From: Clemens Ladisch <clemens@ladisch.de>
Date: Mon, 14 Jan 2008 07:51:45 +0000 (+0100)
Subject: check availability of CLOCK_MONOTONIC
X-Git-Tag: v1.0.16rc1~9
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=0e8a2599143c71a20d043e458f2a9fa3be4efeaa;p=alsa-lib.git

check availability of CLOCK_MONOTONIC

Use monotonic timestamps only after checking that CLOCK_MONOTONIC is
actually supported by the C library.
---

diff --git a/src/pcm/pcm_file.c b/src/pcm/pcm_file.c
index 89f8b751..4b8eaa5c 100644
--- a/src/pcm/pcm_file.c
+++ b/src/pcm/pcm_file.c
@@ -412,7 +412,9 @@ int snd_pcm_file_open(snd_pcm_t **pcmp, const char *name,
 	snd_pcm_t *pcm;
 	snd_pcm_file_t *file;
 	snd_pcm_file_format_t format;
+	struct timespec timespec;
 	int err;
+
 	assert(pcmp);
 	if (fmt == NULL ||
 	    strcmp(fmt, "raw") == 0)
@@ -467,7 +469,11 @@ int snd_pcm_file_open(snd_pcm_t **pcmp, const char *name,
 	pcm->poll_fd = slave->poll_fd;
 	pcm->poll_events = slave->poll_events;
 	pcm->mmap_shadow = 1;
-	pcm->monotonic = 1;
+#ifdef HAVE_CLOCK_GETTIME
+	pcm->monotonic = clock_gettime(CLOCK_MONOTONIC, &timespec) == 0;
+#else
+	pcm->monotonic = 0;
+#endif
 	snd_pcm_link_hw_ptr(pcm, slave);
 	snd_pcm_link_appl_ptr(pcm, slave);
 	*pcmp = pcm;
diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c
index e5de7682..8495f71b 100644
--- a/src/pcm/pcm_hw.c
+++ b/src/pcm/pcm_hw.c
@@ -996,13 +996,16 @@ int snd_pcm_hw_open_fd(snd_pcm_t **pcmp, const char *name,
 
 #ifdef HAVE_CLOCK_GETTIME
 	if (SNDRV_PROTOCOL_VERSION(2, 0, 9) <= ver) {
-		int on = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC;
-		if (ioctl(fd, SNDRV_PCM_IOCTL_TTSTAMP, &on) < 0) {
-			ret = -errno;
-			SNDMSG("TTSTAMP failed\n");
-			return ret;
+		struct timespec timespec;
+		if (clock_gettime(CLOCK_MONOTONIC, &timespec) == 0) {
+			int on = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC;
+			if (ioctl(fd, SNDRV_PCM_IOCTL_TTSTAMP, &on) < 0) {
+				ret = -errno;
+				SNDMSG("TTSTAMP failed\n");
+				return ret;
+			}
+			monotonic = 1;
 		}
-		monotonic = 1;
 	}
 #endif
 	  else if (SNDRV_PROTOCOL_VERSION(2, 0, 5) <= ver) {