/* * Abstraction layer for defining and using TLS variables * * Copyright (c) 2011 Red Hat, Inc * Copyright (c) 2011 Linaro Limited * * Authors: * Paolo Bonzini <pbonzini@redhat.com> * Peter Maydell <peter.maydell@linaro.org> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, see <http://www.gnu.org/licenses/>. */ #ifndef QEMU_TLS_H #define QEMU_TLS_H /* Per-thread variables. Note that we only have implementations * which are really thread-local on Linux; the dummy implementations * define plain global variables. * * This means that for the moment use should be restricted to * per-VCPU variables, which are OK because: * - the only -user mode supporting multiple VCPU threads is linux-user * - TCG system mode is single-threaded regarding VCPUs * - KVM system mode is multi-threaded but limited to Linux * * TODO: proper implementations via Win32 .tls sections and * POSIX pthread_getspecific. */ #ifdef __linux__ #define DECLARE_TLS(type, x) extern DEFINE_TLS(type, x) #define DEFINE_TLS(type, x) __thread __typeof__(type) tls__##x #define tls_var(x) tls__##x #else /* Dummy implementations which define plain global variables */ #define DECLARE_TLS(type, x) extern DEFINE_TLS(type, x) #define DEFINE_TLS(type, x) __typeof__(type) tls__##x #define tls_var(x) tls__##x #endif #endif