lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-07-28 00:21:52 +03:00
Code Activity

Add and use new glibc-internal futex API.

Browse Source 
This adds new functions for futex operations, starting with wait,
abstimed_wait, reltimed_wait, wake.  They add documentation and error
checking according to the current draft of the Linux kernel futex manpage.

Waiting with absolute or relative timeouts is split into separate functions.
This allows for removing a few cases of code duplication in pthreads code,
which uses absolute timeouts; also, it allows us to put platform-specific
code to go from an absolute to a relative timeout into the platform-specific
futex abstractions..

Futex operations that can be canceled are also split out into separate
functions suffixed by "_cancelable".

There are separate versions for both Linux and NaCl; while they currently
differ only slightly, my expectation is that the separate versions of
lowlevellock-futex.h will eventually be merged into futex-internal.h
when we get to move the lll_ functions over to the new futex API.
This commit is contained in:
Torvald Riegel
2014-12-04 14:12:23 +01:00
parent 203c1a898d
commit a2f0363f81
40 changed files with 963 additions and 492 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
nptl/allocatestack.c
View File

@ -29,6 +29,7 @@
#include <tls.h>
#include <list.h>
#include <lowlevellock.h>
#include <futex-internal.h>
#include <kernel-features.h>
#include <stack-aliasing.h>
@ -987,7 +988,7 @@ setxid_mark_thread (struct xid_command *cmdp, struct pthread *t)
if (t->setxid_futex == -1
&& ! atomic_compare_and_exchange_bool_acq (&t->setxid_futex, -2, -1))
do
lll_futex_wait (&t->setxid_futex, -2, LLL_PRIVATE);
futex_wait_simple (&t->setxid_futex, -2, FUTEX_PRIVATE);
while (t->setxid_futex == -2);
/* Don't let the thread exit before the setxid handler runs. */
@ -1005,7 +1006,7 @@ setxid_mark_thread (struct xid_command *cmdp, struct pthread *t)
if ((ch & SETXID_BITMASK) == 0)
{
t->setxid_futex = 1;
lll_futex_wake (&t->setxid_futex, 1, LLL_PRIVATE);
futex_wake (&t->setxid_futex, 1, FUTEX_PRIVATE);
}
return;
}
@ -1032,7 +1033,7 @@ setxid_unmark_thread (struct xid_command *cmdp, struct pthread *t)
/* Release the futex just in case. */
t->setxid_futex = 1;
lll_futex_wake (&t->setxid_futex, 1, LLL_PRIVATE);
futex_wake (&t->setxid_futex, 1, FUTEX_PRIVATE);
}
@ -1141,7 +1142,8 @@ __nptl_setxid (struct xid_command *cmdp)
int cur = cmdp->cntr;
while (cur != 0)
{
lll_futex_wait (&cmdp->cntr, cur, LLL_PRIVATE);
futex_wait_simple ((unsigned int *) &cmdp->cntr, cur,
FUTEX_PRIVATE);
cur = cmdp->cntr;
}
}
@ -1251,7 +1253,8 @@ __wait_lookup_done (void)
continue;
do
lll_futex_wait (gscope_flagp, THREAD_GSCOPE_FLAG_WAIT, LLL_PRIVATE);
futex_wait_simple ((unsigned int *) gscope_flagp,
THREAD_GSCOPE_FLAG_WAIT, FUTEX_PRIVATE);
while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT);
}
@ -1273,7 +1276,8 @@ __wait_lookup_done (void)
continue;
do
lll_futex_wait (gscope_flagp, THREAD_GSCOPE_FLAG_WAIT, LLL_PRIVATE);
futex_wait_simple ((unsigned int *) gscope_flagp,
THREAD_GSCOPE_FLAG_WAIT, FUTEX_PRIVATE);
while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT);
}