use POSIX semaphores in shmtx instead of sched_yield() number of spinlock spins are increased twice
diff --git a/auto/os/freebsd b/auto/os/freebsd index 2098529..0829388 100644 --- a/auto/os/freebsd +++ b/auto/os/freebsd
@@ -49,6 +49,15 @@ have=NGX_HAVE_AIO_SENDFILE . auto/have fi +# POSIX semaphores +# http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/127545 + +if [ $osreldate -ge 701106 ]; then + echo " + POSIX semaphores should work" +else + have=NGX_HAVE_POSIX_SEM . auto/nohave +fi + # kqueue
diff --git a/auto/unix b/auto/unix index c2d3ba2..669314b 100755 --- a/auto/unix +++ b/auto/unix
@@ -234,6 +234,18 @@ . auto/feature +ngx_feature="POSIX semaphores" +ngx_feature_name="NGX_HAVE_POSIX_SEM" +ngx_feature_run=yes +ngx_feature_incs="#include <semaphore.h>" +ngx_feature_path= +ngx_feature_libs= +ngx_feature_test="sem_t sem; + if (sem_init(&sem, 1, 0) == -1) return 1; + sem_destroy(&sem);" +. auto/feature + + ngx_feature="struct msghdr.msg_control" ngx_feature_name="NGX_HAVE_MSGHDR_MSG_CONTROL" ngx_feature_run=no
diff --git a/src/core/ngx_shmtx.c b/src/core/ngx_shmtx.c index ead94e4..3b429c4 100644 --- a/src/core/ngx_shmtx.c +++ b/src/core/ngx_shmtx.c
@@ -16,9 +16,166 @@ { mtx->lock = addr; + if (mtx->spin == (ngx_uint_t) -1) { + return NGX_OK; + } + + mtx->spin = 2048; + +#if (NGX_HAVE_POSIX_SEM) + + if (sem_init(&mtx->sem, 1, 0) == -1) { + ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, + "sem_init() failed"); + } else { + mtx->semaphore = 1; + } + +#endif + return NGX_OK; } + +void +ngx_shmtx_destory(ngx_shmtx_t *mtx) +{ +#if (NGX_HAVE_POSIX_SEM) + + if (mtx->semaphore) { + if (sem_destroy(&mtx->sem) == -1) { + ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, + "sem_destroy() failed"); + } + } + +#endif +} + + +ngx_uint_t +ngx_shmtx_trylock(ngx_shmtx_t *mtx) +{ + ngx_atomic_uint_t val; + + val = *mtx->lock; + + return ((val & 0x80000000) == 0 + && ngx_atomic_cmp_set(mtx->lock, val, val | 0x80000000)); +} + + +void +ngx_shmtx_lock(ngx_shmtx_t *mtx) +{ + ngx_uint_t i, n; + ngx_atomic_uint_t val; + + ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx lock"); + + for ( ;; ) { + + val = *mtx->lock; + + if ((val & 0x80000000) == 0 + && ngx_atomic_cmp_set(mtx->lock, val, val | 0x80000000)) + { + return; + } + + if (ngx_ncpu > 1) { + + for (n = 1; n < mtx->spin; n <<= 1) { + + for (i = 0; i < n; i++) { + ngx_cpu_pause(); + } + + val = *mtx->lock; + + if ((val & 0x80000000) == 0 + && ngx_atomic_cmp_set(mtx->lock, val, val | 0x80000000)) + { + return; + } + } + } + +#if (NGX_HAVE_POSIX_SEM) + + if (mtx->semaphore) { + val = *mtx->lock; + + if ((val & 0x80000000) + && ngx_atomic_cmp_set(mtx->lock, val, val + 1)) + { + ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, + "shmtx wait %XA", val); + + while (sem_wait(&mtx->sem) == -1) { + ngx_err_t err; + + err = ngx_errno; + + if (err != NGX_EINTR) { + ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, err, + "sem_wait() failed while waiting on shmtx"); + break; + } + } + + ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, + "shmtx awoke"); + } + + continue; + } + +#endif + + ngx_sched_yield(); + } +} + + +void +ngx_shmtx_unlock(ngx_shmtx_t *mtx) +{ + ngx_atomic_uint_t val, old, wait; + + if (mtx->spin != (ngx_uint_t) -1) { + ngx_log_debug0(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, "shmtx unlock"); + } + + for ( ;; ) { + + old = *mtx->lock; + wait = old & 0x7fffffff; + val = wait ? wait - 1 : 0; + + if (ngx_atomic_cmp_set(mtx->lock, old, val)) { + break; + } + } + +#if (NGX_HAVE_POSIX_SEM) + + if (wait == 0 || !mtx->semaphore) { + return; + } + + ngx_log_debug1(NGX_LOG_DEBUG_CORE, ngx_cycle->log, 0, + "shmtx wake %XA", old); + + if (sem_post(&mtx->sem) == -1) { + ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_errno, + "sem_post() failed while wake shmtx"); + } + +#endif +} + + #else @@ -65,4 +222,62 @@ } +ngx_uint_t +ngx_shmtx_trylock(ngx_shmtx_t *mtx) +{ + ngx_err_t err; + + err = ngx_trylock_fd(mtx->fd); + + if (err == 0) { + return 1; + } + + if (err == NGX_EAGAIN) { + return 0; + } + +#if __osf__ /* Tru64 UNIX */ + + if (err == NGX_EACCESS) { + return 0; + } + +#endif + + ngx_log_abort(err, ngx_trylock_fd_n " %s failed", mtx->name); + + return 0; +} + + +void +ngx_shmtx_lock(ngx_shmtx_t *mtx) +{ + ngx_err_t err; + + err = ngx_lock_fd(mtx->fd); + + if (err == 0) { + return; + } + + ngx_log_abort(err, ngx_lock_fd_n " %s failed", mtx->name); +} + + +void +ngx_shmtx_unlock(ngx_shmtx_t *mtx) +{ + ngx_err_t err; + + err = ngx_unlock_fd(mtx->fd); + + if (err == 0) { + return; + } + + ngx_log_abort(err, ngx_unlock_fd_n " %s failed", mtx->name); +} + #endif
diff --git a/src/core/ngx_shmtx.h b/src/core/ngx_shmtx.h index 57fe0b9..714f73a 100644 --- a/src/core/ngx_shmtx.h +++ b/src/core/ngx_shmtx.h
@@ -15,95 +15,23 @@ typedef struct { #if (NGX_HAVE_ATOMIC_OPS) ngx_atomic_t *lock; +#if (NGX_HAVE_POSIX_SEM) + ngx_uint_t semaphore; + sem_t sem; +#endif #else ngx_fd_t fd; u_char *name; #endif + ngx_uint_t spin; } ngx_shmtx_t; ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name); - - -#if (NGX_HAVE_ATOMIC_OPS) - -static ngx_inline ngx_uint_t -ngx_shmtx_trylock(ngx_shmtx_t *mtx) -{ - return (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid)); -} - -#define ngx_shmtx_lock(mtx) ngx_spinlock((mtx)->lock, ngx_pid, 1024) - -#define ngx_shmtx_unlock(mtx) (void) ngx_atomic_cmp_set((mtx)->lock, ngx_pid, 0) - -#define ngx_shmtx_destory(mtx) - - -#else - -static ngx_inline ngx_uint_t -ngx_shmtx_trylock(ngx_shmtx_t *mtx) -{ - ngx_err_t err; - - err = ngx_trylock_fd(mtx->fd); - - if (err == 0) { - return 1; - } - - if (err == NGX_EAGAIN) { - return 0; - } - -#if __osf__ /* Tru64 UNIX */ - - if (err == NGX_EACCESS) { - return 0; - } - -#endif - - ngx_log_abort(err, ngx_trylock_fd_n " %s failed", mtx->name); - - return 0; -} - - -static ngx_inline void -ngx_shmtx_lock(ngx_shmtx_t *mtx) -{ - ngx_err_t err; - - err = ngx_lock_fd(mtx->fd); - - if (err == 0) { - return; - } - - ngx_log_abort(err, ngx_lock_fd_n " %s failed", mtx->name); -} - - -static ngx_inline void -ngx_shmtx_unlock(ngx_shmtx_t *mtx) -{ - ngx_err_t err; - - err = ngx_unlock_fd(mtx->fd); - - if (err == 0) { - return; - } - - ngx_log_abort(err, ngx_unlock_fd_n " %s failed", mtx->name); -} - - void ngx_shmtx_destory(ngx_shmtx_t *mtx); - -#endif +ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx); +void ngx_shmtx_lock(ngx_shmtx_t *mtx); +void ngx_shmtx_unlock(ngx_shmtx_t *mtx); #endif /* _NGX_SHMTX_H_INCLUDED_ */
diff --git a/src/event/ngx_event.c b/src/event/ngx_event.c index 3922b0e..c57d37e 100644 --- a/src/event/ngx_event.c +++ b/src/event/ngx_event.c
@@ -519,6 +519,7 @@ shared = shm.addr; ngx_accept_mutex_ptr = (ngx_atomic_t *) shared; + ngx_accept_mutex.spin = (ngx_uint_t) -1; if (ngx_shmtx_create(&ngx_accept_mutex, shared, cycle->lock_file.data) != NGX_OK)
diff --git a/src/os/unix/ngx_darwin_config.h b/src/os/unix/ngx_darwin_config.h index 3900976..88aa6f5 100644 --- a/src/os/unix/ngx_darwin_config.h +++ b/src/os/unix/ngx_darwin_config.h
@@ -56,6 +56,11 @@ #include <ngx_auto_config.h> +#if (NGX_HAVE_POSIX_SEM) +#include <semaphore.h> +#endif + + #if (NGX_HAVE_POLL) #include <poll.h> #endif
diff --git a/src/os/unix/ngx_freebsd_config.h b/src/os/unix/ngx_freebsd_config.h index 20cb666..ec7a375 100644 --- a/src/os/unix/ngx_freebsd_config.h +++ b/src/os/unix/ngx_freebsd_config.h
@@ -68,6 +68,11 @@ #include <ngx_auto_config.h> +#if (NGX_HAVE_POSIX_SEM) +#include <semaphore.h> +#endif + + #if (NGX_HAVE_POLL) #include <poll.h> #endif
diff --git a/src/os/unix/ngx_linux_config.h b/src/os/unix/ngx_linux_config.h index cf45e54..046095d 100644 --- a/src/os/unix/ngx_linux_config.h +++ b/src/os/unix/ngx_linux_config.h
@@ -58,6 +58,11 @@ #include <ngx_auto_config.h> +#if (NGX_HAVE_POSIX_SEM) +#include <semaphore.h> +#endif + + #if (NGX_HAVE_SYS_PRCTL_H) #include <sys/prctl.h> #endif
diff --git a/src/os/unix/ngx_posix_config.h b/src/os/unix/ngx_posix_config.h index 86a80d7..aec8a0a 100644 --- a/src/os/unix/ngx_posix_config.h +++ b/src/os/unix/ngx_posix_config.h
@@ -96,6 +96,11 @@ #include <ngx_auto_config.h> +#if (NGX_HAVE_POSIX_SEM) +#include <semaphore.h> +#endif + + #if (NGX_HAVE_POLL) #include <poll.h> #endif
diff --git a/src/os/unix/ngx_solaris_config.h b/src/os/unix/ngx_solaris_config.h index ae8212d..6b3d42e 100644 --- a/src/os/unix/ngx_solaris_config.h +++ b/src/os/unix/ngx_solaris_config.h
@@ -57,6 +57,11 @@ #include <ngx_auto_config.h> +#if (NGX_HAVE_POSIX_SEM) +#include <semaphore.h> +#endif + + #if (NGX_HAVE_POLL) #include <poll.h> #endif