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author | Rickard Green <[email protected]> | 2012-11-16 09:31:56 +0100 |
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committer | Rickard Green <[email protected]> | 2012-11-16 09:31:56 +0100 |
commit | cb11b4d6ec812813d0df07facc02ac5bd47e6851 (patch) | |
tree | 355c2048bf1fcee6392a32be9ed921b3caa3c188 /erts/doc/src/driver_entry.xml | |
parent | 9b7d4359fd771fc3e7589dc91e091c7c35a65807 (diff) | |
parent | 15f3cb7cb7074d507f70e778862e285e844b8546 (diff) | |
download | otp-cb11b4d6ec812813d0df07facc02ac5bd47e6851.tar.gz otp-cb11b4d6ec812813d0df07facc02ac5bd47e6851.tar.bz2 otp-cb11b4d6ec812813d0df07facc02ac5bd47e6851.zip |
Merge branch 'maint'
* maint:
Add clearer warnings about misuse of NIF and driver functionality
Fix erlang:memory(ets)
Conflicts:
erts/emulator/beam/erl_db.c
Diffstat (limited to 'erts/doc/src/driver_entry.xml')
-rw-r--r-- | erts/doc/src/driver_entry.xml | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/erts/doc/src/driver_entry.xml b/erts/doc/src/driver_entry.xml index a2efdf3ebc..929c485c36 100644 --- a/erts/doc/src/driver_entry.xml +++ b/erts/doc/src/driver_entry.xml @@ -34,6 +34,29 @@ <lib>driver_entry</lib> <libsummary>The driver-entry structure used by erlang drivers.</libsummary> <description> + <marker id="WARNING"/> + <warning><p><em>Use this functionality with extreme care!</em></p> + <p>A driver callback is executed as a direct extension of the + native code of the VM. Execution is not made in a safe environment. + The VM can <em>not</em> provide the same services as provided when + executing Erlang code, such as preemptive scheduling or memory + protection. If the driver callback function doesn't behave well, + the whole VM will misbehave.</p> + <list> + <item><p>A driver callback that crash will crash the whole VM.</p></item> + <item><p>An erroneously implemented driver callback might cause + a VM internal state inconsistency which may cause a crash of the VM, + or miscellaneous misbehaviors of the VM at any point after the call + to the driver callback.</p></item> + <item><p>A driver callback that do + <seealso marker="erl_driver#lengthy_work">lengthy work</seealso> + before returning will degrade responsiveness of the VM, + and may cause miscellaneous strange behaviors. Such strange behaviors + include, but are not limited to, extreme memory usage, and bad load + balancing between schedulers. Strange behaviors that might occur due + to lengthy work may also vary between OTP releases.</p></item> + </list> + </warning> <p> As of erts version 5.9 (OTP release R15B) the driver interface has been changed with larger types for the callbacks |