191 lines
6.8 KiB
C
191 lines
6.8 KiB
C
/** @file */
|
|
|
|
// xos_semaphore.h - XOS Semaphore API interface and data structures.
|
|
|
|
// Copyright (c) 2003-2015 Cadence Design Systems, Inc.
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining
|
|
// a copy of this software and associated documentation files (the
|
|
// "Software"), to deal in the Software without restriction, including
|
|
// without limitation the rights to use, copy, modify, merge, publish,
|
|
// distribute, sublicense, and/or sell copies of the Software, and to
|
|
// permit persons to whom the Software is furnished to do so, subject to
|
|
// the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included
|
|
// in all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
|
|
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
|
|
// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
|
|
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
|
|
// NOTE: Do not include this file directly in your application. Including
|
|
// xos.h will automatically include this file.
|
|
|
|
#ifndef __XOS_SEMAPHORE_H__
|
|
#define __XOS_SEMAPHORE_H__
|
|
|
|
#include "xos_types.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Semaphore flags.
|
|
//-----------------------------------------------------------------------------
|
|
#define XOS_SEM_WAIT_PRIORITY 0x0000 ///< Wake waiters in priority order (default)
|
|
#define XOS_SEM_WAIT_FIFO 0x0001 ///< Wake waiters in FIFO order
|
|
#define XOS_SEM_PRIORITY_INV 0x0004 // Protect against priority inversion
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// XosSem object.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
typedef struct XosSem {
|
|
uint32_t count; ///< Current count
|
|
XosThreadQueue waitq; ///< Queue of waiters.
|
|
uint32_t flags; ///< Properties.
|
|
#if XOS_SEM_DEBUG
|
|
uint32_t sig; // Valid signature indicates inited.
|
|
#endif
|
|
} XosSem;
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// Initialize a semaphore object before first use.
|
|
///
|
|
/// \param sem Pointer to semaphore object.
|
|
///
|
|
/// \param flags Creation flags:
|
|
/// - XOS_SEM_WAIT_FIFO -- queue waiting threads in
|
|
/// fifo order.
|
|
/// - XOS_SEM_WAIT_PRIORITY -- queue waiting threads
|
|
/// by priority. This is the default.
|
|
/// - XOS_SEM_PRIORITY_INV -- protect against priority
|
|
/// inversion.
|
|
///
|
|
/// \param initial_count Initial count for semaphore on creation.
|
|
///
|
|
/// \return Returns XOS_OK on success, else error code.
|
|
///
|
|
/// NOTE: XOS_SEM_PRIORITY_INV is NOT supported in the current release. It will
|
|
/// be supported in a future release.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
int32_t
|
|
xos_sem_create(XosSem * sem, uint32_t flags, uint32_t initial_count);
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// Destroy a semaphore object. Must have been previously created by calling
|
|
/// xos_sem_create().
|
|
///
|
|
/// \param sem Pointer to semaphore object.
|
|
///
|
|
/// \return Returns XOS_OK on success, else error code.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
int32_t
|
|
xos_sem_delete(XosSem * sem);
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// Decrement the semaphore count: block until the decrement is possible.
|
|
/// The semaphore must have been initialized.
|
|
///
|
|
/// \param sem Pointer to semaphore object.
|
|
///
|
|
/// \return Returns XOS_OK on success, else error code.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
int32_t
|
|
xos_sem_get(XosSem * sem);
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// Decrement the semaphore count: block until the decrement is possible or
|
|
/// the timeout expires. The semaphore must have been initialized.
|
|
///
|
|
/// \param sem Pointer to semaphore object.
|
|
///
|
|
/// \param to_cycles Timeout in cycles. Convert from time to cycles
|
|
/// using the helper functions provided in xos_timer.
|
|
/// A value of zero indicates no timeout.
|
|
///
|
|
/// \return Returns XOS_OK on success, XOS_ERR_TIMEOUT on timeout, else error code.
|
|
///
|
|
/// NOTE: If XOS_OPT_WAIT_TIMEOUT is not enabled, then the timeout value is
|
|
/// ignored, and no timeout will occur.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
int32_t
|
|
xos_sem_get_timeout(XosSem * sem, uint64_t to_cycles);
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// Increment the semaphore count. The semaphore must have been initialized.
|
|
/// Remember that this action may wake up a waiting thread, and if that thread
|
|
/// is higher priority then there will be an immediate context switch.
|
|
///
|
|
/// \param sem Pointer to semaphore object.
|
|
///
|
|
/// \return Returns XOS_OK on success, else error code.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
int32_t
|
|
xos_sem_put(XosSem * sem);
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// Try to decrement the semaphore, but do not block if the semaphore count is
|
|
/// zero. Return immediately. The semaphore must have been initialized.
|
|
///
|
|
/// \param sem Pointer to semaphore object.
|
|
///
|
|
/// \return Returns XOS_OK on success (semaphore decremented), else error code.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
int32_t
|
|
xos_sem_tryget(XosSem * sem);
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
///
|
|
/// Return the count of the semaphore but do not attempt to decrement it.
|
|
/// The semaphore must have been initialized.
|
|
///
|
|
/// \param sem Pointer to semaphore object.
|
|
///
|
|
/// \return Returns semaphore count, -1 on error.
|
|
///
|
|
//-----------------------------------------------------------------------------
|
|
static inline int32_t
|
|
xos_sem_test(XosSem * sem)
|
|
{
|
|
XOS_ASSERT(sem);
|
|
|
|
return sem ? sem->count : -1;
|
|
}
|
|
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif // __XOS_SEMAPHORE_H__
|
|
|