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Oracle Solaris Dynamic Tracing Guide     Oracle Solaris 11 Information Library
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Document Information


1.  About DTrace

2.  D Programming Language

D Program Structure

Probe Clauses and Declarations

Probe Descriptions



Order of Execution

Use of the C Preprocessor

Compilation and Instrumentation

Variables and Arithmetic Expressions


Output Formatting


External Symbols and Types

Types, Operators, and Expressions

Identifier Names and Keywords

Data Types and Sizes


Arithmetic Operators

Relational Operators

Logical Operators

Bitwise Operators

Assignment Operators

Increment and Decrement Operators

Conditional Expressions

Type Conversions



Scalar Variables

Associative Arrays

Thread-Local Variables

Clause-Local Variables

Built-in Variables

External Variables

Pointers and Arrays

Pointers and Addresses

Pointer Safety

Array Declarations and Storage

Pointer and Array Relationship

Pointer Arithmetic

Generic Pointers

Multi-Dimensional Arrays

Pointers to DTrace Objects

Pointers and Address Spaces


String Representation

String Constants

String Assignment

String Conversion

String Comparison

Structs and Unions


Pointers to Structs


Member Sizes and Offsets


Type and Constant Definitions




Type Namespaces

3.  Aggregations

4.  Actions and Subroutines

5.  Buffers and Buffering

6.  Output Formatting

7.  Speculative Tracing

8.  dtrace(1M) Utility

9.  Scripting

10.  Options and Tunables

11.  Providers

12.  User Process Tracing

13.  Statically Defined Tracing for User Applications

14.  Security

15.  Anonymous Tracing

16.  Postmortem Tracing

17.  Performance Considerations

18.  Stability

19.  Translators

20.  Versioning

External Symbols and Types

DTrace instrumentation executes inside the Oracle Solaris operating system kernel, so in addition to accessing special DTrace variables and probe arguments, you can also access kernel data structures, symbols, and types. These capabilities enable advanced DTrace users, administrators, service personnel, and driver developers to examine low-level behavior of the operating system kernel and device drivers. The reading list at the start of this book includes books that can help you learn more about Oracle Solaris operating system internals.

D uses the backquote character (`) as a special scoping operator for accessing symbols that are defined in the operating system and not in your D program. For example, the Oracle Solaris kernel contains a C declaration of a system tunable named kmem_flags for enabling memory allocator debugging features. See Oracle Solaris Tunable Parameters Reference Manual for more information about kmem_flags. This tunable is declared in C in the kernel source code as follows:

int kmem_flags;

To trace the value of this variable in a D program, you can write the D statement:


DTrace associates each kernel symbol with the type used for it in the corresponding operating system C code, providing easy source-based access to the native operating system data structures. Kernel symbol names are kept in a separate namespace from D variable and function identifiers, so you never need to worry about these names conflicting with your D variables.

You have now completed a whirlwind tour of DTrace and you've learned many of the basic DTrace building blocks necessary to build larger and more complex D programs. The following chapters describe the complete set of rules for D and demonstrate how DTrace can make complex performance measurements and functional analysis of the system easy. Later, you'll see how to use DTrace to connect user application behavior to system behavior, giving you the capability to analyze your entire software stack.