% PT_ALLOC_ENCODER(3)

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# NAME

pt_alloc_encoder, pt_free_encoder - allocate/free an Intel(R) Processor Trace

packet encoder

# SYNOPSIS

| **\#include `<intel-pt.h>`**

|

| **struct pt_packet_encoder \***

| **pt_alloc_encoder(const struct pt_config \**config*);**

|

| **void pt_free_encoder(struct pt_packet_encoder \**encoder*);**

Link with *-lipt*.

# DESCRIPTION

**pt_alloc_encoder**() allocates a new Intel Processor Trace (Intel PT) packet

encoder and returns a pointer to it.  The packet encoder generates Intel PT

trace from *pt_packet* objects.  See **pt_enc_next**(3).

The *config* argument points to a *pt_config* object.  See **pt_config**(3).

The *config* argument will not be referenced by the returned encoder but the

trace buffer defined by the *config* argument's *begin* and *end* fields will.

The returned packet encoder is initially synchronized onto the beginning of the

trace buffer specified in its *config* argument.  Use **pt_enc_sync_set**(3) to

move it to any other position inside the trace buffer.

**pt_free_encoder**() frees the Intel PT packet encoder pointed to by encoder*.

*The *encoder* argument must be NULL or point to an encoder that has been

*allocated by a call to **pt_alloc_encoder**().

# RETURN VALUE

**pt_alloc_encoder**() returns a pointer to a *pt_packet_encoder* object on

success or NULL in case of an error.

# EXAMPLE

~~~{.c}

int foo(const struct pt_config *config) {

	struct pt_packet_encoder *encoder;

	errcode;

	encoder = pt_alloc_encoder(config);

	if (!encoder)

		return pte_nomem;

	errcode = bar(encoder);

	pt_free_encoder(encoder);

	return errcode;

}

~~~

# SEE ALSO

**pt_config**(3), **pt_enc_sync_set**(3), **pt_enc_get_offset**(3),

**pt_enc_get_config**(3), **pt_enc_next**(3)