diff options
Diffstat (limited to 'nuttx/net/iob/iob_alloc.c')
| -rw-r--r-- | nuttx/net/iob/iob_alloc.c | 78 |
1 files changed, 56 insertions, 22 deletions
diff --git a/nuttx/net/iob/iob_alloc.c b/nuttx/net/iob/iob_alloc.c index be6491dbb..672d1e2e7 100644 --- a/nuttx/net/iob/iob_alloc.c +++ b/nuttx/net/iob/iob_alloc.c @@ -39,7 +39,7 @@ #include <nuttx/config.h> -#if defined(CONFIG_DEBUG) && defined(CONFIG_NET_IOB_DEBUG) +#if defined(CONFIG_DEBUG) && defined(CONFIG_IOB_DEBUG) /* Force debug output (from this file only) */ # undef CONFIG_DEBUG_NET @@ -83,34 +83,59 @@ * ****************************************************************************/ -static FAR struct iob_s *iob_tryalloc(void) +static FAR struct iob_s *iob_tryalloc(bool throttled) { FAR struct iob_s *iob; irqstate_t flags; +#if CONFIG_IOB_THROTTLE > 0 + FAR sem_t *sem; + int semcount; +#endif + +#if CONFIG_IOB_THROTTLE > 0 + /* Select the semaphore count to check. */ + + sem = (throttled ? : &g_throttled_sem, &g_iob_sem); +#endif /* We don't know what context we are called from so we use extreme measures * to protect the free list: We disable interrupts very briefly. */ flags = irqsave(); - iob = g_iob_freelist; - if (iob) + +#if CONFIG_IOB_THROTTLE > 0 + /* If there are free I/O buffers for this allocation */ + + DEBUGVERIFY(sem_getvalue(sem, semcount)); + if (semcount > 0) +#endif { - /* Remove the I/O buffer from the free list and decrement the counting - * semaphore that tracks the number of free IOBs. - */ + /* Take the I/O buffer from the head of the free list */ - g_iob_freelist = iob->io_flink; - DEBUGVERIFY(sem_trywait(&g_iob_sem)); - irqrestore(flags); + iob = g_iob_freelist; + if (iob) + { + /* Remove the I/O buffer from the free list and decrement the + * counting semaphore(s) that tracks the number of available + * IOBs. + */ + + g_iob_freelist = iob->io_flink; + DEBUGVERIFY(sem_trywait(&g_iob_sem)); +#if CONFIG_IOB_THROTTLE > 0 + DEBUGVERIFY(sem_trywait(&g_throttle_sem)); +#endif + irqrestore(flags); - /* Put the I/O buffer in a known state */ + /* Put the I/O buffer in a known state */ - iob->io_flink = NULL; /* Not in a chain */ - iob->io_len = 0; /* Length of the data in the entry */ - iob->io_offset = 0; /* Offset to the beginning of data */ - iob->io_pktlen = 0; /* Total length of the packet */ - return iob; + iob->io_flink = NULL; /* Not in a chain */ + iob->io_len = 0; /* Length of the data in the entry */ + iob->io_offset = 0; /* Offset to the beginning of data */ + iob->io_pktlen = 0; /* Total length of the packet */ + return iob; + } } irqrestore(flags); @@ -126,12 +151,21 @@ static FAR struct iob_s *iob_tryalloc(void) * ****************************************************************************/ -static FAR struct iob_s *iob_allocwait(void) +static FAR struct iob_s *iob_allocwait(bool throttled) { FAR struct iob_s *iob; irqstate_t flags; + FAR sem_t *sem; int ret; +#if CONFIG_IOB_THROTTLE > 0 + /* Select the semaphore count to check. */ + + sem = (throttled ? : &g_throttled_sem, &g_iob_sem); +#else + sem = &g_iob_sem; +#endif + /* The following must be atomic; interrupt must be disabled so that there * is no conflict with interrupt level I/O buffer allocations. This is * not as bad as it sounds because interrupts will be re-enabled while @@ -145,7 +179,7 @@ static FAR struct iob_s *iob_allocwait(void) * will be decremented atomically. */ - iob = iob_tryalloc(); + iob = iob_tryalloc(throttled); if (!iob) { /* If not successful, then the semaphore count was less than or @@ -154,7 +188,7 @@ static FAR struct iob_s *iob_allocwait(void) * count will be incremented. */ - ret = sem_wait(&g_iob_sem); + ret = sem_wait(sem); /* When we wake up from wait, an I/O buffer was returned to * the free list. However, if there are concurrent allocations @@ -182,7 +216,7 @@ static FAR struct iob_s *iob_allocwait(void) * ****************************************************************************/ -FAR struct iob_s *iob_alloc(void) +FAR struct iob_s *iob_alloc(bool throttled) { /* Were we called from the interrupt level? */ @@ -190,12 +224,12 @@ FAR struct iob_s *iob_alloc(void) { /* Yes, then try to allocate an I/O buffer without waiting */ - return iob_tryalloc(); + return iob_tryalloc(throttled); } else { /* Then allocate an I/O buffer, waiting as necessary */ - return iob_allocwait(); + return iob_allocwait(throttled); } } |