diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/port/atomics.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/src/backend/port/atomics.c b/src/backend/port/atomics.c index 3350fb7df30..439b3c18c7b 100644 --- a/src/backend/port/atomics.c +++ b/src/backend/port/atomics.c @@ -20,15 +20,32 @@ */ #define ATOMICS_INCLUDE_DEFINITIONS +#include "miscadmin.h" #include "port/atomics.h" #include "storage/spin.h" #ifdef PG_HAVE_MEMORY_BARRIER_EMULATION +#ifdef WIN32 +#error "barriers are required (and provided) on WIN32 platforms" +#endif +#include <sys/types.h> +#include <signal.h> +#endif + +#ifdef PG_HAVE_MEMORY_BARRIER_EMULATION void pg_spinlock_barrier(void) { - S_LOCK(&dummy_spinlock); - S_UNLOCK(&dummy_spinlock); + /* + * NB: we have to be reentrant here, some barriers are placed in signal + * handlers. + * + * We use kill(0) for the fallback barrier as we assume that kernels on + * systems old enough to require fallback barrier support will include an + * appropriate barrier while checking the existence of the postmaster + * pid. + */ + (void) kill(PostmasterPid, 0); } #endif |