[Tarantool-patches] [PATCH v2 1/1] fiber: extend max fiber name length to 255
Vladislav Shpilevoy
v.shpilevoy at tarantool.org
Tue Mar 17 01:28:46 MSK 2020
Hi! Thanks for the review!
> Thank, Vlad! I like the patch. There is only one concern I have: for
> some reason we has been defining faiber name as
>
> char name[FIBER_NAME_MAX + 1];
>
> where FIBER_NAME_MAX = 32 and finally this expands to "char name[33];"
> I'm too lazy to find who exactly introduced this but it is bloody
> wrong: compiler alings members to eliminate data access penalty, thus
> _actually_ it will be defined as 8 multilier, ie 40 bytes.
>
> Thus, if you don't mind I propose make FIBER_NAME_INLINE = 40
> *including* string terminating zero.
>
> Actually we can make it on top then. Up to you. Anyway
>
> Reviewed-by: Cyrill Gorcunov <gorcunov at gmail.com>
Yes, good point.
Here is diff. The whole patch is in the bottom.
====================
diff --git a/src/lib/core/fiber.c b/src/lib/core/fiber.c
index 359ef1187..5389ce467 100644
--- a/src/lib/core/fiber.c
+++ b/src/lib/core/fiber.c
@@ -912,26 +912,27 @@ fiber_loop(MAYBE_UNUSED void *data)
void
fiber_set_name(struct fiber *fiber, const char *name)
{
- size_t len = strlen(name);
- if (len <= FIBER_NAME_INLINE) {
+ size_t size = strlen(name) + 1;
+ if (size <= FIBER_NAME_INLINE) {
if (fiber->name != fiber->inline_name) {
free(fiber->name);
fiber->name = fiber->inline_name;
}
} else {
- if (len > FIBER_NAME_MAX)
- len = FIBER_NAME_MAX;
+ if (size > FIBER_NAME_MAX)
+ size = FIBER_NAME_MAX;
char *new_name;
if (fiber->name != fiber->inline_name)
- new_name = realloc(fiber->name, len + 1);
+ new_name = realloc(fiber->name, size);
else
- new_name = malloc(len + 1);
+ new_name = malloc(size);
if (new_name == NULL)
panic("fiber_set_name() failed with OOM");
fiber->name = new_name;
}
- memcpy(fiber->name, name, len);
- fiber->name[len] = 0;
+ --size;
+ memcpy(fiber->name, name, size);
+ fiber->name[size] = 0;
}
static inline void *
diff --git a/src/lib/core/fiber.h b/src/lib/core/fiber.h
index fedc37c87..cd9346a55 100644
--- a/src/lib/core/fiber.h
+++ b/src/lib/core/fiber.h
@@ -112,8 +112,9 @@ struct cpu_stat {
#endif /* ENABLE_FIBER_TOP */
enum {
- FIBER_NAME_INLINE = 32,
- FIBER_NAME_MAX = 255
+ /** Both limits include terminating 0. */
+ FIBER_NAME_INLINE = 40,
+ FIBER_NAME_MAX = 256
};
/**
@@ -518,7 +519,7 @@ struct fiber {
* name is allocated on the heap.
*/
char *name;
- char inline_name[FIBER_NAME_INLINE + 1];
+ char inline_name[FIBER_NAME_INLINE];
};
/** Invoke on_stop triggers and delete them. */
@@ -586,7 +587,7 @@ struct cord {
struct slab_cache slabc;
/** The "main" fiber of this cord, the scheduler. */
struct fiber sched;
- char name[FIBER_NAME_INLINE + 1];
+ char name[FIBER_NAME_INLINE];
};
extern __thread struct cord *cord_ptr;
diff --git a/src/lua/fiber.c b/src/lua/fiber.c
index 575a020d0..330eb7e54 100644
--- a/src/lua/fiber.c
+++ b/src/lua/fiber.c
@@ -582,16 +582,16 @@ lbox_fiber_name(struct lua_State *L)
if (top == name_index || top == opts_index) {
/* Set name. */
const char *name = luaL_checkstring(L, name_index);
- int name_len = strlen(name);
+ int name_size = strlen(name) + 1;
if (top == opts_index && lua_istable(L, opts_index)) {
lua_getfield(L, opts_index, "truncate");
/* Truncate the name if needed. */
if (lua_isboolean(L, -1) && lua_toboolean(L, -1) &&
- name_len > FIBER_NAME_MAX)
- name_len = FIBER_NAME_MAX;
+ name_size > FIBER_NAME_MAX)
+ name_size = FIBER_NAME_MAX;
lua_pop(L, 1);
}
- if (name_len > FIBER_NAME_MAX)
+ if (name_size > FIBER_NAME_MAX)
luaL_error(L, "Fiber name is too long");
fiber_set_name(f, name);
return 0;
====================
The whole patch:
====================
fiber: extend max fiber name length to 255
Users keep complaining about too short fiber name. New limit is
255, should be enough for any sane name.
Closes #4394
@TarantoolBot document
Title: fiber.name length limit.
It was 32, now it is 255. Besides, it seems like `fiber.name`
`{truncate = true}` option is not documented.
By default, if a new name is too long, `fiber.name(new_name)`
fails with an exception. To make it always succeed there is an
option 'truncate': `fiber.name(new_name, {truncate = true})`. It
truncates the name to the max length if it is too long.
diff --git a/src/lib/core/fiber.c b/src/lib/core/fiber.c
index ada7972cb..5389ce467 100644
--- a/src/lib/core/fiber.c
+++ b/src/lib/core/fiber.c
@@ -912,8 +912,27 @@ fiber_loop(MAYBE_UNUSED void *data)
void
fiber_set_name(struct fiber *fiber, const char *name)
{
- assert(name != NULL);
- snprintf(fiber->name, sizeof(fiber->name), "%s", name);
+ size_t size = strlen(name) + 1;
+ if (size <= FIBER_NAME_INLINE) {
+ if (fiber->name != fiber->inline_name) {
+ free(fiber->name);
+ fiber->name = fiber->inline_name;
+ }
+ } else {
+ if (size > FIBER_NAME_MAX)
+ size = FIBER_NAME_MAX;
+ char *new_name;
+ if (fiber->name != fiber->inline_name)
+ new_name = realloc(fiber->name, size);
+ else
+ new_name = malloc(size);
+ if (new_name == NULL)
+ panic("fiber_set_name() failed with OOM");
+ fiber->name = new_name;
+ }
+ --size;
+ memcpy(fiber->name, name, size);
+ fiber->name[size] = 0;
}
static inline void *
@@ -1242,6 +1261,9 @@ fiber_destroy(struct cord *cord, struct fiber *f)
region_destroy(&f->gc);
fiber_stack_destroy(f, &cord->slabc);
diag_destroy(&f->diag);
+ if (f->name != f->inline_name)
+ free(f->name);
+ f->name = NULL;
}
void
@@ -1357,6 +1379,7 @@ cord_create(struct cord *cord, const char *name)
fiber_reset(&cord->sched);
diag_create(&cord->sched.diag);
region_create(&cord->sched.gc, &cord->slabc);
+ cord->sched.name = NULL;
fiber_set_name(&cord->sched, "sched");
cord->fiber = &cord->sched;
@@ -1405,6 +1428,8 @@ cord_destroy(struct cord *cord)
}
region_destroy(&cord->sched.gc);
diag_destroy(&cord->sched.diag);
+ if (cord->sched.name != cord->sched.inline_name)
+ free(cord->sched.name);
slab_cache_destroy(&cord->slabc);
}
diff --git a/src/lib/core/fiber.h b/src/lib/core/fiber.h
index 8a3e5aef5..cd9346a55 100644
--- a/src/lib/core/fiber.h
+++ b/src/lib/core/fiber.h
@@ -111,7 +111,11 @@ struct cpu_stat {
#endif /* ENABLE_FIBER_TOP */
-enum { FIBER_NAME_MAX = 32 };
+enum {
+ /** Both limits include terminating 0. */
+ FIBER_NAME_INLINE = 40,
+ FIBER_NAME_MAX = 256
+};
/**
* Fiber ids [0; 100] are reserved.
@@ -510,7 +514,12 @@ struct fiber {
struct ipc_wait_pad *wait_pad;
/** Exception which caused this fiber's death. */
struct diag diag;
- char name[FIBER_NAME_MAX + 1];
+ /**
+ * Name points at inline_name in case it is short. Long
+ * name is allocated on the heap.
+ */
+ char *name;
+ char inline_name[FIBER_NAME_INLINE];
};
/** Invoke on_stop triggers and delete them. */
@@ -578,7 +587,7 @@ struct cord {
struct slab_cache slabc;
/** The "main" fiber of this cord, the scheduler. */
struct fiber sched;
- char name[FIBER_NAME_MAX];
+ char name[FIBER_NAME_INLINE];
};
extern __thread struct cord *cord_ptr;
diff --git a/src/lua/fiber.c b/src/lua/fiber.c
index 575a020d0..330eb7e54 100644
--- a/src/lua/fiber.c
+++ b/src/lua/fiber.c
@@ -582,16 +582,16 @@ lbox_fiber_name(struct lua_State *L)
if (top == name_index || top == opts_index) {
/* Set name. */
const char *name = luaL_checkstring(L, name_index);
- int name_len = strlen(name);
+ int name_size = strlen(name) + 1;
if (top == opts_index && lua_istable(L, opts_index)) {
lua_getfield(L, opts_index, "truncate");
/* Truncate the name if needed. */
if (lua_isboolean(L, -1) && lua_toboolean(L, -1) &&
- name_len > FIBER_NAME_MAX)
- name_len = FIBER_NAME_MAX;
+ name_size > FIBER_NAME_MAX)
+ name_size = FIBER_NAME_MAX;
lua_pop(L, 1);
}
- if (name_len > FIBER_NAME_MAX)
+ if (name_size > FIBER_NAME_MAX)
luaL_error(L, "Fiber name is too long");
fiber_set_name(f, name);
return 0;
diff --git a/test/app/fiber.result b/test/app/fiber.result
index 6d9604ad8..7331f61b3 100644
--- a/test/app/fiber.result
+++ b/test/app/fiber.result
@@ -1186,7 +1186,7 @@ fiber = nil
---
...
--
--- gh-2622, gh-4011: fiber.name() truncates new name.
+-- gh-2622, gh-4011, gh-4394: fiber.name() truncates new name.
--
fiber = require('fiber')
---
@@ -1214,14 +1214,14 @@ fiber.name(long_name, {truncate = true})
...
fiber.name()
---
-- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
...
f = fiber.self()
---
...
fiber.name(f)
---
-- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
...
fiber.name(f, 'new_name')
---
@@ -1239,7 +1239,7 @@ fiber.name(f, long_name, {truncate = true})
...
fiber.name(f)
---
-- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
+- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
...
--
-- gh-3493 fiber.create() does not roll back memtx transaction
diff --git a/test/app/fiber.test.lua b/test/app/fiber.test.lua
index 6df210d9c..b8e9abc6e 100644
--- a/test/app/fiber.test.lua
+++ b/test/app/fiber.test.lua
@@ -504,7 +504,7 @@ test_run:cmd("setopt delimiter ''");
fiber = nil
--
--- gh-2622, gh-4011: fiber.name() truncates new name.
+-- gh-2622, gh-4011, gh-4394: fiber.name() truncates new name.
--
fiber = require('fiber')
long_name = string.rep('a', 300)
diff --git a/test/unit/fiber.cc b/test/unit/fiber.cc
index 91f7d43f9..b0dfc9b14 100644
--- a/test/unit/fiber.cc
+++ b/test/unit/fiber.cc
@@ -171,9 +171,9 @@ fiber_name_test()
note("set new fiber name: %s.\n", fiber_name(fiber()));
- const char *long_name = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
- "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"\
- "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
+ char long_name[FIBER_NAME_MAX + 30];
+ memset(long_name, 'a', sizeof(long_name));
+ long_name[sizeof(long_name) - 1] = 0;
fiber_set_name(fiber(), long_name);
diff --git a/test/unit/fiber.result b/test/unit/fiber.result
index 7c9f85dcd..a61e0a2b8 100644
--- a/test/unit/fiber.result
+++ b/test/unit/fiber.result
@@ -5,7 +5,7 @@ SystemError Failed to allocate 42 bytes in allocator for exception: Cannot alloc
# set new fiber name: Horace.
-# fiber name is truncated: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.
+# fiber name is truncated: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.
*** fiber_name_test: done ***
*** fiber_join_test ***
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