diff options
| author | unknown <heikki@donna.mysql.fi> | 2001-05-31 15:23:40 +0300 |
|---|---|---|
| committer | unknown <heikki@donna.mysql.fi> | 2001-05-31 15:23:40 +0300 |
| commit | 439b74179f2363b6086a39fc075985f05e6a1f3b (patch) | |
| tree | 2d009ee5f802e1c4cc3657fc6f88c1af5c942d71 /innobase | |
| parent | c01c86f90eceb7994df2b8075322b4149a4e5700 (diff) | |
| download | mariadb-git-439b74179f2363b6086a39fc075985f05e6a1f3b.tar.gz | |
sync0sync.ic Use XCHG also to reset the mutex lock word: it makes a serialization point to code on Intel and gives more safety
innobase/include/sync0sync.ic:
Use XCHG also to reset the mutex lock word: it makes a serialization point to code on Intel and gives more safety
BitKeeper/etc/logging_ok:
Logging to logging@openlogging.org accepted
Diffstat (limited to 'innobase')
| -rw-r--r-- | innobase/include/sync0sync.ic | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/innobase/include/sync0sync.ic b/innobase/include/sync0sync.ic index 5a872c6b093..ba948ff35cd 100644 --- a/innobase/include/sync0sync.ic +++ b/innobase/include/sync0sync.ic @@ -94,10 +94,12 @@ mutex_test_and_set( /* In assembly we use the so-called AT & T syntax where the order of operands is inverted compared to the ordinary Intel - syntax. The 'l' after the mnemonics denotes a 32-bit operation. */ + syntax. The 'l' after the mnemonics denotes a 32-bit operation. + The line after the code tells which values come out of the asm + code, and the second line tells the input to the asm code. */ asm volatile("movl $1, %%eax; xchgl (%%ecx), %%eax" : - "=eax" (res): + "=eax" (res), "=m" (*lw) : "ecx" (lw)); return(res); #else @@ -132,12 +134,24 @@ mutex_reset_lock_word( __asm MOV EDX, 0 __asm MOV ECX, lw __asm XCHG EDX, DWORD PTR [ECX] +#elif defined(__GNUC__) && defined(UNIV_INTEL_X86) + ulint* lw; + + lw = &(mutex->lock_word); + + /* In assembly we use the so-called AT & T syntax where + the order of operands is inverted compared to the ordinary Intel + syntax. The 'l' after the mnemonics denotes a 32-bit operation. */ + + asm volatile("movl $0, %%eax; xchgl (%%ecx), %%eax" : + "=m" (*lw) : + "ecx" (lw) : + "eax"); /* gcc does not seem to understand + that our asm code resets eax: tell it + explicitly that after the third ':' */ #else - mutex->lock_word = 0; -#if !(defined(__GNUC__) && defined(UNIV_INTEL_X86)) os_fast_mutex_unlock(&(mutex->os_fast_mutex)); #endif -#endif } /********************************************************************** |