You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
187 lines
6.2 KiB
187 lines
6.2 KiB
Coding
|
|
====================
|
|
|
|
Various coding styles have been used during the history of the codebase,
|
|
and the result is not very consistent. However, we're now trying to converge to
|
|
a single style, so please use it in new code. Old code will be converted
|
|
gradually.
|
|
- Basic rules specified in src/.clang-format. Use a recent clang-format-3.5 to format automatically.
|
|
- Braces on new lines for namespaces, classes, functions, methods.
|
|
- Braces on the same line for everything else.
|
|
- 4 space indentation (no tabs) for every block except namespaces.
|
|
- No indentation for public/protected/private or for namespaces.
|
|
- No extra spaces inside parenthesis; don't do ( this )
|
|
- No space after function names; one space after if, for and while.
|
|
|
|
Block style example:
|
|
```c++
|
|
namespace foo
|
|
{
|
|
class Class
|
|
{
|
|
bool Function(char* psz, int n)
|
|
{
|
|
// Comment summarising what this section of code does
|
|
for (int i = 0; i < n; i++) {
|
|
// When something fails, return early
|
|
if (!Something())
|
|
return false;
|
|
...
|
|
}
|
|
|
|
// Success return is usually at the end
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
```
|
|
|
|
Doxygen comments
|
|
-----------------
|
|
|
|
To facilitate the generation of documentation, use doxygen-compatible comment blocks for functions, methods and fields.
|
|
|
|
For example, to describe a function use:
|
|
```c++
|
|
/**
|
|
* ... text ...
|
|
* @param[in] arg1 A description
|
|
* @param[in] arg2 Another argument description
|
|
* @pre Precondition for function...
|
|
*/
|
|
bool function(int arg1, const char *arg2)
|
|
```
|
|
A complete list of `@xxx` commands can be found at http://www.stack.nl/~dimitri/doxygen/manual/commands.html.
|
|
As Doxygen recognizes the comments by the delimiters (`/**` and `*/` in this case), you don't
|
|
*need* to provide any commands for a comment to be valid, just a description text is fine.
|
|
|
|
To describe a class use the same construct above the class definition:
|
|
```c++
|
|
/**
|
|
* Alerts are for notifying old versions if they become too obsolete and
|
|
* need to upgrade. The message is displayed in the status bar.
|
|
* @see GetWarnings()
|
|
*/
|
|
class CAlert
|
|
{
|
|
```
|
|
|
|
To describe a member or variable use:
|
|
```c++
|
|
int var; //!< Detailed description after the member
|
|
```
|
|
|
|
Also OK:
|
|
```c++
|
|
///
|
|
/// ... text ...
|
|
///
|
|
bool function2(int arg1, const char *arg2)
|
|
```
|
|
|
|
Not OK (used plenty in the current source, but not picked up):
|
|
```c++
|
|
//
|
|
// ... text ...
|
|
//
|
|
```
|
|
|
|
A full list of comment syntaxes picked up by doxygen can be found at http://www.stack.nl/~dimitri/doxygen/manual/docblocks.html,
|
|
but if possible use one of the above styles.
|
|
|
|
Development tips and tricks
|
|
---------------------------
|
|
|
|
**compiling for debugging**
|
|
|
|
Run configure with the --enable-debug option, then make. Or run configure with
|
|
CXXFLAGS="-g -ggdb -O0" or whatever debug flags you need.
|
|
|
|
**debug.log**
|
|
|
|
If the code is behaving strangely, take a look in the debug.log file in the data directory;
|
|
error and debugging messages are written there.
|
|
|
|
The -debug=... command-line option controls debugging; running with just -debug will turn
|
|
on all categories (and give you a very large debug.log file).
|
|
|
|
The Qt code routes qDebug() output to debug.log under category "qt": run with -debug=qt
|
|
to see it.
|
|
|
|
**testnet and regtest modes**
|
|
|
|
Run with the -testnet option to run with "play bitcoins" on the test network, if you
|
|
are testing multi-machine code that needs to operate across the internet.
|
|
|
|
If you are testing something that can run on one machine, run with the -regtest option.
|
|
In regression test mode, blocks can be created on-demand; see qa/rpc-tests/ for tests
|
|
that run in -regtest mode.
|
|
|
|
**DEBUG_LOCKORDER**
|
|
|
|
Bitcoin Core is a multithreaded application, and deadlocks or other multithreading bugs
|
|
can be very difficult to track down. Compiling with -DDEBUG_LOCKORDER (configure
|
|
CXXFLAGS="-DDEBUG_LOCKORDER -g") inserts run-time checks to keep track of which locks
|
|
are held, and adds warnings to the debug.log file if inconsistencies are detected.
|
|
|
|
Locking/mutex usage notes
|
|
-------------------------
|
|
|
|
The code is multi-threaded, and uses mutexes and the
|
|
LOCK/TRY_LOCK macros to protect data structures.
|
|
|
|
Deadlocks due to inconsistent lock ordering (thread 1 locks cs_main
|
|
and then cs_wallet, while thread 2 locks them in the opposite order:
|
|
result, deadlock as each waits for the other to release its lock) are
|
|
a problem. Compile with -DDEBUG_LOCKORDER to get lock order
|
|
inconsistencies reported in the debug.log file.
|
|
|
|
Re-architecting the core code so there are better-defined interfaces
|
|
between the various components is a goal, with any necessary locking
|
|
done by the components (e.g. see the self-contained CKeyStore class
|
|
and its cs_KeyStore lock for example).
|
|
|
|
Threads
|
|
-------
|
|
|
|
- ThreadScriptCheck : Verifies block scripts.
|
|
|
|
- ThreadImport : Loads blocks from blk*.dat files or bootstrap.dat.
|
|
|
|
- StartNode : Starts other threads.
|
|
|
|
- ThreadDNSAddressSeed : Loads addresses of peers from the DNS.
|
|
|
|
- ThreadMapPort : Universal plug-and-play startup/shutdown
|
|
|
|
- ThreadSocketHandler : Sends/Receives data from peers on port 8333.
|
|
|
|
- ThreadOpenAddedConnections : Opens network connections to added nodes.
|
|
|
|
- ThreadOpenConnections : Initiates new connections to peers.
|
|
|
|
- ThreadMessageHandler : Higher-level message handling (sending and receiving).
|
|
|
|
- DumpAddresses : Dumps IP addresses of nodes to peers.dat.
|
|
|
|
- ThreadFlushWalletDB : Close the wallet.dat file if it hasn't been used in 500ms.
|
|
|
|
- ThreadRPCServer : Remote procedure call handler, listens on port 8332 for connections and services them.
|
|
|
|
- BitcoinMiner : Generates bitcoins (if wallet is enabled).
|
|
|
|
- Shutdown : Does an orderly shutdown of everything.
|
|
|
|
Pull Request Terminology
|
|
------------------------
|
|
|
|
Concept ACK - Agree with the idea and overall direction, but haven't reviewed the code changes or tested them.
|
|
|
|
utACK (untested ACK) - Reviewed and agree with the code changes but haven't actually tested them.
|
|
|
|
Tested ACK - Reviewed the code changes and have verified the functionality or bug fix.
|
|
|
|
ACK - A loose ACK can be confusing. It's best to avoid them unless it's a documentation/comment only change in which case there is nothing to test/verify; therefore the tested/untested distinction is not there.
|
|
|
|
NACK - Disagree with the code changes/concept. Should be accompanied by an explanation.
|