-cancel.h>
+#include <futex-internal.h>
#include <stap-probe.h>
@@ -377,39 +378,29 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
int private = (robust
? PTHREAD_ROBUST_MUTEX_PSHARED (mutex)
: PTHREAD_MUTEX_PSHARED (mutex));
- INTERNAL_SYSCALL_DECL (__err);
-
- int e = INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
- __lll_private_flag (FUTEX_LOCK_PI,
- private), 1,
- abstime);
- if (INTERNAL_SYSCALL_ERROR_P (e, __err))
+ int e = futex_lock_pi ((unsigned int *) &mutex->__data.__lock,
+ abstime, private);
+ if (e == ETIMEDOUT)
+ return ETIMEDOUT;
+ else if (e == ESRCH || e == EDEADLK)
{
- if (INTERNAL_SYSCALL_ERRNO (e, __err) == ETIMEDOUT)
- return ETIMEDOUT;
-
- if (INTERNAL_SYSCALL_ERRNO (e, __err) == ESRCH
- || INTERNAL_SYSCALL_ERRNO (e, __err) == EDEADLK)
- {
- assert (INTERNAL_SYSCALL_ERRNO (e, __err) != EDEADLK
- || (kind != PTHREAD_MUTEX_ERRORCHECK_NP
- && kind != PTHREAD_MUTEX_RECURSIVE_NP));
- /* ESRCH can happen only for non-robust PI mutexes where
- the owner of the lock died. */
- assert (INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH
- || !robust);
-
- /* Delay the thread until the timeout is reached.
- Then return ETIMEDOUT. */
- do
- e = lll_timedwait (&(int){0}, 0, clockid, abstime,
- private);
- while (e != ETIMEDOUT);
- return ETIMEDOUT;
- }
-
- return INTERNAL_SYSCALL_ERRNO (e, __err);
+ assert (e != EDEADLK
+ || (kind != PTHREAD_MUTEX_ERRORCHECK_NP
+ && kind != PTHREAD_MUTEX_RECURSIVE_NP));
+ /* ESRCH can happen only for non-robust PI mutexes where
+ the owner of the lock died. */
+ assert (e != ESRCH || !robust);
+
+ /* Delay the thread until the timeout is reached. Then return
+ ETIMEDOUT. */
+ do
+ e = lll_timedwait (&(int){0}, 0, clockid, abstime,
+ private);
+ while (e != ETIMEDOUT);
+ return ETIMEDOUT;
}
+ else if (e != 0)
+ return e;
oldval = mutex->__data.__lock;
@@ -447,11 +438,8 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
/* This mutex is now not recoverable. */
mutex->__data.__count = 0;
- INTERNAL_SYSCALL_DECL (__err);
- INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
- __lll_private_flag (FUTEX_UNLOCK_PI,
- PTHREAD_ROBUST_MUTEX_PSHARED (mutex)),
- 0, 0);
+ futex_unlock_pi ((unsigned int *) &mutex->__data.__lock,
+ PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
/* To the kernel, this will be visible after the kernel has
acquired the mutex in the syscall. */
diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c
index 87e87c013a..d24bb58a8b 100644
--- a/nptl/pthread_mutex_trylock.c
+++ b/nptl/pthread_mutex_trylock.c
@@ -21,6 +21,7 @@
#include <stdlib.h>
#include "pthreadP.h"
#include <lowlevellock.h>
+#include <futex-internal.h>
#ifndef lll_trylock_elision
#define lll_trylock_elision(a,t) lll_trylock(a)
@@ -346,11 +347,8 @@ __pthread_mutex_trylock (pthread_mutex_t *mutex)
/* This mutex is now not recoverable. */
mutex->__data.__count = 0;
- INTERNAL_SYSCALL_DECL (__err);
- INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
- __lll_private_flag (FUTEX_UNLOCK_PI,
- PTHREAD_ROBUST_MUTEX_PSHARED (mutex)),
- 0, 0);
+ futex_unlock_pi ((unsigned int *) &mutex->__data.__lock,
+ PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
/* To the kernel, this will be visible after the kernel has
acquired the mutex in the syscall. */
diff --git a/nptl/pthread_mutex_unlock.c b/nptl/pthread_mutex_unlock.c
index 71038f92e4..53f8b868e4 100644
--- a/nptl/pthread_mutex_unlock.c
+++ b/nptl/pthread_mutex_unlock.c
@@ -22,6 +22,7 @@
#include "pthreadP.h"
#include <lowlevellock.h>
#include <stap-probe.h>
+#include <futex-internal.h>
#ifndef lll_unlock_elision
#define lll_unlock_elision(a,b,c) ({ lll_unlock (a,c); 0; })
@@ -277,9 +278,8 @@ __pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr)
if (((l & FUTEX_WAITERS) != 0)
|| (l != THREAD_GETMEM (THREAD_SELF, tid)))
{
- INTERNAL_SYSCALL_DECL (__err);
- INTERNAL_SYSCALL (futex, __err, 2, &mutex->__data.__lock,
- __lll_private_flag (FUTEX_UNLOCK_PI, private));
+ futex_unlock_pi ((unsigned int *) &mutex->__data.__lock,
+ private);
break;
}
}