1 /* spin_mutex.h -*-C++-*-
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42 * @brief Support for Cilk runtime mutexes.
44 * Cilk runtime mutexes are implemented as simple spin loops.
46 * This file is similar to a worker_mutex, except it does not have an
49 * TBD: This class, worker_mutex, and os_mutex overlap quite a bit in
50 * functionality. Can we unify these mutexes somehow?
52 #ifndef INCLUDED_SPIN_MUTEX_DOT_H
53 #define INCLUDED_SPIN_MUTEX_DOT_H
55 #include <cilk/common.h>
56 #include "rts-common.h"
57 #include "cilk_malloc.h"
59 __CILKRTS_BEGIN_EXTERN_C
62 * Mutexes are treated as an abstract data type within the Cilk
63 * runtime system. They are implemented as simple spin loops.
65 typedef struct spin_mutex
{
66 /** Mutex spin loop variable. 0 if unowned, 1 if owned. */
69 /** Padding so the mutex takes up a cache line. */
70 char pad
[64/sizeof(int) - 1];
75 * @brief Create a new Cilk spin_mutex.
77 * @return Returns an initialized spin mutex.
80 spin_mutex
* spin_mutex_create();
83 * @brief Initialize a Cilk spin_mutex.
85 * @param m Spin_Mutex to be initialized.
88 void spin_mutex_init(spin_mutex
*m
);
91 * @brief Acquire a Cilk spin_mutex.
93 * If statistics are being gathered, the time spent
94 * acquiring the spin_mutex will be attributed to the specified worker.
96 * @param m Spin_Mutex to be initialized.
99 void spin_mutex_lock(struct spin_mutex
*m
);
101 * @brief Attempt to lock a Cilk spin_mutex and fail if it isn't available.
103 * @param m Spin_Mutex to be acquired.
105 * @return 1 if the spin_mutex was acquired.
106 * @return 0 if the spin_mutex was not acquired.
109 int spin_mutex_trylock(struct spin_mutex
*m
);
112 * @brief Release a Cilk spin_mutex.
114 * @param m Spin_Mutex to be released.
117 void spin_mutex_unlock(struct spin_mutex
*m
);
120 * @brief Deallocate a Cilk spin_mutex. Currently does nothing.
122 * @param m Spin_Mutex to be deallocated.
125 void spin_mutex_destroy(struct spin_mutex
*m
);
127 __CILKRTS_END_EXTERN_C
129 #endif // ! defined(INCLUDED_SPIN_MUTEX_DOT_H)