EPICS Base Release 3.15.5

Changes made on the 3.15 branch since 3.15.4

dbStatic Library Speedup and Cleanup

Loading of database files has been optimized to avoid overproportionally long loading times for large databases. As a part of this, the alphabetical ordering of records instances (within a record type) has been dropped. In the unexpected case that applications were relying on the alphabetic order, setting dbRecordsAbcSorted = 1 before loading the databases will retain the old behavior.

The routine dbRenameRecord() has been removed, as it was intended to be used by database configuration tools linked against a host side version of the dbStatic library that is not being built anymore.

Changes from the 3.14 branch since 3.15.4

Launchpad Bug-fixes

In addition to the more detailed change descriptions below, the following Launchpad bugs have also been fixed in this release:

Whole-Program Optimization for MS Visual Studio Targets

When using the Microsoft compilers a new build system variable is provided that controls whether whole program optimization is used or not. For static builds using Visual Studio 2010 this optimization must be disabled. This is controlled in the files configure/os/CONFIG_SITE.Common.windows-x64-static and configure/os/CONFIG_SITE.Common.win32-x86-static by setting the variable OPT_WHOLE_PROGRAM = NO to override the default value YES that would otherwise be used.

Note that enabling this optimization slows down the build process. It is not possible to selectively disable this optimization, when building a particular module say; Microsoft's linker will restart itself automatically with the -LTCG flag set and display a warning if it is asked to link any object files that were compiled with the -GL flag.

Add dynamic (variable length) array support to PCAS

Dynamic array sizing support was added to the IOC server (RSRV) in the Base-3.14.12 release, but has not until now been supported in the Portable Channel Access Server (PCAS). Channel Access server applications using the PCAS may not need to be modified at all; if they already push monitors with different gdd array lengths, those variable sizes will be forwarded to any CA clients who have requested variable length updates. The example CAS server application has been modified to demonstrate this feature.

In implementing the above, the gdd method gdd::put(const gdd *) now copies the full-sized array from the source gdd if the destination gdd is of type array, has no allocated memory and a boundary size of 0.

Additional epicsTime conversion

The EPICS timestamp library (epicsTime) inside libCom's OSI layer has been extended by routines that convert from struct tm to the EPICS internal epicsTime type, assuming UTC - i.e. without going through the timezone mechanism. This solves issues with converting from the structured type to the EPICS timestamp at driver level from multiple threads at a high repetition rate, where the timezone mechanism was blocking on file access.

MinGW Cross-builds from Linux

The build configuration files that allow cross-building of the 32-bit win32-x86-mingw cross-target have been adjusted to default to building shared libraries (DLLs) as this is now supported by recent MinGW compilers. The 64-bit windows-x64-mingw cross-target was already being built that way by default. The configuration options to tell the minGW cross-compiler to link programs with static versions of the compiler support libraries have now been moved into the CONFIG_SITE.linux-x86.target files.

General Time updates

The iocInit code now performs a sanity check of the current time returned by the generalTime subsystem and will print a warning if the wall-clock time returned has not been initialized yet. This is just a warning message; when a time provider does synchonize the IOC will subsequently pick up and use the correct time. This check code also primes the registered event system provider if there is one so the epicsTimeGetEventInt() routine will work on IOCs that ask for event time within an interrupt service routine.

The osiClockTime provider's synchronization thread (which is only used on some embedded targets) will now poll the other time providers at 1Hz until the first time it manages to get a successful timestamp, after which it will poll for updates every 60 seconds as before.

The routine generalTimeGetExceptPriority() was designed for use by backup (lower priority) time providers like the osiClockTime provider which do not have their own absolute time reference and rely on other providers for an absolute time source. This routine no longer implements the ratchet mechanism that prevented the time it returned from going backwards. If the backup clock's tick-timer runs fast the synchronization of the backup time provider would never allow it to be corrected backwards when the ratchet was in place. The regular epicsTimeGetCurrent() API still uses the ratchet mechanism, so this change will not cause the IOC to see time going backwards.

Microsoft Visual Studio builds

The build configuration files for builds using the Microsoft compilers have been updated, although there should be no noticable difference at most sites. One extra compiler warning is now being suppressed for C++ code, C4344: behavior change: use of explicit template arguments results in ... which is gratuitous and was appearing frequently in builds of the EPICS V4 modules.

Cross-builds of the windows-x64 target from a win32-x86 host have been removed as they don't actually work within the context of a single make run. Significant changes to the build configuration files would be necessary for these kinds of cross-builds to work properly, which could be done if someone needs them (email Andrew Johnson before working on this, and see this stack-overflow answer for a starting point).

Bazaar keywords such as 'Revision-Id' removed

In preparation for moving to git in place of the Bazaar revision control system we have removed all the keywords from the Base source code.

Linux systemd service file for CA Repeater

Building this version of Base on a Linux system creates a systemd service file suitable for starting the Channel Access Repeater under systemd. The file will be installed into the target bin directory, from where it can be copied into the appropriate systemd location and modified as necessary. Installation instructions are included as comments in the file.

Changes made between 3.15.3 and 3.15.4

New string input device support "getenv"

A new "getenv" device support for both the stringin and lsi (long string input) record types can be used to read the value of an environment variable from the IOC at runtime. See base/db/softIocExit.db for sample usage.

Build rules and DELAY_INSTALL_LIBS

A new order-only prerequisite build rule has been added to ensure that library files (and DLL stubs on Windows) get installed before linking any executables, which resolves parallel build problems on high-powered CPUs. There are some (rare) cases though where a Makefile has to build an executable and run it to be able to compile code for a library built by the same Makefile. With this new build rule GNUmake will complain about a circular dependency and the build will probably fail in those cases. To avoid this problem the failing Makefile should set DELAY_INSTALL_LIBS = YES before including the $(TOP)/configure/RULES file, disabling the new build rule.

IOC environment variables and build parameters

The IOC now sets a number of environment variables at startup that provide the version of EPICS Base it was built against (EPICS_VERSION_...) and its build architecture (ARCH). In some cases this allows a single iocBoot/ioc directory to be used to run the same IOC on several different architectures without any changes.

There are also 3 new environment parameters (EPICS_BUILD_...) available that C/C++ code can use to find out the target architecture, OS class and compiler class it was built with. These may be useful when writing interfaces to other languages.

New implementation of promptgroup/gui_group field property

The mechanism behind the "promptgroup()" field property inside a record type definition has been changed. Instead of using a fixed set of choices, the static database access library now collects the used gui group names while parsing DBD information. Group names should start with a two-digit number plus space-dash-space to allow proper sorting of groups.

The include file guigroup.h that defined the fixed set of choices has been deprecated. Instead, use the conversion functions between index number and group string that have been added to dbStaticLib.

When a DBD file containing record-type descriptions is expanded, any old-style GUI_xxx group names will be replaced by a new-style string for use by the IOC. This permits an older record type to be used with the 3.15.4 release, although eventually record types should be converted by hand with better group names used.

CA server configuration changes

RSRV now honors EPICS_CAS_INTF_ADDR_LIST and binds only to the provided list of network interfaces. Name searches (UDP and TCP) on other network interfaces are ignored. For example on a computer with interfaces,, and, setting "EPICS_CAS_INTF_ADDR_LIST=''" will accept traffic on the .1.1 and .2.1, but ignore from .3.1

RSRV now honors EPICS_CAS_IGNORE_ADDR_LIST and ignores UDP messages received from addresses in this list.

Previously, CA servers (RSRV and PCAS) would build the beacon address list using EPICS_CA_ADDR_LIST if EPICS_CAS_BEACON_ADDR_LIST was no set. This is no longer done. Sites depending on this should set both envronment variables to the same value.

IPv4 multicast for name search and beacons

libca, RSRV, and PCAS may now use IPv4 multicasting for UDP traffic (name search and beacons). This is disabled by default. To enable multicast address(s) must be listed in EPICS_CA_ADDR_LIST for clients and EPICS_CAS_INTF_ADDR_LIST for servers (IOCs should set both). For example: "EPICS_CAS_INTF_ADDR_LIST='' EPICS_CA_ADDR_LIST=".

Please note that no IPv4 multicast address is officially assigned for Channel Access by IANA. The example is taken from the AD-HOC Block I range.

Moved mlockall() into its own epicsThread routine

Since EPICS Base on Posix OSs the initialization of the epicsThread subsystem has called mlockall() when the OS supports it and thread priority scheduling is enabled. Doing so has caused problems in third-party applications that call the CA client library, so the functionality has been moved to a separate routine epicsThreadRealtimeLock() which will be called by the IOC at iocInit (unless disabled by setting the global variable dbThreadRealtimeLock to zero).

Added dbQuietMacroWarnings control

When loading database files, macros get expanded even on comment lines. If a comment contains an undefined macro, the load still continues but an error message gets printed. For this release the error message has been changed to a warning, but even this warning can be made less verbose by setting this new variable to a non-zero value before loading the file, like this:

var dbQuietMacroWarnings 1      iocsh
dbQuietMacroWarnings=1          VxWorks

This was Launchpad bug 541119.

Changes from the 3.14 branch between 3.15.3 and 3.15.4

NTP Time Provider adjusts to OS tick rate changes

Dirk Zimoch provided code that allows the NTP Time provider (used on VxWorks and RTEMS only) to adapt to changes in the OS clock tick rate after the provider has been initialized. Note that changing the tick rate after iocInit() is not advisable, and that other software might still misbehave if initialized before an OS tick rate change. This change was back-ported from the 3.15 branch.

Making IOC ca_get operations atomic

When a CA client gets data from an IOC record using a compound data type such as DBR_TIME_DOUBLE the value field is fetched from the database in a separate call than the other metadata, without keeping the record locked. This allows some other thread such as a periodic scan thread a chance to interrupt the get operation and process the record in between. CA monitors have always been atomic as long as the value data isn't a string or an array, but this race condition in the CA get path has now been fixed so the record will stay locked between the two fetch operations.

This fixes Launchpad bug #1581212, thanks to Till Strauman and Dehong Zhang.

New CONFIG_SITE variable for running self-tests

The 'make runtests' and 'make tapfiles' build targets normally only run the self-tests for the main EPICS_HOST_ARCH architecture. If the host is able to execute self-test programs for other target architectures that are being built by the host, such as when building a -debug version of the host architecture for example, the names of those other architectures can be added to the new CROSS_COMPILER_RUNTEST_ARCHS variable in either the configure/CONFIG_SITE file or in an appropriate configure/os/CONFIG_SITE.<host>.Common file to have the test programs for those targets be run as well.

Additional RELEASE file checks

An additional check has been added at build-time for the contents of the configure/RELEASE file(s), which will mostly only affect users of the Debian EPICS packages published by NSLS-2. Support modules may share an install path, but all such modules must be listed adjacent to each other in any RELEASE files that point to them. For example the following will fail the new checks:

AUTOSAVE = /usr/lib/epics
ASYN = /home/mdavidsaver/asyn
EPICS_BASE = /usr/lib/epics

giving the compile-time error

This application's RELEASE file(s) define
	EPICS_BASE = /usr/lib/epics
after but not adjacent to
	AUTOSAVE = /usr/lib/epics
Module definitions that share paths must be grouped together.
Either remove a definition, or move it to a line immediately
above or below the other(s).
Any non-module definitions belong in configure/CONFIG_SITE.

In many cases such as the one above the order of the AUTOSAVE and ASYN lines can be swapped to let the checks pass, but if the AUTOSAVE module depended on ASYN and hence had to appear before it in the list this error indicates that AUTOSAVE should also be built in its own private area; a shared copy would likely be incompatible with the version of ASYN built in the home directory.

String field buffer overflows

Two buffer overflow bugs that can crash the IOC have been fixed, caused by initializing a string field with a value larger than the field size (Launchpad bug #1563191).

Fixed stack corruption bug in epicsThread C++ API

The C++ interface to the epicsThread API could corrupt the stack on thread exit in some rare circumstances, usually at program exit. This bug has been fixed (Launchpad bug #1558206).

RTEMS NTP Support Issue

On RTEMS the NTP Time Provider could in some circumstances get out of sync with the server because the osdNTPGet() code wasn't clearing its input socket before sending out a new request. This (Launchpad bug 1549908) has now been fixed.

CALC engine bitwise operator fixes

The bitwise operators in the CALC engine have been modified to work properly with values that have bit 31 (0x80000000) set. This modification involved back-porting some earlier changes from the 3.15 branch, and fixes Launchpad bug #1514520.

Fix ipAddrToAsciiAsync(): Don't try to join the daemon thread

On process exit, don't try to stop the worker thread that makes DNS lookups asynchronous. Previously this would wait for any lookups still in progress, delaying the exit unnecessarily. This was most obvious with catools (eg. cainfo). lp:1527636

Fix epicsTime_localtime() on Windows

Simpler versions of the epicsTime_gmtime() and epicsTime_localtime() routines have been included in the Windows implementations, and a new test program added. The original versions do not report DST status properly. Fixes Launchpad bug 1528284.

Changes made between 3.15.2 and 3.15.3

Make the NTP Time provider optional on VxWorks

Recent versions of VxWorks (sometime after VxWorks 6) provide facilities for automatically synchronizing the OS clock time with an NTP server. The EPICS time system used to assume that it had to provide time synchronization on VxWorks, but now it tests for the existance of either of the two OS synchronization threads before starting the NTP time provider. It is still possible to force the NTP provider to be started even if the OS synchronization is running by defining the environment variable EPICS_TS_FORCE_NTPTIME in the startup script before loading the IOC's .munch file. Forcing may be necessary if the VxWorks image is not correctly configured with the IP address of a local NTP server.

Assembling files from numbered snippets

A tool has been added that assembles file snippets specified on the command line into a single output file, with sorting and replacing/adding of snippets done based on their file names. The build system integration requires the output file to be specified setting COMMON_ASSEMBLIES (arch independent) or ASSEMBLIES (created by arch), then defining the snippets for each assembly setting *_SNIPPETS (explicitly) or *_PATTERN (searched relative to all source directories).

Clean up after GNU readline()

If EPICS Base is built with readline support, any IOC that calls epicsExit() from a thread other than the main thread is likely to leave the user's terminal in a weird state, requiring the user to run something like 'stty sane' to clean it up. This release patches the readline support code to clean up automatically by registering an epicsAtExit() routine.

Removed the last vestiges of RSET::get_value()

The IOC has not called the get_value() routine in the RSET for a very long time, but there was still one implementation left in the event record support code, and a structure definition for one of the original arguments to that routine was defined in recGbl.h. Both of these have now been removed.

Changes made between 3.15.1 and 3.15.2

Raised limit on link field length in database files

The length of INP/OUT link fields in database files was limited to 79 chars by an internal buffer size in the db file parser. This limitation will go away completely in 3.16, and has been statically raised to 255 chars for the 3.15 series.

aoRecord raw conversion overflows

The ao record type now checks converted raw values and limits them to the 32-bit integer range before writing them to the RVAL field. Previously value overflows relied on Undefined Behaviour which could give different results on different platforms. The ROFF fields of the ao and ai record types are now DBF_ULONG to allow an ROFF setting of 0x80000000 to work properly.

Changes to <top>/cfg/* files

The order in which cfg/CONFIG* and cfg/RULES* files are included from support applications listed in the configure/RELEASE* files has been changed. Previously these files were included in the order in which the top areas are listed in the RELEASE file, but it makes more sense to load them in reverse order since later entries override earlier ones in Makefiles but the release file order is supposed to allow earlier entries to take precedence over later ones. The same change has been made to the inclusion of the <top>/configure/RULES_BUILD files.

Two new file types can also be provided in a module's cfg directory. Files named TOP_RULES* will be included by the top-level Makefile of other modules that refer to this module; files name DIR_RULES* will be included by all Makefiles that merely descend into lower-level directories. The cfg/RULES* files are only included when make is building code inside the O.<arch> directories.

The new cfg/DIR_RULES* file inclusion was designed to permit new recursive make actions to be implemented by appending the name of the new action to the ACTIONS variable. There must be a matching rule in one of the cfg/RULES* files when doing this. Similar rules may also be defined in the cfg/TOP_RULES* and/or cfg/DIR_RULES* files, but these should only state prerequisites and not directly provide commands to be executed.

Build rules for RTEMS GESYS modules

RTEMS target builds can now be configured to make GESYS modules by changing the USE_GESYS=NO setting in the file configure/os/CONFIG_SITE.Common.RTEMS to YES.

Added Make variables for command-line use

The following variables are now used during the build process, reserved for setting on the command-line only (Makefiles should continue to use the USR_ equivalents):

For example:

make CMD_INCLUDES=/opt/local/include CMD_LDFLAGS=-L/opt/local/lib

Enhanced API for asTrapWrite listeners

External software such as the CA Put Logging module that registers a listener with the asTrapWrite subsystem was not previously given access to the actual data being sent by the CA client. In most cases this was not a problem as the listener can look at the field being modified both before and after the operation, but if the put processes the record which immediately overwrites the new value, the client's value cannot be observed.

This release adds three fields to the asTrapWriteMessage structure that is passed to the listener routines. These new fields provide the CA data type, the number of array elements, and a pointer to the source data buffer. This change is completely backwards compatible with listener code written against the original API. The new API can be detected at compile-time as follows:

#include "asLib.h"

/* ... */

#ifdef asTrapWriteWithData
    /* Enhanced API */

Use of PATH_FILTER in Makefiles deprecated

The PATH_FILTER variable was being called to convert forward shashes / in file paths into pairs of backward slashes \\ on Windows architectures. This has never been strictly necessary, and was added about 10 years ago to get around some short-comings in Windows tools at the time. All uses of PATH_FILTER in Base have now been removed; the definition is still present, but will result in a warning being printed if it is ever used.

Using msi for dependencies

To reduce confusion the msi program has been modified to allow the generation of dependency rules by adding support for a -D option, and changing the commands in RULES.Db to use this option instead of the mkmf.pl script. The new build rules will not work with old versions of the msi program, so the command variable name used in the rules has been changed from MSI to MSI3_15. Sites that use a modified version of msi must provide support for both the -D and -o outfile options, and should then point the MSI3_15 variable in their applications' CONFIG_SITE files to that updated executable.

Changes made between and 3.15.1

epicsStrnEscapedFromRaw() and epicsStrnRawFromEscaped()

These routines have been rewritten; the previous implementations did not always behave exactly as specified.

Shared Library Versions

On architectures that can support it, the shared library version number for libraries provided with Base has had the third component of the EPICS version number added to it, thus libCom.so.3.15.1 instead of libCom.so.3.15. Windows can only support two components to its internal product version number, and the Darwin bug that external shared libraries were being built using the EPICS version number has been fixed.

Hooking into dbLoadRecords

A function pointer hook has been added to the dbLoadRecords() routine, to allow external modules such as autosave to be notified when new records have been loaded during IOC initialization. The hook is called dbLoadRecordsHook and follows the model of the recGblAlarmHook pointer in that modules that wish to use it must save the current value of the pointer before installing their own function pointer, and must call the original function from their own routine.

The hook is activiated from the dbLoadRecords() routine and gets called only after a database instance file has been read in without error. Note that the dbLoadTemplates() routine directly calls dbLoadRecords() so this hook also provides information about instantiated database templates. It is still possible to load record instances using dbLoadDatabase() though, and doing this will not result in the hook routines being called.

Code to use this hook should look something like this:

#include "dbAccessDefs.h"


static void myRoutine(const char* file, const char* subs) {
    if (previousHook)
        previousHook(file, subs);

    /* Do whatever ... */

void myInit(void) {
    static int done = 0;

    if (!done) {
        previousHook = dbLoadRecordsHook;
        dbLoadRecordsHook = myRoutine;
        done = 1;

As with many other parts of the static database access library there is no mutex to protect the function pointer. Initialization is expected to take place in the context of the IOC's main thread, from either a static C++ constructor or an EPICS registrar routine.

Changes made between and

New iocshLoad command

A new command iocshLoad has been added to iocsh which executes a named iocsh script and can also set one or more shell macro variables at the same time, the values of which will be forgotten immediately after the named script finishes executing. The following example shows the syntax:

iocshLoad "serial.cmd", "DEV=/dev/ttyS0,PORT=com1,TYPE=RS485"
iocshLoad "radmon.cmd", "PORT=com1,ADDR=0"

Support routines for 64-bit integers

The libCom library now provides support for 64-bit integer types on all supported architectures. The epicsTypes.h header file defines epicsInt64 and epicsUInt64 type definitions for both C and C++ code. The epicsStdlib.h header also declares the following for parsing strings into the relevent sized integer variables: Functions epicsParseLLong(), epicsParseULLong() with related macros epicsScanLLong() and epicsScanULLong(), and the functions epicsParseInt64() and epicsParseUInt64(). Use the first two functions and the macros for long long and unsigned long long integer types, and the last two functions for the epicsInt64 and epicsUInt64 types. Note that the latter can map to the types long and unsigned long on some 64-bit architectures such as linux-x86_64, not to the two long long types.

This version does not provide the ability to define 64-bit record fields, the use of the 64-bit types in the IOC database will come in a later release of EPICS Base.

Full support for loadable support modules

Apparently later versions of Base 3.14 permitted support modules to be loaded from a shared library at runtime without the IOC having been linked against that shared library; the registerRecordDeviceDriver.pl program would accept a partial DBD file containing just the entries needed for the library and generate the appropriate registration code. In 3.15 however the registerRecordDeviceDriver.pl program was replaced by one using the new DBD file parser, and in this a device support entry would only be accepted after first loading the record type that it depended on.

The parser has been modified to accept device entries without having seen the record type first, although a warning is given when that happens. To remove the warning the DBD file can provide a record type declaration instead (no fields can be defined, so the braces must be empty), before the device() entry. The result will generate the correct registration code for the device entry without including anything for any merely declared record types. The generated code can be linked into a shared library and loaded by an IOC at runtime using dlload.

Parallel callback threads

The general purpose callback facility can run multiple parallel callback threads per priority level. This makes better use of SMP architectures (e.g. processors with multiple cores), as callback work - which includes second stage processing of records with asynchronuous device support and I/O scanned processing - can be distributed over the available CPUs.

Note that by using parallel callback threads the order of scan callback requests in the queue is not retained. If a device support needs to be informed when scanIoRequest processing has finished, it should use the new scanIoSetComplete() feature to add a user function that will be called after the scanIoRequest record processing has finished.

Parallel callback threads have to be explicitly configured, by default the IOC keeps the old behavior of running one callback thread per priority.

Merge MMIO API from devLib2

Added calls to handle 8, 16, and 32 bit Memory Mapped I/O reads and writes. The calls added include X_iowriteY() and X_ioreadY() where X is nat (native), be or le, and Y is 16 or 32. Also added are ioread8() and iowrite8().

Added optional dbServer API to database

A server layer that sits on top of the IOC database may now register itself as such by calling dbRegisterServer() and providing optional routines that other components can use. The initial purpose of this API allows the Trace Processing implementation in dbProcess() to identify a client that causes a record to process when TPRO is set.

To support the client idenfication, the server provides a routine that returns that identity string when called by one of its own processing threads.

Concatenated database definition files

A series of database definition (dbd) files can now be concatenated during the build process into a newly-created dbd file with result being installed into $(INSTALL_LOCATION)/dbd without expanding it.

The following lines in an EPICS Makefile will create a file name.dbd in the O.Common build directory containing the contents of file1.dbd followed by file2.dbd then file3.dbd. The new file will then be installed into $(INSTALL_LOCATION)/dbd without expanding any of its include statements.

DBDCAT += name.dbd
name_DBD += file1.dbd file2.dbd file3.dbd

The source files file1.dbd, file2.dbd and file3.dbd may be created by the current Makefile, be located in the parent directory or any other directory in the SRC_DIRS list, be specified by their full pathname, exist in the install dbd directory, or be found in any dbd directory linked from the application's RELEASE files.

Posix: Drop SCHED_FIFO before exec() in child process

If Base is compiled with USE_POSIX_THREAD_PRIORITY_SCHEDULING = YES in configure/CONFIG_SITE or related files, the Posix implementation of the libCom osiSpawnDetachedProcess() routine will switch the child process to use the normal SCHED_OTHER (non real-time) scheduler before executing the named executable program. If it needs to use the real-time scheduler the new program can request that for itself.

Posix: Lock all memory when running with FIFO scheduler

On Posix systems, an IOC application's ability to meet timing deadlines is often dependent on its ability to lock part or all of the process's virtual address space into RAM, preventing that memory from being paged to the swap area. This change will attempt to lock the process's virtual address space into RAM if the process has the ability to run threads with different priorities. If unsuccessful, it prints an message to stderr and continues.

On Linux, one can grant a process the ability to run threads with different priorities by using the command ulimit -r unlimited. To use the FIFO scheduler for an IOC, use a command like this:

chrt -f 1 softIoc -d test.db

On Linux, one can grant a process the ability to lock itself into memory using the command ulimit -l unlimited. These limits can also be configured on a per user/per group basis by changing /etc/security/limits.conf or its equivalent.

A child process created via fork() normally inherits its parent's resource limits, so a child of a real-time soft-IOC will get its parent's real-time priority and memlock limits. The memory locks themselves however are not inherited by child processes.

Implement EPICS_CAS_INTF_ADDR_LIST in rsrv

The IOC server can now bind to a single IP address (and optional port number) read from the standard environment parameter EPICS_CAS_INTF_ADDR_LIST. Additional addresses included in that parameter after the first will be ignored and a warning message displayed at iocInit time.

alarmString.h deprecated again

The string arrays that provide string versions of the alarm status and severity values have been moved into libCom and the header file that used to instanciate them is no longer required, although a copy is still provided for backwards compatibility reasons. Only the alarm.h header needs to be included now to declare the epicsAlarmSeverityStrings and epicsAlarmConditionStrings arrays.

General purpose thread pool

A general purpose threaded work queue API epicsThreadPool is added. Multiple pools can be created with controlable priority and number of worker threads. Lazy worker startup is supported.

Database field setting updates

A database (.db) file loaded by an IOC does not have to repeat the record type of a record that has already been loaded. It may replace the first parameter of the record(type, name) statement with an asterisk character inside double-quotes, "*" instead. Thus the following is a legal database file:

record(ao, "ao1") {}
record("*", "ao1") {
    field(VAL, 10)

Note that database configuration tools will not be expected to have to understand this syntax, which is provided for scripted and hand-coded database and template instantiation only. Setting the IOC's dbRecordsOnceOnly flag also makes this syntax illegal, since its purpose is to prevent multiply-defined records from being collapsed into a single instance.

Added echo command to iocsh

The single argument string may contain escaped characters, which will be translated to their raw form before being printed (enclose the string in quotes to avoid double-translation). A newline is always appended to the output, and output stream redirection is supported.

Added macro EPICS_UNUSED to compilerDependencies.h

To prevent the compiler from warning about a known-unused variable, mark it with the macro EPICS_UNUSED. On gcc and clang this will expand to __attribute__((unused)) to prevent the warning.

User specified db substitution file suffix

Per Dirk Zimoch's suggestion, a user specified db substitution file suffix is now allowed by setting the variable SUBST_SUFFIX in a configuration directory CONFIG_SITE file or in a Makefile before the include $(TOP)/configure/RULES line. The default for SUBST_SUFFIX is .substitutions

NTP Time Provider adjusts to OS tick rate changes

Dirk Zimoch provided code that allows the NTP Time provider (used on VxWorks and RTEMS only) to adapt to changes in the OS clock tick rate after the provider has been initialized. Note that changing the tick rate after iocInit() is not advisable, and that other software might still misbehave if initialized before an OS tick rate change.

Added newEpicsMutex macro

Internal C++ uses of new epicsMutex() have been replaced with a new macro which calls a new constructor, passing it the file name and line number of the mutex creation code. C code that creates mutexes has been using a similar macro for a long time, but there was no equivalent constructor for the C++ wrapper class, so identifying a specific mutex was much harder to do.

Post DBE_PROPERTY events automatically

A new record field attribute "prop(YES)" has been added to identify fields holding meta-data. External changes to these fields will cause a CA monitor event to be sent to all record subscribers who have asked for DBE_PROPERTY updates. Meta-data fields have been marked for all Base record types.

errlogRemoveListener() routine changed

Code that calls errlogRemoveListener(myfunc) must be modified to use the new, safer routine errlogRemoveListeners(myfunc, &pvt) instead. The replacement routine takes a second argument which must be the same private pointer that was passed to errlogAddListener() when adding that listener. It also deletes all matching listeners (hence the new plural name) and returns how many were actually deleted, whereas the previous routine only removed the first listener that matched.

Simplified generation of .dbd files

The Perl script makeIncludeDbd.pl has been removed and the rules that created an intermediate xxxInclude.dbd file from the Makefile variable xxx_DBD have been modified to generate the target xxx.dbd file directly. This should simplify applications that might have had to provide dependency rules for the intermediate files in 3.15. Applications which provide their own xxxInclude.dbd source file will continue to have it expanded as before.

New Undefined Severity field UDFS

A new field has been added to dbCommon which configures the alarm severity associated with the record being undefined (when UDF=TRUE). The default value is INVALID so old databases will not be affected, but now individual records can be configured to have a lower severity or even no alarm when undefined. Be careful when changing this on applications where the IVOA field of output records is used, IVOA still requires an INVALID severity to trigger value replacement.

New build target tapfiles

This new make target runs the same tests as the runtests target, but instead of summarizing or displaying the output for each test script it creates a .tap file inside the architecture build directory which contains the detailed test output. The output file can be parsed by continuous integration packages such as Jenkins to show the test results.

Array field double-buffering

Array data can now be moved, without copying, into and out of the VAL field of the waveform, aai, and aao record types by replacing the pointer in BPTR. The basic rules which device support must follow are:

  1. BPTR, and the memory it is currently pointing to, can only be accessed while the record is locked.
  2. NELM may not be changed; NORD should be updated whenever the number of valid data elements changes.
  3. When BPTR is replaced it must always point to a block of memory large enough to hold the maximum number of elements, as given by the NELM and FTVL fields.

Spin-locks API added

The new header file epicsSpin.h adds a portable spin-locks API which is intended for locking very short sections of code (typically one or two lines of C or C++) to provide a critical section that protects against race conditions. On Posix platforms this uses the pthread_spinlock_t type if it's available and the build is not configured to use Posix thread priorities, but otherwise it falls back to a pthread_mutex_t. On the UP VxWorks and RTEMS platforms the implementations lock out CPU interrupts and disable task preemption while a spin-lock is held. The default implementation (used when no other implementation is provided) uses an epicsMutex. Spin-locks may not be taken recursively, and the code inside the critical section should be short and deterministic.

Improvements to aToIPAddr()

The libCom routine aToIPAddr() and the vxWorks implementation of the associated hostToIPAddr() function have been modified to be able to look up hostnames that begin with one or more digits. The epicsSockResolveTest program was added to check this functionality.

mbboDirect and mbbiDirect records

These record types have undergone some significant rework, and will behave slightly differently than they did in their 3.14 versions. The externally visible changes are as follows:


Redirection of the errlog console stream

A new routine has been added to the errlog facility which allows the console error message stream to be redirected from stderr to some other already open file stream:

int errlogSetConsole(FILE *stream);

The stream argument must be a FILE* pointer as returned by fopen() that is open for output. If NULL is passed in, the errlog thread's stderr output stream will be used instead. Note that messages to the console can be disabled and re-enabled using the eltc routine which is also an iocsh command, but there is no iocsh command currently provided for calling errlogSetConsole.

Add cleanup subroutine to aSub record

An aSub routine may set the CADR field with a function pointer which will be run before a new routine in the event that a change to the SNAM field changes the record's process subroutine.

This can be used to free any resources the routine needs to allocate. It can also be used to determine if this is the first time this routine has been called by this record instance. The CADR field is set to NULL immediately after the routine it points to is called.


void cleanup(aSubRecord* prec) {
    prec->dpvt = NULL;

long myAsubRoutine(aSubRecord* prec) {
    if (!prec->cadr) {
        /* check types of inputs and outputs */
        if (prec->ftva != menuFtypeDOUBLE)
            return 1; /* oops */

        dpvt = malloc(42);
        prec->cadr = &cleanup;

    /* normal processing */

Sequence record enhancements

The sequence record type now has 16 link groups numbered 0 through 9 and A through F, instead of the previous 10 groups numbered 1 through 9 and A. The changes to this record are directly equivalent to those described below for the fanout record. The fields OFFS and SHFT have been added and operate on the SELN value exactly the same way. The result is backwards compatible with the 3.14 version of the sequence record as long as none of the new fields are modified and the application does not rely on the SOFT/INVALID alarm that was generated when the selection number exceeded 10. The record also now posts monitors on the SELN field at the end of the sequence if its value changed when read through the SELL link.

Fanout record enhancements

The fanout record type now has 16 output links LNK0-LNK9 and LNKA-LNKF, plus two additional fields which make the result backwards compatible with 3.14 databases, but also allow the link selection to be shifted without having to process the SELN value through a calc or calcout record first.

Previously there was no LNK0 field, so when SELM is Mask bit 0 of SELN controls whether the LNK1 link field was activated; bit 1 controls LNK2 and so on. When SELM is Specified and SELN is zero no output link would be activated at all; LNK1 gets activated when SELN is 1 and so on. Only 6 links were provided, LNK1 through LNK6. The updated record type maintains the original behavior when the new fields are not configured, except that the SOFT/INVALID alarm is not generated when SELN is 7 through 15.

The update involved adding a LNK0 field, as well as fields LNK7 through LNK9 and LNKA through LNKF. To add flexibility and maintain backwards compatibility, two additional fields have been added:

This field holds a signed offset which is added to SELN to select which link to activate when SELM is Specified. If the resulting value is outside the range 0 .. 15 the record will go into a SOFT/INVALID alarm state. The default value of OFFS is zero, so if it is not explicitly set and SELN is 1 the LNK1 link will be activated.
When SELM is Mask the signed field SHFT is used to shift the SELN value by SHFT bits (positive means right-wards, values outside the range -15 .. 15 will result in a SOFT/INVALID alarm), before using the resulting bit-pattern to control which links to activate. The default value is -1, so if SHFT is not explicitly set bit 0 of SELN will be used to control whether LNK1 gets activated.

The record also now posts monitors on the SELN field if it changes as a result of record processing (i.e. when read through the SELL link).

Deleted Java build rules

Java has its own build systems now, so we've deleted the rules and associated variables from Base, although they might get added to the Extensions build rules for a while in case anyone still needs them.

Changes made between 3.14.x and

Application clean rules

The clean Makefile target has changed between a single-colon rule and a double-colon rule more than once in the life of the EPICS build rules, and it just changed back to a single-colon rule, but now we recommend that applications that wish to provide a Makefile that is backwards compatible with the 3.14 build rules use the construct shown below. The 3.15 rules now support a variable called CLEANS to which a Makefile can add a list of files to be deleted when the user does a make clean like this:

CLEANS += <list of files to be cleaned>

ifndef BASE_3_15
	$(RM) $(CLEANS)

The conditional rule provides compatibility for use with the 3.14 build system.

MSI included with Base

An enhanced version of the Macro Substitution and Include program msi has been included with Base. Both this new version of msi and the IOC's dbLoadTemplates command now support setting global macros in substitution files, and dbLoadTemplates can now take a list of global macro settings as the second argument on its command line. The substitution file syntax is documented in the Application Developers Guide.

Cross-builds targeting win32-x86-mingw

Some Linux distributions now package the MinGW cross-compiler which makes it possible to cross-build the win32-x86-mingw target from a linux-x86 host. Build configuration files for this combination are now included; adjust the settings in configure/os/CONFIG_SITE.linux-x86.win32-x86-mingw and add win32-x86-mingw to the CROSS_COMPILER_TARGET_ARCHS variable in configure/CONFIG_SITE or in configure/os/CONFIG_SITE.linux-x86.Common.

Architecture win32-x86-cygwin Removed

The ability to compile non-cygwin binaries using the Cygwin build tools is no longer supported by current versions of Cygwin, so this architecture has been removed. Use the MinWG tools and the win32-x86-mingw architecture instead.

RTEMS and VxWorks Test Harnesses

The original libCom test harness has been renamed libComTestHarness, and two additional test harnesses have been created dbTestHarness and filterTestHarness which are all built for RTEMS and vxWorks targets. The new ones include tests in src/ioc/db/test and src/std/filters/test.

Running the new tests requires additional .db and .dbd files to be loaded at runtime, which can be found in the relevant source directory or its O.Common subdirectory. If the target can access the Base source tree directly it may be simplest to cd to the relevant source directory before running the test. If not, the files needed are listed in the generated 'testspec' file found in the associated build (O.arch) directory.

For RTEMS users the current directory is determined in a BSP specific way. See rtems_init.c and setBootConfigFromNVRAM.c in src/libCom/RTEMS.

New API to hook into thread creation

A hook API has been added allowing user-supplied functions to be called whenever a thread starts. The calls are made from the thread's context, and can be used to control additional thread properties not handled inside EPICS base, e.g. setting the scheduling policy or CPU affinity (on SMP systems).

The API also supports a mapping operation, calling a user-supplied function for every thread that is currently running.

New scan rate units

Scan rates defined in the menuScan.dbd file may now be specified in seconds, minutes, hours or Hertz, and plural time units will also be accepted (seconds are used if no unit is mentioned in the choice string). At iocInit each scan rate is compared with the OS's clock tick and a warning printed if the rate is too fast or likely to be more than 10% different to the requested rate. For example the rates given below are all valid, although non-standard (the default menuScan choices that come with Base have not been changed):

menu(menuScan) {
    choice(menuScanPassive,     "Passive")
    choice(menuScanEvent,       "Event")
    choice(menuScanI_O_Intr,    "I/O Intr")
    choice(menuScan1_hour,      "1 hour")
    choice(menuScan0_5_hours, "0.5 hours")
    choice(menuScan15_minutes, "15 minutes")
    choice(menuScan5_minutes,   "5 minutes")
    choice(menuScan1_minute,    "1 minute")
    choice(menuScan10_seconds, "10 seconds")
    choice(menuScan5_seconds,   "5 seconds")
    choice(menuScan2_seconds,   "2 seconds")
    choice(menuScan1_second,    "1 second")
    choice(menuScan2_Hertz,     "2 Hertz")
    choice(menuScan5_Hertz,     "5 Hertz")
    choice(menuScan10_Hertz,   "10 Hz")

Alarm filtering added to input record types

The record types ai, calc, longin and mbbi have a new alarm filter added to them. This provides a low-pass filter that can be used to delay the reporting of alarms caused by the input level passing the HIGH, HIHI, LOW or LOLO values. The filter is controlled with a new AFTC field that sets the filter's time constant. The default value for this field is zero, which keeps the record's original alarm behaviour.

The record must be scanned often enough for the filtering action to work effectively and the alarm severity can only change when the record is processed, but that processing does not have to be regular; the filter uses the time since the record last processed in its calculation. Setting AFTC to a positive number of seconds will delay the record going into or out of a minor alarm severity or from minor to major severity until the input signal has been in that range for that number of seconds.

Post events on Waveform record's NORD field

When the record type or device support modify the NORD field of a waveform record, the record support code now posts DBE_VALUE and DBE_LOG events for that field, signalling the array length change to any client monitoring the NORD field.

Attributes of Non-VAL Fields

Non-VAL fields now report meaningful information for precision, units, graphic limits, control limits, and alarm limits instead of simply using PREC, EGU, HOPR, LOPR, DRVL, DRVH, HIHI, HIGH, LOW, and LOLO. All delay fields have a default precision of 2 digits, units "s" and control limits of 0 to 100,000 seconds (these precision and limit values can be changed for each record type as a whole at runtime by updating a registered global variable). Input fields like A-L of the calc record read their metadata from the corresponding INPn link if possible.

epicsStdioRedirect.h merged into epicsStdio.h

The definitions from the header file epicsStdioRedirect.h have been moved into epicsStdio.h so all calls to printf(), puts() and putchar() in files that include that OSI header will now be subject to stdout redirection. In past releases (3.14.7 and later) it was necessary to request the redirection support by including the epicsStdioRedirect.h header file. The header file is still provided, but now it just includes epicsStdio.h.

Named Soft Events

Soft events can now be given meaningful names instead of just using the numbers 1-255. The EVNT field is now a DBF_STRING. The post_event() API is now deprecated but still works. It should be replaced by code that in advance looks up the EVNTPVT event handle associated with the named event by calling eventNameToHandle(char *), and when that event occurs passes that handle to the new postEvent(EVNTPVT) routine (which may be called from interrupt level). A new iocsh command postEvent name will trigger a named event from the command-line or a startup script (on vxWorks the expression postEvent(eventNameToHandle("name")) must be used instead though).

Parallel Builds

As EPICS sites get computers with more CPUs they report additional bugs in our parallel build rules. Various issues have been fixed by separating out the build rules that generate dependency (.d) files, ensuring that they are constructed at the appropriate time in the build.

These rule changes can cause additional warning messages to appear when building support modules. Where an application provides its own Makefile rules it may now have to add rules to construct an associated dependency file. In many cases though the change needed is just to replace a dependency for a target$(OBJ) with the target$(DEP) so this

    myLib$(OBJ): myLib_lex.c


    myLib$(DEP): myLib_lex.c

To debug build issues assocated with dependency files, use the command make --debug=m which tells GNUmake to display information about what it is doing during the first pass when it updates its makefiles.

Removed tsDefs.h

The deprecated tsDefs API was provided for 3.13 compatibility only, and has now been removed. Convert any remaining code that used it to call the epicsTime API instead.

Changes to epicsVersion.h

The two macros EPICS_UPDATE_LEVEL and EPICS_CVS_SNAPSHOT have been deleted from the epicsVersion.h file; they were deprecated in R3.14 and can be replaced with EPICS_PATCH_LEVEL and EPICS_DEV_SNAPSHOT respectively.

A new pair of macros has been added to make version number comparisons easier. Code that will not work with a version of Base before 3.15.0 can now be written like this to prevent it from compiling:

#  error EPICS Base R3.15.0 or later is required

Added support for iocLogPrefix

Added a iocLogPrefix command to iocsh. This adds a prefix to all messages from this IOC (or other log client) as they get sent to the iocLogServer. This lets sites use the "fac=<facility>" syntax for displaying the facility, process name etc. in log viewers like the cmlogviewer.

Reworked the epicsEvent C & C++ APIs

Enabled histogram record type

The histogram record was not included in the base.dbd file in any 3.14 release, but has now been added along with its associated soft device support. The build system now generates the list of all the record.dbd files in base automatically in src/std/rec/Makefile.

Reorganization of src/

Reorganization of subdirectories of src/ to better represent the relation between different parts as described in the following table.

This change also allows the number of libraries built to be reduced to: libCap5.so, libca.so, libdbCore.so, libdbStaticHost.so, libCom.so, libcas.so, libdbRecStd.so, and libgdd.so

Component Dependency Library name Description
src/tools Build system scripts
src/libCom src/tools Com Utility routines and OS-independant API
src/template src/tools User application templates (e.g. makeBaseApp)
src/ca/client src/libCom ca Channel Access client
src/ca/legacy/gdd src/ca/client gdd Generic data layer for PCAS
src/ca/legacy/pcas src/ca/legacy/gdd cas Portable Channel Access Server
src/ioc src/ca dbCore Core database processing functions
src/std src/ioc dbRecStd Standard records, soft device support and the softIoc

In order to better reflect these relations the following directories and files were moved as described:

src/RTEMS src/libCom/RTEMS
src/toolsComm/flex src/libCom/flex
src/toolsComm/antelope src/libCom/yacc
IOC Core Components
src/bpt src/ioc/bpt
src/db src/ioc/db
src/dbStatic src/ioc/dbStatic
src/dbtools src/ioc/dbtemplate
src/misc src/ioc/misc
src/registry src/ioc/registry
src/rsrv src/ioc/rsrv 1
Standard Record Definitions
src/dev/softDev src/std/dev
src/rec src/std/rec
src/softIoc src/std/softIoc
Channel Access
src/ca src/ca/client
src/catools src/ca/client/tools
src/cap5 src/ca/client/perl
src/gdd src/ca/legacy/gdd
src/cas src/ca/legacy/pcas
src/excas src/ca/legacy/pcas/ex
User Templates
src/makeBaseApp src/template/base
src/makeBaseExt src/template/ext
src/util 2 src/ca/client
src/as 3 src/libCom/as

1 RSRV is built as part of dbCore due to its tight (bidirectional) coupling with the other database code.

2 The contents for src/util/ moved to three locations. The caRepeater init script was moved to src/ca/client/. ca_test is now in src/ca/client/test/. The iocLogServer was moved into the same directory (src/libCom/log) as the log client code.

3 The Access Security code has been divided, with the parts not related to the database (lexer/parser and trap registration) becoming part of libCom. The remaining components are included in the dbCore library

Moved src/RTEMS/base directory

These files are now found under src/RTEMS.

Removed 3.13 compatibility

Removed the 3.13 <top>/config directory and build compatibility rules and variables, and various conversion documents.