From c19318b057ae16baab232b624fc8431196da0071 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Zsolt=20Borb=C3=A9ly?= Date: Thu, 1 Sep 2016 15:47:24 +0200 Subject: [PATCH] Update the webpage and add Port API documentation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit JerryScript-DCO-1.0-Signed-off-by: Zsolt Borbély zsborbely.u-szeged@partner.samsung.com --- 01.GETTING-STARTED.md | 11 ++- 04.INTERNALS.md | 9 +- 05.PORT-API.md | 219 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 230 insertions(+), 9 deletions(-) create mode 100644 05.PORT-API.md diff --git a/01.GETTING-STARTED.md b/01.GETTING-STARTED.md index 23913b144..04c0408c0 100644 --- a/01.GETTING-STARTED.md +++ b/01.GETTING-STARTED.md @@ -11,19 +11,20 @@ permalink: /getting-started/ Currently, only Ubuntu 14.04+ is officially supported as primary development environment. -There are several dependencies, that should be installed manually. The following list is required for building: +There are several dependencies, that should be installed manually. The following list is the absolute minimum for building: -- `gcc` or any C99-compliant compiler - - native - - arm-none-eabi +- `gcc` or any C99-compliant compiler (native or cross, e.g., arm-none-eabi) - `cmake` >= `2.8.12.2` + +Several scripts and tools help the building and development process, thus it is recommended to have the following installed as well: + - `bash` >= `4.3.11` - `cppcheck` >= `1.61` - `vera++` >= `1.2.1` - `python` >= `2.7.6` ```bash -sudo apt-get install gcc g++ gcc-arm-none-eabi cmake cppcheck vera++ python +sudo apt-get install gcc gcc-arm-none-eabi cmake cppcheck vera++ python ``` To make our scripts run correctly, several shell utilities should be available on the system: diff --git a/04.INTERNALS.md b/04.INTERNALS.md index 12891451b..cab915d7f 100644 --- a/04.INTERNALS.md +++ b/04.INTERNALS.md @@ -248,10 +248,11 @@ Compressed pointers were introduced to save heap space. ![Compressed Pointer]({{ site.baseurl }}/img/ecma_compressed.png){: class="thumbnail center-block img-responsive" } -These pointers are 8 byte aligned 16 bit long pointers which can address 512 Kb of memory which is also the maximum size of the JerryScript heap. - -ECMA data elements are allocated in pools (pools are allocated on heap) -Chunk size of the pool is 8 bytes (reduces fragmentation). +These pointers are 8 byte aligned 16 bit long pointers which can address 512 Kb of +memory which is also the maximum size of the JerryScript heap. To support even more +memory the size of compressed pointers can be extended to 32 bit to cover the entire +address space of a 32 bit system by passing "--cpointer_32_bit on" to the build +system. These "uncompressed pointers" increases the memory consumption by around 20%. ### Number diff --git a/05.PORT-API.md b/05.PORT-API.md new file mode 100644 index 000000000..13a79f158 --- /dev/null +++ b/05.PORT-API.md @@ -0,0 +1,219 @@ +--- +layout: page +title: Port API +permalink: /port-api/ +--- + +* toc +{:toc} + +# Reference + +## Termination + +It is questionable whether a library should be able to terminate an application. Any API function can signal an error (ex.: cannot allocate memory), so the engine use the termination approach with this port function. + +```c +/** + * Signal the port that jerry experienced a fatal failure from which it cannot + * recover. + * + * @param code gives the cause of the error. + * + * Note: jerry expects the function not to return. + * + * Example: a libc-based port may implement this with exit() or abort(), or both. + */ +void jerry_port_fatal (jerry_fatal_code_t code); +``` + +Error codes + +```c +typedef enum +{ + ERR_OUT_OF_MEMORY = 10, + ERR_SYSCALL = 11, + ERR_REF_COUNT_LIMIT = 12, + ERR_FAILED_INTERNAL_ASSERTION = 120 +} jerry_fatal_code_t; +``` + +## I/O + +These are the only I/O functions jerry calls. + +```c +/** + * Print a string to the console. The function should implement a printf-like + * interface, where the first argument specifies a format string on how to + * stringify the rest of the parameter list. + * + * This function is only called with strings coming from the executed ECMAScript + * wanting to print something as the result of its normal operation. + * + * It should be the port that decides what a "console" is. + * + * Example: a libc-based port may implement this with vprintf(). + */ +void jerry_port_console (const char *fmt, ...); + +/** + * Jerry log levels. The levels are in severity order + * where the most serious levels come first. + */ +typedef enum +{ + JERRY_LOG_LEVEL_ERROR, /**< the engine will terminate after the message is printed */ + JERRY_LOG_LEVEL_WARNING, /**< a request is aborted, but the engine continues its operation */ + JERRY_LOG_LEVEL_DEBUG, /**< debug messages from the engine, low volume */ + JERRY_LOG_LEVEL_TRACE /**< detailed info about engine internals, potentially high volume */ +} jerry_log_level_t; + +/** + * Display or log a debug/error message. The function should implement a printf-like + * interface, where the first argument specifies the log level + * and the second argument specifies a format string on how to stringify the rest + * of the parameter list. + * + * This function is only called with messages coming from the jerry engine as + * the result of some abnormal operation or describing its internal operations + * (e.g., data structure dumps or tracing info). + * + * It should be the port that decides whether error and debug messages are logged to + * the console, or saved to a database or to a file. + * + * Example: a libc-based port may implement this with vfprintf(stderr) or + * vfprintf(logfile), or both, depending on log level. + */ +void jerry_port_log (jerry_log_level_t level, const char *fmt, ...); +``` + +## Date + +```c +/** + * Jerry time zone structure + */ +typedef struct +{ + int offset; /**< minutes from west */ + int daylight_saving_time; /**< daylight saving time (1 - DST applies, 0 - not on DST) */ +} jerry_time_zone_t; + +/** + * Get timezone and daylight saving data + * + * @return true - if success + * false - otherwise + */ +bool jerry_port_get_time_zone (jerry_time_zone_t *); + +/** + * Get system time + * + * @return milliseconds since Unix epoch + */ +double jerry_port_get_current_time (void); +``` + +# How to port JerryScript + +This section describes a basic port implementation which was created for Unix based systems. + +## Termination + +```c +#include +#include "jerry-port.h" + +/** + * Default implementation of jerry_port_fatal. + */ +void jerry_port_fatal (jerry_fatal_code_t code) +{ + exit (code); +} /* jerry_port_fatal */ +``` + +## I/O + +```c +#include +#include "jerry-port.h" + +/** + * Provide console message implementation for the engine. + */ +void +jerry_port_console (const char *format, /**< format string */ + ...) /**< parameters */ +{ + va_list args; + va_start (args, format); + vfprintf (stdout, format, args); + va_end (args); +} /* jerry_port_console */ + +/** + * Provide log message implementation for the engine. + * + * Note: + * This example ignores the log level. + */ +void +jerry_port_log (jerry_log_level_t level, /**< log level */ + const char *format, /**< format string */ + ...) /**< parameters */ +{ + va_list args; + va_start (args, format); + vfprintf (stderr, format, args); + va_end (args); +} /* jerry_port_log */ +``` + +## Date + +```c +#include +#include "jerry-port.h" + +/** + * Default implementation of jerry_port_get_time_zone. + */ +bool jerry_port_get_time_zone (jerry_time_zone_t *tz_p) +{ + struct timeval tv; + struct timezone tz; + + /* gettimeofday may not fill tz, so zero-initializing */ + tz.tz_minuteswest = 0; + tz.tz_dsttime = 0; + + if (gettimeofday (&tv, &tz) != 0) + { + return false; + } + + tz_p->offset = tz.tz_minuteswest; + tz_p->daylight_saving_time = tz.tz_dsttime > 0 ? 1 : 0; + + return true; +} /* jerry_port_get_time_zone */ + +/** + * Default implementation of jerry_port_get_current_time. + */ +double jerry_port_get_current_time () +{ + struct timeval tv; + + if (gettimeofday (&tv, NULL) != 0) + { + return 0; + } + + return ((double) tv.tv_sec) * 1000.0 + ((double) tv.tv_usec) / 1000.0; +} /* jerry_port_get_current_time */ +```