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Removed duplicated code, fixed comment

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This commit is contained in:
Martin Elshuber 2017-02-20 12:11:02 +01:00
parent b9bb22b393
commit 6cd3d34686
1 changed files with 16 additions and 27 deletions
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43
core/rmutex.c
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@ -32,7 +32,7 @@
#define ENABLE_DEBUG (0) #define ENABLE_DEBUG (0)
#include "debug.h" #include "debug.h"
void rmutex_lock(rmutex_t *rmutex) static int _lock(rmutex_t *rmutex, int trylock)
{ {
kernel_pid_t owner; kernel_pid_t owner;
@ -70,7 +70,7 @@ void rmutex_lock(rmutex_t *rmutex)
* Condition 2: holds * Condition 2: holds
* rmutex->owner == thread_getpid() * rmutex->owner == thread_getpid()
* *
* Note for Case 1: * Note for Case 2:
* *
* Because the mutex rmutex->owner is only written be the * Because the mutex rmutex->owner is only written be the
* owner (me), rmutex->owner stays constant througout the * owner (me), rmutex->owner stays constant througout the
@ -87,7 +87,12 @@ void rmutex_lock(rmutex_t *rmutex)
/* wait for the mutex */ /* wait for the mutex */
DEBUG("rmutex %" PRIi16" : locking mutex\n", thread_getpid()); DEBUG("rmutex %" PRIi16" : locking mutex\n", thread_getpid());
mutex_lock(&rmutex->mutex); if (trylock) {
return 0;
}
else {
mutex_lock(&rmutex->mutex);
}
} }
/* Case 2: Mutex is held be me (relock) */ /* Case 2: Mutex is held be me (relock) */
/* Note: There is nothing to do for Case 2; refcount is incremented below */ /* Note: There is nothing to do for Case 2; refcount is incremented below */
@ -105,34 +110,18 @@ void rmutex_lock(rmutex_t *rmutex)
/* increase the refcount */ /* increase the refcount */
rmutex->refcount++; rmutex->refcount++;
return 1;
}
void rmutex_lock(rmutex_t *rmutex)
{
_lock(rmutex, 0);
} }
int rmutex_trylock(rmutex_t *rmutex) int rmutex_trylock(rmutex_t *rmutex)
{ {
kernel_pid_t owner; return _lock(rmutex, 1);
/* try to lock the mutex */
if (mutex_trylock(&rmutex->mutex) == 0) {
/* ensure that owner is read atomically, since I need a consistent value */
owner = atomic_load_explicit( &rmutex->owner, memory_order_relaxed);
/* Case 1: Mutex is not held by me */
if ( owner != thread_getpid() ) {
/* wait for the mutex */
return 0;
}
/* Case 2: Mutex is held be me (relock) */
/* Note: There is nothing to do for Case 2; refcount is incremented below */
}
/* I am are holding the recursive mutex */
/* ensure that owner is written atomically, since others need a consistent value */
atomic_store_explicit(&rmutex->owner, thread_getpid(), memory_order_relaxed);
/* increase the refcount */
rmutex->refcount++;
return 1;
} }
void rmutex_unlock(rmutex_t *rmutex) void rmutex_unlock(rmutex_t *rmutex)