diff options
Diffstat (limited to 'erts/emulator/sys/unix/sys.c')
| -rw-r--r-- | erts/emulator/sys/unix/sys.c | 253 |
1 files changed, 233 insertions, 20 deletions
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c index c3d7440409..eed93cb2a0 100644 --- a/erts/emulator/sys/unix/sys.c +++ b/erts/emulator/sys/unix/sys.c @@ -34,6 +34,7 @@ #include <termios.h> #include <ctype.h> #include <sys/utsname.h> +#include <sys/select.h> #ifdef ISC32 #include <sys/bsdtypes.h> @@ -91,8 +92,10 @@ static erts_smp_rwmtx_t environ_rwmtx; # else # define CHLDWTHR 0 # endif +# define FDBLOCK 1 #else # define CHLDWTHR 0 +# define FDBLOCK 0 #endif /* * [OTP-3906] @@ -121,6 +124,15 @@ struct ErtsSysReportExit_ { #endif }; +/* Used by the fd driver iff the fd could not be set to non-blocking */ +typedef struct ErtsSysBlocking_ { + ErlDrvPDL pdl; + int res; + int err; + unsigned int pkey; +} ErtsSysBlocking; + + /* This data is shared by these drivers - initialized by spawn_init() */ static struct driver_data { ErlDrvPort port_num; @@ -129,6 +141,8 @@ static struct driver_data { int pid; int alive; int status; + int terminating; + ErtsSysBlocking *blocking; } *driver_data; /* indexed by fd */ static ErtsSysReportExit *report_exit_list; @@ -1108,11 +1122,16 @@ void fini_getenv_state(GETENV_STATE *state) /* Driver interfaces */ static ErlDrvData spawn_start(ErlDrvPort, char*, SysDriverOpts*); static ErlDrvData fd_start(ErlDrvPort, char*, SysDriverOpts*); +#if FDBLOCK +static void fd_async(void *); +static void fd_ready_async(ErlDrvData drv_data, ErlDrvThreadData thread_data); +#endif static ErlDrvSSizeT fd_control(ErlDrvData, unsigned int, char *, ErlDrvSizeT, char **, ErlDrvSizeT); static ErlDrvData vanilla_start(ErlDrvPort, char*, SysDriverOpts*); static int spawn_init(void); static void fd_stop(ErlDrvData); +static void fd_flush(ErlDrvData); static void stop(ErlDrvData); static void ready_input(ErlDrvData, ErlDrvEvent); static void ready_output(ErlDrvData, ErlDrvEvent); @@ -1157,8 +1176,12 @@ struct erl_drv_entry fd_driver_entry = { fd_control, NULL, outputv, - NULL, /* ready_async */ - NULL, /* flush */ +#if FDBLOCK + fd_ready_async, /* ready_async */ +#else + NULL, +#endif + fd_flush, /* flush */ NULL, /* call */ NULL, /* event */ ERL_DRV_EXTENDED_MARKER, @@ -1212,13 +1235,28 @@ static RETSIGTYPE onchld(int signum) #endif } +static int set_blocking_data(struct driver_data *dd) { + + dd->blocking = erts_alloc(ERTS_ALC_T_SYS_BLOCKING, sizeof(ErtsSysBlocking)); + + erts_smp_atomic_add_nob(&sys_misc_mem_sz, sizeof(ErtsSysBlocking)); + + dd->blocking->pdl = driver_pdl_create(dd->port_num); + dd->blocking->res = 0; + dd->blocking->err = 0; + dd->blocking->pkey = driver_async_port_key(dd->port_num); + + return 1; +} + static int set_driver_data(ErlDrvPort port_num, int ifd, int ofd, int packet_bytes, int read_write, int exit_status, - int pid) + int pid, + int is_blocking) { Port *prt; ErtsSysReportExit *report_exit; @@ -1250,8 +1288,13 @@ static int set_driver_data(ErlDrvPort port_num, driver_data[ifd].pid = pid; driver_data[ifd].alive = 1; driver_data[ifd].status = 0; + driver_data[ifd].terminating = 0; + driver_data[ifd].blocking = NULL; if (read_write & DO_WRITE) { driver_data[ifd].ofd = ofd; + if (is_blocking && FDBLOCK) + if (!set_blocking_data(driver_data+ifd)) + return -1; if (ifd != ofd) driver_data[ofd] = driver_data[ifd]; /* structure copy */ } else { /* DO_READ only */ @@ -1267,6 +1310,11 @@ static int set_driver_data(ErlDrvPort port_num, driver_data[ofd].pid = pid; driver_data[ofd].alive = 1; driver_data[ofd].status = 0; + driver_data[ofd].terminating = 0; + driver_data[ofd].blocking = NULL; + if (is_blocking && FDBLOCK) + if (!set_blocking_data(driver_data+ofd)) + return -1; return(ofd); } } @@ -1276,6 +1324,7 @@ static int spawn_init() int i; #if CHLDWTHR erts_thr_opts_t thr_opts = ERTS_THR_OPTS_DEFAULT_INITER; + thr_opts.detached = 0; thr_opts.suggested_stack_size = 0; /* Smallest possible */ #endif @@ -1755,7 +1804,7 @@ static ErlDrvData spawn_start(ErlDrvPort port_num, char* name, SysDriverOpts* op } res = set_driver_data(port_num, ifd[0], ofd[1], opts->packet_bytes, - opts->read_write, opts->exit_status, pid); + opts->read_write, opts->exit_status, pid, 0); /* Don't unblock SIGCHLD until now, since the call above must first complete putting away the info about our new subprocess. */ unblock_signals(); @@ -1840,6 +1889,7 @@ static ErlDrvData fd_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts) { ErlDrvData res; + int non_blocking = 0; if (((opts->read_write & DO_READ) && opts->ifd >= max_files) || ((opts->read_write & DO_WRITE) && opts->ofd >= max_files)) @@ -1912,6 +1962,20 @@ static ErlDrvData fd_start(ErlDrvPort port_num, char* name, * case - it can be called with any old pre-existing file descriptors, * the relations between which (if they're even two) we can only guess * at - still, we try our best... + * + * Added note OTP 18: Some systems seem to use stdout/stderr to log data + * using unix pipes, so we cannot allow the system to block on a write. + * Therefore we use an async thread to write the data to fd's that could + * not be set to non-blocking. When no async threads are available we + * fall back on the old behaviour. + * + * Also the guarantee about what is delivered to the OS has changed. + * Pre 18 the fd driver did no flushing of data before terminating. + * Now it does. This is because we want to be able to guarantee that things + * such as escripts and friends really have outputted all data before + * terminating. This could potentially block the termination of the system + * for a very long time, but if the user wants to terminate fast she should + * use erlang:halt with flush=false. */ if (opts->read_write & DO_READ) { @@ -1934,6 +1998,7 @@ static ErlDrvData fd_start(ErlDrvPort port_num, char* name, imagine a scenario where setting non-blocking mode here would cause problems - go ahead and do it. */ + non_blocking = 1; SET_NONBLOCKING(opts->ofd); } else { /* output fd is a tty, input fd isn't */ @@ -1976,6 +2041,7 @@ static ErlDrvData fd_start(ErlDrvPort port_num, char* name, (nfd = open(tty, O_WRONLY)) != -1) { dup2(nfd, opts->ofd); close(nfd); + non_blocking = 1; SET_NONBLOCKING(opts->ofd); } } @@ -1984,8 +2050,9 @@ static ErlDrvData fd_start(ErlDrvPort port_num, char* name, } CHLD_STAT_LOCK; res = (ErlDrvData)(long)set_driver_data(port_num, opts->ifd, opts->ofd, - opts->packet_bytes, - opts->read_write, 0, -1); + opts->packet_bytes, + opts->read_write, 0, -1, + !non_blocking); CHLD_STAT_UNLOCK; return res; } @@ -2011,14 +2078,30 @@ static void nbio_stop_fd(ErlDrvPort prt, int fd) SET_BLOCKING(fd); } -static void fd_stop(ErlDrvData fd) /* Does not close the fds */ +static void fd_stop(ErlDrvData ev) /* Does not close the fds */ { int ofd; + int fd = (int)(long)ev; + ErlDrvPort prt = driver_data[fd].port_num; - nbio_stop_fd(driver_data[(int)(long)fd].port_num, (int)(long)fd); - ofd = driver_data[(int)(long)fd].ofd; - if (ofd != (int)(long)fd && ofd != -1) - nbio_stop_fd(driver_data[(int)(long)fd].port_num, (int)(long)ofd); +#if FDBLOCK + if (driver_data[fd].blocking) { + erts_free(ERTS_ALC_T_SYS_BLOCKING,driver_data[fd].blocking); + driver_data[fd].blocking = NULL; + erts_smp_atomic_add_nob(&sys_misc_mem_sz, -1*sizeof(ErtsSysBlocking)); + } +#endif + + nbio_stop_fd(prt, fd); + ofd = driver_data[fd].ofd; + if (ofd != fd && ofd != -1) + nbio_stop_fd(prt, ofd); +} + +static void fd_flush(ErlDrvData fd) +{ + if (!driver_data[(int)(long)fd].terminating) + driver_data[(int)(long)fd].terminating = 1; } static ErlDrvData vanilla_start(ErlDrvPort port_num, char* name, @@ -2041,8 +2124,8 @@ static ErlDrvData vanilla_start(ErlDrvPort port_num, char* name, CHLD_STAT_LOCK; res = (ErlDrvData)(long)set_driver_data(port_num, fd, fd, - opts->packet_bytes, - opts->read_write, 0, -1); + opts->packet_bytes, + opts->read_write, 0, -1, 0); CHLD_STAT_UNLOCK; return res; } @@ -2079,6 +2162,7 @@ static void stop(ErlDrvData fd) } } +/* used by fd_driver */ static void outputv(ErlDrvData e, ErlIOVec* ev) { int fd = (int)(long)e; @@ -2104,12 +2188,21 @@ static void outputv(ErlDrvData e, ErlIOVec* ev) ev->iov[0].iov_base = lbp; ev->iov[0].iov_len = pb; ev->size += pb; + + if (driver_data[fd].blocking && FDBLOCK) + driver_pdl_lock(driver_data[fd].blocking->pdl); + if ((sz = driver_sizeq(ix)) > 0) { driver_enqv(ix, ev, 0); + + if (driver_data[fd].blocking && FDBLOCK) + driver_pdl_unlock(driver_data[fd].blocking->pdl); + if (sz + ev->size >= (1 << 13)) set_busy_port(ix, 1); } - else { + else if (!driver_data[fd].blocking || !FDBLOCK) { + /* We try to write directly if the fd in non-blocking */ int vsize = ev->vsize > MAX_VSIZE ? MAX_VSIZE : ev->vsize; n = writev(ofd, (const void *) (ev->iov), vsize); @@ -2125,10 +2218,22 @@ static void outputv(ErlDrvData e, ErlIOVec* ev) driver_enqv(ix, ev, n); /* n is the skip value */ driver_select(ix, ofd, ERL_DRV_WRITE|ERL_DRV_USE, 1); } +#if FDBLOCK + else { + if (ev->size != 0) { + driver_enqv(ix, ev, 0); + driver_pdl_unlock(driver_data[fd].blocking->pdl); + driver_async(ix, &driver_data[fd].blocking->pkey, + fd_async, driver_data+fd, NULL); + } else { + driver_pdl_unlock(driver_data[fd].blocking->pdl); + } + } +#endif /* return 0;*/ } - +/* Used by spawn_driver and vanilla driver */ static void output(ErlDrvData e, char* buf, ErlDrvSizeT len) { int fd = (int)(long)e; @@ -2191,6 +2296,23 @@ static int port_inp_failure(ErlDrvPort port_num, int ready_fd, int res) ASSERT(res <= 0); (void) driver_select(port_num, ready_fd, ERL_DRV_READ|ERL_DRV_WRITE, 0); clear_fd_data(ready_fd); + + if (driver_data[ready_fd].blocking && FDBLOCK) { + driver_pdl_lock(driver_data[ready_fd].blocking->pdl); + if (driver_sizeq(driver_data[ready_fd].port_num) > 0) { + driver_pdl_unlock(driver_data[ready_fd].blocking->pdl); + /* We have stuff in the output queue, so we just + set the state to terminating and wait for fd_async_ready + to terminate the port */ + if (res == 0) + driver_data[ready_fd].terminating = 2; + else + driver_data[ready_fd].terminating = -err; + return 0; + } + driver_pdl_unlock(driver_data[ready_fd].blocking->pdl); + } + if (res == 0) { if (driver_data[ready_fd].report_exit) { CHLD_STAT_LOCK; @@ -2241,6 +2363,7 @@ static void ready_input(ErlDrvData e, ErlDrvEvent ready_fd) port_num = driver_data[fd].port_num; packet_bytes = driver_data[fd].packet_bytes; + if (packet_bytes == 0) { byte *read_buf = (byte *) erts_alloc(ERTS_ALC_T_SYS_READ_BUF, ERTS_SYS_READ_BUF_SZ); @@ -2364,6 +2487,8 @@ static void ready_output(ErlDrvData e, ErlDrvEvent ready_fd) if ((iv = (struct iovec*) driver_peekq(ix, &vsize)) == NULL) { driver_select(ix, ready_fd, ERL_DRV_WRITE, 0); + if (driver_data[fd].terminating) + driver_failure_atom(driver_data[fd].port_num,"normal"); return; /* 0; */ } vsize = vsize > MAX_VSIZE ? MAX_VSIZE : vsize; @@ -2389,6 +2514,82 @@ static void stop_select(ErlDrvEvent fd, void* _) close((int)fd); } +#if FDBLOCK + +static void +fd_async(void *async_data) +{ + int res; + struct driver_data *dd = (struct driver_data*)async_data; + SysIOVec *iov0; + SysIOVec *iov; + int iovlen; + int iovcnt; + int p; + /* much of this code is stolen from efile_drv:invoke_writev */ + driver_pdl_lock(dd->blocking->pdl); + iov0 = driver_peekq(dd->port_num, &iovlen); + /* Calculate iovcnt */ + for (p = 0, iovcnt = 0; iovcnt < iovlen; + p += iov0[iovcnt++].iov_len) + ; + iov = erts_alloc_fnf(ERTS_ALC_T_SYS_WRITE_BUF, + sizeof(SysIOVec)*iovcnt); + if (!iov) { + res = -1; + errno = ENOMEM; + erts_free(ERTS_ALC_T_SYS_WRITE_BUF, iov); + driver_pdl_unlock(dd->blocking->pdl); + } else { + memcpy(iov,iov0,iovcnt*sizeof(SysIOVec)); + driver_pdl_unlock(dd->blocking->pdl); + + res = writev(dd->ofd, iov, iovlen); + + erts_free(ERTS_ALC_T_SYS_WRITE_BUF, iov); + } + dd->blocking->res = res; + dd->blocking->err = errno; +} + +void fd_ready_async(ErlDrvData drv_data, + ErlDrvThreadData thread_data) { + struct driver_data *dd = (struct driver_data *)thread_data; + ErlDrvPort port_num = dd->port_num; + + ASSERT(dd->blocking); + ASSERT(dd == (driver_data + (int)(long)drv_data)); + + if (dd->blocking->res > 0) { + driver_pdl_lock(dd->blocking->pdl); + if (driver_deq(port_num, dd->blocking->res) == 0) { + driver_pdl_unlock(dd->blocking->pdl); + set_busy_port(port_num, 0); + if (dd->terminating) { + /* The port is has been ordered to terminate + from either fd_flush or port_inp_failure */ + if (dd->terminating == 1) + driver_failure_atom(port_num, "normal"); + else if (dd->terminating == 2) + driver_failure_eof(port_num); + else if (dd->terminating < 0) + driver_failure_posix(port_num, -dd->terminating); + return; /* -1; */ + } + } else { + driver_pdl_unlock(dd->blocking->pdl); + /* still data left to write in queue */ + driver_async(port_num, &dd->blocking->pkey, fd_async, dd, NULL); + return /* 0; */; + } + } else if (dd->blocking->res < 0) { + driver_failure_posix(port_num, dd->blocking->err); + return; /* -1; */ + } + return; /* 0; */ +} + +#endif void erts_do_break_handling(void) { @@ -2658,18 +2859,30 @@ void sys_preload_end(Preload* p) /* Nothing */ } -/* Read a key from console (?) */ - +/* Read a key from console, used by break.c + 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 c; + int c, ret; unsigned char rbuf[64]; + fd_set fds; fflush(stdout); /* Flush query ??? */ - if ((c = read(fd,rbuf,64)) <= 0) { - return c; + FD_ZERO(&fds); + FD_SET(fd,&fds); + + ret = select(fd+1, &fds, NULL, NULL, NULL); + + if (ret == 1) { + do { + c = read(fd,rbuf,64); + } while (c < 0 && errno == EAGAIN); + if (c <= 0) + return c; } return rbuf[0]; |