-/* Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
#ifndef _DESCR_H
#define _DESCR_H 1
#include <stdbool.h>
#include <sys/types.h>
#include <hp-timing.h>
-#include <list.h>
+#include <list_t.h>
#include <lowlevellock.h>
#include <pthreaddef.h>
#include <dl-sysdep.h>
-#include "../nptl_db/thread_db.h"
+#include <thread_db.h>
#include <tls.h>
-#ifdef HAVE_FORCED_UNWIND
-# include <unwind.h>
-#endif
-#define __need_res_state
-#include <resolv.h>
+#include <unwind.h>
+#include <bits/types/res_state.h>
+#include <kernel-features.h>
#ifndef TCB_ALIGNMENT
# define TCB_ALIGNMENT sizeof (double)
int syscall_no;
long int id[3];
volatile int cntr;
+ volatile int error; /* -1: no call yet, 0: success seen, >0: error seen. */
};
#else
struct
{
+ /* multiple_threads is enabled either when the process has spawned at
+ least one thread or when a single-threaded process cancels itself.
+ This enables additional code to introduce locking before doing some
+ compare_and_exchange operations and also enable cancellation points.
+ The concepts of multiple threads and cancellation points ideally
+ should be separate, since it is not necessary for multiple threads to
+ have been created for cancellation points to be enabled, as is the
+ case is when single-threaded process cancels itself.
+
+ Since enabling multiple_threads enables additional code in
+ cancellation points and compare_and_exchange operations, there is a
+ potential for an unneeded performance hit when it is enabled in a
+ single-threaded, self-canceling process. This is OK though, since a
+ single-threaded process will enable async cancellation only when it
+ looks to cancel itself and is hence going to end anyway. */
int multiple_threads;
+ int gscope_flag;
} header;
#endif
is private and subject to change without affecting the official ABI.
We just have it here in case it might be convenient for some
implementation-specific instrumentation hack or suchlike. */
- void *__padding[16];
+ void *__padding[24];
};
/* This descriptor's link on the `stack_used' or `__stack_user' list. */
therefore stack) used' flag. */
pid_t tid;
- /* Process ID - thread group ID in kernel speak. */
- pid_t pid;
+ /* Ununsed. */
+ pid_t pid_ununsed;
/* List of robust mutexes the thread is holding. */
-#ifdef __PTHREAD_MUTEX_HAVE_PREV
+#if __PTHREAD_MUTEX_HAVE_PREV
void *robust_prev;
struct robust_list_head robust_head;
but the pointer to the next/previous element of the list points
in the middle of the object, the __next element. Whenever
casting to __pthread_list_t we need to adjust the pointer
- first. */
+ first.
+ These operations are effectively concurrent code in that the thread
+ can get killed at any point in time and the kernel takes over. Thus,
+ the __next elements are a kind of concurrent list and we need to
+ enforce using compiler barriers that the individual operations happen
+ in such a way that the kernel always sees a consistent list. The
+ backward links (ie, the __prev elements) are not used by the kernel.
+ FIXME We should use relaxed MO atomic operations here and signal fences
+ because this kind of concurrency is similar to synchronizing with a
+ signal handler. */
# define QUEUE_PTR_ADJUST (offsetof (__pthread_list_t, __next))
# define ENQUEUE_MUTEX_BOTH(mutex, val) \
mutex->__data.__list.__next = THREAD_GETMEM (THREAD_SELF, \
robust_head.list); \
mutex->__data.__list.__prev = (void *) &THREAD_SELF->robust_head; \
+ /* Ensure that the new list entry is ready before we insert it. */ \
+ __asm ("" ::: "memory"); \
THREAD_SETMEM (THREAD_SELF, robust_head.list, \
(void *) (((uintptr_t) &mutex->__data.__list.__next) \
| val)); \
((char *) (((uintptr_t) mutex->__data.__list.__prev) & ~1ul) \
- QUEUE_PTR_ADJUST); \
prev->__next = mutex->__data.__list.__next; \
+ /* Ensure that we remove the entry from the list before we change the \
+ __next pointer of the entry, which is read by the kernel. */ \
+ __asm ("" ::: "memory"); \
mutex->__data.__list.__prev = NULL; \
mutex->__data.__list.__next = NULL; \
} while (0)
do { \
mutex->__data.__list.__next \
= THREAD_GETMEM (THREAD_SELF, robust_list.__next); \
+ /* Ensure that the new list entry is ready before we insert it. */ \
+ __asm ("" ::: "memory"); \
THREAD_SETMEM (THREAD_SELF, robust_list.__next, \
- ((uintptr_t) &mutex->__data.__list) | val); \
+ (void *) (((uintptr_t) &mutex->__data.__list) | val)); \
} while (0)
# define DEQUEUE_MUTEX(mutex) \
do { \
} \
\
runp->__next = next->__next; \
+ /* Ensure that we remove the entry from the list before we change the \
+ __next pointer of the entry, which is read by the kernel. */ \
+ __asm ("" ::: "memory"); \
mutex->__data.__list.__next = NULL; \
} \
} while (0)
int cancelhandling;
/* Bit set if cancellation is disabled. */
#define CANCELSTATE_BIT 0
-#define CANCELSTATE_BITMASK 0x01
+#define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT)
/* Bit set if asynchronous cancellation mode is selected. */
#define CANCELTYPE_BIT 1
-#define CANCELTYPE_BITMASK 0x02
+#define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT)
/* Bit set if canceling has been initiated. */
#define CANCELING_BIT 2
-#define CANCELING_BITMASK 0x04
+#define CANCELING_BITMASK (0x01 << CANCELING_BIT)
/* Bit set if canceled. */
#define CANCELED_BIT 3
-#define CANCELED_BITMASK 0x08
+#define CANCELED_BITMASK (0x01 << CANCELED_BIT)
/* Bit set if thread is exiting. */
#define EXITING_BIT 4
-#define EXITING_BITMASK 0x10
+#define EXITING_BITMASK (0x01 << EXITING_BIT)
/* Bit set if thread terminated and TCB is freed. */
#define TERMINATED_BIT 5
-#define TERMINATED_BITMASK 0x20
+#define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
/* Bit set if thread is supposed to change XID. */
#define SETXID_BIT 6
-#define SETXID_BITMASK 0x40
+#define SETXID_BITMASK (0x01 << SETXID_BIT)
/* Mask for the rest. Helps the compiler to optimize. */
#define CANCEL_RESTMASK 0xffffff80
| EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK)) \
== (CANCELTYPE_BITMASK | CANCELED_BITMASK))
+ /* Flags. Including those copied from the thread attribute. */
+ int flags;
+
/* We allocate one block of references here. This should be enough
to avoid allocating any memory dynamically for most applications. */
struct pthread_key_data
int parent_cancelhandling;
/* Lock to synchronize access to the descriptor. */
- lll_lock_t lock;
+ int lock;
/* Lock for synchronizing setxid calls. */
- lll_lock_t setxid_futex;
+ unsigned int setxid_futex;
-#if HP_TIMING_AVAIL
- /* Offset of the CPU clock at start thread start time. */
- hp_timing_t cpuclock_offset;
+#if HP_TIMING_INLINE
+ hp_timing_t cpuclock_offset_ununsed;
#endif
/* If the thread waits to join another one the ID of the latter is
/* Check whether a thread is detached. */
#define IS_DETACHED(pd) ((pd)->joinid == (pd))
- /* Flags. Including those copied from the thread attribute. */
- int flags;
-
/* The result of the thread function. */
void *result;
/* Next descriptor with a pending event. */
struct pthread *nextevent;
-#ifdef HAVE_FORCED_UNWIND
/* Machine-specific unwind info. */
struct _Unwind_Exception exc;
-#endif
- /* If nonzero pointer to area allocated for the stack and its
- size. */
+ /* If nonzero, pointer to the area allocated for the stack and guard. */
void *stackblock;
+ /* Size of the stackblock area including the guard. */
size_t stackblock_size;
/* Size of the included guard area. */
size_t guardsize;
/* Resolver state. */
struct __res_state res;
+ /* Indicates whether is a C11 thread created by thrd_creat. */
+ bool c11;
+
/* This member must be last. */
char end_padding[];
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