From 595ab64169be9063d64c3b1aa1c249fbe2662221 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 7 Aug 2012 11:07:59 +0200 Subject: migration: handle EAGAIN while reading QEMUFile This will never happen right now (the assertion would fail). The next patch will set the socket or pipe in non-blocking mode, thus enabling this part of the code. Coroutines can just stop whenever they want with qemu_coroutine_yield. As soon as select tells the main loop that the migration stream is readable, the coroutine is re-entered directly in qemu_get_buffer, where it will read more data and pass it to the loading routines. Signed-off-by: Paolo Bonzini --- savevm.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) (limited to 'savevm.c') diff --git a/savevm.c b/savevm.c index cdad3ad8e4..5d04d59688 100644 --- a/savevm.c +++ b/savevm.c @@ -200,13 +200,22 @@ static int socket_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) QEMUFileSocket *s = opaque; ssize_t len; - do { + for (;;) { len = qemu_recv(s->fd, buf, size, 0); - } while (len == -1 && socket_error() == EINTR); + if (len != -1) { + break; + } + if (socket_error() == EAGAIN) { + assert(qemu_in_coroutine()); + qemu_coroutine_yield(); + } else if (socket_error() != EINTR) { + break; + } + } - if (len == -1) + if (len == -1) { len = -socket_error(); - + } return len; } @@ -237,10 +246,19 @@ static int stdio_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) FILE *fp = s->stdio_file; int bytes; - do { + for (;;) { clearerr(fp); bytes = fread(buf, 1, size, fp); - } while ((bytes == 0) && ferror(fp) && (errno == EINTR)); + if (bytes != 0 || !ferror(fp)) { + break; + } + if (errno == EAGAIN) { + assert(qemu_in_coroutine()); + qemu_coroutine_yield(); + } else if (errno != EINTR) { + break; + } + } return bytes; } -- cgit v1.2.1