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-rw-r--r--erts/doc/src/erl_nif.xml81
-rw-r--r--erts/doc/src/erlang.xml333
-rw-r--r--erts/doc/src/notes.xml16
-rw-r--r--erts/doc/src/time_correction.xml87
4 files changed, 362 insertions, 155 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index 3de94be9ff..4bad8b253c 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -66,34 +66,6 @@
</list>
</warning>
- <p>The NIF concept is officially supported from R14B. NIF source code
- written for earlier experimental versions might need adaption to run on R14B
- or later versions:</p>
- <list>
- <item>No incompatible changes between <em>R14B</em> and R14A.</item>
- <item>Incompatible changes between <em>R14A</em> and R13B04:
- <list>
- <item>Environment argument removed for <c>enif_alloc</c>,
- <c>enif_realloc</c>, <c>enif_free</c>, <c>enif_alloc_binary</c>,
- <c>enif_realloc_binary</c>, <c>enif_release_binary</c>,
- <c>enif_alloc_resource</c>, <c>enif_release_resource</c>,
- <c>enif_is_identical</c> and <c>enif_compare</c>.</item>
- <item>Character encoding argument added to <c>enif_get_atom</c>
- and <c>enif_make_existing_atom</c>.</item>
- <item>Module argument added to <c>enif_open_resource_type</c>
- while changing name spaces of resource types from global to module local.</item>
- </list>
- </item>
- <item>Incompatible changes between <em>R13B04</em> and R13B03:
- <list>
- <item>The function prototypes of the NIFs have changed to expect <c>argc</c> and <c>argv</c>
- arguments. The arity of a NIF is by that no longer limited to 3.</item>
- <item><c>enif_get_data</c> renamed as <c>enif_priv_data</c>.</item>
- <item><c>enif_make_string</c> got a third argument for character encoding.</item>
- </list>
- </item>
- </list>
-
<p>A minimal example of a NIF library can look like this:</p>
<p/>
<code type="none">
@@ -806,6 +778,12 @@ typedef enum {
and return true, or return false if <c>term</c> is not an unsigned integer or is
outside the bounds of type <c>unsigned long</c>.</p></desc>
</func>
+ <func><name><ret>int</ret><nametext>enif_has_pending_exception(ErlNifEnv* env)</nametext></name>
+ <fsummary>Check if an exception has been raised.</fsummary>
+ <desc><p>Return true if a pending exception is associated
+ with the environment <c>env</c>. The only possible exception is currently
+ <c>badarg</c> (see <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>).</p></desc>
+ </func>
<func><name><ret>int</ret><nametext>enif_inspect_binary(ErlNifEnv* env, ERL_NIF_TERM bin_term, ErlNifBinary* bin)</nametext></name>
<fsummary>Inspect the content of a binary</fsummary>
<desc><p>Initialize the structure pointed to by <c>bin</c> with
@@ -898,23 +876,37 @@ typedef enum {
<func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_atom(ErlNifEnv* env, const char* name)</nametext></name>
<fsummary>Create an atom term</fsummary>
<desc><p>Create an atom term from the null-terminated C-string <c>name</c>
- with iso-latin-1 encoding.</p></desc>
+ with iso-latin-1 encoding. If the length of <c>name</c> exceeds the maximum length
+ allowed for an atom (255 characters), <c>enif_make_atom</c> invokes
+ <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>.
+ </p></desc>
</func>
<func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_atom_len(ErlNifEnv* env, const char* name, size_t len)</nametext></name>
<fsummary>Create an atom term</fsummary>
<desc><p>Create an atom term from the string <c>name</c> with length <c>len</c>.
- Null-characters are treated as any other characters.</p></desc>
+ Null-characters are treated as any other characters. If <c>len</c> is greater than the maximum length
+ allowed for an atom (255 characters), <c>enif_make_atom</c> invokes
+ <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>.
+ </p></desc>
</func>
<func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_badarg(ErlNifEnv* env)</nametext></name>
<fsummary>Make a badarg exception.</fsummary>
- <desc><p>Make a badarg exception to be returned from a NIF, and set
- an associated exception reason in <c>env</c>. If
- <c>enif_make_badarg</c> is called, the term it returns <em>must</em>
- be returned from the function that called it. No other return value
- is allowed. Also, the term returned from <c>enif_make_badarg</c> may
- be passed only to
- <seealso marker="#enif_is_exception">enif_is_exception</seealso> and
- not to any other NIF API function.</p></desc>
+ <desc><p>Make a badarg exception to be returned from a NIF, and associate
+ it with the environment <c>env</c>. Once a NIF or any function
+ it calls invokes <c>enif_make_badarg</c>, the runtime ensures that a
+ <c>badarg</c> exception is raised when the NIF returns, even if the NIF
+ attempts to return a non-exception term instead.
+ The return value from <c>enif_make_badarg</c> may only be used as
+ return value from the NIF that invoked it (direct or indirectly)
+ or be passed to
+ <seealso marker="#enif_is_exception">enif_is_exception</seealso>, but
+ not to any other NIF API function.</p>
+ <p>See also: <seealso marker="#enif_has_pending_exception">enif_has_pending_exception</seealso>.
+ </p>
+ <note><p>In earlier versions (older than erts-7.0, OTP 18) the return value
+ from <c>enif_make_badarg</c> had to be returned from the NIF. This
+ requirement is now lifted as the return value from the NIF is ignored
+ if <c>enif_make_badarg</c> has been invoked.</p></note></desc>
</func>
<func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_binary(ErlNifEnv* env, ErlNifBinary* bin)</nametext></name>
<fsummary>Make a binary term.</fsummary>
@@ -931,7 +923,10 @@ typedef enum {
</func>
<func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_double(ErlNifEnv* env, double d)</nametext></name>
<fsummary>Create a floating-point term</fsummary>
- <desc><p>Create a floating-point term from a <c>double</c>.</p></desc>
+ <desc><p>Create a floating-point term from a <c>double</c>. If the <c>double</c> argument is
+ not finite or is NaN, <c>enif_make_double</c> invokes
+ <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>.
+ </p></desc>
</func>
<func><name><ret>int</ret><nametext>enif_make_existing_atom(ErlNifEnv* env, const char* name, ERL_NIF_TERM* atom, ErlNifCharEncoding encode)</nametext></name>
<fsummary>Create an existing atom term</fsummary>
@@ -939,7 +934,9 @@ typedef enum {
the null-terminated C-string <c>name</c> with encoding
<seealso marker="#ErlNifCharEncoding">encode</seealso>. If the atom
already exists store the term in <c>*atom</c> and return true, otherwise
- return false.</p></desc>
+ return false. If the length of <c>name</c> exceeds the maximum length
+ allowed for an atom (255 characters), <c>enif_make_existing_atom</c>
+ returns false.</p></desc>
</func>
<func><name><ret>int</ret><nametext>enif_make_existing_atom_len(ErlNifEnv* env, const char* name, size_t len, ERL_NIF_TERM* atom, ErlNifCharEncoding encoding)</nametext></name>
<fsummary>Create an existing atom term</fsummary>
@@ -947,7 +944,9 @@ typedef enum {
string <c>name</c> with length <c>len</c> and encoding
<seealso marker="#ErlNifCharEncoding">encode</seealso>. Null-characters
are treated as any other characters. If the atom already exists store the term
- in <c>*atom</c> and return true, otherwise return false.</p></desc>
+ in <c>*atom</c> and return true, otherwise return false. If <c>len</c> is greater
+ than the maximum length allowed for an atom (255 characters),
+ <c>enif_make_existing_atom_len</c> returns false.</p></desc>
</func>
<func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_int(ErlNifEnv* env, int i)</nametext></name>
<fsummary>Create an integer term</fsummary>
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index ba5f80a9c1..3fea64cef5 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -536,29 +536,108 @@
</desc>
</func>
<func>
- <name name="cancel_timer" arity="1"/>
+ <name name="cancel_timer" arity="2"/>
<fsummary>Cancel a timer</fsummary>
<desc>
- <p>Cancels a timer, where <c><anno>TimerRef</anno></c> was returned by
- either
- <seealso marker="#send_after/3">erlang:send_after/3</seealso>
- or
- <seealso marker="#start_timer/3">erlang:start_timer/3</seealso>.
- If the timer is there to be removed, the function returns
- the time in milliseconds left until the timer would have expired,
- otherwise <c>false</c> (which means that <c><anno>TimerRef</anno></c> was
- never a timer, that it has already been cancelled, or that it
- has already delivered its message).</p>
+ <p>
+ Cancels a timer that has been created by either
+ <seealso marker="#start_timer/4"><c>erlang:start_timer()</c></seealso>,
+ or <seealso marker="#send_after/4"><c>erlang:send_after()</c></seealso>.
+ <c><anno>TimerRef</anno></c> identifies the timer, and
+ was returned by the BIF that created the timer.
+ </p>
+ <p>Currently available <c><anno>Option</anno></c>s:</p>
+ <taglist>
+ <tag><c>{async, Async}</c></tag>
+ <item>
+ <p>
+ Asynchronous request for cancellation. <c>Async</c>
+ defaults to <c>false</c> which will cause the
+ cancellation to be performed synchronously. When
+ <c>Async</c> is set to <c>true</c>, the cancel
+ operation will be performed asynchronously. That is,
+ <c>erlang:cancel_timer()</c> will send an asynchronous
+ request for cancellation to the timer service that
+ manages the timer, and then return <c>ok</c>.
+ </p>
+ </item>
+ <tag><c>{info, Info}</c></tag>
+ <item>
+ <p>
+ Request information about the <c><anno>Result</anno></c>
+ of the cancellation. <c>Info</c> defaults to <c>true</c>
+ which means that the <c><anno>Result</anno></c> will
+ be given. When <c>Info</c> is set to <c>false</c>, no
+ information about the result of the cancellation
+ will be given. When the operation is performed</p>
+ <taglist>
+ <tag>synchronously</tag>
+ <item>
+ <p>
+ If <c>Info</c> is <c>true</c>, the <c>Result</c> will
+ returned by <c>erlang:cancel_timer()</c>; otherwise,
+ <c>ok</c> will be returned.
+ </p>
+ </item>
+ <tag>asynchronously</tag>
+ <item>
+ <p>
+ If <c>Info</c> is <c>true</c>, a message on the form
+ <c>{cancel_timer, <anno>TimerRef</anno>,
+ <anno>Result</anno>}</c> will be sent to the
+ caller of <c>erlang:cancel_timer()</c> when the
+ cancellation operation has been performed; otherwise,
+ no message will be sent.
+ </p>
+ </item>
+ </taglist>
+ </item>
+ </taglist>
+ <p>
+ More <c><anno>Option</anno></c>s may be added in the future.
+ </p>
+ <p>
+ When the <c><anno>Result</anno></c> equals <c>false</c>, a
+ timer corresponding to <c><anno>TimerRef</anno></c> could not
+ be found. This can be either because the timer had expired,
+ already had been canceled, or because <c><anno>TimerRef</anno></c>
+ never has corresponded to a timer. If the timer has expired,
+ the timeout message has been sent, but it does not tell you
+ whether or not it has arrived at its destination yet. When the
+ <c><anno>Result</anno></c> is an integer, it represents the
+ time in milli-seconds left until the timer will expire.
+ </p>
+ <note>
+ <p>
+ The timer service that manages the timer may be co-located
+ with another scheduler than the scheduler that the calling
+ process is executing on. If this is the case, communication
+ with the timer service will take much longer time than if it
+ is located locally. If the calling process is in critical
+ path, and can do other things while waiting for the result
+ of this operation, or is not interested in the result of
+ the operation, you want to use the <c>{async, true}</c>
+ option. If using the <c>{async, false}</c> option, the calling
+ process will be blocked until the operation has been
+ performed.
+ </p>
+ </note>
<p>See also
- <seealso marker="#send_after/3">erlang:send_after/3</seealso>,
- <seealso marker="#start_timer/3">erlang:start_timer/3</seealso>,
+ <seealso marker="#send_after/4"><c>erlang:send_after/4</c></seealso>,
+ <seealso marker="#start_timer/4"><c>erlang:start_timer/4</c></seealso>,
and
- <seealso marker="#read_timer/1">erlang:read_timer/1</seealso>.</p>
- <p>Note: Cancelling a timer does not guarantee that the message
- has not already been delivered to the message queue.</p>
+ <seealso marker="#read_timer/2"><c>erlang:read_timer/2</c></seealso>.</p>
+ </desc>
+ </func>
+ <func>
+ <name name="cancel_timer" arity="1"/>
+ <fsummary>Cancel a timer</fsummary>
+ <desc>
+ <p>Cancels a timer. The same as calling
+ <seealso marker="#cancel_timer/2"><c>erlang:cancel_timer(TimerRef,
+ [])</c></seealso>.</p>
</desc>
</func>
-
<func>
<name name="check_old_code" arity="1"/>
<fsummary>Check if a module has old code</fsummary>
@@ -4505,23 +4584,77 @@ os_prompt% </pre>
</desc>
</func>
<func>
- <name name="read_timer" arity="1"/>
- <fsummary>Number of milliseconds remaining for a timer</fsummary>
- <desc>
- <p><c><anno>TimerRef</anno></c> is a timer reference returned by
- <seealso marker="#send_after/3">erlang:send_after/3</seealso>
- or
- <seealso marker="#start_timer/3">erlang:start_timer/3</seealso>.
- If the timer is active, the function returns the time in
- milliseconds left until the timer will expire, otherwise
- <c>false</c> (which means that <c><anno>TimerRef</anno></c> was never a
- timer, that it has been cancelled, or that it has already
- delivered its message).</p>
+ <name name="read_timer" arity="2"/>
+ <fsummary>Read the state of a timer</fsummary>
+ <desc>
+ <p>
+ Read the state of a timer that has been created by either
+ <seealso marker="#start_timer/4"><c>erlang:start_timer()</c></seealso>,
+ or <seealso marker="#send_after/4"><c>erlang:send_after()</c></seealso>.
+ <c><anno>TimerRef</anno></c> identifies the timer, and
+ was returned by the BIF that created the timer.
+ </p>
+ <p>Currently available <c><anno>Option</anno>s</c>:</p>
+ <taglist>
+ <tag><c>{async, Async}</c></tag>
+ <item>
+ <p>
+ Asynchronous request for state information. <c>Async</c>
+ defaults to <c>false</c> which will cause the operation
+ to be performed synchronously. In this case, the <c>Result</c>
+ will be returned by <c>erlang:read_timer()</c>. When
+ <c>Async</c> is set to <c>true</c>, <c>erlang:read_timer()</c>
+ will send an asynchronous request for the state information
+ to the timer service that manages the timer, and then return
+ <c>ok</c>. A message on the format <c>{read_timer,
+ <anno>TimerRef</anno>, <anno>Result</anno>}</c> will be
+ sent to the caller of <c>erlang:read_timer()</c> when the
+ operation has been processed.
+ </p>
+ </item>
+ </taglist>
+ <p>
+ More <c><anno>Option</anno></c>s may be added in the future.
+ </p>
+ <p>
+ When the <c><anno>Result</anno></c> equals <c>false</c>, a
+ timer corresponding to <c><anno>TimerRef</anno></c> could not
+ be found. This can be either because the timer had expired,
+ had been canceled, or because <c><anno>TimerRef</anno></c>
+ never has corresponded to a timer. If the timer has expired,
+ the timeout message has been sent, but it does not tell you
+ whether or not it has arrived at its destination yet. When the
+ <c><anno>Result</anno></c> is an integer, it represents the
+ time in milli-seconds left until the timer will expire.
+ </p>
+ <note>
+ <p>
+ The timer service that manages the timer may be co-located
+ with another scheduler than the scheduler that the calling
+ process is executing on. If this is the case, communication
+ with the timer service will take much longer time than if it
+ is located locally. If the calling process is in critical
+ path, and can do other things while waiting for the result
+ of this operation you want to use the <c>{async, true}</c>
+ option. If using the <c>{async, false}</c> option, the calling
+ process will be blocked until the operation has been
+ performed.
+ </p>
+ </note>
<p>See also
- <seealso marker="#send_after/3">erlang:send_after/3</seealso>,
- <seealso marker="#start_timer/3">erlang:start_timer/3</seealso>,
+ <seealso marker="#send_after/4"><c>erlang:send_after/4</c></seealso>,
+ <seealso marker="#start_timer/4"><c>erlang:start_timer/4</c></seealso>,
and
- <seealso marker="#cancel_timer/1">erlang:cancel_timer/1</seealso>.</p>
+ <seealso marker="#cancel_timer/2"><c>erlang:cancel_timer/2</c></seealso>.</p>
+ </desc>
+ </func>
+ <func>
+ <name name="read_timer" arity="1"/>
+ <fsummary>Read the state of a timer</fsummary>
+ <desc>
+ <p>Read the state of a timer. The same as calling
+ <seealso marker="#read_timer/2"><c>erlang:read_timer(TimerRef,
+ [])</c></seealso>.</p>
</desc>
</func>
<func>
@@ -4670,31 +4803,26 @@ true</pre>
</desc>
</func>
<func>
+ <name name="send_after" arity="4"/>
+ <fsummary>Start a timer</fsummary>
+ <desc>
+ <p>
+ Starts a timer. When the timer expires, the message
+ <c><anno>Msg</anno></c> will be sent to the process
+ identified by <c><anno>Dest</anno></c>. Appart from
+ the format of the message sent to
+ <c><anno>Dest</anno></c> when the timer expires
+ <c>erlang:send_after/4</c> works exactly as
+ <seealso marker="#start_timer/4"><c>erlang:start_timer/4</c></seealso>.</p>
+ </desc>
+ </func>
+ <func>
<name name="send_after" arity="3"/>
- <type_desc variable="Time">0 &lt;= Time &lt;= 4294967295</type_desc>
<fsummary>Start a timer</fsummary>
<desc>
- <p>Starts a timer which will send the message <c>Msg</c>
- to <c><anno>Dest</anno></c> after <c><anno>Time</anno></c> milliseconds.</p>
- <p>If <c><anno>Dest</anno></c> is a <c>pid()</c> it has to be a <c>pid()</c> of a local process, dead or alive.</p>
- <p>The <c><anno>Time</anno></c> value can, in the current implementation, not be greater than 4294967295.</p>
- <p>If <c><anno>Dest</anno></c> is an <c>atom()</c>, it is supposed to be the name of
- a registered process. The process referred to by the name is
- looked up at the time of delivery. No error is given if
- the name does not refer to a process.</p>
-
- <p>If <c><anno>Dest</anno></c> is a <c>pid()</c>, the timer will be automatically
- canceled if the process referred to by the <c>pid()</c> is not alive,
- or when the process exits. This feature was introduced in
- erts version 5.4.11. Note that timers will not be
- automatically canceled when <c><anno>Dest</anno></c> is an <c>atom</c>.</p>
- <p>See also
- <seealso marker="#start_timer/3">erlang:start_timer/3</seealso>,
- <seealso marker="#cancel_timer/1">erlang:cancel_timer/1</seealso>,
- and
- <seealso marker="#read_timer/1">erlang:read_timer/1</seealso>.</p>
- <p>Failure: <c>badarg</c> if the arguments does not satisfy
- the requirements specified above.</p>
+ <p>Starts a timer. The same as calling
+ <seealso marker="#send_after/4"><c>erlang:send_after(<anno>Time</anno>,
+ <anno>Dest</anno>, <anno>Msg</anno>, [])</c></seealso>.</p>
</desc>
</func>
<func>
@@ -5100,34 +5228,81 @@ true</pre>
</desc>
</func>
<func>
- <name name="start_timer" arity="3"/>
- <type_desc variable="Time">0 &lt;= Time &lt;= 4294967295</type_desc>
+ <name name="start_timer" arity="4"/>
<fsummary>Start a timer</fsummary>
<desc>
- <p>Starts a timer which will send the message
- <c>{timeout, <anno>TimerRef</anno>, <anno>Msg</anno>}</c> to <c><anno>Dest</anno></c>
- after <c><anno>Time</anno></c> milliseconds.</p>
- <p>If <c><anno>Dest</anno></c> is a <c>pid()</c> it has to be a <c>pid()</c> of a local process, dead or alive.</p>
- <p>The <c><anno>Time</anno></c> value can, in the current implementation, not be greater than 4294967295.</p>
- <p>If <c><anno>Dest</anno></c> is an <c>atom()</c>, it is supposed to be the name of
- a registered process. The process referred to by the name is
- looked up at the time of delivery. No error is given if
- the name does not refer to a process.</p>
- <p>If <c><anno>Dest</anno></c> is a <c>pid()</c>, the timer will be automatically
- canceled if the process referred to by the <c>pid()</c> is not alive,
- or when the process exits. This feature was introduced in
- erts version 5.4.11. Note that timers will not be
- automatically canceled when <c><anno>Dest</anno></c> is an <c>atom()</c>.</p>
+ <p>
+ Starts a timer. When the timer expires, the message
+ <c>{timeout, <anno>TimerRef</anno>, <anno>Msg</anno>}</c>
+ will be sent to the process identified by
+ <c><anno>Dest</anno></c>.
+ </p>
+ <p>Currently available <c><anno>Option</anno></c>s:</p>
+ <taglist>
+ <tag><c>{abs, Abs}</c></tag>
+ <item>
+ <p>
+ Absolute <c><anno>Time</anno></c> value. <c>Abs</c>
+ defaults to <c>false</c> which means that the
+ <c><anno>Time</anno></c> value will be interpreted
+ as a time in milli-seconds relative current
+ <seealso marker="time_correction#Erlang_Monotonic_Time">Erlang
+ monotonic time</seealso>. When <c>Abs</c> is set to
+ <c>true</c>, the <c><anno>Time</anno></c> value will
+ be interpreted as an absolute Erlang monotonic time of
+ milli-seconds
+ <seealso marker="#type_time_unit">time unit</seealso>.
+ </p>
+ </item>
+ </taglist>
+ <p>
+ More <c><anno>Option</anno></c>s may be added in the future.
+ </p>
+ <p>
+ The absolute point in time that the timer is set to expire on
+ has to be in the interval
+ <c>[</c><seealso marker="#system_info_start_time"><c>erlang:system_info(start_time)</c></seealso><c>,
+ </c><seealso marker="#system_info_end_time"><c>erlang:system_info(end_time)</c></seealso><c>]</c>.
+ Further, if a relative time is specified, the <c><anno>Time</anno></c> value
+ is not allowed to be negative.
+ </p>
+ <p>
+ If <c><anno>Dest</anno></c> is a <c>pid()</c>, it has to
+ be a <c>pid()</c> of a process created on the current
+ runtime system instance. This process may or may not
+ have terminated. If <c><anno>Dest</anno></c> is an
+ <c>atom()</c>, it will be interpreted as the name of a
+ locally registered process. The process referred to by the
+ name is looked up at the time of timer expiration. No error
+ is given if the name does not refer to a process.
+ </p>
+ <p>
+ If <c><anno>Dest</anno></c> is a <c>pid()</c>, the timer will
+ be automatically canceled if the process referred to by the
+ <c>pid()</c> is not alive, or when the process exits. This
+ feature was introduced in erts version 5.4.11. Note that
+ timers will not be automatically canceled when
+ <c><anno>Dest</anno></c> is an <c>atom()</c>.
+ </p>
<p>See also
- <seealso marker="#send_after/3">erlang:send_after/3</seealso>,
- <seealso marker="#cancel_timer/1">erlang:cancel_timer/1</seealso>,
+ <seealso marker="#send_after/4"><c>erlang:send_after/4</c></seealso>,
+ <seealso marker="#cancel_timer/2"><c>erlang:cancel_timer/2</c></seealso>,
and
- <seealso marker="#read_timer/1">erlang:read_timer/1</seealso>.</p>
+ <seealso marker="#read_timer/2"><c>erlang:read_timer/2</c></seealso>.</p>
<p>Failure: <c>badarg</c> if the arguments does not satisfy
the requirements specified above.</p>
</desc>
</func>
<func>
+ <name name="start_timer" arity="3"/>
+ <fsummary>Start a timer</fsummary>
+ <desc>
+ <p>Starts a timer. The same as calling
+ <seealso marker="#start_timer/4"><c>erlang:start_timer(<anno>Time</anno>,
+ <anno>Dest</anno>, <anno>Msg</anno>, [])</c></seealso>.</p>
+ </desc>
+ </func>
+ <func>
<name name="statistics" arity="1" clause_i="1"/>
<fsummary>Information about context switches</fsummary>
<desc>
@@ -6236,6 +6411,14 @@ ok
(i.e. <c>system_info(dynamic_trace)</c> returns
<c>dtrace</c> or <c>systemtap</c>).</p>
</item>
+ <tag><marker id="system_info_end_time"/><c>end_time</c></tag>
+ <item><p>The last <seealso marker="#monotonic_time/0">Erlang monotonic
+ time</seealso> in <c>native</c>
+ <seealso marker="#type_time_unit">time unit</seealso> that
+ can be represented internally in the current Erlang runtime system
+ instance. The time between the
+ <seealso marker="#system_info_start_time">start time</seealso> and
+ the end time is at least a quarter of a millennium.</p></item>
<tag><c>elib_malloc</c></tag>
<item>
<p>This option will be removed in a future release.
@@ -6680,7 +6863,9 @@ ok
<item><p>The <seealso marker="#monotonic_time/0">Erlang monotonic
time</seealso> in <c>native</c>
<seealso marker="#type_time_unit">time unit</seealso> at the
- time when current Erlang runtime system instance started.</p></item>
+ time when current Erlang runtime system instance started. See also
+ <seealso marker="#system_info_end_time"><c>erlang:system_info(end_time)</c></seealso>.
+ </p></item>
<tag><c>system_version</c></tag>
<item>
<p>Returns a string containing version number and
diff --git a/erts/doc/src/notes.xml b/erts/doc/src/notes.xml
index a2b4ae49a4..35e6e55e72 100644
--- a/erts/doc/src/notes.xml
+++ b/erts/doc/src/notes.xml
@@ -30,6 +30,22 @@
</header>
<p>This document describes the changes made to the ERTS application.</p>
+<section><title>Erts 6.4.1</title>
+
+ <section><title>Fixed Bugs and Malfunctions</title>
+ <list>
+ <item>
+ <p>
+ The VTS mode in Common Test has been modified to use a
+ private version of the Webtool application (ct_webtool).</p>
+ <p>
+ Own Id: OTP-12704 Aux Id: OTP-10922 </p>
+ </item>
+ </list>
+ </section>
+
+</section>
+
<section><title>Erts 6.4</title>
<section><title>Fixed Bugs and Malfunctions</title>
diff --git a/erts/doc/src/time_correction.xml b/erts/doc/src/time_correction.xml
index 979a37d7ff..8af98acc19 100644
--- a/erts/doc/src/time_correction.xml
+++ b/erts/doc/src/time_correction.xml
@@ -137,6 +137,14 @@
<p>The correctness of time values.</p>
</section>
+ <marker id="Time_Warp"/>
+ <section>
+ <title>Time Warp</title>
+ <p>A time warp is a leap forwards or backwards in time. That
+ is, the difference of time values taken before and after the
+ time warp will not correspond to the actual elapsed time.</p>
+ </section>
+
<marker id="OS_System_Time"/>
<section>
<title>OS System Time</title>
@@ -146,7 +154,7 @@
<seealso marker="kernel:os#system_time/0"><c>os:system_time()</c></seealso>.
This may or may not be an accurate view of POSIX time. This time
may typically be adjusted both backwards and forwards without
- limitation. That is, huge leaps both backwards and forwards in time
+ limitation. That is, <seealso marker="#Time_Warp">time warps</seealso>
may be observed. You can get information about the Erlang runtime
system's source of OS system time by calling
<seealso marker="erlang#system_info_os_system_time_source"><c>erlang:system_info(os_system_time_source)</c></seealso>.</p>
@@ -159,12 +167,12 @@
system. This time does not leap and have a relatively steady
frequency although not completely correct. However, it is not
uncommon that the OS monotonic time stops if the system is
- suspended. This time typically increase since some unspecified
- point in time that is not connected to
- <seealso marker="#OS_System_Time">OS system time</seealso>. Note that
- this type of time is not necessarily provided by all operating
- systems. You can get information about the Erlang runtime
- system's source of OS monotonic time by calling
+ suspended. This time typically increase since some
+ unspecified point in time that is not connected to
+ <seealso marker="#OS_System_Time">OS system time</seealso>. Note
+ that this type of time is not necessarily provided by all
+ operating systems. You can get information about the Erlang
+ runtime system's source of OS monotonic time by calling
<seealso marker="erlang#system_info_os_monotonic_time_source"><c>erlang:system_info(os_monotonic_time_source)</c></seealso>.</p>
</section>
@@ -177,9 +185,11 @@
<seealso marker="erlang#system_time/0"><c>erlang:system_time()</c></seealso>.
This time may or may not be an accurate view of POSIX time, and may
or may not align with <seealso marker="#OS_System_Time">OS system
- time</seealso>. The <seealso marker="#Time_Warp_Modes">time
- warp mode</seealso> determines how it behaves when OS system
- time suddenly change.</p>
+ time</seealso>. The runtime system works towards aligning the two
+ system times. Depending on <seealso marker="#Time_Warp_Modes">time
+ warp mode</seealso> used, this may be achieved by letting the Erlang
+ system time perform a <seealso marker="#Time_Warp">time
+ warp</seealso>.</p>
</section>
<marker id="Erlang_Monotonic_Time"/>
@@ -219,12 +229,6 @@
</p>
</section>
- <marker id="Time_Warp"/>
- <section>
- <title>Time Warp</title>
- <p>A time warp is a leap forwards or backwards in time.</p>
- </section>
-
</section>
<section>
@@ -332,7 +336,7 @@
<section>
<title>Time Warp Safe Code</title>
<p>Time warp safe code is code that is able to handle
- a time warp of
+ a <seealso marker="#Time_Warp">time warp</seealso> of
<seealso marker="#Erlang_System_Time">Erlang system time</seealso>.
</p>
@@ -378,11 +382,11 @@
<p>The time offset is determined at runtime system start
and will after this not change. This is the default behavior.
Not because it is the best mode (which it isn't). It is
- default only because this is how the runtime system always
- has behaved until ERTS version 7.0, and you have to ensure
- that your Erlang code that may execute during a time warp is
- <seealso marker="#Time_Warp_Safe_Code">time warp safe</seealso>
- before you can enable other modes.</p>
+ default <em>only</em> because this is how the runtime system
+ always has behaved up until ERTS version 7.0, and you have to
+ ensure that your Erlang code that may execute during a time
+ warp is <seealso marker="#Time_Warp_Safe_Code">time warp
+ safe</seealso> before you can enable other modes.</p>
<p>Since the time offset is not allowed to change, time
correction needs to adjust the frequency of the Erlang
@@ -422,9 +426,9 @@
system time has been corrected, you may want to use the single
time warp mode. Note that there are limitations to when you can
execute time warp unsafe code using this mode. If it is possible
- to only utilize time warp safe code, it is much better to use
- the <seealso marker="#Multi_Time_Warp_Mode">multi time warp
- mode</seealso> instead.
+ to only utilize time warp safe code, it is <em>much</em> better
+ to use the <seealso marker="#Multi_Time_Warp_Mode">multi time
+ warp mode</seealso> instead.
</p>
<p>Using the single time warp mode, the time offset is
@@ -438,12 +442,14 @@
current OS system time is determined. This offset will
from now on be fixed during the whole preliminary phase.</p>
- <p>If time correction is enabled, the Erlang
- monotonic clock will only use the OS monotonic time as
- time source during this phase. That is, during the
- preliminary phase changes in OS system time will have
- no effect on Erlang system time and/or Erlang
- monotonic time what so ever.</p>
+ <p>If time correction is enabled, adjustments to the
+ Erlang monotonic clock will be made to keep its
+ frequency as correct as possible, but <em>no</em>
+ adjustments will be made trying to align Erlang system
+ time and OS system time. That is, during the preliminary
+ Erlang system time and OS system time might diverge
+ from each other, and no attempt to prevent this will
+ be made.</p>
<p>If time correction is disabled, changes in OS system
time will effect the monotonic clock the same way as
@@ -462,15 +468,16 @@
<p>During finalization, the time offset is adjusted and
fixated so that current Erlang system time align with
- current OS system time. Since the time offset
- may be changed, the Erlang system time may do
- a time warp at this point. The time offset will from
- now on be fixed until the runtime system terminates.
- If time correction has been enabled, the time correction
- also begins when this phase begins. When the system is
- in the final phase it behaves exactly as in the
- <seealso marker="#No_Time_Warp_Mode">no time warp
- mode</seealso>.</p>
+ current OS system time. Since the time offset may
+ change during the finalization, the Erlang system time
+ may do a time warp at this point. The time offset will
+ from now on be fixed until the runtime system terminates.
+ If time correction has been enabled, the time
+ correction will from now on also make adjustments
+ in order to align Erlang system time with OS system
+ time. When the system is in the final phase it behaves
+ exactly as in the <seealso marker="#No_Time_Warp_Mode">no
+ time warp mode</seealso>.</p>
</item>
</taglist>
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-19 12:45:23 +0000