diff options
Diffstat (limited to 'erts/doc/src/erlang.xml')
| -rw-r--r-- | erts/doc/src/erlang.xml | 128 |
1 files changed, 119 insertions, 9 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index 871fc0fd63..28b040a441 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -4,7 +4,7 @@ <erlref> <header> <copyright> - <year>1996</year><year>2009</year> + <year>1996</year><year>2010</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -13,12 +13,12 @@ compliance with the License. You should have received a copy of the Erlang Public License along with this software. If not, it can be retrieved online at http://www.erlang.org/. - + Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License. - + </legalnotice> <title>erlang</title> @@ -342,8 +342,50 @@ iolist() = [char() | binary() | iolist()] <desc> <p>Returns an Erlang term which is the result of decoding the binary object <c>Binary</c>, which must be encoded - according to the Erlang external term format. See also - <seealso marker="#term_to_binary/1">term_to_binary/1</seealso>.</p> + according to the Erlang external term format.</p> + <warning> + <p>When decoding binaries from untrusted sources, consider using + <c>binary_to_term/2</c> to prevent denial of service attacks.</p> + </warning> + <p>See also + <seealso marker="#term_to_binary/1">term_to_binary/1</seealso> + and + <seealso marker="#binary_to_term/2">binary_to_term/2</seealso>.</p> + </desc> + </func> + <func> + <name>erlang:binary_to_term(Binary, Opts) -> term()</name> + <fsummary>Decode an Erlang external term format binary</fsummary> + <type> + <v>Opts = [safe]</v> + <v>Binary = ext_binary()</v> + </type> + <desc> + <p>As <c>binary_to_term/1</c>, but takes options that affect decoding + of the binary.</p> + <taglist> + <tag><c>safe</c></tag> + <item> + <p>Use this option when receiving binaries from an untrusted + source.</p> + <p>When enabled, it prevents decoding data that may be used to + attack the Erlang system. In the event of receiving unsafe + data, decoding fails with a badarg error.</p> + <p>Currently, this prevents creation of new atoms directly, + creation of new atoms indirectly (as they are embedded in + certain structures like pids, refs, funs, etc.), and creation of + new external function references. None of those resources are + currently garbage collected, so unchecked creation of them can + exhaust available memory.</p> + </item> + </taglist> + <p>Failure: <c>badarg</c> if <c>safe</c> is specified and unsafe data + is decoded.</p> + <p>See also + <seealso marker="#term_to_binary/1">term_to_binary/1</seealso>, + <seealso marker="#binary_to_term/1">binary_to_term/1</seealso>, + and <seealso marker="#list_to_existing_atom/1"> + list_to_existing_atom/1</seealso>.</p> </desc> </func> <func> @@ -3427,6 +3469,11 @@ os_prompt%</pre> <p>This changes the minimum heap size for the calling process.</p> </item> + <tag><c>process_flag(min_bin_vheap_size, MinBinVHeapSize)</c></tag> + <item> + <p>This changes the minimum binary virtual heap size for the calling + process.</p> + </item> <tag><c>process_flag(priority, Level)</c></tag> <item> <marker id="process_flag_priority"></marker> @@ -3758,6 +3805,14 @@ os_prompt%</pre> <p><c>MessageQueue</c> is a list of the messages to the process, which have not yet been processed.</p> </item> + <tag><c>{min_heap_size, MinHeapSize}</c></tag> + <item> + <p><c>MinHeapSize</c> is the minimum heap size for the process.</p> + </item> + <tag><c>{min_bin_vheap_size, MinBinVHeapSize}</c></tag> + <item> + <p><c>MinBinVHeapSize</c> is the minimum binary virtual heap size for the process.</p> + </item> <tag><c>{monitored_by, Pids}</c></tag> <item> <p>A list of pids that are monitoring the process (with @@ -4491,10 +4546,11 @@ true</pre> <fsummary>Create a new process with a fun as entry point</fsummary> <type> <v>Fun = fun()</v> - <v>Option = link | monitor | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size}</v> + <v>Option = link | monitor | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size} | {min_bin_vheap_size, VSize}</v> <v> Level = low | normal | high</v> <v> Number = int()</v> <v> Size = int()</v> + <v> VSize = int()</v> </type> <desc> <p>Returns the pid of a new process started by the application @@ -4512,10 +4568,11 @@ true</pre> <type> <v>Node = node()</v> <v>Fun = fun()</v> - <v>Option = link | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size}</v> + <v>Option = link | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size} | {min_bin_vheap_size, VSize}</v> <v> Level = low | normal | high</v> <v> Number = int()</v> <v> Size = int()</v> + <v> VSize = int()</v> </type> <desc> <p>Returns the pid of a new process started by the application @@ -4531,10 +4588,11 @@ true</pre> <type> <v>Module = Function = atom()</v> <v>Args = [term()]</v> - <v>Option = link | monitor | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size}</v> + <v>Option = link | monitor | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size} | {min_bin_vheap_size, VSize}</v> <v> Level = low | normal | high</v> <v> Number = int()</v> <v> Size = int()</v> + <v> VSize = int()</v> </type> <desc> <p>Works exactly like @@ -4614,6 +4672,23 @@ true</pre> fine-tuning an application and to measure the execution time with various <c>Size</c> values.</p> </item> + <tag><c>{min_bin_vheap_size, VSize}</c></tag> + <item> + <p>This option is only useful for performance tuning. + In general, you should not use this option unless you + know that there is problem with execution times and/or + memory consumption, and you should measure to make sure + that the option improved matters. + </p> + <p>Gives a minimum binary virtual heap size in words. Setting this value + higher than the system default might speed up some + processes because less garbage collection is done. + Setting too high value, however, might waste memory. + Therefore, it is recommended to use this option only for + fine-tuning an application and to measure the execution + time with various <c>VSize</c> values.</p> + </item> + </taglist> </desc> </func> @@ -4624,10 +4699,11 @@ true</pre> <v>Node = node()</v> <v>Module = Function = atom()</v> <v>Args = [term()]</v> - <v>Option = link | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size}</v> + <v>Option = link | {priority, Level} | {fullsweep_after, Number} | {min_heap_size, Size} | {min_bin_vheap_size, VSize}</v> <v> Level = low | normal | high</v> <v> Number = int()</v> <v> Size = int()</v> + <v> VSize = int()</v> </type> <desc> <p>Returns the pid of a new process started by the application @@ -4960,6 +5036,17 @@ true</pre> <seealso marker="#spawn_opt/4">spawn_opt/N</seealso> or <seealso marker="#process_flag/2">process_flag/2</seealso>. </p> </item> + <tag><c>erlang:system_flag(min_bin_vheap_size, MinBinVHeapSize)</c></tag> + <item> + <p>Sets the default minimum binary virtual heap size for processes. The + size is given in words. The new <c>min_bin_vhheap_size</c> only + effects processes spawned after the change of + <c>min_bin_vhheap_size</c> has been made. + The <c>min_bin_vheap_size</c> can be set for individual + processes by use of + <seealso marker="#spawn_opt/4">spawn_opt/N</seealso> or + <seealso marker="#process_flag/2">process_flag/2</seealso>. </p> + </item> <tag><c>erlang:system_flag(multi_scheduling, BlockState)</c></tag> <item> <marker id="system_flag_multi_scheduling"></marker> @@ -5571,6 +5658,16 @@ true</pre> <item> <p>Returns a string containing the Erlang machine name.</p> </item> + <tag><c>min_heap_size</c></tag> + <item> + <p>Returns <c>{min_heap_size, MinHeapSize}</c> where <c>MinHeapSize</c> is the current system wide + minimum heap size for spawned processes.</p> + </item> + <tag><c>min_bin_vheap_size</c></tag> + <item> + <p>Returns <c>{min_bin_vheap_size, MinBinVHeapSize}</c> where <c>MinBinVHeapSize</c> is the current system wide + minimum binary virtual heap size for spawned processes.</p> + </item> <tag><c>modified_timing_level</c></tag> <item> <p>Returns the modified timing level (an integer) if @@ -6407,6 +6504,19 @@ true</pre> <tag><c>mbuf_size</c></tag> <item>The combined size of message buffers associated with the process.</item> + + <tag><c>bin_vheap_size</c></tag> + <item>The total size of unique off-heap binaries referenced from the process heap.</item> + <tag><c>bin_vheap_block_size</c></tag> + <item>The total size of binaries, in words, allowed in the virtual + heap in the process before doing a garbage collection. </item> + <tag><c>bin_old_vheap_size</c></tag> + <item>The total size of unique off-heap binaries referenced from the process old heap.</item> + <tag><c>bin_vheap_block_size</c></tag> + <item>The total size of binaries, in words, allowed in the virtual + old heap in the process before doing a garbage collection. </item> + + </taglist> <p>All sizes are in words.</p> </item> |