From: Richard Mudgett Date: Tue, 12 Jun 2018 19:09:54 +0000 (-0500) Subject: channel.c: Fix usage of CHECK_BLOCKING() X-Git-Tag: 13.22.0-rc1~19^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1abcc41ffff95d5a5f4aae55055a53487c9c909c;p=thirdparty%2Fasterisk.git channel.c: Fix usage of CHECK_BLOCKING() The CHECK_BLOCKING() macro is used to indicate if a channel's handling thread is about to do a blocking operation (poll, read, or write) of media. A few operations such as ast_queue_frame(), soft hangup, and masquerades use the indication to wake up the blocked thread to reevaluate what is going on. ASTERISK-27625 Change-Id: I4dfc33e01e60627d962efa29d0a4244cf151a84d --- diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h index 0fc236af4b..8c171b6f1b 100644 --- a/include/asterisk/channel.h +++ b/include/asterisk/channel.h @@ -2649,15 +2649,30 @@ static inline enum ast_t38_state ast_channel_get_t38_state(struct ast_channel *c return state; } -#define CHECK_BLOCKING(c) do { \ - if (ast_test_flag(ast_channel_flags(c), AST_FLAG_BLOCKING)) {\ - ast_debug(1, "Thread %p is blocking '%s', already blocked by thread %p in procedure %s\n", \ - (void *) pthread_self(), ast_channel_name(c), (void *) ast_channel_blocker(c), ast_channel_blockproc(c)); \ - } else { \ +/*! + * \brief Set the blocking indication on the channel. + * + * \details + * Indicate that the thread handling the channel is about to do a blocking + * operation to wait for media on the channel. (poll, read, or write) + * + * Masquerading and ast_queue_frame() use this indication to wake up the thread. + * + * \pre The channel needs to be locked + */ +#define CHECK_BLOCKING(c) \ + do { \ + if (ast_test_flag(ast_channel_flags(c), AST_FLAG_BLOCKING)) { \ + /* This should not happen as there should only be one thread handling a channel's media at a time. */ \ + ast_log(LOG_DEBUG, "Thread %p is blocking '%s', already blocked by thread %p in procedure %s\n", \ + (void *) pthread_self(), ast_channel_name(c), \ + (void *) ast_channel_blocker(c), ast_channel_blockproc(c)); \ + ast_assert(0); \ + } \ ast_channel_blocker_set((c), pthread_self()); \ ast_channel_blockproc_set((c), __PRETTY_FUNCTION__); \ ast_set_flag(ast_channel_flags(c), AST_FLAG_BLOCKING); \ - } } while (0) + } while (0) ast_group_t ast_get_group(const char *s); diff --git a/main/channel.c b/main/channel.c index 27a959a4b9..2a72aeed21 100644 --- a/main/channel.c +++ b/main/channel.c @@ -3266,11 +3266,11 @@ static struct ast_channel *ast_waitfor_nandfds_simple(struct ast_channel *chan, } } - ast_channel_unlock(chan); - /* Time to make this channel block... */ CHECK_BLOCKING(chan); + ast_channel_unlock(chan); + if (*ms > 0) { start = ast_tvnow(); } @@ -3279,7 +3279,9 @@ static struct ast_channel *ast_waitfor_nandfds_simple(struct ast_channel *chan, res = epoll_wait(ast_channel_epfd(chan), ev, 1, rms); /* Stop blocking */ + ast_channel_lock(chan); ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); + ast_channel_unlock(chan); /* Simulate a timeout if we were interrupted */ if (res < 0) { @@ -3305,12 +3307,14 @@ static struct ast_channel *ast_waitfor_nandfds_simple(struct ast_channel *chan, /* See what events are pending */ aed = ev[0].data.ptr; + ast_channel_lock(chan); ast_channel_fdno_set(chan, aed->which); if (ev[0].events & EPOLLPRI) { ast_set_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION); } else { ast_clear_flag(ast_channel_flags(chan), AST_FLAG_EXCEPTION); } + ast_channel_unlock(chan); if (*ms > 0) { *ms -= ast_tvdiff_ms(ast_tvnow(), start); @@ -3346,8 +3350,8 @@ static struct ast_channel *ast_waitfor_nandfds_complex(struct ast_channel **c, i whentohangup = diff; } } - ast_channel_unlock(c[i]); CHECK_BLOCKING(c[i]); + ast_channel_unlock(c[i]); } rms = *ms; @@ -3365,7 +3369,9 @@ static struct ast_channel *ast_waitfor_nandfds_complex(struct ast_channel **c, i res = epoll_wait(ast_channel_epfd(c[0]), ev, 25, rms); for (i = 0; i < n; i++) { + ast_channel_lock(c[i]); ast_clear_flag(ast_channel_flags(c[i]), AST_FLAG_BLOCKING); + ast_channel_unlock(c[i]); } if (res < 0) { @@ -3400,12 +3406,14 @@ static struct ast_channel *ast_waitfor_nandfds_complex(struct ast_channel **c, i } winner = aed->chan; + ast_channel_lock(winner); if (ev[i].events & EPOLLPRI) { ast_set_flag(ast_channel_flags(winner), AST_FLAG_EXCEPTION); } else { ast_clear_flag(ast_channel_flags(winner), AST_FLAG_EXCEPTION); } ast_channel_fdno_set(winner, aed->which); + ast_channel_unlock(winner); } if (*ms > 0) { @@ -5220,11 +5228,9 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) /* There is a generator running while we're in the middle of a digit. * It's probably inband DTMF, so go ahead and pass it so it can * stop the generator */ - ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); ast_channel_unlock(chan); res = ast_senddigit_end(chan, fr->subclass.integer, fr->len); ast_channel_lock(chan); - CHECK_BLOCKING(chan); } else if (fr->frametype == AST_FRAME_CONTROL && fr->subclass.integer == AST_CONTROL_UNHOLD) { /* @@ -5242,7 +5248,6 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) /* High bit prints debugging */ if (ast_channel_fout(chan) & DEBUGCHAN_FLAG) ast_frame_dump(ast_channel_name(chan), fr, ">>"); - CHECK_BLOCKING(chan); switch (fr->frametype) { case AST_FRAME_CONTROL: indicate_data_internal(chan, fr->subclass.integer, fr->data.ptr, fr->datalen); @@ -5256,11 +5261,9 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) f = fr; } send_dtmf_begin_event(chan, DTMF_SENT, fr->subclass.integer); - ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); ast_channel_unlock(chan); res = ast_senddigit_begin(chan, fr->subclass.integer); ast_channel_lock(chan); - CHECK_BLOCKING(chan); break; case AST_FRAME_DTMF_END: if (ast_channel_audiohooks(chan)) { @@ -5272,13 +5275,12 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) } } send_dtmf_end_event(chan, DTMF_SENT, fr->subclass.integer, fr->len); - ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); ast_channel_unlock(chan); res = ast_senddigit_end(chan, fr->subclass.integer, fr->len); ast_channel_lock(chan); - CHECK_BLOCKING(chan); break; case AST_FRAME_TEXT: + CHECK_BLOCKING(chan); if (ast_format_cmp(fr->subclass.format, ast_format_t140) == AST_FORMAT_CMP_EQUAL) { res = (ast_channel_tech(chan)->write_text == NULL) ? 0 : ast_channel_tech(chan)->write_text(chan, fr); @@ -5286,19 +5288,26 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) res = (ast_channel_tech(chan)->send_text == NULL) ? 0 : ast_channel_tech(chan)->send_text(chan, (char *) fr->data.ptr); } + ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); break; case AST_FRAME_HTML: + CHECK_BLOCKING(chan); res = (ast_channel_tech(chan)->send_html == NULL) ? 0 : ast_channel_tech(chan)->send_html(chan, fr->subclass.integer, (char *) fr->data.ptr, fr->datalen); + ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); break; case AST_FRAME_VIDEO: /* XXX Handle translation of video codecs one day XXX */ + CHECK_BLOCKING(chan); res = (ast_channel_tech(chan)->write_video == NULL) ? 0 : ast_channel_tech(chan)->write_video(chan, fr); + ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); break; case AST_FRAME_MODEM: + CHECK_BLOCKING(chan); res = (ast_channel_tech(chan)->write == NULL) ? 0 : ast_channel_tech(chan)->write(chan, fr); + ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); break; case AST_FRAME_VOICE: if (ast_channel_tech(chan)->write == NULL) @@ -5459,6 +5468,7 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) /* the translator on chan->writetrans may have returned multiple frames from the single frame we passed in; if so, feed each one of them to the channel, freeing each one after it has been written */ + CHECK_BLOCKING(chan); if ((f != fr) && AST_LIST_NEXT(f, frame_list)) { struct ast_frame *cur, *next = NULL; unsigned int skip = 0; @@ -5487,6 +5497,7 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) } else { res = ast_channel_tech(chan)->write(chan, f); } + ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); break; case AST_FRAME_NULL: case AST_FRAME_IAX: @@ -5497,13 +5508,14 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr) /* At this point, fr is the incoming frame and f is NULL. Channels do * not expect to get NULL as a frame pointer and will segfault. Hence, * we output the original frame passed in. */ + CHECK_BLOCKING(chan); res = ast_channel_tech(chan)->write(chan, fr); + ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); break; } if (f && f != fr) ast_frfree(f); - ast_clear_flag(ast_channel_flags(chan), AST_FLAG_BLOCKING); /* Consider a write failure to force a soft hangup */ if (res < 0) {