Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 1 | /* |
| 2 | * GThread coroutine initialization code |
| 3 | * |
| 4 | * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws> |
| 5 | * Copyright (C) 2011 Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| 6 | * |
| 7 | * This library is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.0 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * This library is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| 19 | */ |
| 20 | |
| 21 | #include <glib.h> |
| 22 | #include "qemu-common.h" |
Paolo Bonzini | 737e150 | 2012-12-17 18:19:44 +0100 | [diff] [blame] | 23 | #include "block/coroutine_int.h" |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 24 | |
| 25 | typedef struct { |
| 26 | Coroutine base; |
| 27 | GThread *thread; |
| 28 | bool runnable; |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 29 | bool free_on_thread_exit; |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 30 | CoroutineAction action; |
| 31 | } CoroutineGThread; |
| 32 | |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 33 | static GStaticMutex coroutine_lock = G_STATIC_MUTEX_INIT; |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 34 | |
| 35 | /* GLib 2.31 and beyond deprecated various parts of the thread API, |
| 36 | * but the new interfaces are not available in older GLib versions |
| 37 | * so we have to cope with both. |
| 38 | */ |
| 39 | #if GLIB_CHECK_VERSION(2, 31, 0) |
| 40 | /* Default zero-initialisation is sufficient for 2.31+ GCond */ |
| 41 | static GCond the_coroutine_cond; |
| 42 | static GCond *coroutine_cond = &the_coroutine_cond; |
| 43 | static inline void init_coroutine_cond(void) |
| 44 | { |
| 45 | } |
| 46 | |
| 47 | /* Awkwardly, the GPrivate API doesn't provide a way to update the |
| 48 | * GDestroyNotify handler for the coroutine key dynamically. So instead |
| 49 | * we track whether or not the CoroutineGThread should be freed on |
| 50 | * thread exit / coroutine key update using the free_on_thread_exit |
| 51 | * field. |
| 52 | */ |
| 53 | static void coroutine_destroy_notify(gpointer data) |
| 54 | { |
| 55 | CoroutineGThread *co = data; |
| 56 | if (co && co->free_on_thread_exit) { |
| 57 | g_free(co); |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | static GPrivate coroutine_key = G_PRIVATE_INIT(coroutine_destroy_notify); |
| 62 | |
| 63 | static inline CoroutineGThread *get_coroutine_key(void) |
| 64 | { |
| 65 | return g_private_get(&coroutine_key); |
| 66 | } |
| 67 | |
| 68 | static inline void set_coroutine_key(CoroutineGThread *co, |
| 69 | bool free_on_thread_exit) |
| 70 | { |
| 71 | /* Unlike g_static_private_set() this does not call the GDestroyNotify |
| 72 | * if the previous value of the key was NULL. Fortunately we only need |
| 73 | * the GDestroyNotify in the non-NULL key case. |
| 74 | */ |
| 75 | co->free_on_thread_exit = free_on_thread_exit; |
| 76 | g_private_replace(&coroutine_key, co); |
| 77 | } |
| 78 | |
| 79 | static inline GThread *create_thread(GThreadFunc func, gpointer data) |
| 80 | { |
| 81 | return g_thread_new("coroutine", func, data); |
| 82 | } |
| 83 | |
| 84 | #else |
| 85 | |
| 86 | /* Handle older GLib versions */ |
| 87 | static GCond *coroutine_cond; |
| 88 | static inline void init_coroutine_cond(void) |
| 89 | { |
| 90 | coroutine_cond = g_cond_new(); |
| 91 | } |
| 92 | |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 93 | static GStaticPrivate coroutine_key = G_STATIC_PRIVATE_INIT; |
| 94 | |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 95 | static inline CoroutineGThread *get_coroutine_key(void) |
| 96 | { |
| 97 | return g_static_private_get(&coroutine_key); |
| 98 | } |
| 99 | |
| 100 | static inline void set_coroutine_key(CoroutineGThread *co, |
| 101 | bool free_on_thread_exit) |
| 102 | { |
| 103 | g_static_private_set(&coroutine_key, co, |
| 104 | free_on_thread_exit ? (GDestroyNotify)g_free : NULL); |
| 105 | } |
| 106 | |
| 107 | static inline GThread *create_thread(GThreadFunc func, gpointer data) |
| 108 | { |
| 109 | return g_thread_create_full(func, data, 0, TRUE, TRUE, |
| 110 | G_THREAD_PRIORITY_NORMAL, NULL); |
| 111 | } |
| 112 | |
| 113 | #endif |
| 114 | |
| 115 | |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 116 | static void __attribute__((constructor)) coroutine_init(void) |
| 117 | { |
| 118 | if (!g_thread_supported()) { |
Alon Levy | 42ed372 | 2011-12-20 13:41:04 +0200 | [diff] [blame] | 119 | #if !GLIB_CHECK_VERSION(2, 31, 0) |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 120 | g_thread_init(NULL); |
Alon Levy | 42ed372 | 2011-12-20 13:41:04 +0200 | [diff] [blame] | 121 | #else |
| 122 | fprintf(stderr, "glib threading failed to initialize.\n"); |
| 123 | exit(1); |
| 124 | #endif |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 125 | } |
| 126 | |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 127 | init_coroutine_cond(); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 128 | } |
| 129 | |
| 130 | static void coroutine_wait_runnable_locked(CoroutineGThread *co) |
| 131 | { |
| 132 | while (!co->runnable) { |
| 133 | g_cond_wait(coroutine_cond, g_static_mutex_get_mutex(&coroutine_lock)); |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | static void coroutine_wait_runnable(CoroutineGThread *co) |
| 138 | { |
| 139 | g_static_mutex_lock(&coroutine_lock); |
| 140 | coroutine_wait_runnable_locked(co); |
| 141 | g_static_mutex_unlock(&coroutine_lock); |
| 142 | } |
| 143 | |
| 144 | static gpointer coroutine_thread(gpointer opaque) |
| 145 | { |
| 146 | CoroutineGThread *co = opaque; |
| 147 | |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 148 | set_coroutine_key(co, false); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 149 | coroutine_wait_runnable(co); |
| 150 | co->base.entry(co->base.entry_arg); |
| 151 | qemu_coroutine_switch(&co->base, co->base.caller, COROUTINE_TERMINATE); |
| 152 | return NULL; |
| 153 | } |
| 154 | |
| 155 | Coroutine *qemu_coroutine_new(void) |
| 156 | { |
| 157 | CoroutineGThread *co; |
| 158 | |
Anthony Liguori | 7267c09 | 2011-08-20 22:09:37 -0500 | [diff] [blame] | 159 | co = g_malloc0(sizeof(*co)); |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 160 | co->thread = create_thread(coroutine_thread, co); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 161 | if (!co->thread) { |
Anthony Liguori | 7267c09 | 2011-08-20 22:09:37 -0500 | [diff] [blame] | 162 | g_free(co); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 163 | return NULL; |
| 164 | } |
| 165 | return &co->base; |
| 166 | } |
| 167 | |
| 168 | void qemu_coroutine_delete(Coroutine *co_) |
| 169 | { |
| 170 | CoroutineGThread *co = DO_UPCAST(CoroutineGThread, base, co_); |
| 171 | |
| 172 | g_thread_join(co->thread); |
Anthony Liguori | 7267c09 | 2011-08-20 22:09:37 -0500 | [diff] [blame] | 173 | g_free(co); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 174 | } |
| 175 | |
| 176 | CoroutineAction qemu_coroutine_switch(Coroutine *from_, |
| 177 | Coroutine *to_, |
| 178 | CoroutineAction action) |
| 179 | { |
| 180 | CoroutineGThread *from = DO_UPCAST(CoroutineGThread, base, from_); |
| 181 | CoroutineGThread *to = DO_UPCAST(CoroutineGThread, base, to_); |
| 182 | |
| 183 | g_static_mutex_lock(&coroutine_lock); |
| 184 | from->runnable = false; |
| 185 | from->action = action; |
| 186 | to->runnable = true; |
| 187 | to->action = action; |
| 188 | g_cond_broadcast(coroutine_cond); |
| 189 | |
| 190 | if (action != COROUTINE_TERMINATE) { |
| 191 | coroutine_wait_runnable_locked(from); |
| 192 | } |
| 193 | g_static_mutex_unlock(&coroutine_lock); |
| 194 | return from->action; |
| 195 | } |
| 196 | |
| 197 | Coroutine *qemu_coroutine_self(void) |
| 198 | { |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 199 | CoroutineGThread *co = get_coroutine_key(); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 200 | if (!co) { |
Anthony Liguori | 7267c09 | 2011-08-20 22:09:37 -0500 | [diff] [blame] | 201 | co = g_malloc0(sizeof(*co)); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 202 | co->runnable = true; |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 203 | set_coroutine_key(co, true); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 204 | } |
| 205 | |
| 206 | return &co->base; |
| 207 | } |
| 208 | |
| 209 | bool qemu_in_coroutine(void) |
| 210 | { |
Peter Maydell | d1b719e | 2012-03-03 04:52:56 +0000 | [diff] [blame] | 211 | CoroutineGThread *co = get_coroutine_key(); |
Aneesh Kumar K.V | d0e2fce | 2011-06-09 23:11:06 +0530 | [diff] [blame] | 212 | |
| 213 | return co && co->base.caller; |
| 214 | } |