| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Definition for thread-local data handling. Generic version. |
| 2 | Copyright (C) 2002-2015 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | /* An architecture-specific version of this file has to defined a |
| 20 | number of symbols: |
| 21 | |
| 22 | TLS_TCB_AT_TP or TLS_DTV_AT_TP |
| 23 | |
| 24 | The presence of one of these symbols signals which variant of |
| 25 | the TLS ABI is used. There are in the moment two variants |
| 26 | available: |
| 27 | |
| 28 | * the thread pointer points to a thread control block |
| 29 | |
| 30 | * the thread pointer points to the dynamic thread vector |
| 31 | |
| 32 | |
| 33 | TLS_TCB_SIZE |
| 34 | |
| 35 | This is the size of the thread control block structure. How |
| 36 | this is actually defined depends on the ABI. The thread control |
| 37 | block could be internal descriptor of the thread library or |
| 38 | just a data structure which allows finding the DTV. |
| 39 | |
| 40 | TLS_INIT_TCB_SIZE |
| 41 | |
| 42 | Similarly, but this value is only used at startup and in the |
| 43 | dynamic linker itself. There are no threads in use at that time. |
| 44 | |
| 45 | |
| 46 | TLS_TCB_ALIGN |
| 47 | |
| 48 | Alignment requirements for the TCB structure. |
| 49 | |
| 50 | TLS_INIT_TCB_ALIGN |
| 51 | |
| 52 | Similarly, but for the structure used at startup time. |
| 53 | |
| 54 | |
| 55 | INSTALL_DTV(tcb, init_dtv) |
| 56 | |
| 57 | This macro must install the given initial DTV into the thread control |
| 58 | block TCB. The normal runtime functionality must then be able to |
| 59 | use the value. |
| 60 | |
| 61 | |
| 62 | TLS_INIT_TP(tcb) |
| 63 | |
| 64 | This macro must initialize the thread pointer to enable normal TLS |
| 65 | operation. The parameter is a pointer to the thread control block. |
| 66 | ld.so calls this macro once. |
| 67 | |
| 68 | |
| 69 | THREAD_DTV() |
| 70 | |
| 71 | This macro returns the address of the DTV of the current thread. |
| 72 | This normally is done using the thread register which points |
| 73 | to the dtv or the TCB (from which the DTV can found). |
| 74 | */ |