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author | Alex AUVOLAT <alexis211@gmail.com> | 2012-05-18 11:25:25 +0200 |
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committer | Alex AUVOLAT <alexis211@gmail.com> | 2012-05-18 11:25:25 +0200 |
commit | f3e03796652b792bb3fd5d3d25b687b9a7f14633 (patch) | |
tree | feef62986de699702136aaf0d56295fde9297115 /src/kernel/lib/sched.c | |
parent | c19415d2ffb6f063f91983ff505e2530ab500908 (diff) | |
download | TCE-f3e03796652b792bb3fd5d3d25b687b9a7f14633.tar.gz TCE-f3e03796652b792bb3fd5d3d25b687b9a7f14633.zip |
A bit of a change in the directory layout.
Diffstat (limited to 'src/kernel/lib/sched.c')
-rw-r--r-- | src/kernel/lib/sched.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/kernel/lib/sched.c b/src/kernel/lib/sched.c new file mode 100644 index 0000000..29ea8a8 --- /dev/null +++ b/src/kernel/lib/sched.c @@ -0,0 +1,26 @@ +#include <sched.h> + +/* Internal use only. This function is atomic, meaning it cannot be interrupted by a system task switch. */ +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; +} + +int mutex_lock(uint32_t* mutex) { + while (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) { + schedule(); + } + return 0; +} + +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; +} |