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-rw-r--r--lauxlib.c46
-rw-r--r--lauxlib.h5
-rw-r--r--liolib.c54
-rw-r--r--loslib.c2
-rw-r--r--manual/manual.of14
5 files changed, 71 insertions, 50 deletions
diff --git a/lauxlib.c b/lauxlib.c
index a8f2cc2e..53b8c9bb 100644
--- a/lauxlib.c
+++ b/lauxlib.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lauxlib.c,v 1.294 2018/02/27 18:47:32 roberto Exp roberto $ 2** $Id: lauxlib.c $
3** Auxiliary functions for building Lua libraries 3** Auxiliary functions for building Lua libraries
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -292,6 +292,50 @@ LUALIB_API int luaL_execresult (lua_State *L, int stat) {
292 292
293/* 293/*
294** {====================================================== 294** {======================================================
295** 'luaL_resourcetryagain'
296** This function uses 'errno' to check whether the last error was
297** related to lack of resources (e.g., not enough memory or too many
298** open files). If so, the function performs a full garbage collection
299** to try to release resources, and then it returns 1 to signal to
300** the caller that it is worth trying again the failed operation.
301** Otherwise, it returns 0. Because error codes are not ANSI C, the
302** code must handle any combination of error codes that are defined.
303** =======================================================
304*/
305
306LUALIB_API int luaL_resourcetryagain (lua_State *L) {
307
308/* these are the resource-related errors in Linux */
309#if defined(EMFILE) || defined(ENFILE) || defined(ENOMEM)
310
311#if !defined(EMFILE) /* too many open files in the process */
312#define EMFILE -1 /* if not defined, use an impossible value */
313#endif
314
315#if !defined(ENFILE) /* too many open files in the system */
316#define ENFILE -1
317#endif
318
319#if !defined(ENOMEM) /* not enough memory */
320#define ENOMEM -1
321#endif
322
323 if (errno == EMFILE || errno == ENFILE || errno == ENOMEM) {
324 lua_gc(L, LUA_GCCOLLECT); /* try to release resources with a full GC */
325 return 1; /* signal to try again the creation */
326 }
327
328#endif
329
330 return 0; /* else, asume errors are not due to lack of resources */
331
332}
333
334/* }====================================================== */
335
336
337/*
338** {======================================================
295** Userdata's metatable manipulation 339** Userdata's metatable manipulation
296** ======================================================= 340** =======================================================
297*/ 341*/
diff --git a/lauxlib.h b/lauxlib.h
index 9f91f6a6..cd4d01e5 100644
--- a/lauxlib.h
+++ b/lauxlib.h
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lauxlib.h,v 1.133 2017/06/27 18:32:49 roberto Exp roberto $ 2** $Id: lauxlib.h $
3** Auxiliary functions for building Lua libraries 3** Auxiliary functions for building Lua libraries
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -77,6 +77,9 @@ LUALIB_API int (luaL_checkoption) (lua_State *L, int arg, const char *def,
77LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname); 77LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname);
78LUALIB_API int (luaL_execresult) (lua_State *L, int stat); 78LUALIB_API int (luaL_execresult) (lua_State *L, int stat);
79 79
80LUALIB_API int (luaL_resourcetryagain) (lua_State *L);
81
82
80/* predefined references */ 83/* predefined references */
81#define LUA_NOREF (-2) 84#define LUA_NOREF (-2)
82#define LUA_REFNIL (-1) 85#define LUA_REFNIL (-1)
diff --git a/liolib.c b/liolib.c
index 75e10ded..21305b8c 100644
--- a/liolib.c
+++ b/liolib.c
@@ -133,50 +133,6 @@ static int l_checkmode (const char *mode) {
133/* }====================================================== */ 133/* }====================================================== */
134 134
135 135
136/*
137** {======================================================
138** 'resourcetryagain'
139** This function uses 'errno' to check whether the last error was
140** related to lack of resources (e.g., not enough memory or too many
141** open files). If so, the function performs a full garbage collection
142** to try to release resources, and then it returns 1 to signal to
143** the caller that it is worth trying again the failed operation.
144** Otherwise, it returns 0. Because error codes are not ANSI C, the
145** code must handle any combination of error codes that are defined.
146** =======================================================
147*/
148
149static int resourcetryagain (lua_State *L) {
150
151/* these are the resource-related errors in Linux */
152#if defined(EMFILE) || defined(ENFILE) || defined(ENOMEM)
153
154#if !defined(EMFILE) /* too many open files in the process */
155#define EMFILE -1 /* if not defined, use an impossible value */
156#endif
157
158#if !defined(ENFILE) /* too many open files in the system */
159#define ENFILE -1
160#endif
161
162#if !defined(ENOMEM) /* not enough memory */
163#define ENOMEM -1
164#endif
165
166 if (errno == EMFILE || errno == ENFILE || errno == ENOMEM) {
167 lua_gc(L, LUA_GCCOLLECT); /* try to release resources with a full GC */
168 return 1; /* signal to try again the creation */
169 }
170
171#endif
172
173 return 0; /* else, asume errors are not due to lack of resources */
174
175}
176
177/* }====================================================== */
178
179
180 136
181#define IO_PREFIX "_IO_" 137#define IO_PREFIX "_IO_"
182#define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1) 138#define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1)
@@ -292,12 +248,12 @@ static LStream *newfile (lua_State *L) {
292 248
293/* 249/*
294** Equivalent to 'fopen', but if it fails due to a lack of resources 250** Equivalent to 'fopen', but if it fails due to a lack of resources
295** (see 'resourcetryagain'), do an "emergency" garbage collection to try 251** (see 'luaL_resourcetryagain'), do an "emergency" garbage collection
296** to close some files and then tries to open the file again. 252** to try to close some files and then tries to open the file again.
297*/ 253*/
298static FILE *trytoopen (lua_State *L, const char *path, const char *mode) { 254static FILE *trytoopen (lua_State *L, const char *path, const char *mode) {
299 FILE *f = fopen(path, mode); 255 FILE *f = fopen(path, mode);
300 if (f == NULL && resourcetryagain(L)) /* resource failure? */ 256 if (f == NULL && luaL_resourcetryagain(L)) /* resource failure? */
301 f = fopen(path, mode); /* try to open again */ 257 f = fopen(path, mode); /* try to open again */
302 return f; 258 return f;
303} 259}
@@ -336,7 +292,7 @@ static int io_popen (lua_State *L) {
336 const char *mode = luaL_optstring(L, 2, "r"); 292 const char *mode = luaL_optstring(L, 2, "r");
337 LStream *p = newprefile(L); 293 LStream *p = newprefile(L);
338 p->f = l_popen(L, filename, mode); 294 p->f = l_popen(L, filename, mode);
339 if (p->f == NULL && resourcetryagain(L)) /* resource failure? */ 295 if (p->f == NULL && luaL_resourcetryagain(L)) /* resource failure? */
340 p->f = l_popen(L, filename, mode); /* try to open again */ 296 p->f = l_popen(L, filename, mode); /* try to open again */
341 p->closef = &io_pclose; 297 p->closef = &io_pclose;
342 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; 298 return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
@@ -346,6 +302,8 @@ static int io_popen (lua_State *L) {
346static int io_tmpfile (lua_State *L) { 302static int io_tmpfile (lua_State *L) {
347 LStream *p = newfile(L); 303 LStream *p = newfile(L);
348 p->f = tmpfile(); 304 p->f = tmpfile();
305 if (p->f == NULL && luaL_resourcetryagain(L)) /* resource failure? */
306 p->f = tmpfile(); /* try to open again */
349 return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1; 307 return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
350} 308}
351 309
diff --git a/loslib.c b/loslib.c
index 8809e5ea..1962f55f 100644
--- a/loslib.c
+++ b/loslib.c
@@ -166,6 +166,8 @@ static int os_tmpname (lua_State *L) {
166 char buff[LUA_TMPNAMBUFSIZE]; 166 char buff[LUA_TMPNAMBUFSIZE];
167 int err; 167 int err;
168 lua_tmpnam(buff, err); 168 lua_tmpnam(buff, err);
169 if (err && luaL_resourcetryagain(L)) /* resource failure? */
170 lua_tmpnam(buff, err); /* try again */
169 if (err) 171 if (err)
170 return luaL_error(L, "unable to generate a unique filename"); 172 return luaL_error(L, "unable to generate a unique filename");
171 lua_pushstring(L, buff); 173 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.
5538 5538
5539} 5539}
5540 5540
5541@APIEntry{int luaL_resourcetryagain (lua_State *L);|
5542@apii{0,0,m}
5543
5544Try to release resources in case of errors.
5545This function uses @id{errno} to check whether the last error was
5546related to lack of resources (e.g., not enough memory or too many
5547open files).
5548If so, the function performs a full garbage collection
5549to try to release resources, and then it returns 1 to signal to
5550the caller that it is worth trying again the failed operation.
5551Otherwise, it returns 0.
5552
5553}
5554
5541@APIEntry{void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);| 5555@APIEntry{void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);|
5542@apii{nup,0,m} 5556@apii{nup,0,m}
5543 5557