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kernel/pipe: Spinlockify

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One spinlock per pipe object.  Also removed some vestigial locking
around _ready_thread().  That call is internally synchronized now.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This commit is contained in:
Andy Ross 2019-02-05 16:10:18 -08:00 • committed by Anas Nashif
commit f582b55dd6
2 changed files with 16 additions and 20 deletions
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1
include/kernel.h
View file

@ -3631,6 +3631,7 @@ struct k_pipe {
size_t bytes_used; /**< # bytes used in buffer */
size_t read_index; /**< Where in buffer to read from */
size_t write_index; /**< Where in buffer to write */
struct k_spinlock lock; /**< Synchronization lock */
struct {
_wait_q_t readers; /**< Reader wait queue */

35
kernel/pipes.c
View file

@ -413,8 +413,6 @@ static int pipe_return_code(size_t min_xfer, size_t bytes_remaining,
*/
static void pipe_thread_ready(struct k_thread *thread)
{
unsigned int key;
#if (CONFIG_NUM_PIPE_ASYNC_MSGS > 0)
if ((thread->base.thread_state & _THREAD_DUMMY) != 0) {
pipe_async_finish((struct k_pipe_async *)thread);
@ -422,9 +420,7 @@ static void pipe_thread_ready(struct k_thread *thread)
}
#endif
key = irq_lock();
_ready_thread(thread);
irq_unlock(key);
}
/**
@ -438,7 +434,6 @@ int _k_pipe_put_internal(struct k_pipe *pipe, struct k_pipe_async *async_desc,
struct k_thread *reader;
struct k_pipe_desc *desc;
sys_dlist_t xfer_list;
unsigned int key;
size_t num_bytes_written = 0;
size_t bytes_copied;
@ -446,7 +441,7 @@ int _k_pipe_put_internal(struct k_pipe *pipe, struct k_pipe_async *async_desc,
ARG_UNUSED(async_desc);
#endif
key = irq_lock();
k_spinlock_key_t key = k_spin_lock(&pipe->lock);
/*
* Create a list of "working readers" into which the data will be
@ -456,13 +451,13 @@ int _k_pipe_put_internal(struct k_pipe *pipe, struct k_pipe_async *async_desc,
if (!pipe_xfer_prepare(&xfer_list, &reader, &pipe->wait_q.readers,
pipe->size - pipe->bytes_used, bytes_to_write,
min_xfer, timeout)) {
irq_unlock(key);
k_spin_unlock(&pipe->lock, key);
*bytes_written = 0;
return -EIO;
}
_sched_lock();
irq_unlock(key);
k_spin_unlock(&pipe->lock, key);
/*
* 1. 'xfer_list' currently contains a list of reader threads that can
@ -489,9 +484,7 @@ int _k_pipe_put_internal(struct k_pipe *pipe, struct k_pipe_async *async_desc,
desc->bytes_to_xfer -= bytes_copied;
/* The thread's read request has been satisfied. Ready it. */
key = irq_lock();
_ready_thread(thread);
irq_unlock(key);
thread = (struct k_thread *)sys_dlist_get(&xfer_list);
}
@ -539,7 +532,7 @@ int _k_pipe_put_internal(struct k_pipe *pipe, struct k_pipe_async *async_desc,
* Lock interrupts and unlock the scheduler before
* manipulating the writers wait_q.
*/
key = irq_lock();
k_spinlock_key_t key = k_spin_lock(&pipe->lock);
_sched_unlock_no_reschedule();
async_desc->desc.buffer = data + num_bytes_written;
@ -548,7 +541,7 @@ int _k_pipe_put_internal(struct k_pipe *pipe, struct k_pipe_async *async_desc,
_pend_thread((struct k_thread *) &async_desc->thread,
&pipe->wait_q.writers, K_FOREVER);
_reschedule_irqlock(key);
_reschedule(&pipe->lock, key);
return 0;
}
#endif
@ -564,9 +557,10 @@ int _k_pipe_put_internal(struct k_pipe *pipe, struct k_pipe_async *async_desc,
* Lock interrupts and unlock the scheduler before
* manipulating the writers wait_q.
*/
key = irq_lock();
k_spinlock_key_t key = k_spin_lock(&pipe->lock);
_sched_unlock_no_reschedule();
(void)_pend_curr_irqlock(key, &pipe->wait_q.writers, timeout);
(void)_pend_curr(&pipe->lock, key,
&pipe->wait_q.writers, timeout);
} else {
k_sched_unlock();
}
@ -583,14 +577,13 @@ int _impl_k_pipe_get(struct k_pipe *pipe, void *data, size_t bytes_to_read,
struct k_thread *writer;
struct k_pipe_desc *desc;
sys_dlist_t xfer_list;
unsigned int key;
size_t num_bytes_read = 0;
size_t bytes_copied;
__ASSERT(min_xfer <= bytes_to_read, "");
__ASSERT(bytes_read != NULL, "");
key = irq_lock();
k_spinlock_key_t key = k_spin_lock(&pipe->lock);
/*
* Create a list of "working readers" into which the data will be
@ -600,13 +593,13 @@ int _impl_k_pipe_get(struct k_pipe *pipe, void *data, size_t bytes_to_read,
if (!pipe_xfer_prepare(&xfer_list, &writer, &pipe->wait_q.writers,
pipe->bytes_used, bytes_to_read,
min_xfer, timeout)) {
irq_unlock(key);
k_spin_unlock(&pipe->lock, key);
*bytes_read = 0;
return -EIO;
}
_sched_lock();
irq_unlock(key);
k_spin_unlock(&pipe->lock, key);
num_bytes_read = pipe_buffer_get(pipe, data, bytes_to_read);
@ -706,9 +699,11 @@ int _impl_k_pipe_get(struct k_pipe *pipe, void *data, size_t bytes_to_read,
if (timeout != K_NO_WAIT) {
_current->base.swap_data = &pipe_desc;
key = irq_lock();
k_spinlock_key_t key = k_spin_lock(&pipe->lock);
_sched_unlock_no_reschedule();
(void)_pend_curr_irqlock(key, &pipe->wait_q.readers, timeout);
(void)_pend_curr(&pipe->lock, key,
&pipe->wait_q.readers, timeout);
} else {
k_sched_unlock();
}