From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52495) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aPBaV-0005VB-DR for qemu-devel@nongnu.org; Fri, 29 Jan 2016 11:08:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aPBaQ-0007kP-Qb for qemu-devel@nongnu.org; Fri, 29 Jan 2016 11:07:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58579) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aPBaQ-0007kJ-GB for qemu-devel@nongnu.org; Fri, 29 Jan 2016 11:07:50 -0500 From: Stefan Hajnoczi Date: Fri, 29 Jan 2016 16:07:48 +0000 Message-Id: <1454083668-23520-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PATCH] coroutine: drop GThread coroutine backend List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Peter Maydell , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Stefan Hajnoczi The GThread coroutine backend was a portable coroutine implementation. Over the years all platforms got their own optimized coroutine implementations and nothing uses the GThread backend anymore. In fact, ./configure mentions the GThread backend doesn't work but might be useful for debugging. Since GDB macros were added to ease debugging of ucontext coroutines, there seems little point in keeping a broken backend around. Signed-off-by: Stefan Hajnoczi --- configure | 19 ++--- util/coroutine-gthread.c | 198 ----------------------------------------------- 2 files changed, 5 insertions(+), 212 deletions(-) delete mode 100644 util/coroutine-gthread.c diff --git a/configure b/configure index 3506e44..789fd7d 100755 --- a/configure +++ b/configure @@ -1322,7 +1322,7 @@ Advanced options (experts only): --oss-lib path to OSS library --cpu=CPU Build for host CPU [$cpu] --with-coroutine=BACKEND coroutine backend. Supported options: - gthread, ucontext, sigaltstack, windows + ucontext, sigaltstack, windows --enable-gcov enable test coverage analysis with gcov --gcov=GCOV use specified gcov [$gcov_tool] --disable-blobs disable installing provided firmware blobs @@ -4314,10 +4314,8 @@ fi # check and set a backend for coroutine # We prefer ucontext, but it's not always possible. The fallback -# is sigcontext. gthread is not selectable except explicitly, because -# it is not functional enough to run QEMU proper. (It is occasionally -# useful for debugging purposes.) On Windows the only valid backend -# is the Windows-specific one. +# is sigcontext. On Windows the only valid backend is the Windows-specific +# one. ucontext_works=no if test "$darwin" != "yes"; then @@ -4356,7 +4354,7 @@ else feature_not_found "ucontext" fi ;; - gthread|sigaltstack) + sigaltstack) if test "$mingw32" = "yes"; then error_exit "only the 'windows' coroutine backend is valid for Windows" fi @@ -4368,14 +4366,7 @@ else fi if test "$coroutine_pool" = ""; then - if test "$coroutine" = "gthread"; then - coroutine_pool=no - else - coroutine_pool=yes - fi -fi -if test "$coroutine" = "gthread" -a "$coroutine_pool" = "yes"; then - error_exit "'gthread' coroutine backend does not support pool (use --disable-coroutine-pool)" + coroutine_pool=yes fi ########################################## diff --git a/util/coroutine-gthread.c b/util/coroutine-gthread.c deleted file mode 100644 index 0bcd778..0000000 --- a/util/coroutine-gthread.c +++ /dev/null @@ -1,198 +0,0 @@ -/* - * GThread coroutine initialization code - * - * Copyright (C) 2006 Anthony Liguori - * Copyright (C) 2011 Aneesh Kumar K.V - * - * This 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 2.0 of the License, or (at your option) any later version. - * - * This 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 this library; if not, see . - */ - -#include -#include "qemu-common.h" -#include "qemu/coroutine_int.h" - -typedef struct { - Coroutine base; - GThread *thread; - bool runnable; - bool free_on_thread_exit; - CoroutineAction action; -} CoroutineGThread; - -static CompatGMutex coroutine_lock; -static CompatGCond coroutine_cond; - -/* GLib 2.31 and beyond deprecated various parts of the thread API, - * but the new interfaces are not available in older GLib versions - * so we have to cope with both. - */ -#if GLIB_CHECK_VERSION(2, 31, 0) -/* Awkwardly, the GPrivate API doesn't provide a way to update the - * GDestroyNotify handler for the coroutine key dynamically. So instead - * we track whether or not the CoroutineGThread should be freed on - * thread exit / coroutine key update using the free_on_thread_exit - * field. - */ -static void coroutine_destroy_notify(gpointer data) -{ - CoroutineGThread *co = data; - if (co && co->free_on_thread_exit) { - g_free(co); - } -} - -static GPrivate coroutine_key = G_PRIVATE_INIT(coroutine_destroy_notify); - -static inline CoroutineGThread *get_coroutine_key(void) -{ - return g_private_get(&coroutine_key); -} - -static inline void set_coroutine_key(CoroutineGThread *co, - bool free_on_thread_exit) -{ - /* Unlike g_static_private_set() this does not call the GDestroyNotify - * if the previous value of the key was NULL. Fortunately we only need - * the GDestroyNotify in the non-NULL key case. - */ - co->free_on_thread_exit = free_on_thread_exit; - g_private_replace(&coroutine_key, co); -} - -static inline GThread *create_thread(GThreadFunc func, gpointer data) -{ - return g_thread_new("coroutine", func, data); -} - -#else - -/* Handle older GLib versions */ - -static GStaticPrivate coroutine_key = G_STATIC_PRIVATE_INIT; - -static inline CoroutineGThread *get_coroutine_key(void) -{ - return g_static_private_get(&coroutine_key); -} - -static inline void set_coroutine_key(CoroutineGThread *co, - bool free_on_thread_exit) -{ - g_static_private_set(&coroutine_key, co, - free_on_thread_exit ? (GDestroyNotify)g_free : NULL); -} - -static inline GThread *create_thread(GThreadFunc func, gpointer data) -{ - return g_thread_create_full(func, data, 0, TRUE, TRUE, - G_THREAD_PRIORITY_NORMAL, NULL); -} - -#endif - - -static void __attribute__((constructor)) coroutine_init(void) -{ -#if !GLIB_CHECK_VERSION(2, 31, 0) - if (!g_thread_supported()) { - g_thread_init(NULL); - } -#endif -} - -static void coroutine_wait_runnable_locked(CoroutineGThread *co) -{ - while (!co->runnable) { - g_cond_wait(&coroutine_cond, &coroutine_lock); - } -} - -static void coroutine_wait_runnable(CoroutineGThread *co) -{ - g_mutex_lock(&coroutine_lock); - coroutine_wait_runnable_locked(co); - g_mutex_unlock(&coroutine_lock); -} - -static gpointer coroutine_thread(gpointer opaque) -{ - CoroutineGThread *co = opaque; - - set_coroutine_key(co, false); - coroutine_wait_runnable(co); - co->base.entry(co->base.entry_arg); - qemu_coroutine_switch(&co->base, co->base.caller, COROUTINE_TERMINATE); - return NULL; -} - -Coroutine *qemu_coroutine_new(void) -{ - CoroutineGThread *co; - - co = g_malloc0(sizeof(*co)); - co->thread = create_thread(coroutine_thread, co); - if (!co->thread) { - g_free(co); - return NULL; - } - return &co->base; -} - -void qemu_coroutine_delete(Coroutine *co_) -{ - CoroutineGThread *co = DO_UPCAST(CoroutineGThread, base, co_); - - g_thread_join(co->thread); - g_free(co); -} - -CoroutineAction qemu_coroutine_switch(Coroutine *from_, - Coroutine *to_, - CoroutineAction action) -{ - CoroutineGThread *from = DO_UPCAST(CoroutineGThread, base, from_); - CoroutineGThread *to = DO_UPCAST(CoroutineGThread, base, to_); - - g_mutex_lock(&coroutine_lock); - from->runnable = false; - from->action = action; - to->runnable = true; - to->action = action; - g_cond_broadcast(&coroutine_cond); - - if (action != COROUTINE_TERMINATE) { - coroutine_wait_runnable_locked(from); - } - g_mutex_unlock(&coroutine_lock); - return from->action; -} - -Coroutine *qemu_coroutine_self(void) -{ - CoroutineGThread *co = get_coroutine_key(); - if (!co) { - co = g_malloc0(sizeof(*co)); - co->runnable = true; - set_coroutine_key(co, true); - } - - return &co->base; -} - -bool qemu_in_coroutine(void) -{ - CoroutineGThread *co = get_coroutine_key(); - - return co && co->base.caller; -} -- 2.5.0