From c78895d1964ade09c9a006d4d600e592d773e542 Mon Sep 17 00:00:00 2001 From: Thomas White Date: Fri, 20 Jul 2012 14:59:10 -0400 Subject: Simplify signal handling --- src/im-sandbox.c | 119 +++++++++++++++++++++++++------------------------------ 1 file changed, 55 insertions(+), 64 deletions(-) diff --git a/src/im-sandbox.c b/src/im-sandbox.c index e67acfd9..8187612d 100644 --- a/src/im-sandbox.c +++ b/src/im-sandbox.c @@ -76,7 +76,6 @@ struct sandbox { pthread_mutex_t lock; - sigset_t old_sigmask; int n_indexable; int n_processed; @@ -101,36 +100,18 @@ struct sandbox /* Horrible global variable for signal handler */ -struct sandbox *sb; +int signal_pipe[2]; static void lock_sandbox(struct sandbox *sb) { - int r; - sigset_t set; - - sigemptyset(&set); - sigaddset(&set, SIGCHLD); - - r = pthread_sigmask(SIG_BLOCK, &set, &sb->old_sigmask); - if ( r != 0 ) { - ERROR("Failed to block signals.\n"); - } - pthread_mutex_lock(&sb->lock); } static void unlock_sandbox(struct sandbox *sb) { - int r; - pthread_mutex_unlock(&sb->lock); - - r = pthread_sigmask(SIG_SETMASK, &sb->old_sigmask, NULL); - if ( r != 0 ) { - ERROR("Failed to block signals.\n"); - } } @@ -563,11 +544,9 @@ static void start_worker_process(struct sandbox *sb, int slot) return; } - lock_sandbox(sb); p = fork(); if ( p == -1 ) { ERROR("fork() failed!\n"); - unlock_sandbox(sb); return; } @@ -578,9 +557,6 @@ static void start_worker_process(struct sandbox *sb, int slot) struct sigaction sa; int r; - /* FIXME: Is lock inherited? */ - unlock_sandbox(sb); - /* First, disconnect the signal handler */ sa.sa_flags = 0; sigemptyset(&sa.sa_mask); @@ -635,68 +611,62 @@ static void start_worker_process(struct sandbox *sb, int slot) sb->fhs[slot] = fdopen(sb->stream_pipe_read[slot], "r"); if ( sb->fhs[slot] == NULL ) { ERROR("Couldn't fdopen() stream!\n"); - unlock_sandbox(sb); return; } sb->result_fhs[slot] = fdopen(result_pipe[0], "r"); if ( sb->result_fhs[slot] == NULL ) { ERROR("fdopen() failed.\n"); - unlock_sandbox(sb); return; } - - unlock_sandbox(sb); } static void signal_handler(int sig, siginfo_t *si, void *uc_v) { - int i, found; + write(signal_pipe[1], "\n", 1); +} - if ( si->si_signo != SIGCHLD ) { - ERROR("Unhandled signal %i?\n", si->si_signo); - return; - } - found = 0; +static void handle_zombie(struct sandbox *sb) +{ + int i; + lock_sandbox(sb); for ( i=0; in_proc; i++ ) { - if ( (sb->running[i]) && (sb->pids[i] == si->si_pid) ) { - found = 1; - break; + + int status, p; + + if ( !sb->running[i] ) continue; + + p = waitpid(sb->pids[i], &status, WNOHANG); + + if ( p == -1 ) { + ERROR("waitpid() failed.\n"); + continue; } - } - unlock_sandbox(sb); - if ( !found ) { - ERROR("SIGCHLD from unknown child %i?\n", si->si_pid); - return; - } + if ( p == sb->pids[i] ) { - if ( (si->si_code == CLD_TRAPPED) || (si->si_code == CLD_STOPPED) - || (si->si_code == CLD_CONTINUED) ) return; + sb->running[i] = 0; - if ( si->si_code == CLD_EXITED ) - { - lock_sandbox(sb); - sb->running[i] = 0; - unlock_sandbox(sb); - STATUS("Worker process %i exited normally.\n", i); - return; - } + if ( WIFEXITED(status) ) { + STATUS("Worker %i exited normally.\n", i); + continue; + } - if ( (si->si_code != CLD_DUMPED) && (si->si_code != CLD_KILLED) ) { - ERROR("Unhandled si_code %i (worker process %i).\n", - si->si_code, i); - return; - } + if ( WIFSIGNALED(status) ) { + STATUS("Worker %i was killed by signal %i\n", + i, WTERMSIG(status)); + STATUS("Last filename was: %s\n", + sb->last_filename[i]); + start_worker_process(sb, i); + } - ERROR("Worker process %i exited abnormally!\n", i); - ERROR(" -> Signal %i, last filename %s.\n", - si->si_signo, sb->last_filename[i]); + } - start_worker_process(sb, i); + } + unlock_sandbox(sb); } @@ -709,6 +679,7 @@ void create_sandbox(struct index_args *iargs, int n_proc, char *prefix, struct sigaction sa; int r; pthread_t reader_thread; + struct sandbox *sb; sb = calloc(1, sizeof(struct sandbox)); if ( sb == NULL ) { @@ -791,6 +762,11 @@ void create_sandbox(struct index_args *iargs, int n_proc, char *prefix, return; } + if ( pipe(signal_pipe) == -1 ) { + ERROR("Failed to create signal pipe.\n"); + return; + } + /* Set up signal handler to take action if any children die */ sa.sa_flags = SA_SIGINFO | SA_NOCLDSTOP; sigemptyset(&sa.sa_mask); @@ -802,9 +778,11 @@ void create_sandbox(struct index_args *iargs, int n_proc, char *prefix, } /* Fork the right number of times */ + lock_sandbox(sb); for ( i=0; i fdmax ) fdmax = signal_pipe[0]; + r = select(fdmax+1, &fds, NULL, NULL, &tv); if ( r == -1 ) { if ( errno != EINTR ) { @@ -846,6 +827,14 @@ void create_sandbox(struct index_args *iargs, int n_proc, char *prefix, if ( r == 0 ) continue; /* No progress this time. Try again */ + if ( FD_ISSET(signal_pipe[0], &fds) ) { + + char d; + read(signal_pipe[0], &d, 1); + handle_zombie(sb); + + } + lock_sandbox(sb); for ( i=0; ilast_filename[i]); + sb->last_filename[i] = nextImage; + if ( nextImage == NULL ) { /* No more images */ r = write(sb->filename_pipes[i], "\n", 1); @@ -903,7 +895,6 @@ void create_sandbox(struct index_args *iargs, int n_proc, char *prefix, if ( r < 0 ) { ERROR("write pipe\n"); } - free(nextImage); } } -- cgit v1.2.3