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| 1 | +diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c |
| 2 | +index b0dd7d1b37..7415b7f7f5 100644 |
| 3 | +--- a/src/backend/storage/ipc/procsignal.c |
| 4 | ++++ b/src/backend/storage/ipc/procsignal.c |
| 5 | +@@ -27,6 +27,7 @@ |
| 6 | + #include "storage/shmem.h" |
| 7 | + #include "storage/sinval.h" |
| 8 | + #include "tcop/tcopprot.h" |
| 9 | ++#include "utils/memutils.h" |
| 10 | + |
| 11 | + |
| 12 | + /* |
| 13 | +@@ -60,12 +61,17 @@ typedef struct |
| 14 | + */ |
| 15 | + #define NumProcSignalSlots (MaxBackends + NUM_AUXPROCTYPES) |
| 16 | + |
| 17 | ++static bool CustomSignalPendings[NUM_CUSTOM_PROCSIGNALS]; |
| 18 | ++static ProcSignalHandler_type CustomHandlers[NUM_CUSTOM_PROCSIGNALS]; |
| 19 | ++ |
| 20 | + static ProcSignalSlot *ProcSignalSlots = NULL; |
| 21 | + static volatile ProcSignalSlot *MyProcSignalSlot = NULL; |
| 22 | + |
| 23 | + static bool CheckProcSignal(ProcSignalReason reason); |
| 24 | + static void CleanupProcSignalState(int status, Datum arg); |
| 25 | + |
| 26 | ++static void CustomSignalInterrupt(ProcSignalReason reason); |
| 27 | ++ |
| 28 | + /* |
| 29 | + * ProcSignalShmemSize |
| 30 | + * Compute space needed for procsignal's shared memory |
| 31 | +@@ -165,6 +171,57 @@ CleanupProcSignalState(int status, Datum arg) |
| 32 | + slot->pss_pid = 0; |
| 33 | + } |
| 34 | + |
| 35 | ++/* |
| 36 | ++ * RegisterCustomProcSignalHandler |
| 37 | ++ * Assign specific handler for custom process signal with new ProcSignalReason key. |
| 38 | ++ * Return INVALID_PROCSIGNAL if all custom signals have been assigned. |
| 39 | ++ */ |
| 40 | ++ProcSignalReason |
| 41 | ++RegisterCustomProcSignalHandler(ProcSignalHandler_type handler) |
| 42 | ++{ |
| 43 | ++ ProcSignalReason reason; |
| 44 | ++ |
| 45 | ++ /* iterate through custom signal keys to find free spot */ |
| 46 | ++ for (reason = PROCSIG_CUSTOM_1; reason <= PROCSIG_CUSTOM_N; reason++) |
| 47 | ++ if (!CustomHandlers[reason - PROCSIG_CUSTOM_1]) |
| 48 | ++ { |
| 49 | ++ CustomHandlers[reason - PROCSIG_CUSTOM_1] = handler; |
| 50 | ++ return reason; |
| 51 | ++ } |
| 52 | ++ return INVALID_PROCSIGNAL; |
| 53 | ++} |
| 54 | ++ |
| 55 | ++/* |
| 56 | ++ * AssignCustomProcSignalHandler |
| 57 | ++ * Assign handler of custom process signal with specific ProcSignalReason key. |
| 58 | ++ * Return old ProcSignal handler. |
| 59 | ++ * Assume incoming reason is one of custom ProcSignals. |
| 60 | ++ */ |
| 61 | ++ProcSignalHandler_type |
| 62 | ++AssignCustomProcSignalHandler(ProcSignalReason reason, ProcSignalHandler_type handler) |
| 63 | ++{ |
| 64 | ++ ProcSignalHandler_type old; |
| 65 | ++ |
| 66 | ++ AssertArg(reason >= PROCSIG_CUSTOM_1 && reason <= PROCSIG_CUSTOM_N); |
| 67 | ++ |
| 68 | ++ old = CustomHandlers[reason - PROCSIG_CUSTOM_1]; |
| 69 | ++ CustomHandlers[reason - PROCSIG_CUSTOM_1] = handler; |
| 70 | ++ return old; |
| 71 | ++} |
| 72 | ++ |
| 73 | ++/* |
| 74 | ++ * GetCustomProcSignalHandler |
| 75 | ++ * Get handler of custom process signal. |
| 76 | ++ * Assume incoming reason is one of custom ProcSignals. |
| 77 | ++ */ |
| 78 | ++ProcSignalHandler_type |
| 79 | ++GetCustomProcSignalHandler(ProcSignalReason reason) |
| 80 | ++{ |
| 81 | ++ AssertArg(reason >= PROCSIG_CUSTOM_1 && reason <= PROCSIG_CUSTOM_N); |
| 82 | ++ |
| 83 | ++ return CustomHandlers[reason - PROCSIG_CUSTOM_1]; |
| 84 | ++} |
| 85 | ++ |
| 86 | + /* |
| 87 | + * SendProcSignal |
| 88 | + * Send a signal to a Postgres process |
| 89 | +@@ -260,7 +317,8 @@ CheckProcSignal(ProcSignalReason reason) |
| 90 | + void |
| 91 | + procsignal_sigusr1_handler(SIGNAL_ARGS) |
| 92 | + { |
| 93 | +- int save_errno = errno; |
| 94 | ++ int save_errno = errno; |
| 95 | ++ ProcSignalReason reason; |
| 96 | + |
| 97 | + if (CheckProcSignal(PROCSIG_CATCHUP_INTERRUPT)) |
| 98 | + HandleCatchupInterrupt(); |
| 99 | +@@ -292,9 +350,87 @@ procsignal_sigusr1_handler(SIGNAL_ARGS) |
| 100 | + if (CheckProcSignal(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN)) |
| 101 | + RecoveryConflictInterrupt(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN); |
| 102 | + |
| 103 | ++ for (reason = PROCSIG_CUSTOM_1; reason <= PROCSIG_CUSTOM_N; reason++) |
| 104 | ++ if (CheckProcSignal(reason)) |
| 105 | ++ CustomSignalInterrupt(reason); |
| 106 | ++ |
| 107 | + SetLatch(MyLatch); |
| 108 | + |
| 109 | + latch_sigusr1_handler(); |
| 110 | + |
| 111 | + errno = save_errno; |
| 112 | + } |
| 113 | ++ |
| 114 | ++/* |
| 115 | ++ * Handle receipt of an interrupt indicating a custom process signal. |
| 116 | ++ */ |
| 117 | ++static void |
| 118 | ++CustomSignalInterrupt(ProcSignalReason reason) |
| 119 | ++{ |
| 120 | ++ int save_errno = errno; |
| 121 | ++ |
| 122 | ++ AssertArg(reason >= PROCSIG_CUSTOM_1 && reason <= PROCSIG_CUSTOM_N); |
| 123 | ++ |
| 124 | ++ /* set interrupt flags */ |
| 125 | ++ InterruptPending = true; |
| 126 | ++ CustomSignalPendings[reason - PROCSIG_CUSTOM_1] = true; |
| 127 | ++ |
| 128 | ++ /* make sure the event is processed in due course */ |
| 129 | ++ SetLatch(MyLatch); |
| 130 | ++ |
| 131 | ++ errno = save_errno; |
| 132 | ++} |
| 133 | ++ |
| 134 | ++/* |
| 135 | ++ * CheckAndHandleCustomSignals |
| 136 | ++ * Check custom signal flags and call handler assigned to that signal if it is not NULL. |
| 137 | ++ * This function is called within CHECK_FOR_INTERRUPTS if interrupt have been occurred. |
| 138 | ++ */ |
| 139 | ++void |
| 140 | ++CheckAndHandleCustomSignals(void) |
| 141 | ++{ |
| 142 | ++ int i; |
| 143 | ++ MemoryContext oldcontext; |
| 144 | ++ |
| 145 | ++ static MemoryContext hcs_context = NULL; |
| 146 | ++ |
| 147 | ++ /* |
| 148 | ++ * This is invoked from ProcessInterrupts(), and since some of the |
| 149 | ++ * functions it calls contain CHECK_FOR_INTERRUPTS(), there is a potential |
| 150 | ++ * for recursive calls if more signals are received while this runs, so |
| 151 | ++ * let's block interrupts until done. |
| 152 | ++ */ |
| 153 | ++ HOLD_INTERRUPTS(); |
| 154 | ++ |
| 155 | ++ /* |
| 156 | ++ * Moreover, CurrentMemoryContext might be pointing almost anywhere. We |
| 157 | ++ * don't want to risk leaking data into long-lived contexts, so let's do |
| 158 | ++ * our work here in a private context that we can reset on each use. |
| 159 | ++ */ |
| 160 | ++ if (hcs_context == NULL) /* first time through? */ |
| 161 | ++ hcs_context = AllocSetContextCreate(TopMemoryContext, |
| 162 | ++ "HandleCustomSignals", |
| 163 | ++ ALLOCSET_DEFAULT_SIZES); |
| 164 | ++ else |
| 165 | ++ MemoryContextReset(hcs_context); |
| 166 | ++ |
| 167 | ++ oldcontext = MemoryContextSwitchTo(hcs_context); |
| 168 | ++ |
| 169 | ++ for (i = 0; i < NUM_CUSTOM_PROCSIGNALS; i++) |
| 170 | ++ if (CustomSignalPendings[i]) |
| 171 | ++ { |
| 172 | ++ ProcSignalHandler_type handler; |
| 173 | ++ |
| 174 | ++ CustomSignalPendings[i] = false; |
| 175 | ++ handler = CustomHandlers[i]; |
| 176 | ++ if (handler) |
| 177 | ++ handler(); |
| 178 | ++ } |
| 179 | ++ |
| 180 | ++ MemoryContextSwitchTo(oldcontext); |
| 181 | ++ |
| 182 | ++ /* Might as well clear the context on our way out */ |
| 183 | ++ MemoryContextReset(hcs_context); |
| 184 | ++ |
| 185 | ++ RESUME_INTERRUPTS(); |
| 186 | ++} |
| 187 | +diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c |
| 188 | +index 07b956553a..35c9da9d80 100644 |
| 189 | +--- a/src/backend/tcop/postgres.c |
| 190 | ++++ b/src/backend/tcop/postgres.c |
| 191 | +@@ -3062,6 +3062,8 @@ ProcessInterrupts(void) |
| 192 | + |
| 193 | + if (ParallelMessagePending) |
| 194 | + HandleParallelMessages(); |
| 195 | ++ |
| 196 | ++ CheckAndHandleCustomSignals(); |
| 197 | + } |
| 198 | + |
| 199 | + |
| 200 | +diff --git a/src/include/storage/procsignal.h b/src/include/storage/procsignal.h |
| 201 | +index 6db0d69b71..b722a370ed 100644 |
| 202 | +--- a/src/include/storage/procsignal.h |
| 203 | ++++ b/src/include/storage/procsignal.h |
| 204 | +@@ -17,6 +17,8 @@ |
| 205 | + #include "storage/backendid.h" |
| 206 | + |
| 207 | + |
| 208 | ++#define NUM_CUSTOM_PROCSIGNALS 64 |
| 209 | ++ |
| 210 | + /* |
| 211 | + * Reasons for signalling a Postgres child process (a backend or an auxiliary |
| 212 | + * process, like checkpointer). We can cope with concurrent signals for different |
| 213 | +@@ -29,6 +31,8 @@ |
| 214 | + */ |
| 215 | + typedef enum |
| 216 | + { |
| 217 | ++ INVALID_PROCSIGNAL = -1, /* Must be first */ |
| 218 | ++ |
| 219 | + PROCSIG_CATCHUP_INTERRUPT, /* sinval catchup interrupt */ |
| 220 | + PROCSIG_NOTIFY_INTERRUPT, /* listen/notify interrupt */ |
| 221 | + PROCSIG_PARALLEL_MESSAGE, /* message from cooperating parallel backend */ |
| 222 | +@@ -42,9 +46,20 @@ typedef enum |
| 223 | + PROCSIG_RECOVERY_CONFLICT_BUFFERPIN, |
| 224 | + PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK, |
| 225 | + |
| 226 | ++ PROCSIG_CUSTOM_1, |
| 227 | ++ /* |
| 228 | ++ * PROCSIG_CUSTOM_2, |
| 229 | ++ * ..., |
| 230 | ++ * PROCSIG_CUSTOM_N-1, |
| 231 | ++ */ |
| 232 | ++ PROCSIG_CUSTOM_N = PROCSIG_CUSTOM_1 + NUM_CUSTOM_PROCSIGNALS - 1, |
| 233 | ++ |
| 234 | + NUM_PROCSIGNALS /* Must be last! */ |
| 235 | + } ProcSignalReason; |
| 236 | + |
| 237 | ++/* Handler of custom process signal */ |
| 238 | ++typedef void (*ProcSignalHandler_type) (void); |
| 239 | ++ |
| 240 | + /* |
| 241 | + * prototypes for functions in procsignal.c |
| 242 | + */ |
| 243 | +@@ -52,9 +67,15 @@ extern Size ProcSignalShmemSize(void); |
| 244 | + extern void ProcSignalShmemInit(void); |
| 245 | + |
| 246 | + extern void ProcSignalInit(int pss_idx); |
| 247 | ++extern ProcSignalReason RegisterCustomProcSignalHandler(ProcSignalHandler_type handler); |
| 248 | ++extern ProcSignalHandler_type AssignCustomProcSignalHandler(ProcSignalReason reason, |
| 249 | ++ ProcSignalHandler_type handler); |
| 250 | ++extern ProcSignalHandler_type GetCustomProcSignalHandler(ProcSignalReason reason); |
| 251 | + extern int SendProcSignal(pid_t pid, ProcSignalReason reason, |
| 252 | + BackendId backendId); |
| 253 | + |
| 254 | ++extern void CheckAndHandleCustomSignals(void); |
| 255 | ++ |
| 256 | + extern void procsignal_sigusr1_handler(SIGNAL_ARGS); |
| 257 | + |
| 258 | + #endif /* PROCSIGNAL_H */ |
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