mongoose/src/profile.h
2023-12-08 17:00:42 +00:00

75 lines
3.4 KiB
C

#pragma once
#include "iobuf.h"
// Macros to record timestamped events that happens with a connection.
// They are saved into a c->prof IO buffer, each event is a name and a 32-bit
// timestamp in milliseconds since connection init time.
//
// Test (run in two separate terminals):
// make -C examples/http-server/ CFLAGS_EXTRA=-DMG_ENABLE_PROFILE=1
// curl localhost:8000
// Output:
// 1ea1f1e7 2 net.c:150:mg_close_conn 3 profile:
// 1ea1f1e8 2 net.c:150:mg_close_conn 1ea1f1e6 init
// 1ea1f1e8 2 net.c:150:mg_close_conn 0 EV_OPEN
// 1ea1f1e8 2 net.c:150:mg_close_conn 0 EV_ACCEPT
// 1ea1f1e8 2 net.c:150:mg_close_conn 0 EV_READ
// 1ea1f1e8 2 net.c:150:mg_close_conn 0 EV_HTTP_MSG
// 1ea1f1e8 2 net.c:150:mg_close_conn 0 EV_WRITE
// 1ea1f1e8 2 net.c:150:mg_close_conn 1 EV_CLOSE
//
// Usage:
// Enable profiling by setting MG_ENABLE_PROFILE=1
// Invoke MG_PROF_ADD(c, "MY_EVENT_1") in the places you'd like to measure
#if MG_ENABLE_PROFILE
struct mg_profitem {
const char *name; // Event name
uint32_t timestamp; // Milliseconds since connection creation (MG_EV_OPEN)
};
#define MG_PROFILE_ALLOC_GRANULARITY 256 // Can save 32 items wih to realloc
// Adding a profile item to the c->prof. Must be as fast as possible.
// Reallocation of the c->prof iobuf is not desirable here, that's why we
// pre-allocate c->prof with MG_PROFILE_ALLOC_GRANULARITY.
// This macro just inits and copies 8 bytes, and calls mg_millis(),
// which should be fast enough.
#define MG_PROF_ADD(c, name_) \
do { \
struct mg_iobuf *io = &c->prof; \
uint32_t inittime = ((struct mg_profitem *) io->buf)->timestamp; \
struct mg_profitem item = {name_, (uint32_t) mg_millis() - inittime}; \
mg_iobuf_add(io, io->len, &item, sizeof(item)); \
} while (0)
// Initialising profile for a new connection. Not time sensitive
#define MG_PROF_INIT(c) \
do { \
struct mg_profitem first = {"init", (uint32_t) mg_millis()}; \
mg_iobuf_init(&(c)->prof, 0, MG_PROFILE_ALLOC_GRANULARITY); \
mg_iobuf_add(&c->prof, c->prof.len, &first, sizeof(first)); \
} while (0)
#define MG_PROF_FREE(c) mg_iobuf_free(&(c)->prof)
// Dumping the profile. Not time sensitive
#define MG_PROF_DUMP(c) \
do { \
struct mg_iobuf *io = &c->prof; \
struct mg_profitem *p = (struct mg_profitem *) io->buf; \
struct mg_profitem *e = &p[io->len / sizeof(*p)]; \
MG_INFO(("%lu profile:", c->id)); \
while (p < e) { \
MG_INFO(("%5lx %s", (unsigned long) p->timestamp, p->name)); \
p++; \
} \
} while (0)
#else
#define MG_PROF_INIT(c)
#define MG_PROF_FREE(c)
#define MG_PROF_ADD(c, name)
#define MG_PROF_DUMP(c)
#endif