diff options
| -rw-r--r-- | include/grpc/grpc_posix.h | 8 | ||||
| -rw-r--r-- | src/core/lib/iomgr/ev_epoll_linux.c | 45 |
2 files changed, 43 insertions, 10 deletions
diff --git a/include/grpc/grpc_posix.h b/include/grpc/grpc_posix.h index 9742b83374..5e89ae3b1e 100644 --- a/include/grpc/grpc_posix.h +++ b/include/grpc/grpc_posix.h @@ -63,6 +63,14 @@ GRPCAPI void grpc_server_add_insecure_channel_from_fd(grpc_server *server, grpc_completion_queue *cq, int fd); +/** GRPC Core POSIX library may internally use signals to optimize some work. + The library uses (SIGRTMIN + 2) signal by default. Use this API to instruct + the library to use a different signal i.e 'signum' instead. + Note: + - To prevent GRPC library from using any signals, pass a 'signum' of -1 + - This API is optional but if called, it MUST be called before grpc_init() */ +GRPCAPI void grpc_use_signal(int signum); + #ifdef __cplusplus } #endif diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c index d2d5d2852b..7e01ac144f 100644 --- a/src/core/lib/iomgr/ev_epoll_linux.c +++ b/src/core/lib/iomgr/ev_epoll_linux.c @@ -31,6 +31,7 @@ * */ +#include <grpc/grpc_posix.h> #include <grpc/support/port_platform.h> #ifdef GPR_LINUX_EPOLL @@ -58,9 +59,26 @@ #include "src/core/lib/profiling/timers.h" #include "src/core/lib/support/block_annotate.h" -struct polling_island; +static int grpc_wakeup_signal = -1; +static bool is_grpc_wakeup_signal_initialized = false; + +/* Implements the function defined in grpc_posix.h. This function might be + * called before even calling grpc_init() to set either a different signal to + * use. If signum == -1, then the use of signals is disabled */ +void grpc_use_signal(int signum) { + grpc_wakeup_signal = signum; + is_grpc_wakeup_signal_initialized = true; -static int grpc_poller_kick_signum; + if (grpc_wakeup_signal < 0) { + gpr_log(GPR_INFO, + "Use of signals is disabled. Epoll engine will not be used"); + } else { + gpr_log(GPR_INFO, "epoll engine will be using signal: %d", + grpc_wakeup_signal); + } +} + +struct polling_island; /******************************************************************************* * Fd Declarations @@ -854,10 +872,7 @@ static void sig_handler(int sig_num) { #endif } -static void poller_kick_init() { - grpc_poller_kick_signum = SIGRTMIN + 2; - signal(grpc_poller_kick_signum, sig_handler); -} +static void poller_kick_init() { signal(grpc_wakeup_signal, sig_handler); } /* Global state management */ static void pollset_global_init(void) { @@ -874,7 +889,7 @@ static void pollset_global_shutdown(void) { } static void pollset_worker_kick(grpc_pollset_worker *worker) { - pthread_kill(worker->pt_id, grpc_poller_kick_signum); + pthread_kill(worker->pt_id, grpc_wakeup_signal); } /* Return 1 if the pollset has active threads in pollset_work (pollset must @@ -1214,9 +1229,9 @@ static void pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, pollset->kicked_without_pollers = 0; } else if (!pollset->shutting_down) { sigemptyset(&new_mask); - sigaddset(&new_mask, grpc_poller_kick_signum); + sigaddset(&new_mask, grpc_wakeup_signal); pthread_sigmask(SIG_BLOCK, &new_mask, &orig_mask); - sigdelset(&orig_mask, grpc_poller_kick_signum); + sigdelset(&orig_mask, grpc_wakeup_signal); push_front_worker(pollset, &worker); @@ -1497,19 +1512,29 @@ static bool is_epoll_available() { } const grpc_event_engine_vtable *grpc_init_epoll_linux(void) { + /* If use of signals is disabled, we cannot use epoll engine*/ + if (is_grpc_wakeup_signal_initialized && grpc_wakeup_signal < 0) { + return NULL; + } + if (!is_epoll_available()) { return NULL; } + if (!is_grpc_wakeup_signal_initialized) { + grpc_use_signal(SIGRTMIN + 2); + } + fd_global_init(); pollset_global_init(); polling_island_global_init(); return &vtable; } -#else /* defined(GPR_LINUX_EPOLL) */ +#else /* defined(GPR_LINUX_EPOLL) */ /* If GPR_LINUX_EPOLL is not defined, it means epoll is not available. Return * NULL */ const grpc_event_engine_vtable *grpc_init_epoll_linux(void) { return NULL; } +void grpc_use_signal(int signum) {} #endif /* !defined(GPR_LINUX_EPOLL) */ |