[PATCH 3/6] winealsa: Use a pipe to signal the end of the record thread.

[Huw Davies]

This means the thread doesn't have to wake every 250ms to test
"end_thread".

Signed-off-by: Huw Davies 
---
 dlls/winealsa.drv/midi.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/dlls/winealsa.drv/midi.c b/dlls/winealsa.drv/midi.c
index 4cc906b03ca..327d4b7b200 100644
--- a/dlls/winealsa.drv/midi.c
+++ b/dlls/winealsa.drv/midi.c
@@ -54,7 +54,7 @@ static	int 		MIDM_NumDevs = 0;

static	int		numStartedMidiIn = 0;

-static int end_thread;
+static int rec_cancel_pipe[2];
 static HANDLE hThread;

static void seq_lock(void)
@@ -162,18 +162,25 @@ static DWORD WINAPI midRecThread(void *arg)
     struct pollfd *pollfd;
     int ret;

-    num_fds = snd_seq_poll_descriptors_count(midi_seq, POLLIN);
+    /* Add on one for the read end of the cancel pipe */
+    num_fds = snd_seq_poll_descriptors_count(midi_seq, POLLIN) + 1;
     pollfd = malloc(num_fds * sizeof(struct pollfd));

-    while(!end_thread) {
+    while(1) {
+        pollfd[0].fd = rec_cancel_pipe[0];
+        pollfd[0].events = POLLIN;
+
         seq_lock();
-        snd_seq_poll_descriptors(midi_seq, pollfd, num_fds, POLLIN);
+        snd_seq_poll_descriptors(midi_seq, pollfd + 1, num_fds - 1, POLLIN);
         seq_unlock();

/* Check if an event is present */
-        if (poll(pollfd, num_fds, 250) <= 0)
+        if (poll(pollfd, num_fds, -1) <= 0)
             continue;

+        if (pollfd[0].revents & POLLIN) /* cancelled */
+            break;
+
    do {
             snd_seq_event_t *ev;

@@ -259,9 +266,11 @@ static DWORD midOpen(WORD wDevID, LPMIDIOPENDESC lpDesc, DWORD dwFlags)
     TRACE("Input port :%d connected %d:%d\n",port_in,MidiInDev[wDevID].addr.client,MidiInDev[wDevID].addr.port);

if (numStartedMidiIn++ == 0) {
-	end_thread = 0;
+	pipe(rec_cancel_pipe);
    hThread = CreateThread(NULL, 0, midRecThread, midi_seq, 0, NULL);
    if (!hThread) {
+            close(rec_cancel_pipe[0]);
+            close(rec_cancel_pipe[1]);
        numStartedMidiIn = 0;
        WARN("Couldn't create thread for midi-in\n");
        midiCloseSeq();
@@ -302,11 +311,13 @@ static DWORD midClose(WORD wDevID)
     }
     if (--numStartedMidiIn == 0) {
    TRACE("Stopping thread for midi-in\n");
-	end_thread = 1;
+        write(rec_cancel_pipe[1], "x", 1);
    if (WaitForSingleObject(hThread, 5000) != WAIT_OBJECT_0) {
        WARN("Thread end not signaled, force termination\n");
        TerminateThread(hThread, 0);
    }
+        close(rec_cancel_pipe[0]);
+        close(rec_cancel_pipe[1]);
     	TRACE("Stopped thread for midi-in\n");
     }

[Andrew Eikum]

Signed-off-by: Andrew Eikum

On Fri, Mar 25, 2022 at 08:42:16AM +0000, Huw Davies wrote:
> This means the thread doesn't have to wake every 250ms to test
> "end_thread".
> Signed-off-by: Huw Davies
>
> dlls/winealsa.drv/midi.c | 25 ++++++++++++++++++-------
>  1 file changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/dlls/winealsa.drv/midi.c b/dlls/winealsa.drv/midi.c
> index 4cc906b03ca..327d4b7b200 100644
> --- a/dlls/winealsa.drv/midi.c
> +++ b/dlls/winealsa.drv/midi.c
> @@ -54,7 +54,7 @@ static	int 		MIDM_NumDevs = 0;
>
> static	int		numStartedMidiIn = 0;
>
> -static int end_thread;
> +static int rec_cancel_pipe[2];
>  static HANDLE hThread;
>
> static void seq_lock(void)
> @@ -162,18 +162,25 @@ static DWORD WINAPI midRecThread(void *arg)
>      struct pollfd *pollfd;
>      int ret;
> - num_fds = snd_seq_poll_descriptors_count(midi_seq, POLLIN);
> - /* Add on one for the read end of the cancel pipe */
> - num_fds = snd_seq_poll_descriptors_count(midi_seq, POLLIN) + 1;
> pollfd = malloc(num_fds * sizeof(struct pollfd));
> - while(!end_thread) {
> - while(1) {
> -
>    pollfd[0].fd = rec_cancel_pipe[0];
> -
>    pollfd[0].events = POLLIN;
> -
>    seq_lock();
> -
>    snd_seq_poll_descriptors(midi_seq, pollfd, num_fds, POLLIN);
> -
>    snd_seq_poll_descriptors(midi_seq, pollfd + 1, num_fds - 1, POLLIN);
>    seq_unlock();
>
> /* Check if an event is present */
> -
>    if (poll(pollfd, num_fds, 250) <= 0)
> -
>    if (poll(pollfd, num_fds, -1) <= 0)
>        continue;
>
> -
>    if (pollfd[0].revents & POLLIN) /* cancelled */
> -
>        break;
> -
>
> do {
>            snd_seq_event_t *ev;
>
> @@ -259,9 +266,11 @@ static DWORD midOpen(WORD wDevID, LPMIDIOPENDESC lpDesc, DWORD dwFlags)
>      TRACE("Input port :%d connected %d:%d\n",port_in,MidiInDev[wDevID].addr.client,MidiInDev[wDevID].addr.port);
>  if (numStartedMidiIn++ == 0) {
> - end_thread = 0;
> - pipe(rec_cancel_pipe);
> hThread = CreateThread(NULL, 0, midRecThread, midi_seq, 0, NULL);
> if (!hThread) {
> -
>        close(rec_cancel_pipe[0]);
> -
>        close(rec_cancel_pipe[1]);
>  numStartedMidiIn = 0;
>  WARN("Couldn't create thread for midi-in\n");
>  midiCloseSeq();
>
> @@ -302,11 +311,13 @@ static DWORD midClose(WORD wDevID)
>      }
>      if (--numStartedMidiIn == 0) {
>    TRACE("Stopping thread for midi-in\n");
> - end_thread = 1;
> -
>    write(rec_cancel_pipe[1], "x", 1);
> if (WaitForSingleObject(hThread, 5000) != WAIT_OBJECT_0) {
>      WARN("Thread end not signaled, force termination\n");
>      TerminateThread(hThread, 0);
>  }
> -
>    close(rec_cancel_pipe[0]);
> -
>    close(rec_cancel_pipe[1]);
> TRACE("Stopped thread for midi-in\n");
> }
>
> -- 
> 2.25.1