diff options
| -rw-r--r-- | erts/doc/src/driver_entry.xml | 6 | ||||
| -rw-r--r-- | erts/emulator/test/driver_SUITE.erl | 2 | ||||
| -rw-r--r-- | erts/emulator/test/driver_SUITE_data/chkio_drv.c | 15 |
3 files changed, 18 insertions, 5 deletions
diff --git a/erts/doc/src/driver_entry.xml b/erts/doc/src/driver_entry.xml index dd949d4048..7d1585f483 100644 --- a/erts/doc/src/driver_entry.xml +++ b/erts/doc/src/driver_entry.xml @@ -4,7 +4,7 @@ <cref> <header> <copyright> - <year>2001</year><year>2010</year> + <year>2001</year><year>2011</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -219,6 +219,10 @@ typedef struct erl_drv_entry { completes, write to the pipe (use <c>SetEvent</c> on Windows), this will make the emulator call <c>ready_input</c> or <c>ready_output</c>.</p> + <p>Spurious events may happen. That is, calls to <c>ready_input</c> + or <c>ready_output</c> even though no real events are signaled. In + reality it should be rare (and OS dependant), but a robust driver + must nevertheless be able to handle such cases.</p> </item> <tag><marker id="driver_name"/>char *driver_name</tag> <item> diff --git a/erts/emulator/test/driver_SUITE.erl b/erts/emulator/test/driver_SUITE.erl index 6c85c2c3d1..7600a44988 100644 --- a/erts/emulator/test/driver_SUITE.erl +++ b/erts/emulator/test/driver_SUITE.erl @@ -1672,7 +1672,7 @@ smp_select0(Config) -> ProcFun = fun()-> io:format("Worker ~p starting\n",[self()]), ?line Port = open_port({spawn, DrvName}, []), smp_select_loop(Port, 100000), - sleep(500), % wait for driver to handle pending events + sleep(1000), % wait for driver to handle pending events ?line true = erlang:port_close(Port), Master ! {ok,self()}, io:format("Worker ~p finished\n",[self()]) diff --git a/erts/emulator/test/driver_SUITE_data/chkio_drv.c b/erts/emulator/test/driver_SUITE_data/chkio_drv.c index b571cb30e6..bbdb09cfcb 100644 --- a/erts/emulator/test/driver_SUITE_data/chkio_drv.c +++ b/erts/emulator/test/driver_SUITE_data/chkio_drv.c @@ -102,6 +102,7 @@ typedef struct chkio_smp_select { int write_fd; int next_read; int next_write; + int first_write; enum {Closed, Opened, Selected, Waiting} state; int wasSelected; unsigned rand_state; @@ -577,9 +578,16 @@ chkio_drv_ready_input(ErlDrvData drv_data, ErlDrvEvent event) inPipe = (pip->next_write - pip->next_read); if (inPipe == 0) { bytes = read(pip->read_fd, &word, sizeof(word)); - printf("Unexpected empty pipe, expected %u -> %u, bytes=%d, word=%d\n", - pip->next_read, pip->next_write-1, bytes, word); - abort(); + printf("Unexpected empty pipe, expected %u -> %u, bytes=%d, word=%d, written=%d\n", + pip->next_read, pip->next_write-1, bytes, word, + (pip->next_write - pip->first_write)); + /*abort(); + Allow unexpected events as it's been seen to be triggered by epoll + on Linux. Most of the time the unwanted events are filtered by + the erl_check_io layer. But when fd's are reused the events may + slip up to the driver. + */ + break; } n = rand_r(&pip->rand_state) % (inPipe*4); @@ -1252,6 +1260,7 @@ chkio_drv_control(ErlDrvData drv_data, pip->state = Opened; pip->wasSelected = 0; pip->next_write = pip->next_read = rand_r(&pip->rand_state) % 1024; + pip->first_write = pip->next_write; if (op & 1) break; op >>= 1; }/*fall through*/ |