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commit 817259ec2d454a2974b39ad16dc48138dae35931
Author: Jiuzhu Dong <dongjiuz...@xiaomi.com>
AuthorDate: Thu Jun 17 17:00:47 2021 +0800
syslog/ramlog_channel: fix log confusion when multi task writing together
Signed-off-by: Jiuzhu Dong <dongjiuz...@xiaomi.com>
---
drivers/syslog/ramlog.c | 212 ++++++++++++++++++++++------------------
drivers/syslog/syslog_channel.c | 4 +-
include/nuttx/syslog/ramlog.h | 13 +++
3 files changed, 131 insertions(+), 98 deletions(-)
diff --git a/drivers/syslog/ramlog.c b/drivers/syslog/ramlog.c
index df65b4d..e183900 100644
--- a/drivers/syslog/ramlog.c
+++ b/drivers/syslog/ramlog.c
@@ -92,14 +92,14 @@ static int ramlog_addchar(FAR struct ramlog_dev_s
*priv, char ch);
/* Character driver methods */
-static ssize_t ramlog_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen);
-static ssize_t ramlog_write(FAR struct file *filep, FAR const char *buffer,
- size_t buflen);
-static int ramlog_ioctl(FAR struct file *filep, int cmd,
- unsigned long arg);
-static int ramlog_poll(FAR struct file *filep, FAR struct pollfd *fds,
- bool setup);
+static ssize_t ramlog_file_read(FAR struct file *filep, FAR char *buffer,
+ size_t buflen);
+static ssize_t ramlog_file_write(FAR struct file *filep,
+ FAR const char *buffer, size_t buflen);
+static int ramlog_file_ioctl(FAR struct file *filep, int cmd,
+ unsigned long arg);
+static int ramlog_file_poll(FAR struct file *filep,
+ FAR struct pollfd *fds, bool setup);
/****************************************************************************
* Private Data
@@ -107,15 +107,15 @@ static int ramlog_poll(FAR struct file *filep, FAR
struct pollfd *fds,
static const struct file_operations g_ramlogfops =
{
- NULL, /* open */
- NULL, /* close */
- ramlog_read, /* read */
- ramlog_write, /* write */
- NULL, /* seek */
- ramlog_ioctl, /* ioctl */
- ramlog_poll /* poll */
+ NULL, /* open */
+ NULL, /* close */
+ ramlog_file_read, /* read */
+ ramlog_file_write, /* write */
+ NULL, /* seek */
+ ramlog_file_ioctl, /* ioctl */
+ ramlog_file_poll /* poll */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- , NULL /* unlink */
+ , NULL /* unlink */
#endif
};
@@ -287,11 +287,88 @@ again:
}
/****************************************************************************
+ * Name: ramlog_addbuf
+ ****************************************************************************/
+
+static ssize_t ramlog_addbuf(FAR struct ramlog_dev_s *priv,
+ FAR const char *buffer, size_t len)
+{
+ int readers_waken;
+ ssize_t nwritten;
+ char ch;
+ int ret;
+
+ ret = nxsem_wait(&priv->rl_exclsem);
+ if (ret < 0)
+ {
+ return ret;
+ }
+
+ for (nwritten = 0; (size_t)nwritten < len; nwritten++)
+ {
+ /* Get the next character to output */
+
+ ch = buffer[nwritten];
+
+ /* Then output the character */
+
+ ret = ramlog_addchar(priv, ch);
+ if (ret < 0)
+ {
+ /* The buffer is full and nothing was saved. The remaining
+ * data to be written is dropped on the floor.
+ */
+
+ break;
+ }
+ }
+
+ /* Was anything written? */
+
+ if (nwritten > 0)
+ {
+ readers_waken = 0;
+
+#ifndef CONFIG_RAMLOG_NONBLOCKING
+ /* Are there threads waiting for read data? */
+
+ readers_waken = ramlog_readnotify(priv);
+#endif
+
+ /* If there are multiple readers, some of them might block despite
+ * POLLIN because first reader might read all data. Favor readers
+ * and notify poll waiters only if no reader was awaken, even if the
+ * latter may starve.
+ *
+ * This also implies we do not have to make these two notify
+ * operations a critical section.
+ */
+
+ if (readers_waken == 0)
+ {
+ /* Notify all poll/select waiters that they can read from the
+ * FIFO.
+ */
+
+ ramlog_pollnotify(priv, POLLIN);
+ }
+ }
+
+ /* We always have to return the number of bytes requested and NOT the
+ * number of bytes that were actually written. Otherwise, callers
+ * probably retry, causing same error condition again.
+ */
+
+ nxsem_post(&priv->rl_exclsem);
+ return len;
+}
+
+/****************************************************************************
* Name: ramlog_read
****************************************************************************/
-static ssize_t ramlog_read(FAR struct file *filep, FAR char *buffer,
- size_t len)
+static ssize_t ramlog_file_read(FAR struct file *filep, FAR char *buffer,
+ size_t len)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ramlog_dev_s *priv;
@@ -354,8 +431,8 @@ static ssize_t ramlog_read(FAR struct file *filep, FAR char
*buffer,
/* Otherwise, wait for something to be written to the circular
* buffer. Increment the number of waiters so that the
- * ramlog_write() will note that it needs to post the semaphore
- * to wake us up.
+ * ramlog_file_write() will note that it needs to post the
+ * semaphore to wake us up.
*/
sched_lock();
@@ -452,96 +529,29 @@ errout_without_sem:
}
/****************************************************************************
- * Name: ramlog_write
+ * Name: ramlog_file_write
****************************************************************************/
-static ssize_t ramlog_write(FAR struct file *filep, FAR const char *buffer,
- size_t len)
+static ssize_t ramlog_file_write(FAR struct file *filep,
+ FAR const char *buffer, size_t len)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ramlog_dev_s *priv;
- int readers_waken;
- ssize_t nwritten;
- char ch;
- int ret;
/* Some sanity checking */
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct ramlog_dev_s *)inode->i_private;
- /* Loop until all of the bytes have been written. This function may be
- * called from an interrupt handler! Semaphores cannot be used!
- *
- * The write logic only needs to modify the rl_head index. Therefore,
- * there is a difference in the way that rl_head and rl_tail are protected:
- * rl_tail is protected with a semaphore; rl_head is protected by disabling
- * interrupts.
- */
-
- for (nwritten = 0; (size_t)nwritten < len; nwritten++)
- {
- /* Get the next character to output */
-
- ch = buffer[nwritten];
-
- /* Then output the character */
-
- ret = ramlog_addchar(priv, ch);
- if (ret < 0)
- {
- /* The buffer is full and nothing was saved. The remaining
- * data to be written is dropped on the floor.
- */
-
- break;
- }
- }
-
- /* Was anything written? */
-
- if (nwritten > 0)
- {
- readers_waken = 0;
-
-#ifndef CONFIG_RAMLOG_NONBLOCKING
- /* Are there threads waiting for read data? */
-
- readers_waken = ramlog_readnotify(priv);
-#endif
-
- /* If there are multiple readers, some of them might block despite
- * POLLIN because first reader might read all data. Favor readers
- * and notify poll waiters only if no reader was awaken, even if the
- * latter may starve.
- *
- * This also implies we do not have to make these two notify
- * operations a critical section.
- */
-
- if (readers_waken == 0)
- {
- /* Notify all poll/select waiters that they can read from the
- * FIFO.
- */
-
- ramlog_pollnotify(priv, POLLIN);
- }
- }
-
- /* We always have to return the number of bytes requested and NOT the
- * number of bytes that were actually written. Otherwise, callers
- * probably retry, causing same error condition again.
- */
-
- return len;
+ return ramlog_addbuf(priv, buffer, len);
}
/****************************************************************************
- * Name: ramlog_ioctl
+ * Name: ramlog_file_ioctl
****************************************************************************/
-static int ramlog_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
+static int ramlog_file_ioctl(FAR struct file *filep, int cmd,
+ unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ramlog_dev_s *priv;
@@ -573,11 +583,11 @@ static int ramlog_ioctl(FAR struct file *filep, int cmd,
unsigned long arg)
}
/****************************************************************************
- * Name: ramlog_poll
+ * Name: ramlog_file_poll
****************************************************************************/
-static int ramlog_poll(FAR struct file *filep, FAR struct pollfd *fds,
- bool setup)
+static int ramlog_file_poll(FAR struct file *filep, FAR struct pollfd *fds,
+ bool setup)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ramlog_dev_s *priv;
@@ -868,6 +878,14 @@ int ramlog_putc(FAR struct syslog_channel_s *channel, int
ch)
return ch;
}
+
+ssize_t ramlog_write(FAR struct syslog_channel_s *channel,
+ FAR const char *buffer, size_t buflen)
+{
+ FAR struct ramlog_dev_s *priv = &g_sysdev;
+
+ return ramlog_addbuf(priv, buffer, buflen);
+}
#endif
#endif /* CONFIG_RAMLOG */
diff --git a/drivers/syslog/syslog_channel.c b/drivers/syslog/syslog_channel.c
index 2357993..c05c4ba 100644
--- a/drivers/syslog/syslog_channel.c
+++ b/drivers/syslog/syslog_channel.c
@@ -68,7 +68,9 @@ static ssize_t syslog_default_write(FAR struct
syslog_channel_s *channel,
static const struct syslog_channel_ops_s g_ramlog_channel_ops =
{
ramlog_putc,
- ramlog_putc
+ ramlog_putc,
+ NULL,
+ ramlog_write
};
static struct syslog_channel_s g_ramlog_channel =
diff --git a/include/nuttx/syslog/ramlog.h b/include/nuttx/syslog/ramlog.h
index 0d13010..a71f02e 100644
--- a/include/nuttx/syslog/ramlog.h
+++ b/include/nuttx/syslog/ramlog.h
@@ -140,6 +140,19 @@ void ramlog_syslog_register(void);
int ramlog_putc(FAR struct syslog_channel_s *channel, int ch);
#endif
+/****************************************************************************
+ * Name: ramlog_write
+ *
+ * Description:
+ * This is the low-level system logging interface.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_RAMLOG_SYSLOG
+ssize_t ramlog_write(FAR struct syslog_channel_s *channel,
+ FAR const char *buffer, size_t buflen);
+#endif
+
#undef EXTERN
#ifdef __cplusplus
}
