haiwan
/
ck
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ck_pflock: Load acquire semantics are sufficient for read_unlock.

Browse Source 
Also, make sure to implement acquire semantics if there are no
contending writers.
ck_pring
Samy Al Bahra 12 years ago
parent 7ce276f5eb
commit aec2797d27
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File

5
include/ck_pflock.h
Unescape View File

@ -110,7 +110,7 @@ CK_CC_INLINE static void
ck_pflock_read_unlock(ck_pflock_t *pf) ck_pflock_read_unlock(ck_pflock_t *pf)
{ {
ck_pr_fence_memory(); ck_pr_fence_load();
ck_pr_faa_32(&pf->rout, CK_PFLOCK_RINC); ck_pr_faa_32(&pf->rout, CK_PFLOCK_RINC);
return; return;
} }
@ -126,13 +126,14 @@ ck_pflock_read_lock(ck_pflock_t *pf)
*/ */
w = ck_pr_faa_32(&pf->rin, CK_PFLOCK_RINC) & CK_PFLOCK_WBITS; w = ck_pr_faa_32(&pf->rin, CK_PFLOCK_RINC) & CK_PFLOCK_WBITS;
if (w == 0) if (w == 0)
return; goto leave;
/* Wait for current write phase to complete. */ /* Wait for current write phase to complete. */
while ((ck_pr_load_32(&pf->rin) & CK_PFLOCK_WBITS) == w) while ((ck_pr_load_32(&pf->rin) & CK_PFLOCK_WBITS) == w)
ck_pr_stall(); ck_pr_stall();
/* Acquire semantics. */ /* Acquire semantics. */
leave:
ck_pr_fence_load(); ck_pr_fence_load();
return; return;
} }

Write Preview
Loading…
Cancel
Save