Peter Maydell | 754fd93 | 2011-10-28 10:52:40 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Abstraction layer for defining and using TLS variables |
| 3 | * |
| 4 | * Copyright (c) 2011 Red Hat, Inc |
| 5 | * Copyright (c) 2011 Linaro Limited |
| 6 | * |
| 7 | * Authors: |
| 8 | * Paolo Bonzini <pbonzini@redhat.com> |
| 9 | * Peter Maydell <peter.maydell@linaro.org> |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or |
| 12 | * modify it under the terms of the GNU General Public License as |
| 13 | * published by the Free Software Foundation; either version 2 of |
| 14 | * the License, or (at your option) any later version. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | * GNU General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License along |
| 22 | * with this program; if not, see <http://www.gnu.org/licenses/>. |
| 23 | */ |
| 24 | |
| 25 | #ifndef QEMU_TLS_H |
| 26 | #define QEMU_TLS_H |
| 27 | |
| 28 | /* Per-thread variables. Note that we only have implementations |
| 29 | * which are really thread-local on Linux; the dummy implementations |
| 30 | * define plain global variables. |
| 31 | * |
| 32 | * This means that for the moment use should be restricted to |
| 33 | * per-VCPU variables, which are OK because: |
| 34 | * - the only -user mode supporting multiple VCPU threads is linux-user |
| 35 | * - TCG system mode is single-threaded regarding VCPUs |
| 36 | * - KVM system mode is multi-threaded but limited to Linux |
| 37 | * |
| 38 | * TODO: proper implementations via Win32 .tls sections and |
| 39 | * POSIX pthread_getspecific. |
| 40 | */ |
| 41 | #ifdef __linux__ |
| 42 | #define DECLARE_TLS(type, x) extern DEFINE_TLS(type, x) |
| 43 | #define DEFINE_TLS(type, x) __thread __typeof__(type) tls__##x |
Jan Kiszka | 4a2dd92 | 2011-12-05 15:18:54 +0100 | [diff] [blame] | 44 | #define tls_var(x) tls__##x |
Peter Maydell | 754fd93 | 2011-10-28 10:52:40 +0100 | [diff] [blame] | 45 | #else |
| 46 | /* Dummy implementations which define plain global variables */ |
| 47 | #define DECLARE_TLS(type, x) extern DEFINE_TLS(type, x) |
| 48 | #define DEFINE_TLS(type, x) __typeof__(type) tls__##x |
Jan Kiszka | 4a2dd92 | 2011-12-05 15:18:54 +0100 | [diff] [blame] | 49 | #define tls_var(x) tls__##x |
Peter Maydell | 754fd93 | 2011-10-28 10:52:40 +0100 | [diff] [blame] | 50 | #endif |
| 51 | |
| 52 | #endif |