diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h | 60 |
1 files changed, 57 insertions, 3 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h index a3c02498f4..470dcf6108 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h +++ b/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h @@ -139,7 +139,8 @@ extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; <0 - taken by more users */ -#define lll_trylock(futex) \ +#if defined NOT_IN_libc || defined UP +# define lll_trylock(futex) \ ({ unsigned char ret; \ __asm __volatile (LOCK_INSTR "cmpxchgl %2, %1; setne %0" \ : "=a" (ret), "=m" (futex) \ @@ -148,7 +149,7 @@ extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; ret; }) -#define lll_lock(futex) \ +# define lll_lock(futex) \ (void) ({ int ignore1, ignore2; \ __asm __volatile (LOCK_INSTR "xaddl %0, %2\n\t" \ "jne 1f\n\t" \ @@ -163,7 +164,7 @@ extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; : "memory"); }) -#define lll_unlock(futex) \ +# define lll_unlock(futex) \ (void) ({ int ignore; \ __asm __volatile (LOCK_INSTR "incl %0\n\t" \ "jng 1f\n\t" \ @@ -176,6 +177,59 @@ extern int lll_unlock_wake_cb (int *__futex) attribute_hidden; : "=m" (futex), "=&a" (ignore) \ : "0" (futex) \ : "memory"); }) +#else +/* Special versions of the macros for use in libc itself. They avoid + the lock prefix when the thread library is not used. + + XXX In future we might even want to avoid it on UP machines. */ + +# define lll_trylock(futex) \ + ({ unsigned char ret; \ + __asm __volatile ("cmpl $0, __libc_locking_needed\n\t" \ + "je,pt 0f\n\t" \ + "lock\n" \ + "0:\tcmpxchgl %2, %1; setne %0" \ + : "=a" (ret), "=m" (futex) \ + : "r" (0), "1" (futex), "0" (1) \ + : "memory"); \ + ret; }) + + +# define lll_lock(futex) \ + (void) ({ int ignore1, ignore2; \ + __asm __volatile ("cmpl $0, __libc_locking_needed\n\t" \ + "je,pt 0f\n\t" \ + "lock\n" \ + "0:\txaddl %0, %2\n\t" \ + "jne 1f\n\t" \ + ".subsection 1\n" \ + "1:\tleal %2, %%ecx\n\t" \ + "call __lll_lock_wait\n\t" \ + "jmp 2f\n\t" \ + ".previous\n" \ + "2:" \ + : "=a" (ignore1), "=&c" (ignore2), "=m" (futex) \ + : "0" (-1), "2" (futex) \ + : "memory"); }) + + +# define lll_unlock(futex) \ + (void) ({ int ignore; \ + __asm __volatile ("cmpl $0, __libc_locking_needed\n\t" \ + "je,pt 0f\n\t" \ + "lock\n" \ + "0:\tincl %0\n\t" \ + "jng 1f\n\t" \ + ".subsection 1\n" \ + "1:\tleal %0, %%eax\n\t" \ + "call __lll_unlock_wake\n\t" \ + "jmp 2f\n\t" \ + ".previous\n" \ + "2:" \ + : "=m" (futex), "=&a" (ignore) \ + : "0" (futex) \ + : "memory"); }) +#endif #define lll_islocked(futex) \ |