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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 | /* low level locking for pthread library. Generic futex-using version. Copyright (C) 2003, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library 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 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, see <http://www.gnu.org/licenses/>. */ #include <errno.h> #include <sysdep.h> #include <lowlevellock.h> #include <sys/time.h> #include <tls.h> void #ifndef IS_IN_libpthread weak_function #endif __lll_lock_wait_private (int *futex) { if (*futex == 2) lll_futex_wait (futex, 2, LLL_PRIVATE); while (atomic_exchange_acq (futex, 2) != 0) lll_futex_wait (futex, 2, LLL_PRIVATE); } /* These functions don't get included in libc.so */ #ifdef IS_IN_libpthread void __lll_lock_wait (int *futex, int private) { if (*futex == 2) lll_futex_wait (futex, 2, private); while (atomic_exchange_acq (futex, 2) != 0) lll_futex_wait (futex, 2, private); } int __lll_timedlock_wait (int *futex, const struct timespec *abstime, int private) { /* Reject invalid timeouts. */ if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) return EINVAL; /* Try locking. */ while (atomic_exchange_acq (futex, 2) != 0) { struct timeval tv; /* Get the current time. */ (void) gettimeofday (&tv, NULL); /* Compute relative timeout. */ struct timespec rt; rt.tv_sec = abstime->tv_sec - tv.tv_sec; rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000; if (rt.tv_nsec < 0) { rt.tv_nsec += 1000000000; --rt.tv_sec; } if (rt.tv_sec < 0) return ETIMEDOUT; /* Wait. */ lll_futex_timed_wait (futex, 2, &rt, private); } return 0; } int __lll_timedwait_tid (int *tidp, const struct timespec *abstime) { int tid; if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) return EINVAL; /* Repeat until thread terminated. */ while ((tid = *tidp) != 0) { struct timeval tv; struct timespec rt; /* Get the current time. */ (void) __gettimeofday (&tv, NULL); /* Compute relative timeout. */ rt.tv_sec = abstime->tv_sec - tv.tv_sec; rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000; if (rt.tv_nsec < 0) { rt.tv_nsec += 1000000000; --rt.tv_sec; } /* Already timed out? */ if (rt.tv_sec < 0) return ETIMEDOUT; /* Wait until thread terminates. The kernel so far does not use the private futex operations for this. */ if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT) return ETIMEDOUT; } return 0; } #endif |