vnc: don't mess up with iohandlers in the vnc thread

The threaded VNC servers messed up with QEMU fd handlers without
any kind of locking, and that can cause some nasty race conditions.

Using qemu_mutex_lock_iothread() won't work because vnc_dpy_cpy(),
which will wait for the current job queue to finish, can be called with
the iothread lock held.

Instead, we now store the data in a temporary buffer, and use a bottom
half to notify the main thread that new data is available.

vnc_[un]lock_ouput() is still needed to access VncState members like
abort, csock or jobs_buffer.

Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
4 files changed
tree: 109f343f1e5207c3c6a2fc4c339465f4a1e81dc6
  1. audio/
  2. block/
  3. bsd-user/
  4. darwin-user/
  5. default-configs/
  6. docs/
  7. fpu/
  8. fsdev/
  9. gdb-xml/
  10. hw/
  11. include/
  12. libcacard/
  13. linux-headers/
  14. linux-user/
  15. net/
  16. pc-bios/
  17. qapi/
  18. qga/
  19. QMP/
  20. qom/
  21. roms/
  22. scripts/
  23. slirp/
  24. sysconfigs/
  25. target-alpha/
  26. target-arm/
  27. target-cris/
  28. target-i386/
  29. target-lm32/
  30. target-m68k/
  31. target-microblaze/
  32. target-mips/
  33. target-ppc/
  34. target-s390x/
  35. target-sh4/
  36. target-sparc/
  37. target-unicore32/
  38. target-xtensa/
  39. tcg/
  40. tests/
  41. trace/
  42. ui/
  43. .gitignore
  44. .gitmodules
  45. .mailmap
  46. a.out.h
  47. acl.c
  48. acl.h
  49. aes.c
  50. aes.h
  51. aio.c
  52. alpha-dis.c
  53. alpha.ld
  54. arch_init.c
  55. arch_init.h
  56. arm-dis.c
  57. arm-semi.c
  58. arm.ld
  59. async.c
  60. balloon.c
  61. balloon.h
  62. bitmap.c
  63. bitmap.h
  64. bitops.c
  65. bitops.h
  66. block-migration.c
  67. block-migration.h
  68. block.c
  69. block.h
  70. block_int.h
  71. blockdev.c
  72. blockdev.h
  73. bswap.h
  74. bt-host.c
  75. bt-host.h
  76. bt-vhci.c
  77. buffered_file.c
  78. buffered_file.h
  79. cache-utils.c
  80. cache-utils.h
  81. Changelog
  82. check-qdict.c
  83. check-qfloat.c
  84. check-qint.c
  85. check-qjson.c
  86. check-qlist.c
  87. check-qstring.c
  88. cmd.c
  89. cmd.h
  90. CODING_STYLE
  91. compatfd.c
  92. compatfd.h
  93. compiler.h
  94. config.h
  95. configure
  96. console.c
  97. console.h
  98. COPYING
  99. COPYING.LIB
  100. coroutine-gthread.c
  101. coroutine-sigaltstack.c
  102. coroutine-ucontext.c
  103. coroutine-win32.c
  104. cpu-all.h
  105. cpu-common.h
  106. cpu-defs.h
  107. cpu-exec.c
  108. cpus.c
  109. cpus.h
  110. cris-dis.c
  111. cursor.c
  112. cursor_hidden.xpm
  113. cursor_left_ptr.xpm
  114. cutils.c
  115. def-helper.h
  116. device_tree.c
  117. device_tree.h
  118. dis-asm.h
  119. disas.c
  120. disas.h
  121. dma-helpers.c
  122. dma.h
  123. dyngen-exec.h
  124. elf.h
  125. envlist.c
  126. envlist.h
  127. error.c
  128. error.h
  129. error_int.h
  130. event_notifier.c
  131. event_notifier.h
  132. exec-all.h
  133. exec-memory.h
  134. exec-obsolete.h
  135. exec.c
  136. gdbstub.c
  137. gdbstub.h
  138. gen-icount.h
  139. HACKING
  140. hmp-commands.hx
  141. hmp.c
  142. hmp.h
  143. host-utils.c
  144. host-utils.h
  145. hppa-dis.c
  146. hppa.ld
  147. i386-dis.c
  148. i386.ld
  149. ia64-dis.c
  150. ia64.ld
  151. input.c
  152. int128.h
  153. iohandler.c
  154. ioport-user.c
  155. ioport.c
  156. ioport.h
  157. iorange.h
  158. iov.c
  159. iov.h
  160. json-lexer.c
  161. json-lexer.h
  162. json-parser.c
  163. json-parser.h
  164. json-streamer.c
  165. json-streamer.h
  166. kvm-all.c
  167. kvm-stub.c
  168. kvm.h
  169. libfdt_env.h
  170. LICENSE
  171. linux-aio.c
  172. m68k-dis.c
  173. m68k-semi.c
  174. m68k.ld
  175. main-loop.c
  176. main-loop.h
  177. MAINTAINERS
  178. Makefile
  179. Makefile.dis
  180. Makefile.hw
  181. Makefile.objs
  182. Makefile.target
  183. Makefile.user
  184. memory.c
  185. memory.h
  186. microblaze-dis.c
  187. migration-exec.c
  188. migration-fd.c
  189. migration-tcp.c
  190. migration-unix.c
  191. migration.c
  192. migration.h
  193. mips-dis.c
  194. mips.ld
  195. module.c
  196. module.h
  197. monitor.c
  198. monitor.h
  199. nbd.c
  200. nbd.h
  201. net.c
  202. net.h
  203. notify.c
  204. notify.h
  205. os-posix.c
  206. os-win32.c
  207. osdep.c
  208. osdep.h
  209. oslib-posix.c
  210. oslib-win32.c
  211. path.c
  212. pci-ids.txt
  213. pflib.c
  214. pflib.h
  215. poison.h
  216. posix-aio-compat.c
  217. ppc-dis.c
  218. ppc.ld
  219. ppc64.ld
  220. qapi-schema-guest.json
  221. qapi-schema-test.json
  222. qapi-schema.json
  223. qbool.c
  224. qbool.h
  225. qdict-test-data.txt
  226. qdict.c
  227. qdict.h
  228. qemu-aio.h
  229. qemu-barrier.h
  230. qemu-bridge-helper.c
  231. qemu-char.c
  232. qemu-char.h
  233. qemu-common.h
  234. qemu-config.c
  235. qemu-config.h
  236. qemu-coroutine-int.h
  237. qemu-coroutine-io.c
  238. qemu-coroutine-lock.c
  239. qemu-coroutine-sleep.c
  240. qemu-coroutine.c
  241. qemu-coroutine.h
  242. qemu-doc.texi
  243. qemu-error.c
  244. qemu-error.h
  245. qemu-file.h
  246. qemu-ga.c
  247. qemu-img-cmds.hx
  248. qemu-img.c
  249. qemu-img.texi
  250. qemu-io.c
  251. qemu-lock.h
  252. qemu-log.h
  253. qemu-nbd.c
  254. qemu-nbd.texi
  255. qemu-objects.h
  256. qemu-option.c
  257. qemu-option.h
  258. qemu-options-wrapper.h
  259. qemu-options.h
  260. qemu-options.hx
  261. qemu-os-posix.h
  262. qemu-os-win32.h
  263. qemu-progress.c
  264. qemu-queue.h
  265. qemu-sockets.c
  266. qemu-tech.texi
  267. qemu-thread-posix.c
  268. qemu-thread-posix.h
  269. qemu-thread-win32.c
  270. qemu-thread-win32.h
  271. qemu-thread.h
  272. qemu-timer-common.c
  273. qemu-timer.c
  274. qemu-timer.h
  275. qemu-tls.h
  276. qemu-tool.c
  277. qemu-user.c
  278. qemu-x509.h
  279. qemu-xattr.h
  280. qemu.sasl
  281. qemu_socket.h
  282. qerror.c
  283. qerror.h
  284. qfloat.c
  285. qfloat.h
  286. qint.c
  287. qint.h
  288. qjson.c
  289. qjson.h
  290. qlist.c
  291. qlist.h
  292. qmp-commands.hx
  293. qmp.c
  294. qobject.h
  295. qstring.c
  296. qstring.h
  297. range.h
  298. readline.c
  299. readline.h
  300. README
  301. rules.mak
  302. s390-dis.c
  303. s390.ld
  304. savevm.c
  305. sh4-dis.c
  306. softmmu-semi.h
  307. softmmu_defs.h
  308. softmmu_exec.h
  309. softmmu_header.h
  310. softmmu_template.h
  311. sparc-dis.c
  312. sparc.ld
  313. sparc64.ld
  314. spice-qemu-char.c
  315. sysemu.h
  316. targphys.h
  317. tcg-runtime.c
  318. tci-dis.c
  319. tci.c
  320. test-coroutine.c
  321. test-qmp-commands.c
  322. test-qmp-input-visitor.c
  323. test-qmp-output-visitor.c
  324. test-string-input-visitor.c
  325. test-string-output-visitor.c
  326. thunk.c
  327. thunk.h
  328. TODO
  329. trace-events
  330. translate-all.c
  331. uboot_image.h
  332. user-exec.c
  333. VERSION
  334. version.rc
  335. vgafont.h
  336. vl.c
  337. vmstate.h
  338. x86_64.ld
  339. xen-all.c
  340. xen-mapcache.c
  341. xen-mapcache.h
  342. xen-stub.c
  343. xtensa-semi.c