From 949ee23d72e4412fed3059c04e395f995388a5fb Mon Sep 17 00:00:00 2001 From: Per Hedeland Date: Wed, 4 Jan 2012 10:57:59 +0100 Subject: Fix returned error from gen_tcp:accept/1,2 when running out of ports The {error, enfile} return value is badly misleading and confusing for this case, since the Posix ENFILE errno value has a well-defined meaning that has nothing to do with Erlang ports. The fix changes the return value to {error, system_limit}, which is consistent with e.g. various file(3) functions. inet:format_error/1 has also been updated to support system_limit in the same manner as file:format_error/1. --- erts/emulator/drivers/common/inet_drv.c | 38 +++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 16 deletions(-) (limited to 'erts/emulator/drivers') diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c index eeaa4d24ea..7cee4cb928 100644 --- a/erts/emulator/drivers/common/inet_drv.c +++ b/erts/emulator/drivers/common/inet_drv.c @@ -553,6 +553,12 @@ static int my_strncasecmp(const char *s1, const char *s2, size_t n) # define VALGRIND_MAKE_MEM_DEFINED(ptr,size) #endif +/* + Magic errno value used locally for return of {error, system_limit} + - the emulator definition of SYSTEM_LIMIT is not available here. +*/ +#define INET_ERRNO_SYSTEM_LIMIT (15 << 8) + /*---------------------------------------------------------------------------- ** Interface constants. ** @@ -1645,6 +1651,17 @@ static struct erl_drv_entry dummy_sctp_driver_entry = #endif +/* return lowercase string form of errno value */ +static char *errno_str(int err) +{ + switch (err) { + case INET_ERRNO_SYSTEM_LIMIT: + return "system_limit"; + default: + return erl_errno_id(err); + } +} + /* general control reply function */ static ErlDrvSSizeT ctl_reply(int rep, char* buf, ErlDrvSizeT len, char** rbuf, ErlDrvSizeT rsize) @@ -1665,13 +1682,9 @@ static ErlDrvSSizeT ctl_reply(int rep, char* buf, ErlDrvSizeT len, /* general control error reply function */ static ErlDrvSSizeT ctl_error(int err, char** rbuf, ErlDrvSizeT rsize) { - char response[256]; /* Response buffer. */ - char* s; - char* t; + char* s = errno_str(err); - for (s = erl_errno_id(err), t = response; *s; s++, t++) - *t = tolower(*s); - return ctl_reply(INET_REP_ERROR, response, t-response, rbuf, rsize); + return ctl_reply(INET_REP_ERROR, s, strlen(s), rbuf, rsize); } static ErlDrvSSizeT ctl_xerror(char* xerr, char** rbuf, ErlDrvSizeT rsize) @@ -1683,14 +1696,7 @@ static ErlDrvSSizeT ctl_xerror(char* xerr, char** rbuf, ErlDrvSizeT rsize) static ErlDrvTermData error_atom(int err) { - char errstr[256]; - char* s; - char* t; - - for (s = erl_errno_id(err), t = errstr; *s; s++, t++) - *t = tolower(*s); - *t = '\0'; - return driver_mk_atom(errstr); + return driver_mk_atom(errno_str(err)); } @@ -8050,7 +8056,7 @@ static ErlDrvData tcp_inet_start(ErlDrvPort port, char* args) /* Copy a descriptor, by creating a new port with same settings * as the descriptor desc. - * return NULL on error (ENFILE no ports avail) + * return NULL on error (SYSTEM_LIMIT no ports avail) */ static tcp_descriptor* tcp_inet_copy(tcp_descriptor* desc,SOCKET s, ErlDrvTermData owner, int* err) @@ -8089,7 +8095,7 @@ static tcp_descriptor* tcp_inet_copy(tcp_descriptor* desc,SOCKET s, /* The new port will be linked and connected to the original caller */ port = driver_create_port(port, owner, "tcp_inet", (ErlDrvData) copy_desc); if ((long)port == -1) { - *err = ENFILE; + *err = INET_ERRNO_SYSTEM_LIMIT; FREE(copy_desc); return NULL; } -- cgit v1.2.3