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authorBjörn-Egil Dahlberg <[email protected]>2017-02-03 15:22:06 +0100
committerBjörn-Egil Dahlberg <[email protected]>2017-02-03 15:22:06 +0100
commite53e74c5349061857d8eeb9c564768e54446012a (patch)
tree1c7ebcd38ff44e9ca0d8ba558e334791858b5096 /erts/emulator/sys/unix/sys.c
parent08726ff1c6a0bfb9989034920184438aed9db8bd (diff)
parent1409b6ae110f60c410e83d1923dd59ae3659a887 (diff)
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Merge branch 'egil/20/erts/signal-service/OTP-14186'
* egil/20/erts/signal-service/OTP-14186: kernel: Document signal server erts: Use os module instead of erts_internal for set_signal/2 erts: Do not handle SIGILL erts: Fix thread suspend in crashdump erts: Do not enable SIGINT erts: Use generic signal handler erts: Add OS signal tests erts: Handle SIGUSR1 via signal service instead erts: Handle SIGTERM via signal service instead kernel: Add gen_event signal server and default handler erts: Add SIGHUP signal handler erts: Remove whitespace errors Conflicts: erts/emulator/beam/bif.tab
Diffstat (limited to 'erts/emulator/sys/unix/sys.c')
-rw-r--r--erts/emulator/sys/unix/sys.c394
1 files changed, 177 insertions, 217 deletions
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index e135dbff99..cb20c690b4 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -50,7 +50,6 @@
#endif
#define ERTS_WANT_BREAK_HANDLING
-#define ERTS_WANT_GOT_SIGUSR1
#define WANT_NONBLOCKING /* must define this to pull in defs from sys.h */
#include "sys.h"
#include "erl_thr_progress.h"
@@ -96,18 +95,10 @@ static int debug_log = 0;
#endif
#ifdef ERTS_SMP
-erts_smp_atomic32_t erts_got_sigusr1;
-#define ERTS_SET_GOT_SIGUSR1 \
- erts_smp_atomic32_set_mb(&erts_got_sigusr1, 1)
-#define ERTS_UNSET_GOT_SIGUSR1 \
- erts_smp_atomic32_set_mb(&erts_got_sigusr1, 0)
static erts_smp_atomic32_t have_prepared_crash_dump;
#define ERTS_PREPARED_CRASH_DUMP \
((int) erts_smp_atomic32_xchg_nob(&have_prepared_crash_dump, 1))
#else
-volatile int erts_got_sigusr1;
-#define ERTS_SET_GOT_SIGUSR1 (erts_got_sigusr1 = 1)
-#define ERTS_UNSET_GOT_SIGUSR1 (erts_got_sigusr1 = 0)
static volatile int have_prepared_crash_dump;
#define ERTS_PREPARED_CRASH_DUMP \
(have_prepared_crash_dump++)
@@ -116,7 +107,7 @@ static volatile int have_prepared_crash_dump;
erts_smp_atomic_t sys_misc_mem_sz;
#if defined(ERTS_SMP)
-static void smp_sig_notify(char c);
+static void smp_sig_notify(int signum);
static int sig_notify_fds[2] = {-1, -1};
#ifdef ERTS_SYS_SUSPEND_SIGNAL
@@ -152,7 +143,7 @@ volatile int erts_break_requested = 0;
static struct termios initial_tty_mode;
static int replace_intr = 0;
/* assume yes initially, ttsl_init will clear it */
-int using_oldshell = 1;
+int using_oldshell = 1;
#ifdef ERTS_ENABLE_KERNEL_POLL
@@ -403,13 +394,6 @@ erts_sys_pre_init(void)
/* After creation in parent */
eid.thread_create_parent_func = thr_create_cleanup,
-#ifdef ERTS_THR_HAVE_SIG_FUNCS
- sigemptyset(&thr_create_sigmask);
- sigaddset(&thr_create_sigmask, SIGINT); /* block interrupt */
- sigaddset(&thr_create_sigmask, SIGTERM); /* block terminate signal */
- sigaddset(&thr_create_sigmask, SIGUSR1); /* block user defined signal */
-#endif
-
erts_thr_init(&eid);
#ifdef ERTS_ENABLE_LOCK_CHECK
@@ -428,11 +412,9 @@ erts_sys_pre_init(void)
#ifdef ERTS_SMP
erts_smp_atomic32_init_nob(&erts_break_requested, 0);
- erts_smp_atomic32_init_nob(&erts_got_sigusr1, 0);
erts_smp_atomic32_init_nob(&have_prepared_crash_dump, 0);
#else
erts_break_requested = 0;
- erts_got_sigusr1 = 0;
have_prepared_crash_dump = 0;
#endif
@@ -624,6 +606,28 @@ int erts_sys_prepare_crash_dump(int secs)
return prepare_crash_dump(secs);
}
+static void signal_notify_requested(Eterm type) {
+ Process* p = NULL;
+ Eterm msg, *hp;
+ ErtsProcLocks locks = 0;
+ ErlOffHeap *ohp;
+
+ Eterm id = erts_whereis_name_to_id(NULL, am_erl_signal_server);
+
+ if ((p = (erts_pid2proc_opt(NULL, 0, id, 0, ERTS_P2P_FLG_INC_REFC))) != NULL) {
+ ErtsMessage *msgp = erts_alloc_message_heap(p, &locks, 3, &hp, &ohp);
+
+ /* erl_signal_server ! {notify, sighup} */
+ msg = TUPLE2(hp, am_notify, type);
+ erts_queue_message(p, locks, msgp, msg, am_system);
+
+ if (locks)
+ erts_smp_proc_unlock(p, locks);
+ erts_proc_dec_refc(p);
+ }
+}
+
+
static ERTS_INLINE void
break_requested(void)
{
@@ -641,76 +645,15 @@ break_requested(void)
ERTS_CHK_IO_AS_INTR(); /* Make sure we don't sleep in poll */
}
-/* set up signal handlers for break and quit */
-#if (defined(SIG_SIGSET) || defined(SIG_SIGNAL))
-static RETSIGTYPE request_break(void)
-#else
static RETSIGTYPE request_break(int signum)
-#endif
{
#ifdef ERTS_SMP
- smp_sig_notify('I');
+ smp_sig_notify(signum);
#else
break_requested();
#endif
}
-static void stop_requested(void) {
- Process* p = NULL;
- Eterm msg, *hp;
- ErtsProcLocks locks = 0;
- ErlOffHeap *ohp;
- Eterm id = erts_whereis_name_to_id(NULL, am_init);
-
- if ((p = (erts_pid2proc_opt(NULL, 0, id, 0, ERTS_P2P_FLG_INC_REFC))) != NULL) {
- ErtsMessage *msgp = erts_alloc_message_heap(p, &locks, 3, &hp, &ohp);
-
- /* init ! {stop,stop} */
- msg = TUPLE2(hp, am_stop, am_stop);
- erts_queue_message(p, locks, msgp, msg, am_system);
-
- if (locks)
- erts_smp_proc_unlock(p, locks);
- erts_proc_dec_refc(p);
- }
-}
-
-#if (defined(SIG_SIGSET) || defined(SIG_SIGNAL))
-static RETSIGTYPE request_stop(void)
-#else
-static RETSIGTYPE request_stop(int signum)
-#endif
-{
-#ifdef ERTS_SMP
- smp_sig_notify('S');
-#else
- stop_requested();
-#endif
-}
-
-
-static ERTS_INLINE void
-sigusr1_exit(void)
-{
- char env[21]; /* enough to hold any 64-bit integer */
- size_t envsz;
- int i, secs = -1;
-
- /* We do this at interrupt level, since the main reason for
- * wanting to generate a crash dump in this way is that the emulator
- * is hung somewhere, so it won't be able to poll any flag we set here.
- */
- ERTS_SET_GOT_SIGUSR1;
-
- envsz = sizeof(env);
- if ((i = erts_sys_getenv_raw("ERL_CRASH_DUMP_SECONDS", env, &envsz)) >= 0) {
- secs = i != 0 ? 0 : atoi(env);
- }
-
- prepare_crash_dump(secs);
- erts_exit(ERTS_DUMP_EXIT, "Received SIGUSR1\n");
-}
-
#ifdef ETHR_UNUSABLE_SIGUSRX
#warning "Unusable SIGUSR1 & SIGUSR2. Disabling use of these signals"
@@ -731,19 +674,6 @@ sys_thr_resume(erts_tid_t tid) {
}
#endif
-#if (defined(SIG_SIGSET) || defined(SIG_SIGNAL))
-static RETSIGTYPE user_signal1(void)
-#else
-static RETSIGTYPE user_signal1(int signum)
-#endif
-{
-#ifdef ERTS_SMP
- smp_sig_notify('1');
-#else
- sigusr1_exit();
-#endif
-}
-
#ifdef ERTS_SYS_SUSPEND_SIGNAL
#if (defined(SIG_SIGSET) || defined(SIG_SIGNAL))
static RETSIGTYPE suspend_signal(void)
@@ -763,29 +693,101 @@ static RETSIGTYPE suspend_signal(int signum)
#endif /* #ifndef ETHR_UNUSABLE_SIGUSRX */
-static void
-quit_requested(void)
-{
- erts_exit(ERTS_INTR_EXIT, "");
+/*
+ Signal Action Comment
+ ─────────────────────────────────────────────────────────────
+ SIGHUP Term Hangup detected on controlling terminal or death of controlling process
+ !SIGINT Term Interrupt from keyboard
+ SIGQUIT Core Quit from keyboard
+ !SIGILL Core Illegal Instruction
+ SIGABRT Core Abort signal from abort(3)
+ !SIGFPE Core Floating point exception
+ !SIGKILL Term Kill signal
+ !SIGSEGV Core Invalid memory reference
+ !SIGPIPE Term Broken pipe: write to pipe with no readers
+ SIGALRM Term Timer signal from alarm(2)
+ SIGTERM Term Termination signal
+ SIGUSR1 Term User-defined signal 1
+ SIGUSR2 Term User-defined signal 2
+ !SIGCHLD Ign Child stopped or terminated
+ !SIGCONT Cont Continue if stopped
+ SIGSTOP Stop Stop process
+ SIGTSTP Stop Stop typed at terminal
+ !SIGTTIN Stop Terminal input for background process
+ !SIGTTOU Stop Terminal output for background process
+*/
+
+
+static ERTS_INLINE int
+signalterm_to_signum(Eterm signal)
+{
+ switch (signal) {
+ case am_sighup: return SIGHUP;
+ /* case am_sigint: return SIGINT; */
+ case am_sigquit: return SIGQUIT;
+ /* case am_sigill: return SIGILL; */
+ case am_sigabrt: return SIGABRT;
+ /* case am_sigsegv: return SIGSEGV; */
+ case am_sigalrm: return SIGALRM;
+ case am_sigterm: return SIGTERM;
+ case am_sigusr1: return SIGUSR1;
+ case am_sigusr2: return SIGUSR2;
+ case am_sigchld: return SIGCHLD;
+ case am_sigstop: return SIGSTOP;
+ case am_sigtstp: return SIGTSTP;
+ default: return 0;
+ }
}
-#if (defined(SIG_SIGSET) || defined(SIG_SIGNAL))
-static RETSIGTYPE do_quit(void)
-#else
-static RETSIGTYPE do_quit(int signum)
-#endif
+static ERTS_INLINE Eterm
+signum_to_signalterm(int signum)
+{
+ switch (signum) {
+ case SIGHUP: return am_sighup;
+ /* case SIGINT: return am_sigint; */ /* ^c */
+ case SIGQUIT: return am_sigquit; /* ^\ */
+ /* case SIGILL: return am_sigill; */
+ case SIGABRT: return am_sigabrt;
+ /* case SIGSEGV: return am_sigsegv; */
+ case SIGALRM: return am_sigalrm;
+ case SIGTERM: return am_sigterm;
+ case SIGUSR1: return am_sigusr1;
+ case SIGUSR2: return am_sigusr2;
+ case SIGCHLD: return am_sigchld;
+ case SIGSTOP: return am_sigstop;
+ case SIGTSTP: return am_sigtstp; /* ^z */
+ default: return am_error;
+ }
+}
+
+static RETSIGTYPE generic_signal_handler(int signum)
{
#ifdef ERTS_SMP
- smp_sig_notify('Q');
+ smp_sig_notify(signum);
#else
- quit_requested();
+ Eterm signal = signum_to_signalterm(signum);
+ signal_notify_requested(signal);
#endif
}
+int erts_set_signal(Eterm signal, Eterm type) {
+ int signum;
+ if ((signum = signalterm_to_signum(signal)) > 0) {
+ if (type == am_ignore) {
+ sys_signal(signum, SIG_IGN);
+ } else if (type == am_default) {
+ sys_signal(signum, SIG_DFL);
+ } else {
+ sys_signal(signum, generic_signal_handler);
+ }
+ return 1;
+ }
+ return 0;
+}
+
/* Disable break */
void erts_set_ignore_break(void) {
sys_signal(SIGINT, SIG_IGN);
- sys_signal(SIGTERM, SIG_IGN);
sys_signal(SIGQUIT, SIG_IGN);
sys_signal(SIGTSTP, SIG_IGN);
}
@@ -797,11 +799,11 @@ void erts_replace_intr(void) {
if (isatty(0)) {
tcgetattr(0, &mode);
-
+
/* here's an example of how to replace ctrl-c with ctrl-u */
/* mode.c_cc[VKILL] = 0;
mode.c_cc[VINTR] = CKILL; */
-
+
mode.c_cc[VINTR] = 0; /* disable ctrl-c */
tcsetattr(0, TCSANOW, &mode);
replace_intr = 1;
@@ -810,12 +812,13 @@ void erts_replace_intr(void) {
void init_break_handler(void)
{
- sys_signal(SIGINT, request_break);
- sys_signal(SIGTERM, request_stop);
+ sys_signal(SIGINT, request_break);
+ sys_signal(SIGTERM, generic_signal_handler);
+ sys_signal(SIGHUP, generic_signal_handler);
#ifndef ETHR_UNUSABLE_SIGUSRX
- sys_signal(SIGUSR1, user_signal1);
+ sys_signal(SIGUSR1, generic_signal_handler);
#endif /* #ifndef ETHR_UNUSABLE_SIGUSRX */
- sys_signal(SIGQUIT, do_quit);
+ sys_signal(SIGQUIT, generic_signal_handler);
}
void sys_init_suspend_handler(void)
@@ -855,10 +858,7 @@ get_number(char **str_ptr)
}
}
-void
-os_flavor(char* namebuf, /* Where to return the name. */
- unsigned size) /* Size of name buffer. */
-{
+void os_flavor(char* namebuf, unsigned size) {
struct utsname uts; /* Information about the system. */
char* s;
@@ -871,22 +871,16 @@ os_flavor(char* namebuf, /* Where to return the name. */
strcpy(namebuf, uts.sysname);
}
-void
-os_version(pMajor, pMinor, pBuild)
-int* pMajor; /* Pointer to major version. */
-int* pMinor; /* Pointer to minor version. */
-int* pBuild; /* Pointer to build number. */
-{
+void os_version(int *pMajor, int *pMinor, int *pBuild) {
struct utsname uts; /* Information about the system. */
char* release; /* Pointer to the release string:
- * X.Y or X.Y.Z.
- */
+ * X.Y or X.Y.Z. */
(void) uname(&uts);
release = uts.release;
- *pMajor = get_number(&release);
- *pMinor = get_number(&release);
- *pBuild = get_number(&release);
+ *pMajor = get_number(&release); /* Pointer to major version. */
+ *pMinor = get_number(&release); /* Pointer to minor version. */
+ *pBuild = get_number(&release); /* Pointer to build number. */
}
void init_getenv_state(GETENV_STATE *state)
@@ -921,7 +915,7 @@ void erts_do_break_handling(void)
{
struct termios temp_mode;
int saved = 0;
-
+
/*
* Most functions that do_break() calls are intentionally not thread safe;
* therefore, make sure that all threads but this one are blocked before
@@ -939,14 +933,14 @@ void erts_do_break_handling(void)
tcsetattr(0,TCSANOW,&initial_tty_mode);
saved = 1;
}
-
+
/* call the break handling function, reset the flag */
do_break();
ERTS_UNSET_BREAK_REQUESTED;
fflush(stdout);
-
+
/* after break we go back to saved settings */
if (using_oldshell && !replace_intr) {
SET_NONBLOCKING(1);
@@ -1054,37 +1048,12 @@ erts_sys_unsetenv(char *key)
return res;
}
-void
-sys_init_io(void)
-{
-}
-
-#if (0) /* unused? */
-static int write_fill(fd, buf, len)
-int fd, len;
-char *buf;
-{
- int i, done = 0;
-
- do {
- if ((i = write(fd, buf+done, len-done)) < 0) {
- if (errno != EINTR)
- return (i);
- i = 0;
- }
- done += i;
- } while (done < len);
- return (len);
-}
-#endif
+void sys_init_io(void) { }
+void erts_sys_alloc_init(void) { }
extern const char pre_loaded_code[];
extern Preload pre_loaded[];
-void erts_sys_alloc_init(void)
-{
-}
-
#if ERTS_HAVE_ERTS_SYS_ALIGNED_ALLOC
void *erts_sys_aligned_alloc(UWord alignment, UWord size)
{
@@ -1185,9 +1154,7 @@ void sys_preload_end(Preload* p)
Here we assume that all schedulers are stopped so that erl_poll
does not interfere with the select below.
*/
-int sys_get_key(fd)
-int fd;
-{
+int sys_get_key(int fd) {
int c, ret;
unsigned char rbuf[64];
fd_set fds;
@@ -1206,15 +1173,14 @@ int fd;
if (c <= 0)
return c;
}
-
- return rbuf[0];
+ return rbuf[0];
}
extern int erts_initialized;
void
erl_assert_error(const char* expr, const char* func, const char* file, int line)
-{
+{
fflush(stdout);
fprintf(stderr, "%s:%d:%s() Assertion failed: %s\n",
file, line, func, expr);
@@ -1239,7 +1205,7 @@ erl_debug(char* fmt, ...)
{
char sbuf[1024]; /* Temporary buffer. */
va_list va;
-
+
if (debug_log) {
va_start(va, fmt);
vsprintf(sbuf, fmt, va);
@@ -1268,14 +1234,14 @@ erl_sys_schedule(int runnable)
static erts_smp_tid_t sig_dispatcher_tid;
static void
-smp_sig_notify(char c)
+smp_sig_notify(int signum)
{
int res;
do {
/* write() is async-signal safe (according to posix) */
- res = write(sig_notify_fds[1], &c, 1);
+ res = write(sig_notify_fds[1], &signum, sizeof(int));
} while (res < 0 && errno == EINTR);
- if (res != 1) {
+ if (res != sizeof(int)) {
char msg[] =
"smp_sig_notify(): Failed to notify signal-dispatcher thread "
"about received signal";
@@ -1291,60 +1257,55 @@ signal_dispatcher_thread_func(void *unused)
erts_lc_set_thread_name("signal_dispatcher");
#endif
while (1) {
- char buf[32];
- int res, i;
+ union {int signum; char buf[4];} sb;
+ Eterm signal;
+ int res, i = 0;
/* Block on read() waiting for a signal notification to arrive... */
- res = read(sig_notify_fds[0], (void *) &buf[0], 32);
+
+ do {
+ res = read(sig_notify_fds[0], (void *) &sb.buf[i], sizeof(int) - i);
+ i += res;
+ } while ((i != sizeof(int) && res >= 0) || (res < 0 && errno == EINTR));
+
if (res < 0) {
- if (errno == EINTR)
- continue;
erts_exit(ERTS_ABORT_EXIT,
"signal-dispatcher thread got unexpected error: %s (%d)\n",
erl_errno_id(errno),
errno);
}
- for (i = 0; i < res; i++) {
- /*
- * NOTE 1: The signal dispatcher thread should not do work
- * that takes a substantial amount of time (except
- * perhaps in test and debug builds). It needs to
- * be responsive, i.e, it should only dispatch work
- * to other threads.
- *
- * NOTE 2: The signal dispatcher thread is not a blockable
- * thread (i.e., not a thread managed by the
- * erl_thr_progress module). This is intentional.
- * We want to be able to interrupt writing of a crash
- * dump by hitting C-c twice. Since it isn't a
- * blockable thread it is important that it doesn't
- * change the state of any data that a blocking thread
- * expects to have exclusive access to (unless the
- * signal dispatcher itself explicitly is blocking all
- * blockable threads).
- */
- switch (buf[i]) {
- case 0: /* Emulator initialized */
+ /*
+ * NOTE 1: The signal dispatcher thread should not do work
+ * that takes a substantial amount of time (except
+ * perhaps in test and debug builds). It needs to
+ * be responsive, i.e, it should only dispatch work
+ * to other threads.
+ *
+ * NOTE 2: The signal dispatcher thread is not a blockable
+ * thread (i.e., not a thread managed by the
+ * erl_thr_progress module). This is intentional.
+ * We want to be able to interrupt writing of a crash
+ * dump by hitting C-c twice. Since it isn't a
+ * blockable thread it is important that it doesn't
+ * change the state of any data that a blocking thread
+ * expects to have exclusive access to (unless the
+ * signal dispatcher itself explicitly is blocking all
+ * blockable threads).
+ */
+ switch (sb.signum) {
+ case 0: continue;
+ case SIGINT:
+ break_requested();
break;
- case 'S': /* SIGTERM */
- stop_requested();
- break;
- case 'I': /* SIGINT */
- break_requested();
- break;
- case 'Q': /* SIGQUIT */
- quit_requested();
- break;
- case '1': /* SIGUSR1 */
- sigusr1_exit();
- break;
- default:
- erts_exit(ERTS_ABORT_EXIT,
- "signal-dispatcher thread received unknown "
- "signal notification: '%c'\n",
- buf[i]);
- }
- }
- ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
+ default:
+ if ((signal = signum_to_signalterm(sb.signum)) == am_error) {
+ erts_exit(ERTS_ABORT_EXIT,
+ "signal-dispatcher thread received unknown "
+ "signal notification: '%d'\n",
+ sb.signum);
+ }
+ signal_notify_requested(signal);
+ }
+ ERTS_SMP_LC_ASSERT(!erts_thr_progress_is_blocking());
}
return NULL;
}
@@ -1387,9 +1348,9 @@ init_smp_sig_suspend(void) {
int erts_darwin_main_thread_pipe[2];
int erts_darwin_main_thread_result_pipe[2];
-static void initialize_darwin_main_thread_pipes(void)
+static void initialize_darwin_main_thread_pipes(void)
{
- if (pipe(erts_darwin_main_thread_pipe) < 0 ||
+ if (pipe(erts_darwin_main_thread_pipe) < 0 ||
pipe(erts_darwin_main_thread_result_pipe) < 0) {
erts_exit(ERTS_ERROR_EXIT,"Fatal error initializing Darwin main thread stealing");
}
@@ -1555,5 +1516,4 @@ erl_sys_args(int* argc, char** argv)
argv[j++] = argv[i];
}
*argc = j;
-
}