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-rw-r--r--erts/doc/src/erl_driver.xml20
1 files changed, 15 insertions, 5 deletions
diff --git a/erts/doc/src/erl_driver.xml b/erts/doc/src/erl_driver.xml
index 5705100ab2..c790872fe4 100644
--- a/erts/doc/src/erl_driver.xml
+++ b/erts/doc/src/erl_driver.xml
@@ -157,7 +157,7 @@
</note>
<p>Most functions in this API are <em>not</em> thread-safe, that is,
- they <em>cannot</em> be called from any thread. Functions
+ they <em>cannot</em> be called from arbitrary threads. Functions
that are not documented as thread-safe can only be called from
driver callbacks or function calls descending from a driver
callback call. Notice that driver callbacks can be called from
@@ -2304,8 +2304,13 @@ r = driver_async(myPort, &myKey, myData, myFunc); ]]></code>
buffer is too small, a value &gt; <c>0</c> is returned and
<c>*value_size</c> has been set to the buffer size needed.</p>
<warning>
- <p>Do <em>not</em> use libc's <c>getenv</c> or similar C library
- interfaces from a driver.</p>
+ <p>This function reads the emulated environment used by
+ <seealso marker="os:getenv/1"><c>os:getenv/1</c></seealso> and not
+ the environment used by libc's <c>getenv(3)</c> or similar. Drivers
+ that <em>require</em> that these are in sync will need to do so
+ themselves, but keep in mind that they are segregated for a reason;
+ <c>getenv(3)</c> and its friends are <em>not thread-safe</em> and
+ may cause unrelated code to misbehave or crash the emulator.</p>
</warning>
<p>This function is thread-safe.</p>
</desc>
@@ -2650,8 +2655,13 @@ erl_drv_output_term(driver_mk_port(drvport), spec, sizeof(spec) / sizeof(spec[0]
environment variable is removed.</p>
</note>
<warning>
- <p>Do <em>not</em> use libc's <c>putenv</c> or similar C library
- interfaces from a driver.</p>
+ <p>This function modifies the emulated environment used by
+ <seealso marker="os:putenv/2"><c>os:putenv/2</c></seealso> and not
+ the environment used by libc's <c>putenv(3)</c> or similar. Drivers
+ that <em>require</em> that these are in sync will need to do so
+ themselves, but keep in mind that they are segregated for a reason;
+ <c>putenv(3)</c> and its friends are <em>not thread-safe</em> and
+ may cause unrelated code to misbehave or crash the emulator.</p>
</warning>
<p>This function is thread-safe.</p>
</desc>