diff options
| -rw-r--r-- | lauxlib.c | 46 | ||||
| -rw-r--r-- | lauxlib.h | 5 | ||||
| -rw-r--r-- | liolib.c | 54 | ||||
| -rw-r--r-- | loslib.c | 2 | ||||
| -rw-r--r-- | manual/manual.of | 14 |
5 files changed, 71 insertions, 50 deletions
@@ -1,5 +1,5 @@ /* -** $Id: lauxlib.c,v 1.294 2018/02/27 18:47:32 roberto Exp roberto $ +** $Id: lauxlib.c $ ** Auxiliary functions for building Lua libraries ** See Copyright Notice in lua.h */ @@ -292,6 +292,50 @@ LUALIB_API int luaL_execresult (lua_State *L, int stat) { /* ** {====================================================== +** 'luaL_resourcetryagain' +** This function uses 'errno' to check whether the last error was +** related to lack of resources (e.g., not enough memory or too many +** open files). If so, the function performs a full garbage collection +** to try to release resources, and then it returns 1 to signal to +** the caller that it is worth trying again the failed operation. +** Otherwise, it returns 0. Because error codes are not ANSI C, the +** code must handle any combination of error codes that are defined. +** ======================================================= +*/ + +LUALIB_API int luaL_resourcetryagain (lua_State *L) { + +/* these are the resource-related errors in Linux */ +#if defined(EMFILE) || defined(ENFILE) || defined(ENOMEM) + +#if !defined(EMFILE) /* too many open files in the process */ +#define EMFILE -1 /* if not defined, use an impossible value */ +#endif + +#if !defined(ENFILE) /* too many open files in the system */ +#define ENFILE -1 +#endif + +#if !defined(ENOMEM) /* not enough memory */ +#define ENOMEM -1 +#endif + + if (errno == EMFILE || errno == ENFILE || errno == ENOMEM) { + lua_gc(L, LUA_GCCOLLECT); /* try to release resources with a full GC */ + return 1; /* signal to try again the creation */ + } + +#endif + + return 0; /* else, asume errors are not due to lack of resources */ + +} + +/* }====================================================== */ + + +/* +** {====================================================== ** Userdata's metatable manipulation ** ======================================================= */ @@ -1,5 +1,5 @@ /* -** $Id: lauxlib.h,v 1.133 2017/06/27 18:32:49 roberto Exp roberto $ +** $Id: lauxlib.h $ ** Auxiliary functions for building Lua libraries ** See Copyright Notice in lua.h */ @@ -77,6 +77,9 @@ LUALIB_API int (luaL_checkoption) (lua_State *L, int arg, const char *def, LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname); LUALIB_API int (luaL_execresult) (lua_State *L, int stat); +LUALIB_API int (luaL_resourcetryagain) (lua_State *L); + + /* predefined references */ #define LUA_NOREF (-2) #define LUA_REFNIL (-1) @@ -133,50 +133,6 @@ static int l_checkmode (const char *mode) { /* }====================================================== */ -/* -** {====================================================== -** 'resourcetryagain' -** This function uses 'errno' to check whether the last error was -** related to lack of resources (e.g., not enough memory or too many -** open files). If so, the function performs a full garbage collection -** to try to release resources, and then it returns 1 to signal to -** the caller that it is worth trying again the failed operation. -** Otherwise, it returns 0. Because error codes are not ANSI C, the -** code must handle any combination of error codes that are defined. -** ======================================================= -*/ - -static int resourcetryagain (lua_State *L) { - -/* these are the resource-related errors in Linux */ -#if defined(EMFILE) || defined(ENFILE) || defined(ENOMEM) - -#if !defined(EMFILE) /* too many open files in the process */ -#define EMFILE -1 /* if not defined, use an impossible value */ -#endif - -#if !defined(ENFILE) /* too many open files in the system */ -#define ENFILE -1 -#endif - -#if !defined(ENOMEM) /* not enough memory */ -#define ENOMEM -1 -#endif - - if (errno == EMFILE || errno == ENFILE || errno == ENOMEM) { - lua_gc(L, LUA_GCCOLLECT); /* try to release resources with a full GC */ - return 1; /* signal to try again the creation */ - } - -#endif - - return 0; /* else, asume errors are not due to lack of resources */ - -} - -/* }====================================================== */ - - #define IO_PREFIX "_IO_" #define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1) @@ -292,12 +248,12 @@ static LStream *newfile (lua_State *L) { /* ** Equivalent to 'fopen', but if it fails due to a lack of resources -** (see 'resourcetryagain'), do an "emergency" garbage collection to try -** to close some files and then tries to open the file again. +** (see 'luaL_resourcetryagain'), do an "emergency" garbage collection +** to try to close some files and then tries to open the file again. */ static FILE *trytoopen (lua_State *L, const char *path, const char *mode) { FILE *f = fopen(path, mode); - if (f == NULL && resourcetryagain(L)) /* resource failure? */ + if (f == NULL && luaL_resourcetryagain(L)) /* resource failure? */ f = fopen(path, mode); /* try to open again */ return f; } @@ -336,7 +292,7 @@ static int io_popen (lua_State *L) { const char *mode = luaL_optstring(L, 2, "r"); LStream *p = newprefile(L); p->f = l_popen(L, filename, mode); - if (p->f == NULL && resourcetryagain(L)) /* resource failure? */ + if (p->f == NULL && luaL_resourcetryagain(L)) /* resource failure? */ p->f = l_popen(L, filename, mode); /* try to open again */ p->closef = &io_pclose; return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; @@ -346,6 +302,8 @@ static int io_popen (lua_State *L) { static int io_tmpfile (lua_State *L) { LStream *p = newfile(L); p->f = tmpfile(); + if (p->f == NULL && luaL_resourcetryagain(L)) /* resource failure? */ + p->f = tmpfile(); /* try to open again */ return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1; } @@ -166,6 +166,8 @@ static int os_tmpname (lua_State *L) { char buff[LUA_TMPNAMBUFSIZE]; int err; lua_tmpnam(buff, err); + if (err && luaL_resourcetryagain(L)) /* resource failure? */ + lua_tmpnam(buff, err); /* try again */ if (err) return luaL_error(L, "unable to generate a unique filename"); lua_pushstring(L, buff); diff --git a/manual/manual.of b/manual/manual.of index 659daa55..5a8b1b2c 100644 --- a/manual/manual.of +++ b/manual/manual.of @@ -5538,6 +5538,20 @@ Leaves a copy of the module on the stack. } +@APIEntry{int luaL_resourcetryagain (lua_State *L);| +@apii{0,0,m} + +Try to release resources in case of errors. +This function uses @id{errno} to check whether the last error was +related to lack of resources (e.g., not enough memory or too many +open files). +If so, the function performs a full garbage collection +to try to release resources, and then it returns 1 to signal to +the caller that it is worth trying again the failed operation. +Otherwise, it returns 0. + +} + @APIEntry{void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);| @apii{nup,0,m} |