/Users/deen/code/yugabyte-db/src/postgres/src/backend/jit/jit.c
Line | Count | Source (jump to first uncovered line) |
1 | | /*------------------------------------------------------------------------- |
2 | | * |
3 | | * jit.c |
4 | | * Provider independent JIT infrastructure. |
5 | | * |
6 | | * Code related to loading JIT providers, redirecting calls into JIT providers |
7 | | * and error handling. No code specific to a specific JIT implementation |
8 | | * should end up here. |
9 | | * |
10 | | * |
11 | | * Copyright (c) 2016-2018, PostgreSQL Global Development Group |
12 | | * |
13 | | * IDENTIFICATION |
14 | | * src/backend/jit/jit.c |
15 | | * |
16 | | *------------------------------------------------------------------------- |
17 | | */ |
18 | | #include "postgres.h" |
19 | | |
20 | | |
21 | | #include <sys/types.h> |
22 | | #include <sys/stat.h> |
23 | | #include <unistd.h> |
24 | | |
25 | | |
26 | | #include "fmgr.h" |
27 | | #include "executor/execExpr.h" |
28 | | #include "jit/jit.h" |
29 | | #include "miscadmin.h" |
30 | | #include "utils/resowner_private.h" |
31 | | #include "utils/fmgrprotos.h" |
32 | | |
33 | | |
34 | | /* GUCs */ |
35 | | bool jit_enabled = false; |
36 | | char *jit_provider = NULL; |
37 | | bool jit_debugging_support = false; |
38 | | bool jit_dump_bitcode = false; |
39 | | bool jit_expressions = true; |
40 | | bool jit_profiling_support = false; |
41 | | bool jit_tuple_deforming = true; |
42 | | double jit_above_cost = 100000; |
43 | | double jit_inline_above_cost = 500000; |
44 | | double jit_optimize_above_cost = 500000; |
45 | | |
46 | | static JitProviderCallbacks provider; |
47 | | static bool provider_successfully_loaded = false; |
48 | | static bool provider_failed_loading = false; |
49 | | |
50 | | |
51 | | static bool provider_init(void); |
52 | | static bool file_exists(const char *name); |
53 | | |
54 | | |
55 | | /* |
56 | | * SQL level function returning whether JIT is available in the current |
57 | | * backend. Will attempt to load JIT provider if necessary. |
58 | | */ |
59 | | Datum |
60 | | pg_jit_available(PG_FUNCTION_ARGS) |
61 | 0 | { |
62 | 0 | PG_RETURN_BOOL(provider_init()); |
63 | 0 | } |
64 | | |
65 | | |
66 | | /* |
67 | | * Return whether a JIT provider has successfully been loaded, caching the |
68 | | * result. |
69 | | */ |
70 | | static bool |
71 | | provider_init(void) |
72 | 0 | { |
73 | 0 | char path[MAXPGPATH]; |
74 | 0 | JitProviderInit init; |
75 | | |
76 | | /* don't even try to load if not enabled */ |
77 | 0 | if (!jit_enabled) |
78 | 0 | return false; |
79 | | |
80 | | /* |
81 | | * Don't retry loading after failing - attempting to load JIT provider |
82 | | * isn't cheap. |
83 | | */ |
84 | 0 | if (provider_failed_loading) |
85 | 0 | return false; |
86 | 0 | if (provider_successfully_loaded) |
87 | 0 | return true; |
88 | | |
89 | | /* |
90 | | * Check whether shared library exists. We do that check before actually |
91 | | * attempting to load the shared library (via load_external_function()), |
92 | | * because that'd error out in case the shlib isn't available. |
93 | | */ |
94 | 0 | snprintf(path, MAXPGPATH, "%s/%s%s", pkglib_path, jit_provider, DLSUFFIX); |
95 | 0 | elog(DEBUG1, "probing availability of JIT provider at %s", path); |
96 | 0 | if (!file_exists(path)) |
97 | 0 | { |
98 | 0 | elog(DEBUG1, |
99 | 0 | "provider not available, disabling JIT for current session"); |
100 | 0 | provider_failed_loading = true; |
101 | 0 | return false; |
102 | 0 | } |
103 | | |
104 | | /* |
105 | | * If loading functions fails, signal failure. We do so because |
106 | | * load_external_function() might error out despite the above check if |
107 | | * e.g. the library's dependencies aren't installed. We want to signal |
108 | | * ERROR in that case, so the user is notified, but we don't want to |
109 | | * continually retry. |
110 | | */ |
111 | 0 | provider_failed_loading = true; |
112 | | |
113 | | /* and initialize */ |
114 | 0 | init = (JitProviderInit) |
115 | 0 | load_external_function(path, "_PG_jit_provider_init", true, NULL); |
116 | 0 | init(&provider); |
117 | |
|
118 | 0 | provider_successfully_loaded = true; |
119 | 0 | provider_failed_loading = false; |
120 | |
|
121 | 0 | elog(DEBUG1, "successfully loaded JIT provider in current session"); |
122 | | |
123 | 0 | return true; |
124 | 0 | } |
125 | | |
126 | | /* |
127 | | * Reset JIT provider's error handling. This'll be called after an error has |
128 | | * been thrown and the main-loop has re-established control. |
129 | | */ |
130 | | void |
131 | | jit_reset_after_error(void) |
132 | 46.4k | { |
133 | 46.4k | if (provider_successfully_loaded) |
134 | 0 | provider.reset_after_error(); |
135 | 46.4k | } |
136 | | |
137 | | /* |
138 | | * Release resources required by one JIT context. |
139 | | */ |
140 | | void |
141 | | jit_release_context(JitContext *context) |
142 | 0 | { |
143 | 0 | if (provider_successfully_loaded) |
144 | 0 | provider.release_context(context); |
145 | |
|
146 | 0 | ResourceOwnerForgetJIT(context->resowner, PointerGetDatum(context)); |
147 | 0 | pfree(context); |
148 | 0 | } |
149 | | |
150 | | /* |
151 | | * Ask provider to JIT compile an expression. |
152 | | * |
153 | | * Returns true if successful, false if not. |
154 | | */ |
155 | | bool |
156 | | jit_compile_expr(struct ExprState *state) |
157 | 1.32M | { |
158 | | /* |
159 | | * We can easily create a one-off context for functions without an |
160 | | * associated PlanState (and thus EState). But because there's no executor |
161 | | * shutdown callback that could deallocate the created function, they'd |
162 | | * live to the end of the transactions, where they'd be cleaned up by the |
163 | | * resowner machinery. That can lead to a noticeable amount of memory |
164 | | * usage, and worse, trigger some quadratic behaviour in gdb. Therefore, |
165 | | * at least for now, don't create a JITed function in those circumstances. |
166 | | */ |
167 | 1.32M | if (!state->parent) |
168 | 114k | return false; |
169 | | |
170 | | /* if no jitting should be performed at all */ |
171 | 1.20M | if (!(state->parent->state->es_jit_flags & PGJIT_PERFORM)) |
172 | 1.20M | return false; |
173 | | |
174 | | /* or if expressions aren't JITed */ |
175 | 18.4E | if (!(state->parent->state->es_jit_flags & PGJIT_EXPR)) |
176 | 0 | return false; |
177 | | |
178 | | /* this also takes !jit_enabled into account */ |
179 | 18.4E | if (provider_init()) |
180 | 0 | return provider.compile_expr(state); |
181 | | |
182 | 18.4E | return false; |
183 | 18.4E | } |
184 | | |
185 | | /* Aggregate JIT instrumentation information */ |
186 | | void |
187 | | InstrJitAgg(JitInstrumentation *dst, JitInstrumentation *add) |
188 | 0 | { |
189 | 0 | dst->created_functions += add->created_functions; |
190 | 0 | INSTR_TIME_ADD(dst->generation_counter, add->generation_counter); |
191 | 0 | INSTR_TIME_ADD(dst->inlining_counter, add->inlining_counter); |
192 | 0 | INSTR_TIME_ADD(dst->optimization_counter, add->optimization_counter); |
193 | 0 | INSTR_TIME_ADD(dst->emission_counter, add->emission_counter); |
194 | 0 | } |
195 | | |
196 | | static bool |
197 | | file_exists(const char *name) |
198 | 0 | { |
199 | 0 | struct stat st; |
200 | |
|
201 | 0 | AssertArg(name != NULL); |
202 | | |
203 | 0 | if (stat(name, &st) == 0) |
204 | 0 | return S_ISDIR(st.st_mode) ? false : true; |
205 | 0 | else if (!(errno == ENOENT || errno == ENOTDIR)) |
206 | 0 | ereport(ERROR, |
207 | 0 | (errcode_for_file_access(), |
208 | 0 | errmsg("could not access file \"%s\": %m", name))); |
209 | | |
210 | 0 | return false; |
211 | 0 | } |