From 8d94ae49601e0e4023bcdc35191669b2c24f6c96 Mon Sep 17 00:00:00 2001 From: Alexis211 Date: Mon, 5 Apr 2010 16:56:17 +0200 Subject: More work on IPC. --- src/library/std/mutex.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 src/library/std/mutex.c (limited to 'src/library/std') diff --git a/src/library/std/mutex.c b/src/library/std/mutex.c new file mode 100644 index 0000000..ac0ee8f --- /dev/null +++ b/src/library/std/mutex.c @@ -0,0 +1,22 @@ +#include + +static uint32_t atomic_exchange(uint32_t* ptr, uint32_t newval) { + uint32_t r; + asm volatile("xchg (%%ecx), %%eax" : "=a"(r) : "c"(ptr), "a"(newval)); + return r; +} + +void mutex_lock(uint32_t* mutex) { + while (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) { + thread_sleep(1); + } +} + +int mutex_lockE(uint32_t* mutex) { + if (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) return 0; + return 1; +} + +void mutex_unlock(uint32_t* mutex) { + *mutex = MUTEX_UNLOCKED; +} -- cgit v1.2.3