From d899fca42570d53c714d7656f628551939a2ac0c Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Fri, 23 May 2014 02:59:46 +0200 Subject: Implement a different fix for the waitpid race condition not needing a reaper thread for each child --- src/shell.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) (limited to 'src/shell.c') diff --git a/src/shell.c b/src/shell.c index 9d03fbc..2be7f82 100644 --- a/src/shell.c +++ b/src/shell.c @@ -103,18 +103,15 @@ static void shell_command_setenv(pid_t pid, const fastd_shell_env_t *env) { } } -static bool shell_command_do_exec(const fastd_shell_command_t *command, const fastd_shell_env_t *env, pid_t *pid_ret) { +static bool shell_command_do_exec(const fastd_shell_command_t *command, const fastd_shell_env_t *env, pid_t *pid) { pid_t parent = getpid(); - pid_t pid = fork(); - if (pid < 0) { + *pid = fork(); + if (*pid < 0) { pr_error_errno("shell_command_do_exec: fork"); return false; } - else if (pid > 0) { - if (pid_ret) - *pid_ret = pid; - + else if (*pid > 0) { return true; } @@ -174,6 +171,19 @@ bool fastd_shell_command_exec_sync(const fastd_shell_command_t *command, const f return true; } +static void shell_command_exec_async(const fastd_shell_command_t *command, const fastd_shell_env_t *env) { + /* block SIGCHLD */ + sigset_t set, oldset; + sigemptyset(&set); + sigaddset(&set, SIGCHLD); + pthread_sigmask(SIG_BLOCK, &set, &oldset); + + pid_t pid; + if (shell_command_do_exec(command, env, &pid)) + VECTOR_ADD(ctx.async_pids, pid); + + pthread_sigmask(SIG_SETMASK, &oldset, NULL); +} void fastd_shell_command_exec(const fastd_shell_command_t *command, const fastd_shell_env_t *env) { if (!fastd_shell_command_isset(command)) @@ -182,5 +192,5 @@ void fastd_shell_command_exec(const fastd_shell_command_t *command, const fastd_ if (command->sync) fastd_shell_command_exec_sync(command, env, NULL); else - shell_command_do_exec(command, env, NULL); + shell_command_exec_async(command, env); } -- cgit v1.2.3