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1 | #ifndef LTT_H |
2 | #define LTT_H |
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3 | |
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4 | #include <ltt/LTTTypes.h> |
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5 | |
6 | /* A trace is associated with a tracing session run on a single, possibly |
7 | multi-cpu, system. It is defined as a pathname to a directory containing |
8 | all the relevant trace files. All the tracefiles for a trace were |
9 | generated in a single system for the same time period by the same |
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10 | trace daemon. They simply contain different events. Typically control |
11 | tracefiles contain the important events (process creations and registering |
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12 | tracing facilities) for all CPUs, and one file for each CPU contains all |
13 | the events for that CPU. All the tracefiles within the same trace directory |
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14 | then use the exact same id numbers for event types. |
15 | |
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16 | A tracefile (LttTracefile) contains a list of events (LttEvent) sorted |
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17 | by time for each CPU; events from different CPUs may be slightly out of |
18 | order, especially using the (possibly drifting) cycle counters as |
19 | time unit. |
20 | |
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21 | A facility is a list of event types (LttEventType), declared in a special |
22 | eventdefs file. A corresponding checksum differentiates different |
23 | facilities which would have the same name but a different content |
24 | (e.g., different versions). The files are stored within the trace |
25 | directory and are accessed automatically upon opening a trace. |
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26 | The list of facilities (and associated checksum) used in a trace |
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27 | must be known in order to properly decode the contained events. An event |
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28 | is stored in the "facilities" control tracefile to denote each different |
29 | facility used. |
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30 | |
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31 | Event types (LttEventType) refer to data types (LttType) describing |
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32 | their content. The data types supported are integer and unsigned integer |
33 | (of various length), enumerations (a special form of unsigned integer), |
34 | floating point (of various length), fixed size arrays, sequence |
35 | (variable sized arrays), structures and null terminated strings. |
36 | The elements of arrays and sequences, and the data members for |
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37 | structures, may be of any nested data type (LttType). |
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38 | |
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39 | An LttField is a special object to denote a specific, possibly nested, |
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40 | field within an event type. Suppose an event type socket_connect is a |
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41 | structure containing two data members, source and destination, of type |
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42 | socket_address. Type socket_address contains two unsigned integer |
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43 | data members, ip and port. An LttField is different from a data type |
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44 | structure member since it can denote a specific nested field, like the |
45 | source port, and store associated access information (byte offset within |
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46 | the event data). The LttField objects are trace specific since the |
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47 | contained information (byte offsets) may vary with the architecture |
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48 | associated to the trace. */ |
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49 | |
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50 | typedef struct _LttTrace LttTrace; |
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51 | |
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52 | typedef struct _LttTracefile LttTracefile; |
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53 | |
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54 | typedef struct _LttFacility LttFacility; |
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55 | |
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56 | typedef struct _LttEventType LttEventType; |
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57 | |
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58 | typedef struct _LttType LttType; |
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59 | |
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60 | typedef struct _LttField LttField; |
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61 | |
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62 | typedef struct _LttEvent LttEvent; |
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63 | |
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64 | typedef struct _LttSystemDescription LttSystemDescription; |
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65 | |
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66 | /* Checksums are used to differentiate facilities which have the same name |
67 | but differ. */ |
68 | |
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69 | typedef unsigned long LttChecksum; |
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70 | |
71 | |
72 | /* Events are usually stored with the easily obtained CPU clock cycle count, |
73 | ltt_cycle_count. This can be converted to the real time value, ltt_time, |
74 | using linear interpolation between regularly sampled values (e.g. a few |
75 | times per second) of the real time clock with their corresponding |
76 | cycle count values. */ |
77 | |
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78 | typedef struct timespec LttTime; |
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79 | |
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80 | typedef uint64_t LttCycleCount; |
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81 | |
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82 | |
83 | /* Differences between architectures include word sizes, endianess, |
84 | alignment, floating point format and calling conventions. For a |
85 | packed binary trace, endianess and size matter, assuming that the |
86 | floating point format is standard (and is seldom used anyway). */ |
87 | |
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88 | typedef enum _LttArchSize |
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89 | { LTT_LP32, LTT_ILP32, LTT_LP64, LTT_ILP64, LTT_UNKNOWN |
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90 | } LttArchSize; |
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91 | |
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92 | |
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93 | typedef enum _LttArchEndian |
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94 | { LTT_LITTLE_ENDIAN, LTT_BIG_ENDIAN |
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95 | } LttArchEndian; |
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96 | |
97 | |
98 | |
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99 | #include <ltt/ltt-private.h> |
100 | |
101 | |
102 | #endif // LTT_H |